{"rowid": 305, "title": "CSS Writing Modes", "contents": "Since you may not have a lot of time, I\u2019m going to start at the end, with the dessert.\nYou can use a little-known, yet important and powerful CSS property to make text run vertically. Like this.\n\nOr instead of running text vertically, you can layout a set of icons or interface buttons in this way. Or, of course, with anything on your page.  \nThe CSS I\u2019ve applied makes the browser rethink the orientation of the world, and flow the layout of this element at a 90\u00b0 angle to \u201cnormal\u201d. Check out the live demo, highlight the headline, and see how the cursor is now sideways.\nSee the Pen Writing Mode Demo \u2014 Headline by Jen Simmons (@jensimmons) on CodePen.\n\nThe code for accomplishing this is pretty simple. \nh1 { \n  writing-mode: vertical-rl;\n}\nThat\u2019s all it takes to switch the writing mode from the web\u2019s default horizontal top-to-bottom mode to a vertical right-to-left mode. If you apply such code to the html element, the entire page is switched, affecting the scroll direction, too. \nIn my example above, I\u2019m telling the browser that only the h1 will be in this vertical-rl mode, while the rest of my page stays in the default of horizontal-tb.\nSo now the dessert course is over. Let me serve up this whole meal, and explain the the CSS Writing Mode Specification.\nWhy learn about writing modes?\nThere are three reasons I\u2019m teaching writing modes to everyone\u2014including western audiences\u2014and explaining the whole system, instead of quickly showing you a simple trick.\n\n\nWe live in a big, diverse world, and learning about other languages is fascinating. Many of you lay out pages in languages like Chinese, Japanese and Korean. Or you might be inspired to in the future.\n\n\nUsing writing-mode to turn bits sideways is cool. This CSS can be used in all kinds of creative ways, even if you are working only in English.\n\nMost importantly, I\u2019ve found understanding Writing Modes incredibly helpful when understanding Flexbox and CSS Grid. Before I learned Writing Mode, I felt like there was still a big hole in my knowledge, something I just didn\u2019t get about why Grid and Flexbox work the way they do. Once I wrapped my head around Writing Modes, Grid and Flexbox got a lot easier. Suddenly the Alignment properties, align-* and justify-*, made sense.\n\nWhether you know about it or not, the writing mode is the first building block of every layout we create. You can do what we\u2019ve been doing for 25 years \u2013 and leave your page set to the default left-to-right direction, horizontal top-to-bottom writing mode. Or you can enter a world of new possibilities where content flows in other directions.\nCSS properties\nI\u2019m going to focus on the CSS writing-mode property in this article. It has five possible options:\n  writing-mode: horizontal-tb;\n  writing-mode: vertical-rl;\n  writing-mode: vertical-lr;\n  writing-mode: sideways-rl;\n  writing-mode: sideways-lr;\nThe CSS Writing Modes Specification is designed to support a wide range of written languages in all our human and linguistic complexity. Which\u2014spoiler alert\u2014is pretty insanely complex. The global evolution of written languages has been anything but simple. \nSo I\u2019ve got to start with explaining some basic concepts of web page layout and writing systems. Then I can show you what these CSS properties do. \nInline Direction, Block Direction, and Character Direction\nIn the world of the web, there\u2019s a concept of \u2018block\u2019 and \u2018inline\u2019 layout. If you\u2019ve ever written display: block or display: inline, you\u2019ve leaned on these concepts.  \nIn the default writing mode, blocks stack vertically starting at the top of the page and working their way down. Think of how a bunch of block-levels elements stack\u2014like a bunch of a paragraphs\u2014that\u2019s the block direction. \n\nInline is how each line of text flows. The default on the web is from left to right, in horizontal lines. Imagine this text that you are reading right now, being typed out one character at a time on a typewriter. That\u2019s the inline direction. \n\nThe character direction is which way the characters point. If you type a capital \u201cA\u201d for instance, on which side is the top of the letter? Different languages can point in different directions. Most languages have their characters pointing towards the top of the page, but not all.\n\nPut all three together, and you start to see how they work as a system. \nThe default settings for the web work like this.\nNow that we know what block, inline, and character directions mean, let\u2019s see how they are used in different writing systems from around the world.\nThe four writing systems of CSS Writing Modes\nThe CSS Writing Modes Specification handles all the use cases for four major writing systems; Latin, Arabic, Han and Mongolian. \nLatin-based systems\nOne writing system dominates the world more than any other, reportedly covering about 70% of the world\u2019s population. \n\nThe text is horizontal, running from left to right, or LTR. The block direction runs from top to bottom. \nIt\u2019s called the Latin-based system because it includes all languages that use the Latin alphabet, including English, Spanish, German, French, and many others. But there are many non-Latin-alphabet languages that also use this system, including Greek, Cyrillic (Russian, Ukrainian, Bulgarian, Serbian, etc.), and Brahmic scripts (Devanagari, Thai, Tibetan), and many more.\nYou don\u2019t need to do anything in your CSS to trigger this mode. This is the default. \nBest practices, however, dictate that you declare in your opening <html> element which language and which direction (LTR or RTL) you are using. This website, for instance, uses <html lang='en-gb' dir='ltr'> to let the browser know this content is published in Great Britian\u2019s version of English, in a left to right direction. \nArabic-based systems\nArabic, Hebrew and a few other languages run the inline direction from right to left. This is commonly known as RTL.  \nNote that the inline direction still runs horizontally. The block direction runs from top to bottom. And the characters are upright.\n\nIt\u2019s not just the flow of text that runs from right to left, but everything about the layout of the website. The upper right-hand corner is the starting position. Important things are on the right. The eyes travel from right to left. So, typically RTL websites use layouts that are just like LTR websites, only flipped.\nOn websites that support both LTR and RTL, like the United Nations\u2019 site at un.org, the two layouts are mirror images of each other.\nFor many web developers, our experiences with internationalization have focused solely on supporting Arabic and Hebrew script. \nCSS layout hacks for internationalization & RTL\nTo prepare an LTR project to support RTL, developers have had to create all sorts of hacks. For example, the Drupal community started a convention of marking every margin-left and -right, every padding-left and -right, every float: left and float: right with the comment /* LTR */. Then later developers could search for each instance of that exact comment, and create stylesheets to override each left with right, and vice versa. It\u2019s a tedious and error prone way to work. CSS itself needed a better way to let web developers write their layout code once, and easily switch language directions with a single command.\nOur new CSS layout system does exactly that. Flexbox, Grid and Alignment use start and end instead of left and right. This lets us define everything in relationship to the writing system, and switch directions easily. By writing justify-content: flex-start, justify-items: end, and eventually margin-inline-start: 1rem we have code that doesn\u2019t need to be changed. \nThis is a much better way to work. I know it can be confusing to think through start and end as replacements for left and right. But it\u2019s better for any multiligual project, and it\u2019s better for the web as a whole.\nSadly, I\u2019ve seen CSS preprocessor tools that claim to \u201cfix\u201d the new CSS layout system by getting rid of start and end and bringing back left and right. They want you to use their tool, write justify-content: left, and feel self-righteous. It seems some folks think the new way of working is broken and should be discarded. It was created, however, to fulfill real needs. And to reflect a global internet. As Bruce Lawson says, WWW stands for the World Wide Web, not the Wealthy Western Web. Please don\u2019t try to convince the industry that there\u2019s something wrong with no longer being biased towards western culture. Instead, spread the word about why this new system is here.  \nSpend a bit of time drilling the concept of inline and block into your head, and getting used to start and end. It will be second nature soon enough. \nI\u2019ve also seen CSS preprocessors that let us use this new way of thinking today, even as all the parts aren\u2019t fully supported by browsers yet. Some tools let you write text-align: start instead of text-align: left, and let the preprocessor handle things for you. That is terrific, in my opinion. A great use of the power of a preprocessor to help us switch over now. \nBut let\u2019s get back to RTL. \nHow to declare your direction\nYou don\u2019t want to use CSS to tell the browser to switch from an LTR language to RTL. You want to do this in your HTML. That way the browser has the information it needs to display the document even if the CSS doesn\u2019t load.\nThis is accomplished mainly on the html element. You should also declare your main language. As I mentioned above, the 24 ways website is using <html lang='en-gb' dir='ltr'> to declare the LTR direction and the use of British English. The UN Arabic website uses <html lang='ar' dir='rtl'>to declare the site as an Arabic site, using a RTL layout. \nThings get more complicated when you\u2019ve got a page with a mix of languages. But I\u2019m not going to get into all of that, since this article is focused on CSS and layouts, not explaining everything about internationalization. \nLet me just leave direction here by noting that much of the heavy work of laying out the characters which make up each word is handled by Unicode. If you are interested in learning more about LTR, RTL and bidirectional text, watch this video: Introduction to Bidirectional Text, a presentation by Elika Etemad. \nMeanwhile, let\u2019s get back to CSS.\nThe writing mode CSS for Latin-based and Arabic-based systems\nFor both of these systems\u2014Latin-based and Arabic-based, whether LTR or RTL\u2014the same CSS property applies for specifying the writing mode: writing-mode: horizontal-tb. That\u2019s because in both systems, the inline text flow is horizontal, while the block direction is top-to-bottom. This is expressed as horizontal-tb.\nhorizontal-tb is the default writing mode for the web, so you don\u2019t need to specify it unless you are overriding something else higher up in the cascade. You can just imagine that every site you\u2019ve ever built came with:\nhtml {\n  writing-mode: horizontal-tb;\n}\nNow let\u2019s turn our attention to the vertical writing systems. \nHan-based systems\nThis is where things start to get interesting. \nHan-based writing systems include CJK languages, Chinese, Japanese, Korean and others. There are two options for laying out a page, and sometimes both are used at the same time.\nMuch of CJK text is laid out like Latin-based languages, with a horizontal top-to-bottom block direction, and a left-to-right inline direction. This is the more modern way to doing things, started in the 20th century in many places, and further pushed into domination by the computer and later the web. \nThe CSS to do this bit of the layouts is the same as above:\nsection {\n  writing-mode: horizontal-tb;\n}\nOr, you know, do nothing, and get that result as a default. \nAlternatively Han-based languages can be laid out in a vertical writing mode, where the inline direction runs vertically, and the block direction goes from right to left. \nSee both options in this diagram:\n\nNote that the horizontal text flows from left to right, while the vertical text flows from right to left. Wild, eh? \nThis Japanese issue of Vogue magazine is using a mix of writing modes. The cover opens on the left spine, opposite of what an English magazine does.  \n\nThis page mixes English and Japanese, and typesets the Japanese text in both horizontal and vertical modes. Under the title \u201cRichard Stark\u201d in red, you can see a passage that\u2019s horizontal-tb and LTR, while the longer passage of text at the bottom of the page is typeset vertical-rl. The red enlarged cap marks the beginning of that passage. The long headline above the vertical text is typeset LTR, horizontal-tb.\n\nThe details of how to set the default of the whole page will depend on your use case. But each element, each headline, each section, each article can be marked to flow the opposite of the default however you\u2019d like.\nFor example, perhaps you leave the default as horizontal-tb, and specify your vertical elements like this:\ndiv.articletext {\n  writing-mode: vertical-rl;\n}\nOr alternatively you could change the default for the page to a vertical orientation, and then set specific elements to horizontal-tb, like this:\nhtml { \n  writing-mode: vertical-rl;\n}\nh2, .photocaptions, section {\n  writing-mode: horizontal-tb;\n}\nIf your page has a sideways scroll, then the writing mode will determine whether the page loads with upper left corner as the starting point, and scroll to the right (horizontal-tb as we are used to), or if the page loads with the upper right corner as the starting point, scrolling to the left to display overflow. Here\u2019s an example of that change in scrolling direction, in a CSS Writing Mode demo by Chen Hui Jing. Check out her demo \u2014 you can switch from horizontal to vertical writing modes with a checkbox and see the difference. \n\nMongolian-based systems\nNow, hopefully so far all of this kind of makes sense. It might be a bit more complicated than expected, but it\u2019s not so hard. Well, enter the Mongolian-based systems.\nMongolian is also a vertical script language. Text runs vertically down the page. Just like Han-based systems. There are two major differences. First, the block direction runs the other way. In Mongolian, block-level elements stack from left to right. \nHere\u2019s a drawing of how Wikipedia would look in Mongolian if it were laid out correctly.\nPerhaps the Mongolian version of Wikipedia will be redone with this layout.\nNow you might think, that doesn\u2019t look so weird. Tilt your head to the left, and it\u2019s very familiar. The block direction starts on the left side of the screen and goes to the right. The inline direction starts on the top of the page and moves to the bottom (similar to RTL text, just turned 90\u00b0 counter-clockwise). But here comes the other huge difference. The character direction is \u201cupside down\u201d. The top of the Mongolian characters are not pointing to the left, towards the start edge of the block direction. They point to the right. Like this:\n\nNow you might be tempted to ignore all this. Perhaps you don\u2019t expect to be typesetting Mongolian content anytime soon. But here\u2019s why this is important for everyone \u2014 the way Mongolian works defines the results writing-mode: vertical-lr. And it means we cannot use vertical-lr for typesetting content in other languages in the way we might otherwise expect. \nIf we took what we know about vertical-rl and guessed how vertical-lr works, we might imagine this:\n\nBut that\u2019s wrong. Here\u2019s how they actually compare:\n\nSee the unexpected situation? In both writing-mode: vertical-rl and writing-mode: vertical-lr latin text is rotated clockwise. Neither writing mode let\u2019s us rotate text counter-clockwise. \nIf you are typesetting Mongolian content, apply this CSS in the same way you would apply writing-mode to Han-based writing systems. To the whole page on the html element, or to specific pages of the page like this:\nsection {\n  writing-mode: vertical-lr;\n}\nNow, if you are using writing-mode for a graphic design effect on a language that is otherwise typesets horizontally, I don\u2019t think writing-mode: vertical-lr is useful. If the text wraps onto two lines, it stacks in a very unexpected way. So I\u2019ve sort of obliterated it from my toolkit. I find myself using writing-mode: vertical-rl a lot. And never using -lr. Hm.\nWriting modes for graphic design\nSo how do we use writing-mode to turn English headlines sideways? We could rely on transform: rotate()\nHere are two examples, one for each direction. (By the way, each of these demos use CSS Grid for their overall layout, so be sure to test them in a browser that supports CSS Grid, like Firefox Nightly.)\n\nIn this demo 4A, the text is rotated clockwise using this code: \nh1 {\n  writing-mode: vertical-rl;\n}\n\nIn this demo 4B, the text is rotated counter-clockwise using this code: \nh1 {\n  writing-mode: vertical-rl;\n  transform: rotate(180deg);\n  text-align: right;\n}\nI use vertical-rl to rotate the text so that it takes up the proper amount of space in the overall flow of the layout. Then I rotate it 180\u00b0 to spin it around to the other direction. And then I use text-align: right to get it to rise up to the top of it\u2019s container. This feels like a hack, but it\u2019s a hack that works.\nNow what I would like to do instead is use another CSS value that was designed for this use case \u2014 one of the two other options for writing mode.\nIf I could, I would lay out example 4A with:\nh1 {\n  writing-mode: sideways-rl;\n}\nAnd layout example 4B with: \nh1 {\n  writing-mode: sideways-lr;\n}\nThe problem is that these two values are only supported in Firefox. None of the other browsers recognize sideways-*. Which means we can\u2019t really use it yet. \nIn general, the writing-mode property is very well supported across browsers. So I\u2019ll use writing-mode: vertical-rl for now, with the transform: rotate(180deg); hack to fake the other direction. \nThere\u2019s much more to what we can do with the CSS designed to support multiple languages, but I\u2019m going to stop with this intermediate introduction. \nIf you do want a bit more of a taste, look at this example that adds text-orientation: upright; to the mix \u2014 turning the individual letters of the latin font to be upright instead of sideways.\n\nIt\u2019s this demo 4C, with this CSS applied: \nh1 {\n  writing-mode: vertical-rl;\n  text-orientation: upright;\n  text-transform: uppercase;\n  letter-spacing: -25px;\n}\nYou can check out all my Writing Modes demos at labs.jensimmons.com/#writing-modes. \n\nI\u2019ll leave you with this last demo. One that applies a vertical writing mode to the sub headlines of a long article. I like how small details like this can really bring a fresh feeling to the content. \nSee the Pen Writing Mode Demo \u2014 Article Subheadlines by Jen Simmons (@jensimmons) on CodePen.", "year": "2016", "author": "Jen Simmons", "author_slug": "jensimmons", "published": "2016-12-23T00:00:00+00:00", "url": "https://24ways.org/2016/css-writing-modes/", "topic": "code"}
{"rowid": 99, "title": "A Christmas hCard From Me To You", "contents": "So apparently Christmas is coming. And what is Christmas all about? Well, cleaning out your address book, of course! What better time to go through your contacts, making sure everyone\u2019s details are up date and that you\u2019ve deleted all those nasty clients who never paid on time?\n\nIt\u2019s also a good time to make sure your current clients and colleagues have your most up-to-date details, so instead of filling up their inboxes with e-cards, why not send them something useful? Something like a\u2026 vCard! (See what I did there?)\n\nJust in case you\u2019ve been working in a magical toy factory in the upper reaches of Scandinavia for the last few years, I\u2019m going to tell you that now would also be the perfect time to get into microformats. Using the hCard format, we\u2019ll build a very simple web page and markup our contact details in such a way that they\u2019ll be understood by microformats plugins, like Operator or Tails for Firefox, or the cross-browser Microformats Bookmarklet.\n\nOh, and because Christmas is all about dressing up and being silly, we\u2019ll make the whole thing look nice and have a bit of fun with some CSS3 progressive enhancement. \n\nIf you can\u2019t wait to see what we end up with, you can preview it here.\n\n\n\nStep 1: Contact Details\n\nFirst, let\u2019s decide what details we want to put on the page. I\u2019d put my full name, my email address, my phone number, and my postal address, but I\u2019d rather not get surprise visits from strangers when I\u2019m fannying about with my baubles, so I\u2019m going to use Father Christmas instead (that\u2019s Santa to you Yanks).\n\nFather Christmas\nfatherchristmas@elliotjaystocks.com\n25 Laughingallthe Way\nSnow Falls\nLapland\nFinland\n010 60 58 000\n\nStep 2: hCard Creator\n\nNow I\u2019m not sure about you, but I rather like getting the magical robot pixies to do the work for me, so head on over to the hCard Creator and put those pixies to work! Pop in your details and they\u2019ll give you some nice microformatted HTML in turn.\n\n\n\n<div id=\"hcard-Father-Christmas\" class=\"vcard\">\n\t<a class=\"url fn\" href=\"http://elliotjaystocks.com/fatherchristmas\">Father Christmas</a>\n\t<a class=\"email\" href=\"mailto:fatherchristmas@elliotjaystocks.com\"> fatherchristmas@elliotjaystocks.com</a>\n\t<div class=\"adr\">\n\t<div class=\"street-address\">25 Laughingallthe Way</div>\n\t<span class=\"locality\">Snow Falls</span>\n\t, \n\t<span class=\"region\">Lapland</span>\n\t, \n\t<span class=\"postal-code\">FI-00101</span>\n\t<span class=\"country-name\">Finland</span>\n</div>\n<div class=\"tel\">010 60 58 000</div>\n\t<p style=\"font-size:smaller;\">This <a href=\"http://microformats.org/wiki/hcard\">hCard</a> created with the <a href=\"http://microformats.org/code/hcard/creator\">hCard creator</a>.</p>\n</div>\n\nStep 3: Editing The Code\n\nOne of the great things about microformats is that you can use pretty much whichever HTML tags you want, so just because the hCard Creator Fairies say something should be wrapped in a <span> doesn\u2019t mean you can\u2019t change it to a <blink>. Actually, no, don\u2019t do that. That\u2019s not even excusable at Christmas.\n\nI personally have a penchant for marking up each line of an address inside a <li> tag, where the parent url retains the class of adr. As long as you keep the class names the same, you\u2019ll be fine.\n\n<div id=\"hcard-Father-Christmas\" class=\"vcard\">\n\t<h1><a class=\"url fn\" href=\"http://elliotjaystocks.com/fatherchristmas\">Father Christmas </a></h1>\n\t<a class=\"email\" href=\"mailto:fatherchristmas@elliotjaystocks.com?subject=Here, have some Christmas cheer!\">fatherchristmas@elliotjaystocks.com</a>\n\t<ul class=\"adr\">\n\t\t<li class=\"street-address\">25 Laughingallthe Way</li>\n\t\t<li class=\"locality\">Snow Falls</li>\n\t\t<li class=\"region\">Lapland</li>\n\t\t<li class=\"postal-code\">FI-00101</li>\n\t\t<li class=\"country-name\">Finland</li>\n\t</ul>\n\t<span class=\"tel\">010 60 58 000</span>\n</div>\n\nStep 4: Testing The Microformats\n\nWith our microformats in place, now would be a good time to test that they\u2019re working before we start making things look pretty. If you\u2019re on Firefox, you can install the Operator or Tails extensions, but if you\u2019re on another browser, just add the Microformats Bookmarklet. Regardless of your choice, the results is the same: if you\u2019ve code microformatted content on a web page, one of these bad boys should pick it up for you and allow you to export the contact info. Give it a try and you should see father Christmas appearing in your address book of choice. Now you\u2019ll never forget where to send those Christmas lists!\n\n\n\nStep 5: Some Extra Markup\n\nOne of the first things we\u2019re going to do is put a photo of Father Christmas on the hCard. We\u2019ll be using CSS to apply a background image to a div, so we\u2019ll be needing an extra div with a class name of \u201cphoto\u201d. In turn, we\u2019ll wrap the text-based elements of our hCard inside a div cunningly called \u201ctext\u201d. Unfortunately, because of the float technique we\u2019ll be using, we\u2019ll have to use one of those nasty float-clearing techniques. I shall call this \u201cchristmas-cheer\u201d, since that is what its presence will inevitably bring, of course.\n\nOh, and let\u2019s add a bit of text to give the page context, too:\n\n<p>Send your Christmas lists my way...</p>\n<div id=\"hcard-Father-Christmas\" class=\"vcard\">\n\t<div class=\"text\">\n\t\t<h1><a class=\"url fn\" href=\"http://elliotjaystocks.com/fatherchristmas\">Father Christmas </a></h1>\n\t\t<a class=\"email\" href=\"mailto:fatherchristmas@elliotjaystocks.com?subject=Here, have some Christmas cheer!\">fatherchristmas@elliotjaystocks.com</a>\n\t\t<ul class=\"adr\">\n\t\t\t<li class=\"street-address\">25 Laughingallthe Way</li>\n\t\t\t<li class=\"locality\">Snow Falls</li>\n\t\t\t<li class=\"region\">Lapland</li>\n\t\t\t<li class=\"postal-code\">FI-00101</li>\n\t\t\t<li class=\"country-name\">Finland</li>\n\t\t</ul>\n\t\t<span class=\"tel\">010 60 58 000</span>\n\t</div>\n\t<div class=\"photo\"></div>\n\t<br class=\"christmas-cheer\" />\n</div>\n<div class=\"credits\">\n\t<p>A tutorial by <a href=\"http://elliotjaystocks.com\">Elliot Jay Stocks</a> for <a href=\"http://24ways.org/\">24 Ways</a></p>\n\t<p>Background: <a href=\"http://sxc.hu/photo/1108741\">stock.xchng</a> | Father Christmas: <a href=\"http://istockphoto.com/file_closeup/people/4575943-active-santa.php?id=4575943\">iStockPhoto</a></p>\n</div>\n\nStep 6: Some Christmas Sparkle\n\nSo far, our hCard-housing web page is slightly less than inspiring, isn\u2019t it? It\u2019s time to add a bit of CSS. There\u2019s nothing particularly radical going on here; just a simple layout, some basic typographic treatment, and the placement of the Father Christmas photo. I\u2019d usually use a more thorough CSS reset like the one found in the YUI or Eric Meyer\u2019s, but for this basic page, the simple * solution will do.\n\nCheck out the step 6 demo to see our basic styles in place.\n\nFrom this\u2026\n\n\n\n\u2026 to this:\n\n\n\nStep 7: Fun With imagery\n\nNow it\u2019s time to introduce a repeating background image to the <body> element. This will seamlessly repeat for as wide as the browser window becomes.\n\nBut that\u2019s fairly straightforward. How about having some fun with the Father Christmas image? If you look at the image file itself, you\u2019ll see that it\u2019s twice as wide as the area we can see and contains a \u2018hidden\u2019 photo of our rather camp St. Nick.\n\n\n\nAs a light-hearted visual\u2026 er\u2026 \u2018treat\u2019 for users who move their mouse over the image, we move the position of the background image on the \u201cphoto\u201d div. Check out the step 7 demo to see it working.\n\nStep 8: Progressive Enhancement\n\nFinally, this fun little project is a great opportunity for us to mess around with some advanced CSS features (some from the CSS3 spec) that we rarely get to use on client projects. (Don\u2019t forget: no Christmas pressies for clients who want you to support IE6!)\n\nHere are the rules we\u2019re using to give some browsers a superior viewing experience:\n\n\n\t@font-face allows us to use Jos Buivenga\u2019s free font \u2018Fertigo Pro\u2019 on all text;\n\ttext-shadow adds a little emphasis on the opening paragraph;\n\tbody > p:first-child causes only the first paragraph to receive this treatment;\n\tborder-radius created rounded corners on our main div and the links within it;\n\tand webkit-transition allows us to gently fade in between the default and hover states of those links.\n\n\nAnd with that, we\u2019re done! You can see the results here. It\u2019s time to customise the page to your liking, upload it to your site, and send out the URL. And do it quickly, because I\u2019m sure you\u2019ve got some last-minute Christmas shopping to finish off!", "year": "2008", "author": "Elliot Jay Stocks", "author_slug": "elliotjaystocks", "published": "2008-12-10T00:00:00+00:00", "url": "https://24ways.org/2008/a-christmas-hcard-from-me-to-you/", "topic": "code"}
{"rowid": 223, "title": "Calculating Color Contrast", "contents": "Some websites and services allow you to customize your profile by uploading pictures, changing the background color or other aspects of the design. As a customer, this personalization turns a web app into your little nest where you store your data. As a designer, letting your customers have free rein over the layout and design is a scary prospect. So what happens to all the stock text and images that are designed to work on nice white backgrounds? Even the Mac only lets you choose between two colors for the OS, blue or graphite! Opening up the ability to customize your site\u2019s color scheme can be a recipe for disaster unless you are flexible and understand how to find maximum color contrasts.\n\nIn this article I will walk you through two simple equations to determine if you should be using white or black text depending on the color of the background. The equations are both easy to implement and produce similar results. It isn\u2019t a matter of which is better, but more the fact that you are using one at all! That way, even with the craziest of Geocities color schemes that your customers choose, at least your text will still be readable.\n\nLet\u2019s have a look at a range of various possible colors. Maybe these are pre-made color schemes, corporate colors, or plucked from an image.\n\n\n\nNow that we have these potential background colors and their hex values, we need to find out whether the corresponding text should be in white or black, based on which has a higher contrast, therefore affording the best readability. This can be done at runtime with JavaScript or in the back-end before the HTML is served up.\n\nThere are two functions I want to compare. The first, I call \u201950%\u2019. It takes the hex value and compares it to the value halfway between pure black and pure white. If the hex value is less than half, meaning it is on the darker side of the spectrum, it returns white as the text color. If the result is greater than half, it\u2019s on the lighter side of the spectrum and returns black as the text value.\n\nIn PHP:\n\nfunction getContrast50($hexcolor){\n    return (hexdec($hexcolor) > 0xffffff/2) ? 'black':'white';\n}\n\nIn JavaScript:\n\nfunction getContrast50(hexcolor){\n    return (parseInt(hexcolor, 16) > 0xffffff/2) ? 'black':'white';\n}\n\nIt doesn\u2019t get much simpler than that! The function converts the six-character hex color into an integer and compares that to one half the integer value of pure white. The function is easy to remember, but is naive when it comes to understanding how we perceive parts of the spectrum. Different wavelengths have greater or lesser impact on the contrast.\n\nThe second equation is called \u2018YIQ\u2019 because it converts the RGB color space into YIQ, which takes into account the different impacts of its constituent parts. Again, the equation returns white or black and it\u2019s also very easy to implement.\n\nIn PHP:\n\nfunction getContrastYIQ($hexcolor){\n\t$r = hexdec(substr($hexcolor,0,2));\n\t$g = hexdec(substr($hexcolor,2,2));\n\t$b = hexdec(substr($hexcolor,4,2));\n\t$yiq = (($r*299)+($g*587)+($b*114))/1000;\n\treturn ($yiq >= 128) ? 'black' : 'white';\n}\n\nIn JavaScript:\n\nfunction getContrastYIQ(hexcolor){\n\tvar r = parseInt(hexcolor.substr(0,2),16);\n\tvar g = parseInt(hexcolor.substr(2,2),16);\n\tvar b = parseInt(hexcolor.substr(4,2),16);\n\tvar yiq = ((r*299)+(g*587)+(b*114))/1000;\n\treturn (yiq >= 128) ? 'black' : 'white';\n}\n\nYou\u2019ll notice first that we have broken down the hex value into separate RGB values. This is important because each of these channels is scaled in accordance to its visual impact. Once everything is scaled and normalized, it will be in a range between zero and 255. Much like the previous \u201950%\u2019 function, we now need to check if the input is above or below halfway. Depending on where that value is, we\u2019ll return the corresponding highest contrasting color.\n\nThat\u2019s it: two simple contrast equations which work really well to determine the best readability.\n\nIf you are interested in learning more, the W3C has a few documents about color contrast and how to determine if there is enough contrast between any two colors. This is important for accessibility to make sure there is enough contrast between your text and link colors and the background.\n\nThere is also a great article by Kevin Hale on Particletree about his experience with choosing light or dark themes. To round it out, Jonathan Snook created a color contrast picker which allows you to play with RGB sliders to get values for YIQ, contrast and others. That way you can quickly fiddle with the knobs to find the right balance.\n\nComparing results\n\nLet\u2019s revisit our color schemes and see which text color is recommended for maximum contrast based on these two equations.\n\n\n\nIf we use the simple \u201950%\u2019 contrast function, we can see that it recommends black against all the colors except the dark green and purple on the second row. In general, the equation feels the colors are light and that black is a better choice for the text.\n\n\n\nThe more complex \u2018YIQ\u2019 function, with its weighted colors, has slightly different suggestions. White text is still recommended for the very dark colors, but there are some surprises. The red and pink values show white text rather than black. This equation takes into account the weight of the red value and determines that the hue is dark enough for white text to show the most contrast.\n\nAs you can see, the two contrast algorithms agree most of the time. There are some instances where they conflict, but overall you can use the equation that you prefer. I don\u2019t think it is a major issue if some edge-case colors get one contrast over another, they are still very readable.\n\nNow let\u2019s look at some common colors and then see how the two functions compare. You can quickly see that they do pretty well across the whole spectrum.\n\n\n\nIn the first few shades of grey, the white and black contrasts make sense, but as we test other colors in the spectrum, we do get some unexpected deviation. Pure red #FF0000 has a flip-flop. This is due to how the \u2018YIQ\u2019 function weights the RGB parts. While you might have a personal preference for one style over another, both are justifiable.\n\n\n\nIn this second round of colors, we go deeper into the spectrum, off the beaten track. Again, most of the time the contrasting algorithms are in sync, but every once in a while they disagree. You can select which you prefer, neither of which is unreadable.\n\nConclusion\n\nContrast in color is important, especially if you cede all control and take a hands-off approach to the design. It is important to select smart defaults by making the contrast between colors as high as possible. This makes it easier for your customers to read, increases accessibility and is generally just easier on the eyes. \n\nSure, there are plenty of other equations out there to determine contrast; what is most important is that you pick one and implement it into your system.\n\nSo, go ahead and experiment with color in your design. You now know how easy it is to guarantee that your text will be the most readable in any circumstance.", "year": "2010", "author": "Brian Suda", "author_slug": "briansuda", "published": "2010-12-24T00:00:00+00:00", "url": "https://24ways.org/2010/calculating-color-contrast/", "topic": "code"}
{"rowid": 55, "title": "How Tabs Should Work", "contents": "Tabs in browsers (not browser tabs) are one of the oldest custom UI elements in a browser that I can think of. They\u2019ve been done to death. But, sadly, most of the time I come across them, the tabs have been badly, or rather partially, implemented.\nSo this post is my definition of how a tabbing system should work, and one approach of implementing that.\nBut\u2026 tabs are easy, right?\nI\u2019ve been writing code for tabbing systems in JavaScript for coming up on a decade, and at one point I was pretty proud of how small I could make the JavaScript for the tabbing system:\nvar tabs = $('.tab').click(function () {\n  tabs.hide().filter(this.hash).show();\n}).map(function () {\n  return $(this.hash)[0];\n});\n\n$('.tab:first').click();\nSimple, right? Nearly fits in a tweet (ignoring the whole jQuery library\u2026). Still, it\u2019s riddled with problems that make it a far from perfect solution.\nRequirements: what makes the perfect tab?\n\nAll content is navigable and available without JavaScript (crawler-compatible and low JS-compatible).\nARIA roles.\nThe tabs are anchor links that:\n\nare clickable\nhave block layout\nhave their href pointing to the id of the panel element\nuse the correct cursor (i.e. cursor: pointer).\n\nSince tabs are clickable, the user can open in a new tab/window and the page correctly loads with the correct tab open.\nRight-clicking (and Shift-clicking) doesn\u2019t cause the tab to be selected.\nNative browser Back/Forward button correctly changes the state of the selected tab (think about it working exactly as if there were no JavaScript in place).\n\nThe first three points are all to do with the semantics of the markup and how the markup has been styled. I think it\u2019s easy to do a good job by thinking of tabs as links, and not as some part of an application. Links are navigable, and they should work the same way other links on the page work.\nThe last three points are JavaScript problems. Let\u2019s investigate that.\nThe shitmus test\nLike a litmus test, here\u2019s a couple of quick ways you can tell if a tabbing system is poorly implemented:\n\nChange tab, then use the Back button (or keyboard shortcut) and it breaks\nThe tab isn\u2019t a link, so you can\u2019t open it in a new tab\n\nThese two basic things are, to me, the bare minimum that a tabbing system should have.\nWhy is this important?\nThe people who push their so-called native apps on users can\u2019t have more reasons why the web sucks. If something as basic as a tab doesn\u2019t work, obviously there\u2019s more ammo to push a closed native app or platform on your users.\nIf you\u2019re going to be a web developer, one of your responsibilities is to maintain established interactivity paradigms. This doesn\u2019t mean don\u2019t innovate. But it does mean: stop fucking up my scrolling experience with your poorly executed scroll effects. </rant> :breath:\nURI fragment, absolute URL or query string?\nA URI fragment (AKA the # hash bit) would be using mysite.com/config#content to show the content panel. A fully addressable URL would be mysite.com/config/content. Using a query string (by way of filtering the page): mysite.com/config?tab=content.\nThis decision really depends on the context of your tabbing system. For something like GitHub\u2019s tabs to view a pull request, it makes sense that the full URL changes.\nFor our problem though, I want to solve the issue when the page doesn\u2019t do a full URL update; that is, your regular run-of-the-mill tabbing system.\nI used to be from the school of using the hash to show the correct tab, but I\u2019ve recently been exploring whether the query string can be used. The biggest reason is that multiple hashes don\u2019t work, and comma-separated hash fragments don\u2019t make any sense to control multiple tabs (since it doesn\u2019t actually link to anything).\nFor this article, I\u2019ll keep focused on using a single tabbing system and a hash on the URL to control the tabs.\nMarkup\nI\u2019m going to assume subcontent, so my markup would look like this (yes, this is a cat demo\u2026):\n<ul class=\"tabs\">\n  <li><a class=\"tab\" href=\"#dizzy\">Dizzy</a></li>\n  <li><a class=\"tab\" href=\"#ninja\">Ninja</a></li>\n  <li><a class=\"tab\" href=\"#missy\">Missy</a></li>\n</ul>\n\n<div id=\"dizzy\">\n  <!-- panel content -->\n</div>\n<div id=\"ninja\">\n  <!-- panel content -->\n</div>\n<div id=\"missy\">\n  <!-- panel content -->\n</div>\nIt\u2019s important to note that in the markup the link used for an individual tab references its panel content using the hash, pointing to the id on the panel. This will allow our content to connect up without JavaScript and give us a bunch of features for free, which we\u2019ll see once we\u2019re on to writing the code.\nURL-driven tabbing systems\nInstead of making the code responsive to the user\u2019s input, we\u2019re going to exclusively use the browser URL and the hashchange event on the window to drive this tabbing system. This way we get Back button support for free.\nWith that in mind, let\u2019s start building up our code. I\u2019ll assume we have the jQuery library, but I\u2019ve also provided the full code working without a library (vanilla, if you will), but it depends on relatively new (polyfillable) tech like classList and dataset (which generally have IE10 and all other browser support).\nNote that I\u2019ll start with the simplest solution, and I\u2019ll refactor the code as I go along, like in places where I keep calling jQuery selectors.\nfunction show(id) {\n  // remove the selected class from the tabs,\n  // and add it back to the one the user selected\n  $('.tab').removeClass('selected').filter(function () {\n    return (this.hash === id);\n  }).addClass('selected');\n\n  // now hide all the panels, then filter to\n  // the one we're interested in, and show it\n  $('.panel').hide().filter(id).show();\n}\n\n$(window).on('hashchange', function () {\n  show(location.hash);\n});\n\n// initialise by showing the first panel\nshow('#dizzy');\nThis works pretty well for such little code. Notice that we don\u2019t have any click handlers for the user and the Back button works right out of the box.\nHowever, there\u2019s a number of problems we need to fix:\n\nThe initialised tab is hard-coded to the first panel, rather than what\u2019s on the URL.\nIf there\u2019s no hash on the URL, all the panels are hidden (and thus broken).\nIf you scroll to the bottom of the example, you\u2019ll find a \u201ctop\u201d link; clicking that will break our tabbing system.\nI\u2019ve purposely made the page long, so that when you click on a tab, you\u2019ll see the page scrolls to the top of the tab. Not a huge deal, but a bit annoying.\n\nFrom our criteria at the start of this post, we\u2019ve already solved items 4 and 5. Not a terrible start. Let\u2019s solve items 1 through 3 next.\nUsing the URL to initialise correctly and protect from breakage\nInstead of arbitrarily picking the first panel from our collection, the code should read the current location.hash and use that if it\u2019s available.\nThe problem is: what if the hash on the URL isn\u2019t actually for a tab?\nThe solution here is that we need to cache a list of known panel IDs. In fact, well-written DOM scripting won\u2019t continuously search the DOM for nodes. That is, when the show function kept calling $('.tab').each(...) it was wasteful. The result of $('.tab') should be cached.\nSo now the code will collect all the tabs, then find the related panels from those tabs, and we\u2019ll use that list to double the values we give the show function (during initialisation, for instance).\n// collect all the tabs\nvar tabs = $('.tab');\n\n// get an array of the panel ids (from the anchor hash)\nvar targets = tabs.map(function () {\n  return this.hash;\n}).get();\n\n// use those ids to get a jQuery collection of panels\nvar panels = $(targets.join(','));\n\nfunction show(id) {\n  // if no value was given, let's take the first panel\n  if (!id) {\n    id = targets[0];\n  }\n  // remove the selected class from the tabs,\n  // and add it back to the one the user selected\n  tabs.removeClass('selected').filter(function () {\n    return (this.hash === id);\n  }).addClass('selected');\n\n  // now hide all the panels, then filter to\n  // the one we're interested in, and show it\n  panels.hide().filter(id).show();\n}\n\n$(window).on('hashchange', function () {\n  var hash = location.hash;\n  if (targets.indexOf(hash) !== -1) {\n    show(hash);\n  }\n});\n\n// initialise\nshow(targets.indexOf(location.hash) !== -1 ? location.hash : '');\nThe core of working out which tab to initialise with is solved in that last line: is there a location.hash? Is it in our list of valid targets (panels)? If so, select that tab.\nThe second breakage we saw in the original demo was that clicking the \u201ctop\u201d link would break our tabs. This was due to the hashchange event firing and the code didn\u2019t validate the hash that was passed. Now this happens, the panels don\u2019t break.\nSo far we\u2019ve got a tabbing system that:\n\nWorks without JavaScript.\nSupports right-click and Shift-click (and doesn\u2019t select in these cases).\nLoads the correct panel if you start with a hash.\nSupports native browser navigation.\nSupports the keyboard.\n\nThe only annoying problem we have now is that the page jumps when a tab is selected. That\u2019s due to the browser following the default behaviour of an internal link on the page. To solve this, things are going to get a little hairy, but it\u2019s all for a good cause.\nRemoving the jump to tab\nYou\u2019d be forgiven for thinking you just need to hook a click handler and return false. It\u2019s what I started with. Only that\u2019s not the solution. If we add the click handler, it breaks all the right-click and Shift-click support.\nThere may be another way to solve this, but what follows is the way I found \u2013 and it works. It\u2019s just a bit\u2026 hairy, as I said.\nWe\u2019re going to strip the id attribute off the target panel when the user tries to navigate to it, and then put it back on once the show code starts to run. This change will mean the browser has nowhere to navigate to for that moment, and won\u2019t jump the page.\nThe change involves the following:\n\nAdd a click handle that removes the id from the target panel, and cache this in a target variable that we\u2019ll use later in hashchange (see point 4).\nIn the same click handler, set the location.hash to the current link\u2019s hash. This is important because it forces a hashchange event regardless of whether the URL actually changed, which prevents the tabs breaking (try it yourself by removing this line).\nFor each panel, put a backup copy of the id attribute in a data property (I\u2019ve called it old-id).\nWhen the hashchange event fires, if we have a target value, let\u2019s put the id back on the panel.\n\nThese changes result in this final code:\n/*global $*/\n\n// a temp value to cache *what* we're about to show\nvar target = null;\n\n// collect all the tabs\nvar tabs = $('.tab').on('click', function () {\n  target = $(this.hash).removeAttr('id');\n\n  // if the URL isn't going to change, then hashchange\n  // event doesn't fire, so we trigger the update manually\n  if (location.hash === this.hash) {\n    // but this has to happen after the DOM update has\n    // completed, so we wrap it in a setTimeout 0\n    setTimeout(update, 0);\n  }\n});\n\n// get an array of the panel ids (from the anchor hash)\nvar targets = tabs.map(function () {\n  return this.hash;\n}).get();\n\n// use those ids to get a jQuery collection of panels\nvar panels = $(targets.join(',')).each(function () {\n  // keep a copy of what the original el.id was\n  $(this).data('old-id', this.id);\n});\n\nfunction update() {\n  if (target) {\n    target.attr('id', target.data('old-id'));\n    target = null;\n  }\n\n  var hash = window.location.hash;\n  if (targets.indexOf(hash) !== -1) {\n    show(hash);\n  }\n}\n\nfunction show(id) {\n  // if no value was given, let's take the first panel\n  if (!id) {\n    id = targets[0];\n  }\n  // remove the selected class from the tabs,\n  // and add it back to the one the user selected\n  tabs.removeClass('selected').filter(function () {\n    return (this.hash === id);\n  }).addClass('selected');\n\n  // now hide all the panels, then filter to\n  // the one we're interested in, and show it\n  panels.hide().filter(id).show();\n}\n\n$(window).on('hashchange', update);\n\n// initialise\nif (targets.indexOf(window.location.hash) !== -1) {\n  update();\n} else {\n  show();\n}\nThis version now meets all the criteria I mentioned in my original list, except for the ARIA roles and accessibility. Getting this support is actually very cheap to add.\nARIA roles\nThis article on ARIA tabs made it very easy to get the tabbing system working as I wanted.\nThe tasks were simple:\n\nAdd aria-role set to tab for the tabs, and tabpanel for the panels.\nSet aria-controls on the tabs to point to their related panel (by id).\nI use JavaScript to add tabindex=0 to all the tab elements.\nWhen I add the selected class to the tab, I also set aria-selected to true and, inversely, when I remove the selected class I set aria-selected to false.\nWhen I hide the panels I add aria-hidden=true, and when I show the specific panel I set aria-hidden=false.\n\nAnd that\u2019s it. Very small changes to get full sign-off that the tabbing system is bulletproof and accessible.\nCheck out the final version (and the non-jQuery version as promised).\nIn conclusion\nThere\u2019s a lot of tab implementations out there, but there\u2019s an equal amount that break the browsing paradigm and the simple linkability of content. Clearly there\u2019s a special hell for those tab systems that don\u2019t even use links, but I think it\u2019s clear that even in something that\u2019s relatively simple, it\u2019s the small details that make or break the user experience.\nObviously there are corners I\u2019ve not explored, like when there\u2019s more than one set of tabs on a page, and equally whether you should deliver the initial markup with the correct tab selected. I think the answer lies in using query strings in combination with hashes on the URL, but maybe that\u2019s for another year!", "year": "2015", "author": "Remy Sharp", "author_slug": "remysharp", "published": "2015-12-22T00:00:00+00:00", "url": "https://24ways.org/2015/how-tabs-should-work/", "topic": "code"}
{"rowid": 147, "title": "Christmas Is In The AIR", "contents": "That\u2019s right, Christmas is coming up fast and there\u2019s plenty of things to do. Get the tree and lights up, get the turkey, buy presents and who know what else. And what about Santa? He\u2019s got a list. I\u2019m pretty sure he\u2019s checking it twice.\n\nSure, we could use an existing list making web site or even a desktop widget. But we\u2019re geeks! What\u2019s the fun in that? Let\u2019s build our own to-do list application and do it with Adobe AIR!\n\nWhat\u2019s Adobe AIR?\n\nAdobe AIR, formerly codenamed Apollo, is a runtime environment that runs on both Windows and OSX (with Linux support to follow). This runtime environment lets you build desktop applications using Adobe technologies like Flash and Flex. Oh, and HTML. That\u2019s right, you web standards lovin\u2019 maniac. You can build desktop applications that can run cross-platform using the trio of technologies, HTML, CSS and JavaScript.\n\nIf you\u2019ve tried developing with AIR before, you\u2019ll need to get re-familiarized with the latest beta release as many things have changed since the last one (such as the API and restrictions within the sandbox.)\n\nTo get started\n\nTo get started in building an AIR application, you\u2019ll need two basic things:\n\n\n\tThe AIR runtime. The runtime is needed to run any AIR-based application.\n\tThe SDK. The software development kit gives you all the pieces to test your application. Unzip the SDK into any folder you wish.\n\n\nYou\u2019ll also want to get your hands on the JavaScript API documentation which you\u2019ll no doubt find yourself getting into before too long. (You can download it, too.)\n\nAlso of interest, some development environments have support for AIR built right in. Aptana doesn\u2019t have support for beta 3 yet but I suspect it\u2019ll be available shortly.\n\nWithin the SDK, there are two main tools that we\u2019ll use: one to test the application (ADL) and another to build a distributable package of our application (ADT). I\u2019ll get into this some more when we get to that stage of development.\n\nBuilding our To-do list application\n\nThe first step to building an application within AIR is to create an XML file that defines our default application settings. I call mine application.xml, mostly because Aptana does that by default when creating a new AIR project. It makes sense though and I\u2019ve stuck with it. Included in the templates folder of the SDK is an example XML file that you can use.\n\nThe first key part to this after specifying things like the application ID, version, and filename, is to specify what the default content should be within the content tags. Enter in the name of the HTML file you wish to load. Within this HTML file will be our application.\n\n<content>ui.html</content>\n\nCreate a new HTML document and name it ui.html and place it in the same directory as the application.xml file. The first thing you\u2019ll want to do is copy over the AIRAliases.js file from the frameworks folder of the SDK and add a link to it within your HTML document.\n\n<script type=\"text/javascript\" src=\"AIRAliases.js\"></script>\n\nThe aliases create shorthand links to all of the Flash-based APIs.\n\nNow is probably a good time to explain how to debug your application.\n\nDebugging our application\n\nSo, with our XML file created and HTML file started, let\u2019s try testing our \u2018application\u2019. We\u2019ll need the ADL application located in BIN folder of the SDK and tell it to run the application.xml file.\n\n/path/to/adl /path/to/application.xml\n\nYou can also just drag the XML file onto ADL and it\u2019ll accomplish the same thing. If you just did that and noticed that your blank application didn\u2019t load, you\u2019d be correct. It\u2019s running but isn\u2019t visible. Which at this point means you\u2019ll have to shut down the ADL process. Sorry about that!\n\nChanging the visibility\n\nYou have two ways to make your application visible. You can do it automatically by setting the placing true in the visible tag within the application.xml file.\n\n<visible>true</visible>\n\nThe other way is to do it programmatically from within your application. You\u2019d want to do it this way if you had other startup tasks to perform before showing the interface. To turn the UI on programmatically, simple set the visible property of nativeWindow to true.\n\n<script type=\"text/javascript\">\n\tnativeWindow.visible = true;\n</script>\n\nSandbox Security\n\nNow that we have an application that we can see when we start it, it\u2019s time to build the to-do list application. In doing so, you\u2019d probably think that using a JavaScript library is a really good idea \u2014 and it can be but there are some limitations within AIR that have to be considered.\n\nAn HTML document, by default, runs within the application sandbox. You have full access to the AIR APIs but once the onload event of the window has fired, you\u2019ll have a limited ability to make use of eval and other dynamic script injection approaches. This limits the ability of external sources from gaining access to everything the AIR API offers, such as database and local file system access. You\u2019ll still be able to make use of eval for evaluating JSON responses, which is probably the most important if you wish to consume JSON-based services.\n\nIf you wish to create a greater wall of security between AIR and your HTML document loading in external resources, you can create a child sandbox. We won\u2019t need to worry about it for our application so I won\u2019t go any further into it but definitely keep this in mind.\n\nFinally, our application\n\nGetting tired of all this preamble? Let\u2019s actually build our to-do list application. I\u2019ll use jQuery because it\u2019s small and should suit our needs nicely. Let\u2019s begin with some structure:\n\n<body>\n\t<input type=\"text\" id=\"text\" value=\"\">\n\t<input type=\"button\" id=\"add\" value=\"Add\">\n\t<ul id=\"list\"></ul>\n</body>\n\nNow we need to wire up that button to actually add a new item to our to-do list.\n\n<script type=\"text/javascript\">\n$(document).ready(function(){\n\t// make sure the application is visible\n\tnativeWindow.visible = true;\n\t$('#add').click(function(){\n\t\tvar t = $('#text').val();\n\t\tif(t)\n\t\t{\n\t\t\t// use DOM methods to create the new list item\n\t\t\tvar li = document.createElement('li');\n\t\t\t// the extra space at the end creates a buffer between the text\n\t\t\t// and the delete link we're about to add\n\t\t\tli.appendChild(document.createTextNode(t + ' '));\n\t\t\t// create the delete link\n\t\t\tvar del = document.createElement('a');\n\t\t\t// this makes it a true link. I feel dirty doing this.\n\t\t\tdel.setAttribute('href', '#');\n\t\t\tdel.addEventListener('click', function(evt){\n\t\t\t\tthis.parentNode.parentNode.removeChild(this.parentNode);\n\t\t\t});\n\t\t\tdel.appendChild(document.createTextNode('[del]'));\n\t\t\tli.appendChild(del);\n\t\t\t// append everything to the list\n\t\t\t$('#list').append(li);\n\t\t\t//reset the text box\n\t\t\t$('#text').val('');\n\t\t}\n\t})\n});\n</script>\n\nAnd just like that, we\u2019ve got a to-do list! That\u2019s it! Just never close your application and you\u2019ll remember everything. Okay, that\u2019s not very practical. You need to have some way of storing your to-do items until the next time you open up the application.\n\nStoring Data\n\nYou\u2019ve essentially got 4 different ways that you can store data:\n\n\n\tUsing the local database. AIR comes with SQLLite built in. That means you can create tables and insert, update and select data from that database just like on a web server.\n\tUsing the file system. You can also create files on the local machine. You have access to a few folders on the local system such as the documents folder and the desktop.\n\tUsing EcryptedLocalStore. I like using the EcryptedLocalStore because it allows you to easily save key/value pairs and have that information encrypted. All this within just a couple lines of code.\n\tSending the data to a remote API. Our to-do list could sync up with Remember the Milk, for example.\n\n\nTo demonstrate some persistence, we\u2019ll use the file system to store our files. In addition, we\u2019ll let the user specify where the file should be saved. This way, we can create multiple to-do lists, keeping them separate and organized.\n\nThe application is now broken down into 4 basic tasks:\n\n\n\tLoad data from the file system.\n\tPerform any interface bindings.\n\tManage creating and deleting items from the list.\n\tSave any changes to the list back to the file system.\n\n\nLoading in data from the file system\n\nWhen the application starts up, we\u2019ll prompt the user to select a file or specify a new to-do list. Within AIR, there are 3 main file objects: File, FileMode, and FileStream. File handles file and path names, FileMode is used as a parameter for the FileStream to specify whether the file should be read-only or for write access. The FileStream object handles all the read/write activity.\n\nThe File object has a number of shortcuts to default paths like the documents folder, the desktop, or even the application store. In this case, we\u2019ll specify the documents folder as the default location and then use the browseForSave method to prompt the user to specify a new or existing file. If the user specifies an existing file, they\u2019ll be asked whether they want to overwrite it.\n\nvar store = air.File.documentsDirectory;\nvar fileStream = new air.FileStream();\nstore.browseForSave(\"Choose To-do List\");\n\nThen we add an event listener for when the user has selected a file. When the file is selected, we check to see if the file exists and if it does, read in the contents, splitting the file on new lines and creating our list items within the interface.\n\nstore.addEventListener(air.Event.SELECT, fileSelected);\nfunction fileSelected()\n{\n\tair.trace(store.nativePath);\n\t// load in any stored data\n\tvar byteData = new air.ByteArray();\n\tif(store.exists)\n\t{\n\t\tfileStream.open(store, air.FileMode.READ);\n\t\tfileStream.readBytes(byteData, 0, store.size);\n\t\tfileStream.close();\n\n\t\tif(byteData.length > 0)\n\t\t{\n\t\t\tvar s = byteData.readUTFBytes(byteData.length);\n\t\t\toldlist = s.split(\u201c\\r\\n\u201d);\n\n\t\t\t// create todolist items\n\t\t\tfor(var i=0; i < oldlist.length; i++)\n\t\t\t{\n\t\t\t\tcreateItem(oldlist[i], (new Date()).getTime() + i );\n\t\t\t}\n\t\t}\n\t}\n}\n\nPerform Interface Bindings\n\nThis is similar to before where we set the click event on the Add button but we\u2019ve moved the code to save the list into a separate function.\n\n$('#add').click(function(){\n\t\tvar t = $('#text').val();\n\t\tif(t){\n\t\t\t// create an ID using the time\n\t\t\tcreateItem(t, (new Date()).getTime() );\n\t\t}\n})\n\nManage creating and deleting items from the list\n\nThe list management is now in its own function, similar to before but with some extra information to identify list items and with calls to save our list after each change.\n\nfunction createItem(t, id)\n{\n\tif(t.length == 0) return;\n\t// add it to the todo list\n\ttodolist[id] = t;\n\t// use DOM methods to create the new list item\n\tvar li = document.createElement('li');\n\t// the extra space at the end creates a buffer between the text\n\t// and the delete link we're about to add\n\tli.appendChild(document.createTextNode(t + ' '));\n\t// create the delete link\n\tvar del = document.createElement('a');\n\t// this makes it a true link. I feel dirty doing this.\n\tdel.setAttribute('href', '#');\n\tdel.addEventListener('click', function(evt){\n\t\tvar id = this.id.substr(1);\n\t\tdelete todolist[id]; // remove the item from the list\n\t\tthis.parentNode.parentNode.removeChild(this.parentNode);\n\t\tsaveList();\n\t});\n\tdel.appendChild(document.createTextNode('[del]'));\n\tdel.id = 'd' + id;\n\tli.appendChild(del);\n\t// append everything to the list\n\t$('#list').append(li);\n\t//reset the text box\n\t$('#text').val('');\n\tsaveList();\n}\n\nSave changes to the file system\n\nAny time a change is made to the list, we update the file. The file will always reflect the current state of the list and we\u2019ll never have to click a save button. It just iterates through the list, adding a new line to each one.\n\nfunction saveList(){\n\tif(store.isDirectory) return;\n\tvar packet = '';\n\tfor(var i in todolist)\n\t{\n\t\tpacket += todolist[i] + '\\r\\n';\n\t}\n\tvar bytes = new air.ByteArray();\n\tbytes.writeUTFBytes(packet);\n\tfileStream.open(store, air.FileMode.WRITE);\n\tfileStream.writeBytes(bytes, 0, bytes.length);\n\tfileStream.close();\n}\n\nOne important thing to mention here is that we check if the store is a directory first. The reason we do this goes back to our browseForSave call. If the user cancels the dialog without selecting a file first, then the store points to the documentsDirectory that we set it to initially. Since we haven\u2019t specified a file, there\u2019s no place to save the list.\n\nHopefully by this point, you\u2019ve been thinking of some cool ways to pimp out your list. Now we need to package this up so that we can let other people use it, too.\n\nCreating a Package\n\nNow that we\u2019ve created our application, we need to package it up so that we can distribute it. This is a two step process. The first step is to create a code signing certificate (or you can pay for one from Thawte which will help authenticate you as an AIR application developer).\n\nTo create a self-signed certificate, run the following command. This will create a PFX file that you\u2019ll use to sign your application.\n\nadt -certificate -cn todo24ways 1024-RSA todo24ways.pfx mypassword\n\nAfter you\u2019ve done that, you\u2019ll need to create the package with the certificate\n\nadt -package -storetype pkcs12 -keystore todo24ways.pfx todo24ways.air application.xml .\n\nThe important part to mention here is the period at the end of the command. We\u2019re telling it to package up all files in the current directory.\n\nAfter that, just run the AIR file, which will install your application and run it.\n\nImportant things to remember about AIR\n\nWhen developing an HTML application, the rendering engine is Webkit. You\u2019ll thank your lucky stars that you aren\u2019t struggling with cross-browser issues. (My personal favourites are multiple backgrounds and border radius!)\n\nBe mindful of memory leaks. Things like Ajax calls and event binding can cause applications to slowly leak memory over time. Web pages are normally short lived but desktop applications are often open for hours, if not days, and you may find your little desktop application taking up more memory than anything else on your machine!\n\nThe WebKit runtime itself can also be a memory hog, usually taking about 15MB just for itself. If you create multiple HTML windows, it\u2019ll add another 15MB to your memory footprint. Our little to-do list application shouldn\u2019t be much of a concern, though.\n\nThe other important thing to remember is that you\u2019re still essentially running within a Flash environment. While you probably won\u2019t notice this working in small applications, the moment you need to move to multiple windows or need to accomplish stuff beyond what HTML and JavaScript can give you, the need to understand some of the Flash-based elements will become more important.\n\nLastly, the other thing to remember is that HTML links will load within the AIR application. If you want a link to open in the users web browser, you\u2019ll need to capture that event and handle it on your own. The following code takes the HREF from a clicked link and opens it in the default web browser.\n\nair.navigateToURL(new air.URLRequest(this.href));\n\nOnly the beginning\n\nOf course, this is only the beginning of what you can do with Adobe AIR. You don\u2019t have the same level of control as building a native desktop application, such as being able to launch other applications, but you do have more control than what you could have within a web application. Check out the Adobe AIR Developer Center for HTML and Ajax for tutorials and other resources.\n\nNow, go forth and create your desktop applications and hopefully you finish all your shopping before Christmas!\n\nDownload the example files.", "year": "2007", "author": "Jonathan Snook", "author_slug": "jonathansnook", "published": "2007-12-19T00:00:00+00:00", "url": "https://24ways.org/2007/christmas-is-in-the-air/", "topic": "code"}
{"rowid": 215, "title": "Teach the CLI to Talk Back", "contents": "The CLI is a daunting tool. It\u2019s quick, powerful, but it\u2019s also incredibly easy to screw things up in \u2013 either with a mistyped command, or a correctly typed command used at the wrong moment. This puts a lot of people off using it, but it doesn\u2019t have to be this way.\nIf you\u2019ve ever interacted with Slack\u2019s Slackbot to set a reminder or ask a question, you\u2019re basically using a command line interface, but it feels more like having a conversation. (My favourite Slack app is Lunch Train which helps with the thankless task of herding colleagues to a particular lunch venue on time.)\nSame goes with voice-operated assistants like Alexa, Siri and Google Home. There are even games, like Lifeline, where you interact with a stranded astronaut via pseudo SMS, and KOMRAD where you chat with a Soviet AI.\nI\u2019m not aiming to build an AI here \u2013 my aspirations are a little more down to earth. What I\u2019d like is to make the CLI a friendlier, more forgiving, and more intuitive tool for new or reluctant users. I want to teach it to talk back.\nInteractive command lines in the wild\nIf you\u2019ve used dev tools in the command line, you\u2019ve probably already used an interactive prompt \u2013 something that asks you questions and responds based on your answers. Here are some examples:\nYeoman\nIf you have Yeoman globally installed, running yo will start a command prompt.\n\nThe prompt asks you what you\u2019d like to do, and gives you options with how to proceed. Seasoned users will run specific commands for these options rather than go through this prompt, but it\u2019s a nice way to start someone off with using the tool.\nnpm\nIf you\u2019re a Node.js developer, you\u2019re probably familiar with typing npm init to initialise a project. This brings up prompts that will populate a package.json manifest file for that project.\n\nThe alternative would be to expect the user to craft their own package.json, which is more error-prone since it\u2019s in JSON format, so something as trivial as an extraneous comma can throw an error.\nSnyk\nSnyk is a dev tool that checks for known vulnerabilities in your dependencies. Running snyk wizard in the CLI brings up a list of all the known vulnerabilities, and gives you options on how to deal with it \u2013 such as patching the issue, applying a fix by upgrading the problematic dependency, or ignoring the issue (you are then prompted for a reason).\n\nThese decisions get mapped to the manifest and a .snyk file, and committed into the repo so that the settings are the same for everyone who uses that project.\nI work at Snyk, and running the wizard is what made me think about building my own personal assistant in the command line to help me with some boring, repetitive tasks.\nWriting your own\nSomething I do a lot is add bookmarks to styleguides.io \u2013 I pull down the entire repo, copy and paste a template YAML file, and edit to contents. Sometimes I get it wrong and break the site. So I\u2019ve been putting together a tool to help me add bookmarks.\nIt\u2019s called bookmarkbot \u2013 it\u2019s a personal assistant squirrel called Mark who will collect and bury your bookmarks for safekeeping.*\n\n*Fortunately, this metaphor also gives me a charming excuse for any situation where bookmarks sometimes get lost \u2013 it\u2019s not my poorly-written code, honest, it\u2019s just being realistic because sometimes squirrels forget where they buried things!\nWhen you run bookmarkbot, it will ask you for some information, and save that information as a Markdown file in YAML format.\nFor this demo, I\u2019m going to use a Node.js package called inquirer, which is a well supported tool for creating command line prompts. I like it because it has a bunch of different question types; from input, which asks for some text back, confirm which expects a yes/no response, or a list which gives you a set of options to choose from. You can even nest questions, Choose Your Own Adventure style.\nPrerequisites\n\nNode.js\nnpm\nRubyGems (Only if you want to go as far as serving a static site for your bookmarks, and you want to use Jekyll for it)\n\nDisclaimer\nBear in mind that this is a really simplified walkthrough. It doesn\u2019t have any error states, and it doesn\u2019t handle the situation where we save a file with the same name. But it gets you in a good place to start building out your tool.\nLet\u2019s go!\nCreate a new folder wherever you keep your projects, and give it an awesome name (I\u2019ve called mine bookmarks and put it in the Sites directory because I\u2019m unimaginative). Now cd to that directory. \ncd Sites/bookmarks\nLet\u2019s use that example I gave earlier, the trusty npm init.\nnpm init\nPop in the information you\u2019d like to provide, or hit ENTER to skip through and save the defaults. Your directory should now have a package.json file in it. Now let\u2019s install some of the dependencies we\u2019ll need.\nnpm install --save inquirer\nnpm install --save slugify\nNext, add the following snippet to your package.json to tell it to run this file when you run npm start.\n\"scripts\": {\n  \u2026\n  \"start\": \"node index.js\"\n}\nThat index.js file doesn\u2019t exist yet, so let\u2019s create it in the root of our folder, and add the following:\n// Packages we need\nvar fs = require('fs'); // Creates our file (part of Node.js so doesn't need installing)\nvar inquirer = require('inquirer'); // The engine for our questions prompt\nvar slugify = require('slugify'); // Will turn a string into a usable filename\n\n// The questions\nvar questions = [\n  {\n    type: 'input',\n    name: 'name',\n    message: 'What is your name?',\n  },\n];\n\n// The questions prompt\nfunction askQuestions() {\n\n  // Ask questions\n  inquirer.prompt(questions).then(answers => {\n\n    // Things we'll need to generate the output\n    var name = answers.name;\n\n    // Finished asking questions, show the output\n    console.log('Hello ' + name + '!');\n\n  });\n\n}\n\n// Kick off the questions prompt\naskQuestions();\nThis is just some barebones where we\u2019re including the inquirer package we installed earlier. I\u2019ve stored the questions in a variable, and the askQuestions function will prompt the user for their name, and then print \u201cHello <your name>\u201d in the console.\nEnough setup, let\u2019s see some magic. Save the file, go back to the command line and run npm start.\n\nExtending what we\u2019ve learnt\nAt the moment, we\u2019re just saving a name to a file, which isn\u2019t really achieving our goal of saving bookmarks. We don\u2019t want our tool to forget our information every time we talk to it \u2013 we need to save it somewhere. So I\u2019m going to add a little function to write the output to a file.\nSaving to a file\nCreate a folder in your project\u2019s directory called _bookmarks. This is where the bookmarks will be saved.\nI\u2019ve replaced my questions array, and instead of asking for a name, I\u2019ve extended out the questions, asking to be provided with a link and title (as a regular input type), a list of tags (using inquirer\u2019s checkbox type), and finally a description, again, using the input type.\nSo this is how my code looks now:\n// Packages we need\nvar fs = require('fs'); // Creates our file\nvar inquirer = require('inquirer'); // The engine for our questions prompt\nvar slugify = require('slugify'); // Will turn a string into a usable filename\n\n// The questions\nvar questions = [\n  {\n    type: 'input',\n    name: 'link',\n    message: 'What is the url?',\n  },\n  {\n    type: 'input',\n    name: 'title',\n    message: 'What is the title?',\n  },\n  {\n    type: 'checkbox',\n    name: 'tags',\n    message: 'Would you like me to add any tags?',\n    choices: [\n      { name: 'frontend' },\n      { name: 'backend' },\n      { name: 'security' },\n      { name: 'design' },\n      { name: 'process' },\n      { name: 'business' },\n    ],\n  },\n  {\n    type: 'input',\n    name: 'description',\n    message: 'How about a description?',\n  },\n];\n\n// The questions prompt\nfunction askQuestions() {\n\n  // Say hello\n  console.log('\ud83d\udc3f  Oh, hello! Found something you want me to bookmark?\\n');\n\n  // Ask questions\n  inquirer.prompt(questions).then((answers) => {\n\n    // Things we'll need to generate the output\n    var title = answers.title;\n    var link = answers.link;\n    var tags = answers.tags + '';\n    var description = answers.description;\n    var output = '---\\n' +\n                 'title: \"' + title + '\"\\n' +\n                 'link: \"' + link + '\"\\n' +\n                 'tags: [' + tags + ']\\n' +\n                 '---\\n' + description + '\\n';\n\n    // Finished asking questions, show the output\n    console.log('\\n\ud83d\udc3f  All done! Here is what I\\'ve written down:\\n');\n    console.log(output);\n\n    // Things we'll need to generate the filename\n    var slug = slugify(title);\n    var filename = '_bookmarks/' + slug + '.md';\n\n    // Write the file\n    fs.writeFile(filename, output, function () {\n      console.log('\\n\ud83d\udc3f  Great! I have saved your bookmark to ' + filename);\n    });\n\n  });\n\n}\n\n// Kick off the questions prompt\naskQuestions();\nThe output is formatted into YAML metadata as a Markdown file, which will allow us to turn it into a static HTML file using a build tool later. Run npm start again and have a look at the file it outputs.\n\nGetting confirmation\nBefore the user makes critical changes, it\u2019s good to verify those changes first. We\u2019re going to add a confirmation step to our tool, before writing the file. More seasoned CLI users may favour speed over a \u201chey, can you wait a sec and just check this is all ok\u201d step, but I always think it\u2019s worth adding one so you can occasionally save someone\u2019s butt.\nSo, underneath our questions array, let\u2019s add a confirmation array.\n// Packages we need\n\u2026\n// The questions\n\u2026\n\n// Confirmation questions\nvar confirm = [\n  {\n    type: 'confirm',\n    name: 'confirm',\n    message: 'Does this look good?',\n  },\n];\n\n// The questions prompt\n\u2026\n\nAs we\u2019re adding the confirm step before the file gets written, we\u2019ll need to add the following inside the askQuestions function:\n// The questions prompt\nfunction askQuestions() {\n  // Say hello\n  \u2026\n  // Ask questions\n  inquirer.prompt(questions).then((answers) => {\n    \u2026\n    // Things we'll need to generate the output\n    \u2026\n    // Finished asking questions, show the output\n    \u2026\n\n    // Confirm output is correct\n    inquirer.prompt(confirm).then(answers => {\n\n      // Things we'll need to generate the filename\n      var slug = slugify(title);\n      var filename = '_bookmarks/' + slug + '.md';\n\n      if (answers.confirm) {\n        // Save output into file\n        fs.writeFile(filename, output, function () {\n          console.log('\\n\ud83d\udc3f  Great! I have saved your bookmark to ' +\n          filename);\n        });\n      } else {\n        // Ask the questions again\n        console.log('\\n\ud83d\udc3f  Oops, let\\'s try again!\\n');\n        askQuestions();\n      }\n\n    });\n\n  });\n}\n\n// Kick off the questions prompt\naskQuestions();\nNow run npm start and give it a go!\n\nTyping y will write the file, and n will take you back to the start. Ideally, I\u2019d store the answers already given as defaults so the user doesn\u2019t have to start from scratch, but I want to keep this demo simple.\nServing the files\nNow that your bookmarking tool is successfully saving formatted Markdown files to a folder, the next step is to serve those files in a way that lets you share them online. The easiest way to do this is to use a static-site generator to convert your YAML files into HTML, and pop them all on one page. Now, you\u2019ve got a few options here and I don\u2019t want to force you down any particular path, as there are plenty out there \u2013 it\u2019s just a case of using the one you\u2019re most comfortable with.\nI personally favour Jekyll because of its tight integration with GitHub Pages \u2013 I don\u2019t want to mess around with hosting and deployment, so it\u2019s really handy to have my bookmarks publish themselves on my site as soon as I commit and push them using Git.\nI\u2019ll give you a very brief run-through of how I\u2019m doing this with bookmarkbot, but I recommend you read my Get Started With GitHub Pages (Plus Bonus Jekyll) guide if you\u2019re unfamiliar with them, because I\u2019ll be glossing over some bits that are already covered in there.\nSetting up a build tool\nIf you haven\u2019t already, install Jekyll and Bundler globally through RubyGems. Jekyll is our static-site generator, and Bundler is what we use to install Ruby dependencies.\ngem install jekyll bundler\nIn my project folder, I\u2019m going to run the following which will install the Jekyll files we\u2019ll need to build our listing page. I\u2019m using --force, otherwise it will complain that the directory isn\u2019t empty.\njekyll new . --force\nIf you check your project folder, you\u2019ll see a bunch of new files. Now run the following to start the server:\nbundle exec jekyll serve\nThis will build a new directory called _site. This is where your static HTML files have been generated. Don\u2019t touch anything in this folder because it will get overwritten the next time you build.\nNow that serve is running, go to http://127.0.0.1:4000/ and you\u2019ll see the default Jekyll page and know that things are set up right. Now, instead, we want to see our list of bookmarks that are saved in the _bookmarks directory (make sure you\u2019ve got a few saved). So let\u2019s get that set up next.\nOpen up the _config.yml file that Jekyll added earlier. In here, we\u2019re going to tell it about our bookmarks. Replace everything in your _config.yml file with the following:\ntitle: My Bookmarks\ndescription: These are some of my favourite articles about the web.\nmarkdown: kramdown\nbaseurl: /bookmarks # This needs to be the same name as whatever you call your repo on GitHub.\ncollections:\n  - bookmarks\nThis will make Jekyll aware of our _bookmarks folder so that we can call it later. Next, create a new directory and file at _layouts/home.html and paste in the following.\n<!doctype html>\n<html lang=\"en\">\n<head>\n  <meta charset=\"UTF-8\" />\n  <title>{{site.title}}</title>\n  <meta name=\"description\" content=\"{{site.description}}\">\n</head>\n\n<body>\n\n  <h1>{{site.title}}</h1>\n  <p>{{site.description}}</p>\n\n  <ul>\n    {% for bookmark in site.bookmarks %}\n    <li>\n      <a href=\"{{bookmark.link}}\">\n        <h2>{{bookmark.title}}</h2>\n      </a>\n      {{bookmark.content}}\n      {% if bookmark.tags %}\n      <ul>\n        {% for tags in bookmark.tags %}<li>{{tags}}</li>{% endfor %}\n      </ul>\n      {% endif %}\n    </li>\n    {% endfor %}\n  </ul>\n\n</body>\n\n</html>\nRestart Jekyll for your config changes to kick in, and go to the url it provides you (probably http://127.0.0.1:4000/bookmarks, unless you gave something different as your baseurl).\n\nIt\u2019s a decent start \u2013 there\u2019s a lot more we can do in this area but now we\u2019ve got a nice list of all our bookmarks, let\u2019s get it online!\nIf you want to use GitHub Pages to host your files, your first step is to push your project to GitHub. Go to your repository and click \u201csettings\u201d. Scroll down to the section labelled \u201cGitHub Pages\u201d, and from here you can enable it. Select your master branch, and it will provide you with a url to view your published pages.\n\nWhat next?\nNow that you\u2019ve got a framework in place for publishing bookmarks, you can really go to town on your listing page and make it your own. First thing you\u2019ll probably want to do is add some CSS, then when you\u2019ve added a bunch of bookmarks, you\u2019ll probably want to have some filtering in place for the tags, perhaps extend the types of questions that you ask to include an image (if you\u2019re feeling extra-fancy, you could just ask for a url and pull in metadata from the site itself). Maybe you\u2019ve got an idea that doesn\u2019t involve bookmarks at all.\nYou could use what you\u2019ve learnt to build a place where you can share quotes, a list of your favourite restaurants, or even Christmas gift ideas.\nHere\u2019s one I made earlier\n\nMy demo, bookmarkbot, is on GitHub, and I\u2019ve reused a lot of the code from styleguides.io. Feel free to grab bits of code from there, and do share what you end up making!", "year": "2017", "author": "Anna Debenham", "author_slug": "annadebenham", "published": "2017-12-11T00:00:00+00:00", "url": "https://24ways.org/2017/teach-the-cli-to-talk-back/", "topic": "code"}
{"rowid": 126, "title": "Intricate Fluid Layouts in Three Easy Steps", "contents": "The Year of the Script may have drawn attention away from CSS but building fluid, multi-column, cross-browser CSS layouts can still be as unpleasant as a lump of coal. Read on for a worry-free approach in three quick steps.\n\nThe layout system I developed, YUI Grids CSS, has three components. They can be used together as we\u2019ll see, or independently.\n\nThe Three Easy Steps\n\n\n\tChoose fluid or fixed layout, and choose the width (in percents or pixels) of the page.\n\tChoose the size, orientation, and source-order of the main and secondary blocks of content.\n\tChoose the number of columns and how they distribute (for example 50%-50% or 25%-75%), using stackable and nestable grid structures.\n\n\nThe Setup\n\nThere are two prerequisites: We need to normalize the size of an em and opt into the browser rendering engine\u2019s Strict Mode.\n\nEms are a superior unit of measure for our case because they represent the current font size and grow as the user increases their font size setting. This flexibility\u2014the container growing with the user\u2019s wishes\u2014means larger text doesn\u2019t get crammed into an unresponsive container. We\u2019ll use YUI Fonts CSS to set the base size because it provides consistent-yet-adaptive font-sizes while preserving user control.\n\nThe second prerequisite is to opt into Strict Mode (more info on rendering modes) by declaring a Doctype complete with URI. You can choose XHTML or HTML, and Transitional or Strict. I prefer HTML 4.01 Strict, which looks like this:\n\n<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\" \"http://www.w3.org/TR/html4/strict.dtd\">\n\nIncluding the CSS\n\nA single small CSS file powers a nearly-infinite number of layouts thanks to a recursive system and the interplay between the three distinct components. You could prune to a particular layout\u2019s specific needs, but why bother when the complete file weighs scarcely 1.8kb uncompressed? Compressed, YUI Fonts and YUI Grids combine for a miniscule 0.9kb over the wire.\n\nYou could save an HTTP request by concatenating the two CSS files, or by adding their contents to your own CSS, but I\u2019ll keep them separate for now:\n\n<link href=\"fonts.css\" rel=\"stylesheet\" type=\"text/css\">\n<link href=\"grids.css\" rel=\"stylesheet\" type=\"text/css\">\n\nExample: The Setup\n\nNow we\u2019re ready to build some layouts.\n\nStep 1: Choose Fluid or Fixed Layout\n\nChoose between preset widths of 750px, 950px, and 100% by giving a document-wrapping div an ID of doc, doc2, or doc3. These options cover most use cases, but it\u2019s easy to define a custom fixed width.\n\nThe fluid 100% grid (doc3) is what I\u2019ve been using almost exclusively since it was introduced in the last YUI released.\n\n<body>\n\t<div id=\"doc3\"></div>\n</body>\n\nAll pages are centered within the viewport, and grow with font size. The 100% width page (doc3) preserves 10px of breathing room via left and right margins. If you prefer your content flush to the viewport, just add doc3 {margin:auto} to your CSS.\n\nRegardless of what you choose in the other two steps, you can always toggle between these widths and behaviors by simply swapping the ID value. It\u2019s really that simple.\n\nExample: 100% fluid layout\n\nStep 2: Choose a Template Preset\n\nThis is perhaps the most frequently omitted step (they\u2019re all optional), but I use it nearly every time. In a source-order-independent way (good for accessibility and SEO), \u201cTemplate Presets\u201d provide commonly used template widths compatible with ad-unit dimension standards defined by the Interactive Advertising Bureau, an industry association.\n\nChoose between the six Template Presets (.yui-t1 through .yui-t6) by setting the class value on the document-wrapping div established in Step 1. Most frequently I use yui-t3, which puts the narrow secondary block on the left and makes it 300px wide. \n\n<body>\n\t<div id=\"doc3\" class=\"yui-t3\"></div>\n</body>\n\nThe Template Presets control two \u201cblocks\u201d of content, which are defined by two divs, each with yui-b (\u201cb\u201d for \u201cblock\u201d) class values. Template Presets describe the width and orientation of the secondary block; the main block will take up the rest of the space.\n\n<body>\n\t<div id=\"doc3\" class=\"yui-t3\">\n\t  <div class=\"yui-b\"></div>\n\t  <div class=\"yui-b\"></div>\n\t</div>\n</body>\n\nUse a wrapping div with an ID of yui-main to structurally indicate which block is the main block. This wrapper\u2014not the source order\u2014identifies the main block.\n\n<body>\n\t<div id=\"doc3\" class=\"yui-t3\">\n\t  <div id=\"yui-main\">\n\t    <div class=\"yui-b\"></div>\n\t  </div>\n\t  <div class=\"yui-b\"></div>\n\t</div>\n</body>\n\nExample: Main and secondary blocks sized and oriented with .yui-t3 Template Preset\n\nAgain, regardless of what values you choose in the other steps, you can always toggle between these Template Presets by toggling the class value of your document-wrapping div. It\u2019s really that simple.\n\nStep 3: Nest and Stack Grid Structures.\n\nThe bulk of the power of the system is in this third step. The key is that columns are built by parents telling children how to behave. By default, two children each consume half of their parent\u2019s area. Put two units inside a grid structure, and they will sit side-by-side, and they will each take up half the space. Nest this structure and two columns become four. Stack them for rows of columns.\n\nAn Even Number of Columns\n\nThe default behavior creates two evenly-distributed columns. It\u2019s easy. Define one parent grid with .yui-g (\u201cg\u201d for grid) and two child units with .yui-u (\u201cu\u201d for unit). The code looks like this:\n\n<div class=\"yui-g\">\n\t<div class=\"yui-u first\"></div>\n\t<div class=\"yui-u\"></div>\n</div>\n\nBe sure to indicate the \u201cfirst\u201c unit because the :first-child pseudo-class selector isn\u2019t supported across all A-grade browsers. It\u2019s unfortunate we need to add this, but luckily it\u2019s not out of place in the markup layer since it is structural information.\n\nExample: Two evenly-distributed columns in the main content block\n\nAn Odd Number of Columns\n\nThe default system does not work for an odd number of columns without using the included \u201cSpecial Grids\u201d classes. To create three evenly distributed columns, use the \u201cyui-gb\u201c Special Grid:\n\n<div class=\"yui-gb\">\n\t<div class=\"yui-u first\"></div>\n\t<div class=\"yui-u\"></div>\n\t<div class=\"yui-u\"></div>\n</div>\n\nExample: Three evenly distributed columns in the main content block\n\nUneven Column Distribution\n\nSpecial Grids are also used for unevenly distributed column widths. For example, .yui-ge tells the first unit (column) to take up 75% of the parent\u2019s space and the other unit to take just 25%.\n\n<div class=\"yui-ge\">\n\t<div class=\"yui-u first\"></div>\n\t<div class=\"yui-u\"></div>\n</div>\n\nExample: Two columns in the main content block split 75%-25%\n\nPutting It All Together\n\nStart with a full-width fluid page (div#doc3). Make the secondary block 180px wide on the right (div.yui-t4). Create three rows of columns: Three evenly distributed columns in the first row (div.yui-gb), two uneven columns (66%-33%) in the second row (div.yui-gc), and two evenly distributed columns in the thrid row.\n\n<body>\n\t<!-- choose fluid page and Template Preset -->\n\t<div id=\"doc3\" class=\"yui-t4\">\n\t\t<!-- main content block -->\n\t\t<div id=\"yui-main\">\n\t\t\t<div class=\"yui-b\">\n\t\t\t\t<!-- stacked grid structure, Special Grid \"b\" -->\n\t\t\t\t<div class=\"yui-gb\">\n\t\t\t\t\t<div class=\"yui-u first\"></div>\n\t\t\t\t\t<div class=\"yui-u\"></div>\n\t\t\t\t\t<div class=\"yui-u\"></div>\n\t\t\t\t</div>\n\t\t\t\t<!-- stacked grid structure, Special Grid \"c\" -->\n\t\t\t\t<div class=\"yui-gc\">\n\t\t\t\t\t<div class=\"yui-u first\"></div>\n\t\t\t\t\t<div class=\"yui-u\"></div>\n\t\t\t\t</div>\n\t\t\t\t<!-- stacked grid structure -->\n\t\t\t\t<div class=\"yui-g\">\n\t\t\t\t\t<div class=\"yui-u first\"></div>\n\t\t\t\t\t<div class=\"yui-u\"></div>\n\t\t\t\t</div>\n\t\t\t</div>\n\t\t</div>\n\t\t<!-- secondary content block -->\n\t\t<div class=\"yui-b\"></div>\n\t</div>\n</body>\n\nExample: A complex layout.\n\nWasn\u2019t that easy? Now that you know the three \u201clevers\u201d of YUI Grids CSS, you\u2019ll be creating headache-free fluid layouts faster than you can say \u201cPeace on Earth\u201d.", "year": "2006", "author": "Nate Koechley", "author_slug": "natekoechley", "published": "2006-12-20T00:00:00+00:00", "url": "https://24ways.org/2006/intricate-fluid-layouts/", "topic": "code"}
{"rowid": 327, "title": "Improving Form Accessibility with DOM Scripting", "contents": "The form label element is an incredibly useful little element \u2013 it lets you link the form field unquestionably with the descriptive label text that sits alongside or above it. This is a very useful feature for people using screen readers, but there are some problems with this element.\n\nWhat happens if you have one piece of data that, for various reasons (validation, the way your data is collected/stored etc), needs to be collected using several form elements?\n\nThe classic example is date of birth \u2013 ideally, you\u2019ll ask for the date of birth once but you may have three inputs, one each for day, month and year, that you also need to provide hints about the format required. The problem is that to be truly accessible you need to label each field. So you end up needing something to say \u201cthis is a date of birth\u201d, \u201cthis is the day field\u201d, \u201cthis is the month field\u201d and \u201cthis is the day field\u201d. Seems like overkill, doesn\u2019t it? And it can uglify a form no end.\n\nThere are various ways that you can approach it (and I think I\u2019ve seen them all). Some people omit the label and rely on the title attribute to help the user through; others put text in a label but make the text 1 pixel high and merging in to the background so that screen readers can still get that information. The most common method, though, is simply to set the label to not display at all using the CSS display:none property/value pairing (a technique which, for the time being, seems to work on most screen readers). But perhaps we can do more with this?\n\nThe technique I am suggesting as another alternative is as follows (here comes the pseudo-code):\n\n\n\tStart with a totally valid and accessible form\n\tEnsure that each form input has a label that is linked to its related form control\n\tApply a class to any label that you don\u2019t want to be visible (for example superfluous)\n\n\nThen, through the magic of unobtrusive JavaScript/the DOM, manipulate the page as follows once the page has loaded:\n\n\n\tFind all the label elements that are marked as superfluous and hide them\n\tFind out what input element each of these label elements is related to\n\tThen apply a hint about formatting required for input (gleaned from the original, now-hidden label text) \u2013 add it to the form input as default text\n\tFinally, add in a behaviour that clears or selects the default text (as you choose)\n\n\nSo, here\u2019s the theory put into practice \u2013 a date of birth, grouped using a fieldset, and with the behaviours added in using DOM, and here\u2019s the JavaScript that does the heavy lifting. \n\nBut why not just use display:none? As demonstrated at Juicy Studio, display:none seems to work quite well for hiding label elements. So why use a sledge hammer to crack a nut? In all honesty, this is something of an experiment, but consider the following:\n\n\n\tUsing the DOM, you can add extra levels of help, potentially across a whole form \u2013 or even range of forms \u2013 without necessarily increasing your markup (it goes beyond simply hiding labels)\n\tScreen readers today may  identify a label that is set not to display, but they may not in the future \u2013 this might provide a way around\n\tBy expanding this technique above, it might be possible to visually change the parent container that groups these items \u2013 in this case, a fieldset and legend, which are notoriously difficult to style consistently across different browsers \u2013 while still retaining the underlying semantic/logical structure\n\n\nWell, it\u2019s an idea to think about at least. How is it for you? How else might you use DOM scripting to improve the accessiblity or usability of your forms?", "year": "2005", "author": "Ian Lloyd", "author_slug": "ianlloyd", "published": "2005-12-03T00:00:00+00:00", "url": "https://24ways.org/2005/improving-form-accessibility-with-dom-scripting/", "topic": "code"}
{"rowid": 184, "title": "Spruce It Up", "contents": "The landscape of web typography is changing quickly these days. We\u2019ve gone from the wild west days of sIFR to Cuf\u00f3n to finally seeing font embedding seeing wide spread adoption by browser developers (and soon web designers) with @font-face. For those who\u2019ve felt limited by the typographic possibilities before, this has been a good year.\n\nAs Mark Boulton has so eloquently elucidated, @font-face embedding doesn\u2019t come without its drawbacks. Font files can be quite large and FOUT\u2014that nasty flash of unstyled text\u2014can be a distraction for users.\n\nData URIs\n\nWe can battle FOUT by using Data URIs. A Data URI allows the font to be encoded right into the CSS file. When the font comes with the CSS, the flash of unstyled text is mitigated. No extra HTTP requests are required. \n\nDon\u2019t be a grinch, though. Sending hundreds of kilobytes down the pipe still isn\u2019t great. Sometimes, all we want to do is spruce up our site with a little typographic sugar. \n\nBe Selective\n\nDan Cederholm\u2019s SimpleBits is an attractive site. \n\n\n\nTake a look at the ampersand within the header of his site. It\u2019s the lovely (and free) Goudy Bookletter 1911 available from The League of Movable Type. The Opentype format is a respectable 28KB. Nothing too crazy but hold on here. Mr. Cederholm is only using the ampersand! Ouch. That\u2019s a lot of bandwidth just for one character.\n\nCan we optimize a font like we can an image? Yes. Image optimization essentially works by removing unnecessary image data such as colour data, hidden comments or using compression algorithms. How do you remove unnecessary information from a font? Subsetting. \n\nIf you\u2019re the adventurous type, grab a copy of FontForge, which is an open source font editing tool. You can open the font, view and edit any of the glyphs and then re-generate the font. The interface is a little clunky but you\u2019ll be able to select any character you don\u2019t want and then cut the glyphs. Re-generate your font and you\u2019ve now got a smaller file. \n\n\n\nThere are certainly more optimizations that can also be made such as removing hinting and kerning information. Keep in mind that removing this information may affect how well the type renders.\n\nAt this time of year, though, I\u2019m sure you\u2019re quite busy. Save yourself some time and head on over to the Font Squirrel Font Generator.\n\n\n\nThe Font Generator is extremely handy and allows for a number of optimizations and cross-platform options to be generated instantly. Select the font from your local system\u2014make sure that you are only using properly licensed fonts! \n\nIn this particular case, we only want the ampersand. Click on Subset Fonts which will open up a new menu. Unselect any preselected sets and enter the ampersand into the Single Characters text box. \n\nGenerate your font and what are you left with? 3KB. \n\n\n\nThe Font Generator even generates a base64 encoded data URI stylesheet to be imported easily into your project.\n\nCheck out the Demo page. (This demo won\u2019t work in Internet Explorer as we\u2019re only demonstrating the Data URI font embedding and not using the EOT file format that IE requires.) \n\nNo Unnecessary Additives\n\nIf you peeked under the hood of that demo, did you notice something interesting? There\u2019s no <span> around the ampersand. The great thing about this is that we can take advantage of the font stack\u2019s natural ability to switch to a fallback font when a character isn\u2019t available.\n\nJust like that, we\u2019ve managed to spruce up our page with a little typographic sugar without having to put on too much weight.", "year": "2009", "author": "Jonathan Snook", "author_slug": "jonathansnook", "published": "2009-12-19T00:00:00+00:00", "url": "https://24ways.org/2009/spruce-it-up/", "topic": "code"}
{"rowid": 192, "title": "Cleaner Code with CSS3 Selectors", "contents": "The parts of CSS3 that seem to grab the most column inches on blogs and in articles are the shiny bits. Rounded corners, text shadow and new ways to achieve CSS layouts are all exciting and bring with them all kinds of possibilities for web design. However what really gets me, as a developer, excited is a bit more mundane.  \n\nIn this article I\u2019m going to take a look at some of the ways our front and back-end code will be simplified by CSS3, by looking at the ways we achieve certain visual effects now in comparison to how we will achieve them in a glorious, CSS3-supported future. I\u2019m also going to demonstrate how we can use these selectors now with a little help from JavaScript \u2013 which can work out very useful if you find yourself in a situation where you can\u2019t change markup that is being output by some server-side code.\n\nThe wonder of nth-child\n\nSo why does nth-child get me so excited? Here is a really common situation, the designer would like the tables in the application to look like this:\n\n\n\nSetting every other table row to a different colour is a common way to enhance readability of long rows. The tried and tested way to implement this is by adding a class to every other row. If you are writing the markup for your table by hand this is a bit of a nuisance, and if you stick a row in the middle you have to change the rows the class is applied to. If your markup is generated by your content management system then you need to get the server-side code to add that class \u2013 if you have access to that code.\n\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n\t  \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\n<head>\n<title>Striping every other row - using classes</title>\n<style type=\"text/css\">\n\tbody {\n\t\tpadding: 40px;\n\t\tmargin: 0;\n\t\tfont: 0.9em Arial, Helvetica, sans-serif;\n\t}\n\ttable {\n\t\tborder-collapse: collapse;\n\t\tborder: 1px solid #124412;\n\t\twidth: 600px;\n\t}\n\tth {\n\t\tborder: 1px solid #124412;\n\t\tbackground-color: #334f33;\n\t\tcolor: #fff;\n\t\tpadding: 0.4em;\n\t\ttext-align: left;\n\t}\n\ttd {\n\t\tpadding: 0.4em;\n\t}\n\ttr.odd td {\n\t\tbackground-color: #86B486;\n\t}\n</style>\n</head>\n<body>\n\t<table>\n\t\t<tr>\n\t\t\t<th>Name</th>\n\t\t\t<th>Cards sent</th>\n\t\t\t<th>Cards received</th>\n\t\t\t<th>Cards written but not sent</th>\n\t\t</tr>\n\t\t<tr>\n\t\t\t<td>Ann</td>\n\t\t\t<td>40</td>\n\t\t\t<td>28</td>\n\t\t\t<td>4</td>\n\t\t</tr>\n\t\t<tr class=\"odd\">\n\t\t\t<td>Joe</td>\n\t\t\t<td>2</td>\n\t\t\t<td>27</td>\n\t\t\t<td>29</td>\n\t\t</tr>\n\t\t<tr>\n\t\t\t<td>Paul</td>\n\t\t\t<td>5</td>\n\t\t\t<td>35</td>\n\t\t\t<td>2</td>\n\t\t</tr>\n\t\t<tr class=\"odd\">\n\t\t\t<td>Louise</td>\n\t\t\t<td>65</td>\n\t\t\t<td>65</td>\n\t\t\t<td>0</td>\n\t\t</tr>\n\t</table>\n</body>\n</html>\n\nView Example 1\n\nThis situation is something I deal with on almost every project, and apart from being an extra thing to do, it just isn\u2019t ideal having the server-side code squirt classes into the markup for purely presentational reasons. This is where the nth-child pseudo-class selector comes in. The server-side code creates a valid HTML table for the data, and the CSS then selects the odd rows with the following selector:\n\ntr:nth-child(odd) td {\n\tbackground-color: #86B486;\n}\n\nView Example 2\n\nThe odd and even keywords are very handy in this situation \u2013 however you can also use a multiplier here. 2n would be equivalent to the keyword \u2018odd\u2019 3n would select every third row and so on.\n\nBrowser support\n\nSadly, nth-child has pretty poor browser support. It is not supported in Internet Explorer 8 and has somewhat buggy support in some other browsers. Firefox 3.5 does have support. In some situations however, you might want to consider using JavaScript to add this support to browsers that don\u2019t have it. This can be very useful if you are dealing with a Content Management System where you have no ability to change the server-side code to add classes into the markup.\n\nI\u2019m going to use jQuery in these examples as it is very simple to use the same CSS selector used in the CSS to target elements with jQuery \u2013 however you could use any library or write your own function to do the same job. In the CSS I have added the original class selector to the nth-child selector:\n\ntr:nth-child(odd) td, tr.odd td {\n\tbackground-color: #86B486;\n}\n\nThen I am adding some jQuery to add a class to the markup once the document has loaded \u2013 using the very same nth-child selector that works for browsers that support it. \n\n<script src=\"http://code.jquery.com/jquery-latest.js\"></script> \n <script>\n  $(document).ready(function(){\n\t$(\"tr:nth-child(odd)\").addClass(\"odd\");\n  });\n </script>\n\nView Example 3\n\nWe could just add a background colour to the element using jQuery, however I prefer not to mix that information into the JavaScript as if we change the colour on our table rows I would need to remember to change it both in the CSS and in the JavaScript.\n\nDoing something different with the last element\n\nSo here\u2019s another thing that we often deal with. You have a list of items all floated left with a right hand margin on each element constrained within a fixed width layout. If each element has the right margin applied the margin on the final element will cause the set to become too wide forcing that last item down to the next row as shown in the below example where I have used a grey border to indicate the fixed width.\n\n\n\nCurrently we have two ways to deal with this. We can put a negative right margin on the list, the same width as the space between the elements. This means that the extra margin on the final element fills that space and the item doesn\u2019t drop down. \n\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n\t  \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\n<head>\n<title>The last item is different</title>\n<style type=\"text/css\">\n\tbody {\n\t\tpadding: 40px;\n\t\tmargin: 0;\n\t\tfont: 0.9em Arial, Helvetica, sans-serif;\n\t}\n\tdiv#wrapper {\n\t\twidth: 740px;\n\t\tfloat: left;\n\t\tborder: 5px solid #ccc;\n\t}\n\tul.gallery {\n\t\tmargin: 0 -10px 0 0;\n\t\tpadding: 0;\n\t\tlist-style: none;\n\t}\n\tul.gallery li {\n\t\tfloat: left;\n\t\twidth: 240px;\n\t\tmargin: 0 10px 10px 0;\n\t}\n</style>\n</head>\n<body>\n\t<div id=\"wrapper\">\n\t\t<ul class=\"gallery\">\n\t\t\t<li><img src=\"xmas1.jpg\" alt=\"baubles\" /></li>\n\t\t\t<li><img src=\"xmas2.jpg\" alt=\"star\" /></li>\n\t\t\t<li><img src=\"xmas3.jpg\" alt=\"wreath\" /></li>\n\t\t</ul>\n\t</div>\n</body>\n</html>\n\nView Example 4\n\nThe other solution will be to put a class on the final element and in the CSS remove the margin for this class. \n\nul.gallery li.last {\n\tmargin-right: 0;\n}\n\nThis second solution may not be easy if the content is generated from server-side code that you don\u2019t have access to change.\n\nIt could all be so different. In CSS3 we have marvellously common-sense selectors such as last-child, meaning that we can simply add rules for the last list item. \n\nul.gallery li:last-child {\n\tmargin-right: 0;\n}\n\nView Example 5\n\nThis removed the margin on the li which is the last-child of the ul with a class of gallery. No messing about sticking classes on the last item, or pushing the width of the item out wit a negative margin.\n\nIf this list of items repeated ad infinitum then you could also use nth-child for this task. Creating a rule that makes every 3rd element margin-less.\n\nul.gallery li:nth-child(3n) {\n\tmargin-right: 0;\n}\n\nView Example 6\n\n\n\nA similar example is where the designer has added borders to the bottom of each element \u2013 but the last item does not have a border or is in some other way different. Again, only a class added to the last element will save you here if you cannot rely on using the last-child selector.\n\nBrowser support for last-child\n\nThe situation for last-child is similar to that of nth-child, in that there is no support in Internet Explorer 8. However, once again it is very simple to replicate the functionality using jQuery. Adding our .last class to the last list item.\n\n$(\"ul.gallery li:last-child\").addClass(\"last\");\n\nWe could also use the nth-child selector to add the .last class to every third list item.\n\n$(\"ul.gallery li:nth-child(3n)\").addClass(\"last\");\n\nView Example 7\n\nFun with forms\n\nStyling forms can be a bit of a trial, made difficult by the fact that any CSS applied to the input element will effect text fields, submit buttons, checkboxes and radio buttons. As developers we are left adding classes to our form fields to differentiate them. In most builds all of my text fields have a simple class of text whereas I wouldn\u2019t dream of adding a class of para to every paragraph element in a document.\n\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n      \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n<html xmlns=\"http://www.w3.org/1999/xhtml\">\n<head>\n<title>Syling form fields</title>\n<style type=\"text/css\">\n\tbody {\n\t\tpadding: 40px;\n\t\tmargin: 0;\n\t\tfont: 0.9em Arial, Helvetica, sans-serif;\n\t}\n\tform div {\n\t\tclear: left;\n\t\tpadding: 0 0 0.8em 0;\n\t}\n\tform label {\n\t\tfloat: left;\n\t\twidth: 120px;\n\t}\n\tform .text, form textarea {\n\t\tborder:1px solid #333;\n\t\tpadding: 0.2em;\n\t\twidth: 400px;\n\t}\n\tform .button {\n\t\tborder: 1px solid #333;\n\t\tbackground-color: #eee;\n\t\tcolor: #000;\n\t\tpadding: 0.1em;\n\t} \n\t</style>\n</head>\n<body>\n\t<h1>Send your Christmas list to Santa</h1>\n\t<form method=\"post\" action=\"\" id=\"christmas-list\">\n\t\t<div><label for=\"fName\">Name</label>\n\t\t<input type=\"text\" name=\"fName\" id=\"fName\" class=\"text\" /></div>\n\t\t<div><label for=\"fEmail\">Email address</label>\n\t\t<input type=\"text\" name=\"fEmail\" id=\"fEmail\" class=\"text\" /></div>\n\t\t<div><label for=\"fList\">Your list</label>\n\t\t<textarea name=\"fList\" id=\"fList\" rows=\"10\" cols=\"30\"></textarea></div>\n\t\t<div><input type=\"submit\" name=\"btnSubmit\" id=\"btnSubmit\" value=\"Submit\" class=\"button\" ></div>\n\t</form>\n</body>\n</html>\n\nView Example 8\n\nAttribute selectors provide a way of targeting elements by looking at the attributes of those elements. Unlike the other examples in this article which are CSS3 selectors, the attribute selector is actually a CSS2.1 selector \u2013 it just doesn\u2019t get much use because of lack of support in Internet Explorer 6. Using attribute selectors we can write rules for text inputs and form buttons without needing to add any classes to the markup. For example after removing the text and button classes from my text and submit button input elements I can use the following rules to target them:\n\nform input[type=\"text\"] {\n    border: 1px solid #333;\n    padding: 0.2em;\n    width: 400px;\n}\nform input[type=\"submit\"]{\n    border: 1px solid #333;\n    background-color: #eee;\n    color: #000;\n    padding: 0.1em;\n} \n\nView Example 9\n\nAnother problem that I encounter with forms is where I am using CSS to position my labels and form elements by floating the labels. This works fine as long as I want all of my labels to be floated, however sometimes we get a set of radio buttons or a checkbox, and I don\u2019t want the label field to be floated. As you can see in the below example the label for the checkbox is squashed up into the space used for the other labels, yet it makes more sense for the checkbox to display after the text.\n\n\n\nI could use a class on this label element however CSS3 lets me to target the label attribute directly by looking at the value of the for attribute.\n\nlabel[for=\"fOptIn\"] {\n    float: none;\n    width: auto;\n}\n\n\n\nBeing able to precisely target attributes in this way is incredibly useful, and once IE6 is no longer an issue this will really help to clean up our markup and save us from having to create all kinds of special cases when generating this markup on the server-side.\n\nBrowser support\n\nThe news for attribute selectors is actually pretty good with Internet Explorer 7+, Firefox 2+ and all other modern browsers all having support. As I have already mentioned this is a CSS2.1 selector and so we really should expect to be able to use it as we head into 2010! Internet Explorer 7 has slightly buggy support and will fail on the label example shown above however I discovered a workaround in the Sitepoint CSS reference comments. Adding the selector label[htmlFor=\"fOptIn\"] to the correct selector will create a match for IE7.\n\nIE6 does not support these selector but, once again, you can use jQuery to plug the holes in IE6 support. The following jQuery will add the text and button classes to your fields and also add a checks class to the label for the checkbox, which you can use to remove the float and width for this element.\n\n$('form input[type=\"submit\"]').addClass(\"button\");\n$('form input[type=\"text\"]').addClass(\"text\");\n$('label[for=\"fOptIn\"]').addClass(\"checks\");\n\nView Example 10\n\nThe selectors I\u2019ve used in this article are easy to overlook as we do have ways to achieve these things currently. As developers \u2013 especially when we have frameworks and existing code that cope with these situations \u2013 it is easy to carry on as we always have done. \n\nI think that the time has come to start to clean up our front and backend code and replace our reliance on classes with these more advanced selectors. With the help of a little JavaScript almost all users will still get the full effect and, where we are dealing with purely visual effects, there is definitely a case to be made for not worrying about the very small percentage of people with old browsers and no JavaScript. They will still receive a readable website, it may just be missing some of the finesse offered to the modern browsing experience.", "year": "2009", "author": "Rachel Andrew", "author_slug": "rachelandrew", "published": "2009-12-20T00:00:00+00:00", "url": "https://24ways.org/2009/cleaner-code-with-css3-selectors/", "topic": "code"}
{"rowid": 31, "title": "Dealing with Emergencies in Git", "contents": "The stockings were hung by the chimney with care,\nIn hopes that version control soon would be there.\n\nThis summer I moved to the UK with my partner, and the onslaught of the Christmas holiday season began around the end of October (October!). It does mean that I\u2019ve had more than a fair amount of time to come up with horrible Git analogies for this article. Analogies, metaphors, and comparisons help the learner hook into existing mental models about how a system works. They only help, however, if the learner has enough familiarity with the topic at hand to make the connection between the old and new information.\n\nLet\u2019s start by painting an updated version of Clement Clarke Moore\u2019s Christmas living room. Empty stockings are hung up next to the fireplace, waiting for Saint Nicholas to come down the chimney and fill them with small treats. Holiday treats are scattered about. A bowl of mixed nuts, the holiday nutcracker, and a few clementines. A string of coloured lights winds its way up an evergreen.\n\nPerhaps a few of these images are familiar, or maybe they\u2019re just settings you\u2019ve seen in a movie. It doesn\u2019t really matter what the living room looks like though. The important thing is to ground yourself in your own experiences before tackling a new subject. Instead of trying to brute-force your way into new information, as an adult learner constantly ask yourself: \u2018What is this like? What does this remind me of? What do I already know that I can use to map out this new territory?\u2019 It\u2019s okay if the map isn\u2019t perfect. As you refine your understanding of a new topic, you\u2019ll outgrow the initial metaphors, analogies, and comparisons.\n\nWith apologies to Mr. Moore, let\u2019s give it a try.\n\nGetting Interrupted in Git\n\nWhen on the roof there arose such a clatter!\n\nYou\u2019re happily working on your software project when all of a sudden there are freaking reindeer on the roof! Whatever you\u2019ve been working on is going to need to wait while you investigate the commotion.\n\nIf you\u2019ve got even a little bit of experience working with Git, you know that you cannot simply change what you\u2019re working on in times of emergency. If you\u2019ve been doing work, you have a dirty working directory and you cannot change branches, or push your work to a remote repository while in this state.\n\nUp to this point, you\u2019ve probably dealt with emergencies by making a somewhat useless commit with a message something to the effect of \u2018switching branches for a sec\u2019. This isn\u2019t exactly helpful to future you, as commits should really contain whole ideas of completed work. If you get interrupted, especially if there are reindeer on the roof, the chances are very high that you weren\u2019t finished with what you were working on.\n\nYou don\u2019t need to make useless commits though. Instead, you can use the stash command. This command allows you to temporarily set aside all of your changes so that you can come back to them later. In this sense, stash is like setting your book down on the side table (or pushing the cat off your lap) so you can go investigate the noise on the roof. You aren\u2019t putting your book away though, you\u2019re just putting it down for a moment so you can come back and find it exactly the way it was when you put it down.\n\nLet\u2019s say you\u2019ve been working in the branch waiting-for-st-nicholas, and now you need to temporarily set aside your changes to see what the noise was on the roof:\n\n$ git stash\n\nAfter running this command, all uncommitted work will be temporarily removed from your working directory, and you will be returned to whatever state you were in the last time you committed your work.\n\nWith the book safely on the side table, and the cat safely off your lap, you are now free to investigate the noise on the roof. It turns out it\u2019s not reindeer after all, but just your boss who thought they\u2019d help out by writing some code on the project you\u2019ve been working on. Bless. Rolling your eyes, you agree to take a look and see what kind of mischief your boss has gotten themselves into this time.\n\nYou fetch an updated list of branches from the remote repository, locate the branch your boss had been working on, and checkout a local copy:\n\n$ git fetch\n$ git branch -r\n$ git checkout -b helpful-boss-branch origin/helpful-boss-branch\n\nYou are now in a local copy of the branch where you are free to look around, and figure out exactly what\u2019s going on.\n\nYou sigh audibly and say, \u2018Okay. Tell me what was happening when you first realised you\u2019d gotten into a mess\u2019 as you look through the log messages for the branch.\n\n$ git log --oneline\n$ git log\n\nBy using the log command you will be able to review the history of the branch and find out the moment right before your boss ended up stuck on your roof.\n\nYou may also want to compare the work your boss has done to the main branch for your project. For this article, we\u2019ll assume the main branch is named master.\n\n$ git diff master\n\nLooking through the commits, you may be able to see that things started out okay but then took a turn for the worse.\n\nChecking out a single commit\n\nUsing commands you\u2019re already familiar with, you can rewind through history and take a look at the state of the code at any moment in time by checking out a single commit, just like you would a branch.\n\nUsing the log command, locate the unique identifier (commit hash) of the commit you want to investigate. For example, let\u2019s say the unique identifier you want to checkout is 25f6d7f.\n\n$ git checkout 25f6d7f\n\nNote: checking out '25f6d7f'.\n\nYou are in 'detached HEAD' state. You can look around,\nmake experimental changes and commit them, and you can\ndiscard any commits you make in this state without\nimpacting any branches by performing another checkout.\n\nIf you want to create a new branch to retain commits you create, you may do so (now or later) by using @-b@ with the checkout command again. Example:\n\n$ git checkout -b new_branch_name\n\nHEAD is now at 25f6d7f... Removed first paragraph.\n\nThis is usually where people start to panic. Your boss screwed something up, and now your HEAD is detached. Under normal circumstances, these words would be a very good reason to panic.\n\nTake a deep breath. Nothing bad is going to happen. Being in a detached HEAD state just means you\u2019ve temporarily disconnected from a known chain of events. In other words, you\u2019re currently looking at the middle of a story (or branch) about what happened \u2013 and you\u2019re not at the endpoint for this particular story.\n\nGit allows you to view the history of your repository as a timeline (technically it\u2019s a directed acyclic graph). When you make commits which are not associated with a branch, they are essentially inaccessible once you return to a known branch. If you make commits while you\u2019re in a detached HEAD state, and then try to return to a known branch, Git will give you a warning and tell you how to save your work.\n\n$ git checkout master\n\nWarning: you are leaving 1 commit behind, not connected to\nany of your branches:\n\n  7a85788 Your witty holiday commit message.\n\nIf you want to keep them by creating a new branch, this may be a good time to do so with:\n\n$ git branch new_branch_name 7a85788\n\nSwitched to branch 'master'\nYour branch is up-to-date with 'origin/master'.\n\nSo, if you want to save the commits you\u2019ve made while in a detached HEAD state, you simply need to put them on a new branch.\n\n$ git branch saved-headless-commits 7a85788\n\nWith this trick under your belt, you can jingle around in history as much as you\u2019d like. It\u2019s not like sliding around on a timeline though. When you checkout a specific commit, you will only have access to the history from that point backwards in time. If you want to move forward in history, you\u2019ll need to move back to the branch tip by checking out the branch again.\n\n$ git checkout helpful-boss-branch\n\nYou\u2019re now back to the present. Your HEAD is now pointing to the endpoint of a known branch, and so it is no longer detached. Any changes you made while on your adventure are safely stored in a new branch, assuming you\u2019ve followed the instructions Git gave you. That wasn\u2019t so scary after all, now, was it?\n\nBack to our reindeer problem.\n\nIf your boss is anything like the bosses I\u2019ve worked with, chances are very good that at least some of their work is worth salvaging. Depending on how your repository is structured, you\u2019ll want to capture the good work using one of several different methods.\n\nBack in the living room, we\u2019ll use our bowl of nuts to illustrate how you can rescue a tiny bit of work.\n\nSaving just one commit\n\nAbout that bowl of nuts. If you\u2019re like me, you probably had some favourite kinds of nuts from an assorted collection. Walnuts were generally the most satisfying to crack open. So, instead of taking the entire bowl of nuts and dumping it into a stocking (merging the stocking and the bowl of nuts), we\u2019re just going to pick out one nut from the bowl. In Git terms, we\u2019re going to cherry-pick a commit and save it to another branch.\n\nFirst, checkout the main branch for your development work. From this branch, create a new branch where you can copy the changes into.\n\n$ git checkout master\n$ git checkout -b rescue-the-boss\n\nFrom your boss\u2019s branch, helpful-boss-branch locate the commit you want to keep.\n\n$ git log --oneline helpful-boss-branch\n\nLet\u2019s say the commit ID you want to keep is e08740b. From your rescue branch, use the command cherry-pick to copy the changes into your current branch.\n\n$ git cherry-pick e08740b\n\nIf you review the history of your current branch again, you will see you now also have the changes made in the commit in your boss\u2019s branch.\n\nAt this point you might need to make a few additional fixes to help your boss out. (You\u2019re angling for a bonus out of all this. Go the extra mile.) Once you\u2019ve made your additional changes, you\u2019ll need to add that work to the branch as well.\n\n$ git add [filename(s)]\n$ git commit -m \"Building on boss's work to improve feature X.\"\n\nGo ahead and test everything, and make sure it\u2019s perfect. You don\u2019t want to introduce your own mistakes during the rescue mission!\n\nUploading the fixed branch\n\nThe next step is to upload the new branch to the remote repository so that your boss can download it and give you a huge bonus for helping you fix their branch.\n\n$ git push -u origin rescue-the-boss\n\nCleaning up and getting back to work\n\nWith your boss rescued, and your bonus secured, you can now delete the local temporary branches.\n\n$ git branch --delete rescue-the-boss\n$ git branch --delete helpful-boss-branch\n\nAnd settle back into your chair to wait for Saint Nicholas with your book, your branch, and possibly your cat.\n\n$ git checkout waiting-for-st-nicholas\n$ git stash pop\n\nYour working directory has been returned to exactly the same state you were in at the beginning of the article.\n\nHaving fun with analogies\n\nI\u2019ve had a bit of fun with analogies in this article. But sometimes those little twists on ideas can really help someone pick up a new idea (git stash: it\u2019s like when Christmas comes around and everyone throws their fashion sense out the window and puts on a reindeer sweater for the holiday party; or git bisect: it\u2019s like trying to find that one broken light on the string of Christmas lights). It doesn\u2019t matter if the analogy isn\u2019t perfect. It\u2019s just a way to give someone a temporary hook into a concept in a way that makes the concept accessible while the learner becomes comfortable with it. As the learner\u2019s comfort increases, the analogies can drop away, making room for the technically correct definition of how something works.\n\nOr, if you\u2019re like me, you can choose to never grow old and just keep mucking about in the analogies. I\u2019d argue it\u2019s a lot more fun to play with a string of Christmas lights and some holiday cheer than a directed acyclic graph anyway.", "year": "2014", "author": "Emma Jane Westby", "author_slug": "emmajanewestby", "published": "2014-12-02T00:00:00+00:00", "url": "https://24ways.org/2014/dealing-with-emergencies-in-git/", "topic": "code"}
{"rowid": 289, "title": "Front-End Developers Are Information Architects Too", "contents": "The theme of this year\u2019s World IA Day was \u201cInformation Everywhere, Architects Everywhere\u201d. This article isn\u2019t about what you may consider an information architect to be: someone in the user-experience field, who maybe studied library science, and who talks about taxonomies. This is about a realisation I had a couple of years ago when I started to run an increasing amount of usability-testing sessions with people who have disabilities: that the structure, labelling, and connections that can be made in front-end code is information architecture. People\u2019s ability to be successful online is unequivocally connected to the quality of the code that is written.\nPlaces made of information\nIn information architecture we talk about creating places made of information. These places are made of ones and zeros, but we talk about them as physical structures. We talk about going onto a social media platform, posting in blogs, getting locked out of an environment, and building applications. In 2002, Andrew Hinton stated:\n\nPeople live and work in these structures, just as they live and work in their homes, offices, factories and malls. These places are not virtual: they are as real as our own minds.\n25 Theses\n\nWe\u2019re creating structures which people rely on for significant parts of their lives, so it\u2019s critical that we carry out our work responsibly. This means we must use our construction materials correctly. Luckily, our most important material, HTML, has a well-documented specification which tells us how to build robust and accessible places. What is most important, I believe, is to understand the semantics of HTML.\nSemantics\nThe word \u201csemantic\u201d has its origin in Greek words meaning \u201csignificant\u201d, \u201csignify\u201d, and \u201csign\u201d. In the physical world, a structure can have semantic qualities that tell us something about it. For example, the stunning Westminster Abbey inspires awe and signifies much about the intent and purpose of the structure. The building\u2019s size; the quality of the stone work; the massive, detailed stained glass: these are all signs that this is a building meant for something the creators deemed important. Alternatively consider a set of large, clean, well-positioned, well-lit doors on the ground floor of an office block: they don\u2019t need an \u201centrance\u201d sign to communicate their use and to stop people trying to use a nearby fire exit to get into the building. The design of the doors signify their usage. Sometimes a more literal and less awe-inspiring approach to communicating a building\u2019s purpose happens, but the affect is similar: the building is signifying something about its purpose.\nHTML has over 115 elements, many of which have semantics to signify structure and affordance to people, browsers, and assistive technology. The HTML 5.1 specification mentions semantics, stating:\n\nElements, attributes, and attribute values in HTML are defined \u2026 to have certain meanings (semantics). For example, the <ol> element represents an ordered list, and the lang attribute represents the language of the content.\nHTML 5.1 Semantics, structure, and APIs of HTML documents\n\nHTML\u2019s baked-in semantics means that developers can architect their code to signify structure, create relationships between elements, and label content so people can understand what they\u2019re interacting with. Structuring and labelling information to make it available, usable, and understandable to people is what an information architect does. It\u2019s also what a front-end developer does, whether they realise it or not.\nA brief introduction to information architecture\nWe\u2019re going to start by looking at what an information architect is. There are many definitions, and I\u2019m going to quote Richard Saul Wurman, who is widely regarded as the father of information architecture. In 1976 he said an information architect is:\n\nthe individual who organizes the patterns inherent in data, making the complex clear; a person who creates the structure or map of information which allows others to find their personal paths to knowledge; the emerging 21st century professional occupation addressing the needs of the age focused upon clarity, human understanding, and the science of the organization of information.\nOf Patterns And Structures\n\nTo me, this clearly defines any developer who creates code that a browser, or other user agent (for example, a screen reader), uses to create a structured, navigable place for people.\nJust as there are many definitions of what an information architect is, there are for information architecture itself. I\u2019m going to use the definition from the fourth edition of Information Architecture For The World Wide Web, in which the authors define it as:\nThe structural design of shared information environments.\nThe synthesis of organization, labeling, search, and navigation systems within digital, physical, and cross-channel ecosystems.\nThe art and science of shaping information products and experiences to support usability, findability, and understanding.\nInformation Architecture For The World Wide Web, 4th Edition\nTo me, this describes front-end development. Done properly, there is an art to creating robust, accessible, usable, and findable spaces that delight all our users. For example, at 2015\u2019s State Of The Browser conference, Edd Sowden talked about the accessibility of <table>s. He discovered that by simply not using the semantically-correct <th> element to mark up <table> headings, in some situations browsers will decide that a <table> is being used for layout and essentially make it invisible to assistive technology. Another example of how coding practices can affect the usability and findability of content is shown by L\u00e9onie Watson in her How ARIA landmark roles help screen reader users video. By using ARIA landmark roles, people who use screen readers are quickly able to identify and jump to common parts of a web page.\nOur definitions of information architects and information architecture mention patterns, rules, organisation, labelling, structure, and relationships. There are numerous different models for how these elements get boiled down to their fundamentals. In his Understanding Context book, Andrew Hinton calls them Labels, Relationships, and Rules; Jorge Arango calls them Links, Nodes, And Order; and Dan Klyn uses Ontology, Taxonomy, and Choreography, which is the one we\u2019re going to use. Dan defines these terms as:\nOntology\nThe definition and articulation of the rules and patterns that govern the meaning of what we intend to communicate.\nWhat we mean when we say what we say.\nTaxonomy\nThe arrangements of the parts. Developing systems and structures for what everything\u2019s called, where everything\u2019s sorted, and the relationships between labels and categories\nChoreography\nRules for interaction among the parts. The structures it creates foster specific types of movement and interaction; anticipating the way users and information want to flow and making affordance for change over time.\n\nWe now have definitions of an information architect, information architecture, and a model of the elements of information architecture. But is writing HTML really creating information or is it just wrangling data and metadata? When does data turn into information? In his book Managing For The Future Peter Drucker states:\n\n\u2026 data is not information. Information is data endowed with relevance and purpose.\nManaging For The Future\n\nIf we use the correct semantic element to mark up content then we\u2019re developing with purpose and creating relevance. For example, if we follow the advice of the HTML 5.1 specification and mark up headings using heading rank instead of the outline algorithm, we\u2019re creating a structure where the depth of one heading is relevant to the previous one. Architected correctly, an <h2> element should be relevant to its parent, which should be the <h1>. By following the HTML specification we can create a structured, searchable, labeled document that will hopefully be relevant to what our users need to be successful. If you\u2019ve never used a screen reader, you might be wondering how the headings on a page are searchable. Screen readers give users the ability to interact with headings in a couple of ways:\n\nby creating a list of headings so users can quickly scan the page for information\nby using a keyboard command to cycle through one heading at a time\n\nIf we had a document for Christmas Day TV we might structure it something like this:\n<h1>Christmas Day TV schedule</h1>\n  <h2>BBC1</h2>\n    <h3>Morning</h3>\n      <h3>Evening</h3>\n  <h2>BBC2</h2>\n    <h3>Morning</h3>\n    <h3>Evening</h3>\n  <h2>ITV</h2>\n    <h3>Morning</h3>\n    <h3>Evening</h3>\n  <h2>Channel 4</h2>\n    <h3>Morning</h3>\n    <h3>Evening</h3>\nIf I use VoiceOver to generate a list of headings, I get this:\n\nOnce I have that list I can use keyboard commands to filter the list based on the heading level. For example, I can press 2 to hear just the <h2>s:\n\nIf we hadn\u2019t used headings, of if we\u2019d nested them incorrectly, our users would be frustrated.\nPutting this together\nLet\u2019s put this together with an example of a button that, when pressed, toggles the appearance of a panel of links. There are numerous ways we could create a button on a web page, but the best way is to just use a <button>. Every browser understands what a <button> is, how it works, and what keyboard shortcuts should be used with them. The HTML specification for the <button> element says:\n\nThe <button> element represents a button labeled by its contents.\n\nThe contents that a <button> can have include the type attribute, any relevant ARIA attributes, and the actual text label that the user sees. This information is more important than the visual design: it doesn\u2019t matter how beautiful or obtuse the design is, if the underlying code is non-semantic and poorly labelled, people are going to struggle to use it. Here are three buttons, each created with the same HTML but with different designs:\n\nRegardless of what they look like, because we\u2019ve used semantic HTML instead of a bunch of meaningless <div>s or <span>s, people who use assistive technology are going to benefit. Out of the box, without any extra development effort, a <button> is accessible and usable with a keyboard. We don\u2019t have to write event handlers to listen for people pressing the Enter key or the space bar, which we would have to do if we\u2019d faked a button with non-semantic elements. Our <button> can also be quickly findable: for example, in the same way it\u2019s possible to create a list of headings with a screen reader, I can also create a list of form elements and then quickly jump to the one I want.\nNow we have our <button>, let\u2019s add the panel we\u2019re toggling the appearance of. Here\u2019s our code:\n<button aria-controls=\"panel\" aria-expanded=\"false\" class=\"settings\" id=\"settings\" type=\"button\">Settings</button>\n\n<div class=\"panel hidden\" id=\"panel\">\n    <ul aria-labelledby=\"settings\">\n        <li><a href=\"\u2026\">Account</a></li>\n        <li><a href=\"\u2026\">Privacy</a></li>\n        <li><a href=\"\u2026\">Security</a></li>\n    </ul>\n</div>\nThere\u2019s quite a bit going on here. We\u2019re using the:\n\naria-controls attribute to architect a connection between the <button> element and the panel whose appearance it controls. When some assistive technology, for example the JAWS screen reader, encounters an element with aria-controls it audibly tells a user about the controlled expanded element and gives them the ability to move focus to it.\naria-expanded attribute to denote whether the panel is visible or not. We toggle this value using JavaScript to true when the panel is visible and false when it\u2019s not. This important attribute tells people who use screen readers about the state of the elements they\u2019re interacting with. For example, VoiceOver announces Settings expanded button when the panel is visible and Settings collapsed button when it\u2019s hidden.\naria-labelledby attribute to give the list a title of \u201cSettings\u201d. This can benefit some users of assistive technology. For example, screen readers can cycle through all the lists on a page, so being able to title them can improve findability. Being able to hear list Settings three items is, I\u2019d argue, more useful than list three items. By doing this we\u2019re supporting usability and findability.\n<ul> element to contain our list of links in our panel.\n\nLet\u2019s look at the choice of <ul> to contain our settings choices. Firstly, our settings are related items, so they belong in a structure that semantically groups things. This is something that a list can do that other elements or patterns can\u2019t. This pattern, for example, isn\u2019t semantic and has no structure:\n<div><a href=\"\u2026\">Account</a></div>\n<div><a href=\"\u2026\">Privacy</a></div>\n<div><a href=\"\u2026\">Security</a></div>\nAll we have there is three elements next to each other on the screen and in the DOM. That is not robust code that signifies anything.\nWhy are we using an unordered list as opposed to an ordered list or a definition list? A quick look at the HTML specification tells us why:\n\nThe <ul> element represents a list of items, where the order of the items is not important \u2014 that is, where changing the order would not materially change the meaning of the document.\nThe HTML 5.1 specification\u2019s description of the  element\n\nWill the meaning of our document materially change if we moved the order of our links around? Nope. Therefore, I\u2019d argue, we\u2019ve used the correct element to structure our content.\nThese coding decisions are information architecture\nI believe that what we\u2019ve done here is pure information architecture. Going back to Dan Klyn\u2019s model, we\u2019ve practiced ontology by looking at the meaning of what we\u2019re intending to communicate:\n\nwe want to communicate there is an interactive element that toggles the appearance of an element on a page so we\u2019ve used one, a <button>, with those semantics.\nprogrammatically we\u2019ve used the type='button' attribute to signify that the button isn\u2019t a menu, reset, or submit element.\nvisually we\u2019ve designed our <button> look like something that can be interacted with and, importantly, we haven\u2019t removed the focus ring.\nwe\u2019ve labelled the <button> with the word \u201cSettings\u201d so that our users will hopefully understand what the button is for.\nwe\u2019ve used an <ul> element to structure and communicate our list of related items.\n\nWe\u2019ve also practiced taxonomy by developing systems and structures and creating relationships between our elements:\n\nby connecting the <button> to the panel using the aria-controls attribute we\u2019ve programmatically created a relationship between two elements.\nwe\u2019ve developed a structure in our elements by labelling our <ul> with the same name as the <button> that controls its appearance.\n\nAnd finally we\u2019ve practiced choreography by creating elements that foster movement and interaction. We\u2019ve anticipated the way users and information want to flow:\n\nwe\u2019ve used a <button> element that is interactive and accessible out of the box.\nour aria-controls attribute can help some people who use screen readers move easily from the <button> to the panel it controls.\nby toggling the value of the aria-expanded attribute we\u2019ve developed a system that tells assistive technology about the status of the relationship between our elements: the panel is visible or the panel is hidden.\nwe\u2019ve made sure our information is more usable and findable no matter how our users want or need to interact with it. Regardless of how someone \u201csees\u201d our work they\u2019re going to be able to use it because we\u2019ve architected multiple ways to access our information.\n\nInformation architecture, robust code, and accessibility\nThe United Nations estimates that around 10% of the world\u2019s population has some form of disability which, at the time of writing, is around 740,000,000 people. That\u2019s a lot of people who rely on well-architected semantic code that can be interpreted by whatever assistive technology they may need to use.\nIf everyone involved in the creation of our places made of information practiced information architecture it would make satisfying the WCAG 2.0 POUR principles so much easier. Our digital construction practices directly affect the quality of life of millions of people, and we have a responsibility to make technology available to them. In her book How To Make Sense Of Any Mess, Abby Covert states:\nIf we\u2019re going to be successful in this new world, we need to see information as a workable material and learn to architect it in a way that gets us to our goals.\nHow To Make Sense Of Any Mess\nI believe that the world will be a better place if we start treating front-end development as information architecture.", "year": "2016", "author": "Francis Storr", "author_slug": "francisstorr", "published": "2016-12-17T00:00:00+00:00", "url": "https://24ways.org/2016/front-end-developers-are-information-architects-too/", "topic": "code"}
{"rowid": 298, "title": "First Steps in VR", "contents": "The web is all around us. As web folk, it is our responsibility to consider the impact our work can have. Part of this includes thinking about the future; the web changes lives and if we are building the web then we are the ones making decisions that affect people in every corner of the world. I find myself often torn between wanting to make the right decisions, and just wanting to have fun. To fiddle and play. We all know how important it is to sometimes just try ideas, whether they will amount to much or not. \nI think of these two mindsets as production and prototyping, though of course there are lots of overlap and phases in between. I mention this because virtual reality is currently seen as a toy for rich people, and in some ways at the moment it is. But with WebVR we are able to create interesting experiences with a relatively low entry point. I want us to have open minds, play around with things, and then see how we can use the tools we have at our disposal to make things that will help people.\nEvery year we see articles saying it will be the \u201cyear of virtual reality\u201d, that was especially prevalent this year. 2016 has been a year of progress, VR isn\u2019t quite mainstream but with efforts like Playstation VR and Google Cardboard, we are definitely seeing much more of it. This year also saw the consumer editions of the Oculus Rift and HTC Vive. So it does seem to be a good time for an overview of how to get involved with creating virtual reality on the web.\nWebVR is an API for connecting to devices and retrieving continuous data such as the position and orientation. Unlike the Web Audio API and some other APIs, WebVR does not feel like a framework. You use it however you want, taking the data and using it as you wish. To make it easier, there are plenty of resources such as Three.js, A-Frame and ReactVR that help to make the heavy lifting a bit easier.\nGetting Started with A-Frame\nI like taking the opportunity to learn new things whenever I can. So while planning this article I thought that instead of trying to teach WebGL or even Three.js in a way that is approachable for all, I would create my first project using A-Frame and write about that. This is not a tutorial as such, I just want to show how to go about getting involved with VR. The beauty of A-Frame is that it is very similar to web components, you can just write HTML to build worlds that will automatically work on all the different types of devices. It uses WebGL and WebVR but in such a way that it quite drastically reduces the learning curve. That\u2019s not to say you can\u2019t build complex things, you have complete access to write JavaScript and shaders.\nI\u2019m lazy. Whenever I learn a new language or framework I have found that the best way, personally, for me to learn is to have a project and to copy the starting code from someone else. A project lets you have a good idea of what you want to produce and it means you can ignore a lot of the irrelevant documentation, focussing purely on what you need. That reduces the stress of figuring things out. Copying code also makes it easier, because you know your boilerplate code is working. There\u2019s nothing worse than getting stuck before anything actually works the first time. So I tinker. I take code and I modify it, I play around. It\u2019s fun.\nFor this project I wanted to keep things as simple as possible, so I can easily explain it without the classic \u201cdraw a circle then draw an owl\u201d. I wrote a list of requirements, with some stretch goals that you can give a try yourself if you fancy:\n\nMust work on Google Cardboard at a minimum, because of price\nTherefore, it must not rely on having a controller\nAuto-moving around a maze would be a good example\nMove in direction you look\nStretch goal: Scoring, time until you hit a wall or get stuck in maze\nStretch goal: Levels, so the map doesn\u2019t need to be random\nStretch goal: Snow!\n\nI decided to  base this project on an example, Platforms, by Don McCurdy who wrote the really useful aframe-extras. Platforms has random 3D blocks that you can jump onto, going up into the sky. So I took his code and reduced it so that the blocks are randomly spread on the ground. \n<!DOCTYPE html>\n<html>\n<head>\n    <meta charset=\"utf-8\">\n    <meta name=\"viewport\" content=\"width=device-width\">\n    <title>24 ways</title>\n    <script src=\"https://aframe.io/releases/0.3.2/aframe.js\"></script>\n    <script src=\"//cdn.rawgit.com/donmccurdy/aframe-extras/v2.6.1/dist/aframe-extras.min.js\"></script>\n</head>\n<body>\n<a-scene>\n    <a-entity id=\"player\"\n              camera\n              universal-controls\n              kinematic-body\n              position=\"0 1.8 0\">\n    </a-entity>\n\n    <a-entity id=\"walls\"></a-entity>\n\n    <a-grid id=\"ground\" static-body></a-grid>\n\n    <a-sky id=\"sky\" color=\"#AADDF0\"></a-sky>\n\n    <!-- Lighting -->\n    <a-light type=\"ambient\" color=\"#ccc\"></a-light>\n</a-scene>\n<script>\n    document.querySelector('a-scene').addEventListener('render-target-loaded', function () {\n        var MAP_SIZE = 10,\n                PLATFORM_SIZE = 5,\n                NUM_PLATFORMS = 50;\n        var platformsEl = document.querySelector('#walls');\n        var v, box;\n        for (var i = 0;  i < NUM_PLATFORMS; i++) {\n            // y: 0 is ground\n            v = {\n                x: (Math.floor(Math.random() * MAP_SIZE) - PLATFORM_SIZE) * PLATFORM_SIZE,\n                y: PLATFORM_SIZE / 2,\n                z: (Math.floor(Math.random() * MAP_SIZE) - PLATFORM_SIZE) * PLATFORM_SIZE\n            };\n            box = document.createElement('a-box');\n            platformsEl.appendChild(box);\n            box.setAttribute('color', '#39BB82');\n            box.setAttribute('width', PLATFORM_SIZE);\n            box.setAttribute('height', PLATFORM_SIZE);\n            box.setAttribute('depth', PLATFORM_SIZE);\n            box.setAttribute('position', v.x + ' ' + v.y + ' ' + v.z);\n            box.setAttribute('static-body', '');\n        }\n        console.info('Platforms loaded.');\n    });\n</script>\n</body>\n</html>\nAs you can see, this is very readable. Especially if you ignore the JavaScript that is used to create the maze. A-Frame (with A-Frame Extras) gives you a lot of power with relatively little to learn. We start with an <a-scene> which is the container for everything that is going to show up on the screen. There are a few <a-entity> which can be compared to <div> as they are essentially non-semantic containers, able to be used for any purpose. The attributes are used to define functionality, for example the camera attribute sets the entity to function as a camera and kinematic-body makes it collide instead of go through objects. Attributes are also used to set position and sizes, often using JavaScript to dynamically define them.\nStyling\nNow we\u2019ve got the HTML written, we need to style it. To do this we add A-Frame compatible attributes such as color and material. I recommend playing around, you can get some quite impressive effects fairly easily. Originally I wanted a light snowy maze but it ended up being dark and foggy, as I really liked the feeling it gave.\nNote, you will probably need a server running for images to work. You can do this by running python -m \"SimpleHTTPServer\" in the folder where the code is, then go to localhost:8000 in browser.\nTextures\nUnless you are going for a cartoony style, you probably want to find some textures. I found some on textures.com, one image worked well for the walls and the other for the floor.\n<a-assets>\n    <img id=\"texture-floor\" src=\"floor.jpg\">\n    <img id=\"texture-wall\" src=\"wall.jpg\">\n</a-assets>\nThe <a-assets> is used to define (as well as preload and cache) all assets, including images, audio and video. As you can see, images in the Asset Management System just use normal img tags. The ids are important here as we can use them later for using the textures. \nTo apply a texture to an object, you create a material. For a simple material where it just shows the image, you set the src to the id selector of the image.\nReplace: \n<a-grid id=\"ground\" static-body></a-grid>\nWith:\n<a-grid id=\"ground\" static-body material=\"src: #texture-floor\"></a-grid>\nThis will automatically make the image repeat over the entire floor, in my case filling it with bricks. The walls are pretty much identical, with the slight exception that it is set in JavaScript as they are dynamically defined.\nbox.setAttribute('material', 'src: #texture-wall');\nThat\u2019s it for the textures, for now at least. These will not look completely realistic, as the light will bump off the rectangular wall rather than texture itself. This can be improved by using maps, textures that are used to modify the shape and physical properties of the object. \nLighting\nThe next part of styling is lighting. By using fog and different types of lighting, we are able to add atmospheric details to the game to make it feel that bit more realistic and polished.\nThere are lots of types of light in A-Frame (most coming from Three.js). You can add a light either by using the <a-light> entity or by attaching a light attribute to any other entity. If there are no lights defined then A-Frame adds some by default so that the scene is always lit.\nTo start with I wanted to light up the scene with a general light, type=\"ambient\", so that the whole game felt slightly dark. I chose to set the light to a reddish colour #92455E. After playing around with intensity I chose 0.4, it added enough light to get the feeling I wanted without it being overly red. I also added a blue skybox (<a-sky>), as it looked a bit odd with a white sky.\n<a-light type=\"ambient\" color=\"#92455E\" intensity=\"0.4\"></a-light>\n<a-sky id=\"sky\" color=\"#0000ff\"></a-sky>\nI felt that the maze looked good with a red tinge but it was a bit flat, everything was the same colour and it was a bit dark. So I added a light within the #player entity, this could have been as an attribute but I set it as a child a-light instead. By using type=\"point\" with a high intensity and low distance, it showed close walls as being lighter. It also added a sort-of object to the player, it isn\u2019t a walking human or anything but by moving light where the player is it feels a bit more physical.\n<a-light color=\"#fff\" distance=\"5\" intensity=\"0.7\" type=\"point\"></a-light>\n\nBy this point it was starting to look decent, so I wanted to add the fog to really give some personality and depth to the maze. To do this I added the fog attribute to the <a-scene> with type=exponential so it looks thicker the further away it is and a mid intensity, so you feel a bit lost but can still see.\n\nI was very happy with this result. It took a lot of playing around with colours and values, which is fun in itself. I highly recommend you take the code (or write your own) and play around with the numbers.\nMovement\nOne of the reasons I decided to use aframe-extras is that it has a few different camera controls built in. As you saw earlier, I am using the universal-controls which gives WASD (keyboard) controls by default. I wanted to make it automatically move in the direction that you\u2019re looking, but I wasn\u2019t quite sure how without rewriting the controls. So I asked Don McCurdy for advice and he very nicely gave me a small snippet of code to get it working.\nAFRAME.registerComponent('automove-controls', {\n    init: function () {\n        this.speed = 0.1;\n        this.isMoving = true;\n        this.velocityDelta = new THREE.Vector3();\n    },\n    isVelocityActive: function () {\n        return this.isMoving;\n    },\n    getVelocityDelta: function () {\n        this.velocityDelta.z = this.isMoving ? -speed : 0;\n        return this.velocityDelta.clone();\n    }\n});\nReplace:\nuniversal-controls\nWith:\nuniversal-controls=\"movementControls: automove, gamepad, keyboard\"\nThis works by creating a component automove-controls that adds auto-move to the player without overriding movement completely. It doesn\u2019t even touch direction, it just checks if isMoving is true then moves the player by the set speed. Components can be creating for adding all kinds of functionality with relative ease. It makes it very powerful for people of all difficulty levels.\nBuilding a map\nCurrently the maze is created randomly, which is great but means there will often be walls that overlap or the player gets trapped with nowhere to go. So to solve this, I decided to use a map editor (Tiled) so that we can create the mazes ourselves. This is a great start towards one of the stretch goals, levels.\nI made the maze in Tiled by finding a random tileset online (we don\u2019t need to actually show the images), I used one tile for the wall and another for the player. Then I exported as a JavaScript file and modified it in my text editor to get rid of everything I didn\u2019t need. I made it so 0 is the path, 1 is the wall and 2 is the player. I then added the script to the HTML, as a separate file so it\u2019s easy to update in the future. \nvar map =\n{\n \"data\":[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],\n \"height\":10,\n \"width\":10\n}\n\nAs you can see, this gives a simple 10x10 maze with some dead ends. The player starts in the bottom right corner (my choice, could be anywhere). I rewrote the random platforms code (from Don\u2019s example) to instead loop over the map data and place walls where it is 1 and position the player where data is 2. I set the position so that the origin of the map would be 0,1.5,0. The y axis is in this case the height (ground being 0), but if a wall is positioned at 0 by its centre then some of it is underground. So the y needed to be the height divided by 2.\ndocument.querySelector('a-scene').addEventListener('render-target-loaded', function () {\n    var WALL_SIZE = 5,\n        WALL_HEIGHT = 3;\n    var el = document.querySelector('#walls');\n    var wall;\n\n    for (var x = 0; x < map.height; x++)  {\n        for (var y = 0; y < map.width; y++) {\n\n            var i = y*map.width + x;\n            var position = (x-map.width/2)*WALL_SIZE + ' ' + 1.5 + ' ' + (y-map.height/2)*WALL_SIZE;\n            if (map.data[i] === 1) {\n                // Create wall\n                wall = document.createElement('a-box');\n                el.appendChild(wall);\n                wall.setAttribute('color', '#fff');\n                wall.setAttribute('material', 'src: #texture-wall;');\n                wall.setAttribute('width', WALL_SIZE);\n                wall.setAttribute('height', WALL_HEIGHT);\n                wall.setAttribute('depth', WALL_SIZE);\n                wall.setAttribute('position', position);\n                wall.setAttribute('static-body', ');\n            }\n\n            if (map.data[i] === 2)  {\n                // Set player position\n                document.querySelector('#player').setAttribute('position', position);\n            }\n\n        }\n    }\n    console.info('Walls added.');\n});\n\nWith this added, it makes it nice and easy to change around the map as well as to add new features. Perhaps you want monsters or objects. Just set the number in the map data and add an if statement to the loop. In the future you could add layers, so multiple things can be in the same position. Or perhaps even make the maze go up the y axis too, with ramps or staircases. There\u2019s a lot you can do with relative ease. As you can see, A-Frame really does reduce the learning curve of 3D and VR on the web.\nIt\u2019s Not All Fun And Games\nA lot of examples of virtual reality are games, including this one. So it is understandable to think that VR is for gaming, but actually that\u2019s just a tiny subset. There are all sorts of applications for VR, including story telling, data visualisation and even meditation.\nThere have been a number of cases where it has been shown virtual reality can help as a tool for therapies:\n\nOxford study finds virtual reality can help treat severe paranoia\nVirtual Reality Therapy for Phobias at the Duke Faculty Practice\nBravemind: Virtual Reality Exposure Therapy at the University of Southern California\n\nThese are just a few examples of where virtual reality is being used around the world to help people feel better and get through some very tough times. There have also been examples of it being used for simulating war zones or medical situations, both as a teaching and journalism tool.\nWrapping Up\nTen years ago, on this very site, Cameron Moll wrote an article explaining the mobile web. He explained how mobile phones with data plans were becoming increasingly common, that WAP 2.0 included the XHTML Mobile Profile meaning it would be familiar with web folk. \u201cThe mobile web is rapidly becoming an XHTML environment, and thus you and I can apply our existing \u201cdesktop web\u201d skills to understand how to develop content for it.\u201d\nWe can look at that and laugh a little, we have come a very long way in the last decade. Even people in developing countries with very little money have mobile phones with access to a web that is far more capable than the \u201cdesktop web\u201d Cameron was referring to.\nSo while I am not saying virtual reality is going to change the world or replace our phones, who knows! We can use our skills as web folk to dabble, we don\u2019t need to learn any new languages. If on the 2026 edition of 24 ways, somebody references this article and looks at how far we have come\u2026 well, let\u2019s hope we have used our skills well and made the world just that little bit better. And if VR is a fad? Well it\u2019s fun\u2026 have a go anyway.", "year": "2016", "author": "Shane Hudson", "author_slug": "shanehudson", "published": "2016-12-11T00:00:00+00:00", "url": "https://24ways.org/2016/first-steps-in-vr/", "topic": "code"}
{"rowid": 38, "title": "Websites of Christmas Past, Present and Future", "contents": "The websites of Christmas past\n\nThe first website was created at CERN. It was launched on 20 December 1990 (just in time for Christmas!), and it still works today, after twenty-four years. Isn\u2019t that incredible?!\n\nWhy does this website still work after all this time? I can think of a few reasons.\n\nFirst, the authors of this document chose HTML. Of course they couldn\u2019t have known back then the extent to which we would be creating documents in HTML, but HTML always had a lot going for it. It\u2019s built on top of plain text, which means it can be opened in any text editor, and it\u2019s pretty readable, even without any parsing.\n\nDespite the fact that HTML has changed quite a lot over the past twenty-four years, extensions to the specification have always been implemented in a backwards-compatible manner. Reading through the 1992 W3C document HTML Tags, you\u2019ll see just how it has evolved. We still have h1 \u2013 h6 elements, but I\u2019d not heard of the <plaintext> element before. Despite being deprecated since HTML2, it still works in several browsers. You can see it in action on my website.\n\nAs well as being written in HTML, there is no run-time compilation of code; the first website simply consists of HTML files transmitted over the web. Due to its lack of complexity, it stood a good chance of surviving in the turbulent World Wide Web.\n\nThat\u2019s all well and good for a simple, static website. But websites created today are increasingly interactive. Many require a login and provide experiences that are tailored to the individual user. This type of dynamic website requires code to be executed somewhere.\n\nTraditionally, dynamic websites would execute such code on the server, and transmit a simple HTML file to the user. As far as the browser was concerned, this wasn\u2019t much different from the first website, as the additional complexity all happened before the document was sent to the browser.\n\nDoing it all in the browser\n\nIn 2003, the first single page interface was created at slashdotslash.com. A single page interface or single page app is a website where the page is created in the browser via JavaScript. The benefit of this technique is that, after the initial page load, subsequent interactions can happen instantly, or very quickly, as they all happen in the browser.\n\nWhen software runs on the client rather than the server, it is often referred to as a fat client. This means that the bulk of the processing happens on the client rather than the server (which can now be thin).\n\nA fat client is preferred over a thin client because:\n\n\n\tIt takes some processing requirements away from the server, thereby reducing the cost of servers (a thin server requires cheaper, or fewer servers).\n\tThey can often continue working offline, provided no server communication is required to complete tasks after initial load.\n\tThe latency of internet communications is bypassed after initial load, as interactions can appear near instantaneous when compared to waiting for a response from the server.\n\n\nBut there are also some big downsides, and these are often overlooked:\n\n\n\tThey can\u2019t work without JavaScript. Obviously JavaScript is a requirement for any client-side code execution. And as the UK Government Digital Service discovered, 1.1% of their visitors did not receive JavaScript enhancements. Of that 1.1%, 81% had JavaScript enabled, but their browsers failed to execute it (possibly due to dropping the internet connection). If you care about 1.1% of your visitors, you should care about the non-JavaScript experience for your website.\n\tThe browser needs to do all the processing. This means that the hardware it runs on needs to be fast. It also means that we require all clients to have largely the same capabilities and browser APIs.\n\tThe initial payload is often much larger, and nothing will be rendered for the user until this payload has been fully downloaded and executed. If the connection drops at any point, or the code fails to execute owing to a bug, we\u2019re left with the non-JavaScript experience.\n\tThey are not easily indexed as every crawler now needs to run JavaScript just to receive the content of the website.\n\n\nThese are not merely edge case issues to shirk off. The first three issues will affect some of your visitors; the fourth affects everyone, including you.\n\nWhat problem are we trying to solve?\n\nSo what can be done to address these issues? Whereas fat clients solve some inherent issues with the web, they seem to create as many problems. When attempting to resolve any issue, it\u2019s always good to try to uncover the original problem and work forwards from there. One of the best ways to frame a problem is as a user story. A user story considers the who, what and why of a need. Here\u2019s a template:\n\n\n\tAs a {who} I want {what} so that {why}\n\n\nI haven\u2019t got a specific project in mind, so let\u2019s refer to the who as user. Here\u2019s one that could explain the use of thick clients.\n\n\n\tAs a user I want the site to respond to my actions quickly so that I get immediate feedback when I do something.\n\n\nThis user story could probably apply to a great number of websites, but so could this:\n\n\n\tAs a user I want to get to the content quickly, so that I don\u2019t have to wait too long to find out what the site is all about or get the content I need.\n\n\nA better solution\n\nHow can we balance both these user needs? How can we have a website that loads fast, and also reacts fast? The solution is to have a thick server, that serves the complete document, and then a thick client, that manages subsequent actions and replaces parts of the page. What we\u2019re talking about here is simply progressive enhancement, but from the user\u2019s perspective.\n\nThe initial payload contains the entire document. At this point, all interactions would happen in a traditional way using links or form elements. Then, once we\u2019ve downloaded the JavaScript (asynchronously, after load) we can enhance the experience with JavaScript interactions. If for whatever reason our JavaScript fails to download or execute, it\u2019s no biggie \u2013 we\u2019ve already got a fully functioning website. If an API that we need isn\u2019t available in this browser, it\u2019s not a problem. We just fall back to the basic experience.\n\nThis second point, of having some minimum requirement for an enhanced experience, is often referred to as cutting the mustard, first used in this sense by the BBC News team. Essentially it\u2019s an if statement like this:\n\nif('querySelector' in document\n && 'localStorage' in window\n && 'addEventListener' in window) {\n // bootstrap the JavaScript application\n }\n\nThis code states that the browser must support the following methods before downloading and executing the JavaScript:\n\n\n\tdocument.querySelector (can it find elements by CSS selectors)\n\twindow.localStorage (can it store strings)\n\twindow.addEventListener (can it bind to events in a standards-compliant way)\n\n\nThese three properties are what the BBC News team decided to test for, as they are present in their website\u2019s JavaScript. Each website will have its own requirements. The last method, window.addEventListener is in interesting one. Although it\u2019s simple to bind to events on IE8 and earlier, these browsers have very inconsistent support for standards. Making any JavaScript-heavy website work on IE8 and earlier is a painful exercise, and comes at a cost to all users on other browsers, as they\u2019ll download unnecessary code to patch support for IE.\n\n JavaScript API support by browser.\n\nI discovered that IE8 supports 12% of the current JavaScript APIs, while IE9 supports 16%, and IE10 51%. It seems, then, that IE10 could be the earliest version of IE that I\u2019d like to develop JavaScript for. That doesn\u2019t mean that users on browsers earlier than 10 can\u2019t use the website. On the contrary, they get the core experience, and because it\u2019s just HTML and CSS, it\u2019s much more likely to be bug-free, and could even provide a better experience than trying to run JavaScript in their browser. They receive the thin client experience.\n\nBy reducing the number of platforms that our enhanced JavaScript version supports, we can better focus our efforts on those platforms and offer an even greater experience to those users. But we can only do that if we use progressive enhancement. Otherwise our website would be completely broken for all other users.\n\nSo what we have is a thick server, capable of serving the entire website to our users, complete with all core functionality needed for our users to complete their tasks; and we have a thick client on supported browsers, which can bring an even greater experience to those users.\n\nThis is all transparent to users. They may notice that the website seems snappier on the new iPhone they received for Christmas than on the Windows 7 machine they got five years ago, but then they probably expected it to be faster on their iPhone anyway.\n\nIsn\u2019t this just more work?\n\nIt\u2019s true that making a thick server and a thick client is more work than just making one or the other. But there are some big advantages:\n\n\n\tThe website works for everyone.\n\tYou can decide when users get the enhanced experience.\n\tYou can enhance features in an iterative (or agile) manner.\n\tWhen the website breaks, it doesn\u2019t break down.\n\tThe more you practise this approach, the quicker you will become.\n\n\nThe websites of Christmas present\n\nThe best way to discover websites using this technique of progressive enhancement is to disable JavaScript and see if the website breaks. I use the Web Developer extension, which is available for Chrome and Firefox. It lets me quickly disable JavaScript.\n\n Web Developer extension.\n\n24 ways works with and without JavaScript. Try using the menu icon to view the navigation. Without JavaScript, it\u2019s a jump link to the bottom of the page, but with JavaScript, the menu slides in from the right.\n\n 24 ways navigation with JavaScript disabled.\n\n 24 ways navigation with working JavaScript.\n\nGoogle search will also work without JavaScript. You won\u2019t get instant search results or any prerendering, because those are enhancements.\n\nFor a more app-like example, try using Twitter. Without JavaScript, it still works, and looks nearly identical. But when you load JavaScript, links open in modal windows and all pages are navigated much quicker, as only the content that has changed is loaded. You can read about how they achieved this in Twitter\u2019s blog posts Improving performance on twitter.com and Implementing pushState for twitter.com.\n\nUnfortunately Facebook doesn\u2019t use progressive enhancement, which not only means that the website doesn\u2019t work without JavaScript, but it takes longer to load. I tested it on WebPagetest and if you compare the load times of Twitter and Facebook, you\u2019ll notice that, despite putting similar content on the page, Facebook takes two and a half times longer to render the core content on the page.\n\n Facebook takes two and a half times longer to load than Twitter.\n\nWebsites of Christmas yet to come\n\nEvery project is different, and making a website that enjoys a long life, or serves a larger number of users may or may not be a high priority. But I hope I\u2019ve convinced you that it certainly is possible to look to the past and future simultaneously, and that there can be significant advantages to doing so.", "year": "2014", "author": "Josh Emerson", "author_slug": "joshemerson", "published": "2014-12-08T00:00:00+00:00", "url": "https://24ways.org/2014/websites-of-christmas-past-present-and-future/", "topic": "code"}
{"rowid": 128, "title": "Boost Your Hyperlink Power", "contents": "There are HTML elements and attributes that we use every day. Headings, paragraphs, lists and images are the mainstay of every Web developer\u2019s toolbox. Perhaps the most common tool of all is the anchor. The humble a element is what joins documents together to create the gloriously chaotic collection we call the World Wide Web.\n\nAnatomy of an Anchor\n\nThe power of the anchor element lies in the href attribute, short for hypertext reference. This creates a one-way link to another resource, usually another page on the Web:\n\n<a href=\"http://allinthehead.com/\">\n\nThe href attribute sits in the opening a tag and some descriptive text sits between the opening and closing tags:\n\n<a href=\"http://allinthehead.com/\">Drew McLellan</a>\n\n\u201cWhoop-dee-freakin\u2019-doo,\u201d I hear you say, \u201cthis is pretty basic stuff\u201d \u2013 and you\u2019re quite right. But there\u2019s more to the anchor element than just the href attribute.\n\nThe Theory of relativity\n\nYou might be familiar with the rel attribute from the link element. I bet you\u2019ve got something like this in the head of your documents:\n\n<link rel=\"stylesheet\" type=\"text/css\" media=\"screen\" href=\"styles.css\" />\n\nThe rel attribute describes the relationship  between the linked document and the current document. In this case, the value of rel is \u201cstylesheet\u201d. This means that the linked document is the stylesheet for the current document: that\u2019s its relationship.\n\nHere\u2019s another common use of rel:\n\n<link rel=\"alternate\" type=\"application/rss+xml\" title=\"my RSS feed\" href=\"index.xml\" />\n\nThis describes the relationship of the linked file \u2013 an RSS feed \u2013 as \u201calternate\u201d: an alternate view of the current document.\n\nBoth of those examples use the link element but you are free to use the rel attribute in regular hyperlinks. Suppose you\u2019re linking to your RSS feed in the body of your page:\n\nSubscribe to <a href=\"index.xml\">my RSS feed</a>.\n\nYou can add extra information to this anchor using the rel attribute:\n\nSubscribe to <a href=\"index.xml\" rel=\"alternate\" type=\"application/rss+xml\">my RSS feed</a>.\n\nThere\u2019s no prescribed list of values for the rel attribute so you can use whatever you decide is semantically meaningful. Let\u2019s say you\u2019ve got a complex e-commerce application that includes a link to a help file. You can explicitly declare the relationship of the linked file as being \u201chelp\u201d:\n\n<a href=\"help.html\" rel=\"help\">need help?</a>\n\nElemental Microformats\n\nAlthough it\u2019s completely up to you what values you use for the rel attribute, some consensus is emerging in the form of microformats. Some of the simplest microformats make good use of rel. For example, if you are linking to a license that covers the current document, use the rel-license microformat:\n\nLicensed under a <a href=\"http://creativecommons.org/licenses/by/2.0/\" rel=\"license\">Creative Commons attribution license</a>\n\nThat describes the relationship of the linked document as \u201clicense.\u201d\n\nThe rel-tag microformat goes a little further. It uses rel to describe the final part of the URL of the linked file as a \u201ctag\u201d for the current document:\n\nLearn more about <a href=\"http://en.wikipedia.org/wiki/Microformats\" rel=\"tag\">semantic markup</a>\n\nThis states that the current document is being tagged with the value \u201cMicroformats.\u201d\n\nXFN, which stands for XHTML Friends Network, is a way of describing relationships between people:\n\n<a href=\"http://allinthehead.com/\" rel=\"friend\">Drew McLellan</a>\n\nThis microformat makes use of a very powerful property of the rel attribute. Like the class attribute, rel can take multiple values, separated by spaces:\n\n<a href=\"http://allinthehead.com/\" rel=\"friend met colleague\">Drew McLellan</a>\n\nHere I\u2019m describing Drew as being a friend, someone I\u2019ve met, and a colleague (because we\u2019re both Web monkies).\n\nYou Say You Want a revolution\n\nWhile rel describes the relationship of the linked resource to the current document, the rev attribute describes the reverse relationship: it describes the relationship of the current document to the linked resource. Here\u2019s an example of a link that might appear on help.html:\n\n<a href=\"shoppingcart.html\" rev=\"help\">continue shopping</a>\n\nThe rev attribute declares that the current document is \u201chelp\u201d for the linked file.\n\nThe vote-links microformat makes use of the rev attribute to allow you to qualify your links. By using the value \u201cvote-for\u201d you can describe your document as being an endorsement of the linked resource:\n\nI agree with <a href=\"http://richarddawkins.net/home\" rev=\"vote-for\">Richard Dawkins</a>.\n\nThere\u2019s a corresponding vote-against value. This means that you can link to a document but explicitly state that you don\u2019t agree with it.\n\nI agree with <a href=\"http://richarddawkins.net/home\" rev=\"vote-for\">Richard Dawkins</a>\nabout those <a href=\"http://www.icr.org/\" rev=\"vote-against\">creationists</a>. \n\nOf course there\u2019s nothing to stop you using both rel and rev on the same hyperlink:\n\n<a href=\"http://richarddawkins.net/home\" rev=\"vote-for\" rel=\"muse\">Richard Dawkins</a>\n\nThe Wisdom of Crowds\n\nThe simplicity of rel and rev belies their power. They allow you to easily add extra semantic richness to your hyperlinks. This creates a bounty that can be harvested by search engines, aggregators and browsers. Make it your New Year\u2019s resolution to make friends with these attributes and extend the power of hypertext.", "year": "2006", "author": "Jeremy Keith", "author_slug": "jeremykeith", "published": "2006-12-18T00:00:00+00:00", "url": "https://24ways.org/2006/boost-your-hyperlink-power/", "topic": "code"}
{"rowid": 241, "title": "Jank-Free Image Loads", "contents": "There are a few fundamental problems with embedding images in pages of hypertext; perhaps chief among them is this: text is very light and loads rather fast; images are much heavier and arrive much later. Consequently, millions (billions?) of times a day, a hapless Web surfer will start reading some text on a page, and then \u2014\nYour browser doesn\u2019t support HTML5 video. Here is\n     a link to the video instead.\n\n\u2014 oops! \u2014 an image pops in above it, pushing said text down the page, and our poor reader loses their place.\nBy default, partially-loaded pages have the user experience of a slippery fish, or spilled jar of jumping beans. For the rest of this article, I shall call that jarring, no-good jumpiness by its name: jank. And I\u2019ll chart a path into a jank-free future \u2013 one in which it\u2019s easy and natural to author <img> elements that load like this:\nYour browser doesn\u2019t support HTML5 video. Here is\n     a link to the video instead.\n\nJank is a very old problem, and there is a very old solution to it: the width and height attributes on <img>. The idea is: if we stick an image\u2019s dimensions right into the HTML, browsers can know those dimensions before the image loads, and reserve some space on the layout for it so that nothing gets bumped down the page when the image finally arrives.\n\nwidth\nSpecifies the intended width of the image in pixels. When given together with the height, this allows user agents to reserve screen space for the image before the image data has arrived over the network.\n\n\u2014The HTML 3.2 Specification, published on January 14 1997\nUnfortunately for us, when width and height were first spec\u2019d and implemented, layouts were largely fixed and images were usually only intended to render at their fixed, actual dimensions. When image sizing gets fluid, width and height get weird:\nSee the Pen fluid width + fixed height = distortion by Eric Portis (@eeeps) on CodePen.\n\nwidth and height are too rigid for the responsive world. What we need, and have needed for a very long time, is a way to specify fixed aspect ratios, to pair with our fluid widths.\nI have good news, bad news, and great news.\nThe good news is, there are ways to do this, now, that work in every browser. Responsible sites, and responsible developers, go through the effort to do them.\nThe bad news is that these techniques are all terrible, cumbersome hacks. They\u2019re difficult to remember, difficult to understand, and they can interact with other pieces of CSS in unexpected ways.\nSo, the great news: there are two on-the-horizon web platform features that are trying to make no-jank, fixed-aspect-ratio, fluid-width images a natural part of the web platform.\naspect-ratio in CSS\nThe first proposed feature? An aspect-ratio property in CSS!\nThis would allow us to write CSS like this:\nimg {\n    width: 100%;\n}\n\n.thumb {\n    aspect-ratio: 1/1;\n}\n\n.hero {\n    aspect-ratio: 16/9;\n}\nThis\u2019ll work wonders when we need to set aspect ratios for whole classes of images, which are all sized to fit within pre-defined layout slots, like the .thumb and .hero images, above.\nAlas, the harder problem, in my experience, is not images with known-ahead-of-time aspect ratios. It\u2019s images \u2013 possibly user generated images \u2013 that can have any aspect ratio. The really tricky problem is unknown-when-you\u2019re-writing-your-CSS aspect ratios that can vary per-image. Using aspect-ratio to reserve space for images like this requires inline styles:\n<img src=\"image.jpg\" style=\"aspect-ratio: 5/4\" />\nAnd inline styles give me the heebie-jeebies! As a web developer of a certain age, I have a tiny man in a blue beanie permanently embedded deep within my hindbrain, who cries out in agony whenever I author a style=\"\" attribute. And you know what? The old man has a point! By sticking super-high-specificity inline styles in my content, I\u2019m cutting off my, (or anyone else\u2019s) ability to change those aspect ratios, for whatever reason, later.\nHow might we specify aspect ratios at a lower level? How might we give browsers information about an image\u2019s dimensions, without giving them explicit instructions about how to style it?\nI\u2019ll tell you: we could give browsers the intrinsic aspect ratio of the image in our HTML, rather than specifying an extrinsic aspect ratio!\nA brief note on intrinsic and extrinsic sizing\nWhat do I mean by \u201cintrinsic\u201d and \u201cextrinsic?\u201d\nThe intrinsic size of an image is, put simply, how big it\u2019d be if you plopped it onto a page and applied no CSS to it whatsoever. An 800\u00d7600 image has an intrinsic width of 800px.\nThe extrinsic size of an image, then, is how large it ends up after CSS has been applied. Stick a width: 300px rule on that same 800\u00d7600 image, and its intrinsic size (accessible via the Image.naturalWidth property, in JavaScript) doesn\u2019t change: its intrinsic size is still 800px. But this image now has an extrinsic size (accessible via Image.clientWidth) of 300px.\nIt surprised me to learn this year that height and width are interpreted as presentational hints and that they end up setting extrinsic dimensions (albeit ones that, unlike inline styles, have absolutely no specificity).\nCSS aspect-ratio lets us avoid setting extrinsic heights and widths \u2013 and instead lets us give images (or anything else) an extrinsic aspect ratio, so that as soon as we set one dimension (possibly to a fluid width, like 100%!), the other dimension is set automatically in relation to it.\nThe last tool I\u2019m going to talk about gets us out of the extrinsic sizing game all together \u2014 which, I think, is only appropriate for a feature that we\u2019re going to be using in HTML.\nintrinsicsize in HTML\nThe proposed intrinsicsize attribute will let you do this:\n<img src=\"image.jpg\" intrinsicsize=\"800x600\" />\nThat tells the browser, \u201chey, this image.jpg that I\u2019m using here \u2013 I know you haven\u2019t loaded it yet but I\u2019m just going to let you know right away that it\u2019s going to have an intrinsic size of 800\u00d7600.\u201d This gives the browser enough information to reserve space on the layout for the image, and ensures that any and all extrinsic sizing instructions, specified in our CSS, will layer cleanly on top of this, the image\u2019s intrinsic size.\nYou may ask (I did!): wait, what if my <img> references multiple resources, which all have different intrinsic sizes? Well, if you\u2019re using srcset, intrinsicsize is a bit of a misnomer \u2013 what the attribute will do then, is specify an intrinsic aspect ratio:\n<img\n    srcset=\"300x200.jpg 300w,\n            600x400.jpg 600w,\n            900x600.jpg 900w,\n            1200x800.jpg 1200w\"\n    sizes=\"75vw\"\n    intrinsicsize=\"3x2\" />\nIn the future (and behind the \u201cExperimental Web Platform Features\u201d flag right now, in Chrome 71+), asking this image for its .naturalWidth would not return 3 \u2013 it will return whatever 75vw is, given the current viewport width. And Image.naturalHeight will return that width, divided by the intrinsic aspect ratio: 3/2.\nCan\u2019t wait\nI seem to have gotten myself into the weeds a bit. Sizing on the web is complicated!\nDon\u2019t let all of these details bury the big takeaway here: sometime soon (\ud83e\udd1e 2019\u203d \ud83e\udd1e), we\u2019ll be able to toss our terrible aspect-ratio hacks into the dustbin of history, get in the habit of setting aspect-ratios in CSS and/or intrinsicsizes in HTML, and surf a less-frustrating, more-performant, less-janky web. I can\u2019t wait!", "year": "2018", "author": "Eric Portis", "author_slug": "ericportis", "published": "2018-12-21T00:00:00+00:00", "url": "https://24ways.org/2018/jank-free-image-loads/", "topic": "code"}
{"rowid": 310, "title": "Fairytale of new Promise", "contents": "There are only four good Christmas songs.\nI know, yeah, JavaScript or whatever. We\u2019ll get to that in a minute, I promise.\nFirst\u2014and I cannot stress this enough\u2014 there are four good Christmas songs. You\u2019re free to disagree with me here, of course, but please try to understand that you will be wrong.\nThey don\u2019t all have the most safe-for-work titles; I can\u2019t list all of them here, but if you choose to let your fingers do the walkin\u2019 to your nearest search engine, I will say that one was released by the band FEAR way back in 1982 and one was on Run the Jewels\u2019 self-titled debut album. The lyrics are a hell of a lot worse than the titles, so maybe wait until you get home from work before you queue them up. Wear headphones, if you\u2019ve got thin walls.\nFor my money, though, the two I can reference by name are the top of that small heap: Tom Waits\u2019 Christmas Card from a Hooker in Minneapolis, and The Pogues\u2019 Fairytale of New York. The former once held the honor of being the only good Christmas song\u2014about which which I was also unequivocally correct, right up until I changed my mind. It\u2019s not the song up for discussion today, but feel free to familiarize yourself just the same\u2014I\u2019ll wait.\nFairytale of New York\u2014the top of the list\u2014starts out by hinting at some pretty standard holiday fare; dreams and cheer and whatnot. Typical seasonal stuff, so long as you ignore that the story seems to be recounted as a drunken flashback in a jail cell. You can probably make a few guesses at the underlying spirit of the song based on that framing: following a lucky break, our bright-eyed protagonists move to New York in search of fame and fortune, only to quickly descend into bad decisions, name-calling, and vaguely festive chaos.\nThis song speaks to me on a couple of levels, not the least of which is as a retelling of my day-to-day interactions with JavaScript. Each day\u2019s melody might vary a little bit, granted, but the lyrics almost always follow a pretty clear arc toward \u201cPARENTAL ADVISORY: EXPLICIT CONTENT.\u201d You might have heard a similar tune yourself; it goes a little somethin\u2019 like setTimeout(function() { console.log( \"this should be happening last\" ); }, 1000); . Callbacks are calling callbacks calling callbacks and something is happening somewhere, as the JavaScript interpreter plods through our code start-to-finish, line-by-line, step-by-step. If we need to take actions based on the results of something that could take its sweet time resolving, well, we\u2019d better fiddle with the order of things to make sure those actions don\u2019t happen too soon.\n\u201cBut I can see a better time,\u201d as the song says, \u201cwhen all our dreams come true.\u201d So, with that Pogues brand of holiday spirit squarely in mind\u2014by which I mean that your humble narrator is almost certainly drunk, and may be incarcerated at the time of publication\u2014gather \u2019round for a story of hope, of hardships, of semi-asynchronous JavaScript programming, and ultimately: of Promise unfulfilled.\nThe Main Thread\nJavaScript is single-minded, in a manner of speaking. Anything we tell the JavaScript runtime to do goes into a single-file queue; you\u2019ll see it referred to as the \u201cmain thread,\u201d or \u201cUI thread.\u201d That thread can be shared by a number of critical browser processes, like rendering and re-rendering parts of the page, and user interactions ranging from the simple\u2014say, highlighting text\u2014to the more complex\u2014interacting with form elements.\nIf that sounds a little scary to you, well, that\u2019s because it is. The more complex our scripts, the more we\u2019re cramming into that single-file main thread, to be processed along with\u2014say\u2014some of our CSS animations. Too much JavaScript clogging up the main thread means a lot of user-facing performance jankiness. Getting away from that single thread is a big part of all the excitement around Web Workers, which allow us to offload entire scripts into their own dedicated background threads\u2014though not without limitations of their own. Outside of Web Workers, that everything-thread is the only game in town: scripts executed one thing at a time, functions calling functions calling functions, taking numbers and crowding up the same deli counter as a user\u2019s interactions\u2014which, in this already strained metaphor, would be ham, I guess?\nAsynchronous JavaScript\nNow, those queued actions may include asynchronous things. For example: AJAX callbacks, setTimeout/setInterval, and addEventListener won\u2019t block the main thread while we\u2019re waiting for a request to come back, a timer to tick away, or an event to trigger. Once those things do kick in, though, the actions they\u2019re meant to perform will get shuffled right back into that single-thread queue.\nThere are a couple of places you might have written asynchronously-fired JavaScript, even if you\u2019re not super familiar with the overarching concept: XMLHttpRequest\u2014\u201cAJAX,\u201d if ya nasty\u2014or just kicking off a function once a user triggers a click or mouseenter event. Event-driven development is writ a little larger, with the overall flow of the script dictated by events, both internal and external. Writing event-driven JavaScript applications is a step in the right direction for sure\u2014it won\u2019t cure what ails the main thread, but it does work with the medium in a reasonable way. Event-driven development allows us to manage our use of the main thread in a way that makes sense. If any of this rings a bell for you, the motivation for Promises should feel familiar.\nFor example, a custom init event might kick things off, and fire a create event that applies our classes and restructures our markup which, on completion, fires a bindEvents event to handle all the event listeners for user interaction. There might not sound like much difference between that and one big function that kicks off, manipulates the DOM, and binds our events line-by-line\u2014but in a script of sufficient size and complexity we\u2019re not only provided with a decoupled flow through the script, but obvious touchpoints for future updates and a predictable structure for ongoing maintenance. \nThis pattern falls apart a little where we were still creating, binding, and listening for events in the same top-to-bottom, one-item-at-a-time way\u2014we had to set a listener on a given object before the event fires, or nothing would happen:\n// Create the event:\nvar event = document.createEvent( \"Event\" );\n\n// Name the event:\nevent.initEvent( \"doTheStuff\", true, true );\n\n// Listen for the custom `doTheStuff` event on `window`:\nwindow.addEventListener( \"doTheStuff\", initializeEverything );\n\n// Fire the custom event\nwindow.dispatchEvent( event );\nThis example is a little contrived, and this stuff is a lot more manageable for sure with the addition of a framework, but that\u2019s the basic gist: create and name the event, add a listener for the event, and\u2014after setting our listener\u2014dispatch the event.\nEvents and callbacks aren\u2019t the only game in town for weaving our way in and out of the main thread, though\u2014at least, not anymore. \nPromises\nA Promise is, at the risk of sounding sentimental, pure potential\u2014an empty container into which a value eventually results. A Promise can exist in several states: \u201cpending,\u201d while the computation they contain is being performed or \u201cresolved\u201d once that computation is complete. Once resolved, a Promise is \u201cfulfilled\u201d if it gave us back something we expect, or \u201crejected\u201d if it didn\u2019t.\nThe Promise constructor accepts a callback with two arguments: resolve and reject. We perform an action\u2014asynchronous or otherwise\u2014within that callback. If everything in there has gone according to plan, we call resolve. If something has gone awry, we call reject\u2014with an error, conventionally. To illustrate, let\u2019s tack something together with a pretty decent chance of doing what we don\u2019t want: a promise meant only to give us the number 1, but has a chance of giving us back a 2. No reasonable person would ever do this, of course, but I wouldn\u2019t necessarily put it past me.\nvar promisedOne = new Promise( function( resolve, reject ) {\n  var coinToss = Math.floor( Math.random() * 2 ) + 1;\n\n  if( coinToss === 1 ) {\n    resolve( coinToss );\n  } else {\n    reject( new Error( \"That ain\u2019t a one.\" ) );\n  }\n});\nThere\u2019s nothing too surprising in there, after you boil it all down. It\u2019s a little return-y, with the exception that we\u2019re flagging results as \u201cas expected\u201d or \u201csomething went wrong.\u201d\nTapping into that Promise uses another new keyword: then\u2014and as someone who attempts to make sense of JavaScript by breaking it down to plain ol\u2019 human-language, I\u2019m a big fan of this syntax. then is tacked onto our Promise identifier, and does just what it says on the tin: once the Promise is resolved, then do one of two things, both supplied as callbacks: the first in the case of a fulfilled promise, and the second in the case of a rejected one. Those two callbacks will have, as arguments, the results we specified with resolve orreject, respectively. It sounds like a lot in prose, but in code it\u2019s a pretty simple pattern:\npromisedOne.then( function( result ) {\n  console.log( result );\n}, function( error ) {\n  console.error( error );\n});\nIf you\u2019ve spent any time working with AJAX\u2014jQuery-wise, in particular\u2014you\u2019ve seen something like this pattern before: a success callback and an error callback. The state of a promise, once fulfilled or rejected, cannot be changed\u2014any reference we make to promisedOne will have a single, fixed result.\nIt may not look like too much the way I\u2019m using it here, but it\u2019s powerful stuff\u2014a pattern for asynchronously resolving anything. I\u2019ve recently used Promises alongside a script that emulates Font Load Events, to apply webfonts asynchronously and avoid a potential performance hit. Font Face Observer allows us to, as the name implies, determine when the files referenced by our @font-face rules have finished loading. \nvar fontObserver = new FontFaceObserver( \"Fancy Font\" );\n\nfontObserver.check().then(function() {\n  document.documentElement.className += \" fonts-loaded\";\n}, function( error ) {\n  console.error( error );\n});\nfontObserver.check() gives us back a Promise, allowing us to chain on a then containing our callbacks for success and failure. We use the fulfilled callback to bolt a class onto the page once the font file has been fully transferred. We don\u2019t bother including an argument in the first function, since we don\u2019t care about the result itself so much as we care that the promise resolved without error\u2014we\u2019re not doing anything with the resolved value, just adding a class to the page. We do include the error argument, since we\u2019ll want to know what happened should something go wrong.\nNow, this isn\u2019t the tidiest syntax around\u2014at least to my eyes\u2014with those two functions just kinda floating in a then. Luckily there\u2019s an similar alternative syntax; one that I find a bit easier to parse at-a-glance:\nfontObserver.check()\n  .then(function() {\n    document.documentElement.className += \" fonts-loaded\";\n  })\n  .catch(function( error ) {\n    console.log( error );\n  });\nThe first callback inside then provides us with our success state, while the catch provides us with a single, explicit \u201csomething went wrong\u201d callback. The two syntaxes aren\u2019t completely identical in all situations, but for a simple case like this, I find it a little neater.\nThe Common Thread\nI guess I still owe you an explanation, huh. Not about the JavaScript-whatever; I think I\u2019ve explained that plenty. No, I mean Fairytale of New York, and why it\u2019s perched up there at the top of the four (4) song heap.\nFairytale is a sad song, ostensibly. If you follow the main thread\u2014start to finish, line-by-line, step by step\u2014 Fairytale is a sad song. And I can see you out there, visions of Die Hard dancing in your heads: \u201cbut is it a Christmas song?\u201d\nWell, for my money, nothing says \u201cholidays\u201d quite like unreliable narration.\nShane MacGowan, the song\u2019s author, has placed the first verse about \u201cChristmas Eve in the drunk tank\u201d as happening right after the \u201clucky one, came in eighteen-to-one\u201d\u2014not at the chronological end of the story. That means the song might not be mostly drunken flashback, but all of it a single, overarching flashback including a Christmas Eve in protective custody. It could be that the man and woman are, together, recounting times long past\u2014good times and bad times\u2014maybe not even in chronological order. Hell, the \u201cNYPD Choir\u201d mentioned in the chorus? There\u2019s no such thing.\nWe\u2019re not big Christmas folks, my family and I. But just the same, every year, the handful of us get together, and every year\u2014like clockwork\u2014there\u2019s a lull in conversation, there\u2019s a sharp exhale, and Ma says \u201cwe all made it.\u201d Not to a house, not to a dinner, but through another year, to another Christmas. At this point, without fail, someone starts telling a story\u2014and one begets another, and so on. Sometimes the stories are happy, sometimes they\u2019re sad, more often than not they\u2019re both. Some are about things we were lucky to walk away from, some are about a time when another one of us didn\u2019t.\nStart-to-finish, line-by-line, step-by-step, the main thread through the year doesn\u2019t change, and maybe there isn\u2019t a whole lot we can do to change it. But by carefully weaving our way in and out of that thread\u2014stories all out of sync and resolving one way or the other, with the results determined by questionably reliable narrators\u2014we can change the way we interact with it and, little by little, we can start making sense of it.", "year": "2016", "author": "Mat Marquis", "author_slug": "matmarquis", "published": "2016-12-19T00:00:00+00:00", "url": "https://24ways.org/2016/fairytale-of-new-promise/", "topic": "code"}
{"rowid": 36, "title": "Naming Things", "contents": "There are only two hard things in computer science: cache invalidation and naming things.\nPhil Karlton\n\n\nBeing a professional web developer means taking responsibility for the code you write and ensuring it is comprehensible to others. Having a documented code style is one means of achieving this, although the size and type of project you\u2019re working on will dictate the conventions used and how rigorously they are enforced.\n\nWorking in-house may mean working with multiple developers, perhaps in distributed teams, who are all committing changes \u2013 possibly to a significant codebase \u2013 at the same time. Left unchecked, this codebase can become unwieldy. Coding conventions ensure everyone can contribute, and help build a product that works as a coherent whole.\n\nEven on smaller projects, perhaps working within an agency or by yourself, at some point the resulting product will need to be handed over to a third party. It\u2019s sensible, therefore, to ensure that your code can be understood by those who\u2019ll eventually take ownership of it.\n\nPut simply, code is read more often than it is written or changed. A consistent and predictable naming scheme can make code easier for other developers to understand, improve and maintain, presumably leaving them free to worry about cache invalidation.\n\nLet\u2019s talk about semantics\n\nNames not only allow us to identify objects, but they can also help us describe the objects being identified.\n\nSemantics (the meaning or interpretation of words) is the cornerstone of standards-based web development. Using appropriate HTML elements allows us to create documents and applications that have implicit structural meaning. Thanks to HTML5, the vocabulary we can choose from has grown even larger.\n\nHTML elements provide one level of meaning: a widely accepted description of a document\u2019s underlying structure. It\u2019s only with the mutual agreement of browser vendors and developers that <p> indicates a paragraph.\n\nYet (with the exception of widely accepted microdata and microformat schemas) only HTML elements convey any meaning that can be parsed consistently by user agents. While using semantic values for class names is a noble endeavour, they provide no additional information to the visitor of a website; take them away and a document will have exactly the same semantic value.\n\nI didn\u2019t always think this was the case, but the real world has a habit of changing your opinion. Much of my thinking around semantics has been informed by the writing of my peers. In \u201cAbout HTML semantics and front-end architecture\u201d, Nicholas Gallagher wrote:\n\n\n\tThe important thing for class name semantics in non-trivial applications is that they be driven by pragmatism and best serve their primary purpose \u2013 providing meaningful, flexible, and reusable presentational/behavioural hooks for developers to use.\n\n\nThese thoughts are echoed by Harry Roberts in his CSS Guidelines:\n\n\n\tThe debate surrounding semantics has raged for years, but it is important that we adopt a more pragmatic, sensible approach to naming things in order to work more efficiently and effectively. Instead of focussing on \u2018semantics\u2019, look more closely at sensibility and longevity \u2013 choose names based on ease of maintenance, not for their perceived meaning.\n\n\nNaming methodologies\n\nFront-end development has undergone a revolution in recent years. As the projects we\u2019ve worked on have grown larger and more important, our development practices have matured. The pros and cons of object-orientated approaches to CSS can be endlessly debated, yet their introduction has highlighted the usefulness of having documented naming schemes.\n\nJonathan Snook\u2019s SMACSS (Scalable and Modular Architecture for CSS) collects style rules into five categories: base, layout, module, state and theme. This grouping makes it clear what each rule does, and is aided by a naming convention:\n\n\n\tBy separating rules into the five categories, naming convention is beneficial for immediately understanding which category a particular style belongs to and its role within the overall scope of the page. On large projects, it is more likely to have styles broken up across multiple files. In these cases, naming convention also makes it easier to find which file a style belongs to.\n\n\tI like to use a prefix to differentiate between layout, state and module rules. For layout, I use l- but layout- would work just as well. Using prefixes like grid- also provide enough clarity to separate layout styles from other styles. For state rules, I like is- as in is-hidden or is-collapsed. This helps describe things in a very readable way.\n\n\nSMACSS is more a set of suggestions than a rigid framework, so its ideas can be incorporated into your own practice. Nicholas Gallagher\u2019s SUIT CSS project is far more strict in its naming conventions:\n\n\n\tSUIT CSS relies on structured class names and meaningful hyphens (i.e., not using hyphens merely to separate words). This helps to work around the current limits of applying CSS to the DOM (i.e., the lack of style encapsulation), and to better communicate the relationships between classes.\n\n\nOver the last year, I\u2019ve favoured a BEM-inspired approach to CSS. BEM stands for block, element, modifier, which describes the three types of rule that contribute to the style of a single component. This means that, given the following markup:\n\n<ul class=\u201csleigh\u201d>\n    <li class=\u201csleigh__reindeer sleigh__reindeer\u2013\u2013famous\u201d>Rudolph</li>\n    <li class=\u201csleigh__reindeer\u201d>Dasher</li>\n    <li class=\u201csleigh__reindeer\u201d>Dancer</li>\n    <li class=\u201csleigh__reindeer\u201d>Prancer</li>\n    <li class=\u201csleigh__reindeer\u201d>Vixen</li>\n    <li class=\u201csleigh__reindeer\u201d>Comet</li>\n    <li class=\u201csleigh__reindeer\u201d>Cupid</li>\n    <li class=\u201csleigh__reindeer\u201d>Dunder</li>\n    <li class=\u201csleigh__reindeer\u201d>Blixem</li>\n</ul>\n\nI know that:\n\n\n\t.sleigh is a containing block or component.\n\t.sleigh__reindeer is used only as a descendent element of .sleigh.\n\t.sleigh__reindeer\u2013\u2013famous is used only as a modifier of .sleigh__reindeer.\n\n\nWith this naming scheme in place, I know which styles relate to a particular component, and which are shared. Beyond reducing specificity-related head-scratching, this approach has given me a framework within which I can consistently label items, and has sped up my workflow considerably.\n\nEach of these methodologies shows that any robust CSS naming convention will have clear rules around case (lowercase, camelCase, PascalCase) and the use of special (allowed) characters like hyphens and underscores.\n\nWhat makes for a good name?\n\nRegardless of higher-level conventions, there\u2019s no getting away from the fact that, at some point, we\u2019re still going to have to name things. Recognising that classes should be named with other developers in mind, what makes for a good name?\n\nUnderstandable\n\nThe most important aspect is for a name to be understandable. Words used in your project may come from a variety of sources: some may be widely understood, and others only be recognised by people working within a particular environment.\n\n\n\tCulture\nMost words you\u2019ll choose will have common currency outside the world of web development, although they may have a particular interpretation among developers (think menu, list, input). However, words may have a narrower cultural significance; for example, in Germany and other German-speaking countries, impressum is the term used for legally mandated statements of ownership.\n\tIndustry\nIndustries often use specific terms to describe common business practices and concepts. Publishing has a number of these (headline, standfirst, masthead, colophon\u2026) all have well understood meanings \u2013 and not all of them are relevant to online usage.\n\tOrganisation\nCompanies may have internal names (or nicknames) for their products and services. The Guardian is rife with such names: bisons (and buffalos), pixies (and super-pixies), bentos (and mini-bentos)\u2026 all of which mean something very different outside the organisation. Although such names can be useful inside smaller teams, in larger organisations they can become a barrier to entry, a sort of secret code used among employees who have been around long enough to know what they mean.\n\tProduct\nYour team will undoubtedly have created names for specific features or interface components used in your product. For example, at Clearleft we coined the term gravigation for a navigation bar that was pinned to the bottom of the viewport. Elements of a visual design language may have names, too. Transport for London\u2019s bar and circle logo is known internally as the roundel, while Nike\u2019s logo is called the swoosh. Branding agencies often christen colours within a brand palette, too, either to evoke aspects of the identity or to indicate intended usage.\n\n\nOnce you recognise the origin of the words you use, you\u2019ll be better able to judge their appropriateness. Using Latin words for class names may satisfy a need to use semantic-sounding terms but, unless you work in a company whose employees have a basic grasp of Latin, a degree of translation will be required. Military ranks might be a clever way of declaring sizes without implying actual values, but I\u2019d venture most people outside the armed forces don\u2019t know how they\u2019re ordered.\n\nObvious\n\nQuite often, the first name that comes into your head will be the best option. Names that obliquely reference the function of a class (e.g. receptacle instead of container, kevlar instead of no-bullets) only serve to add an additional layer of abstraction. Don\u2019t overthink it!\n\nOne way of knowing if the names you use are well understood is to look at what similar concepts are called in existing vocabularies. schema.org, Dublin Core and the BBC\u2019s ontologies are all useful sources for object names.\n\nFunctional\n\nWhile we\u2019ve learned to avoid using presentational classes, there remains a tension between naming things based on their content, and naming them for their intended presentation or behaviour (which may change at different breakpoints). Rather than think about a component\u2019s appearance or behaviour, instead look to its function, its purpose. To clarify, ask what a component\u2019s function is, and not how the component functions.\n\nFor example, the Guardian\u2019s internal content system uses the following names for different types of image placement: supporting, showcase and thumbnail, with inline being the default. These options make no promise of the resulting position on a webpage (or smartphone app, or television screen\u2026), but do suggest intended use, and therefore imply the likely presentation.\n\nConsistent\n\nBeing consistent in your approach to names will allow for easier naming of successive components, and extending the vocabulary when necessary. For example, a predictably named hierarchy might use names like primary and secondary. Should another level need to be added, tertiary is clearly be preferred over third.\n\nAppropriate\n\nYour project will feature a mix of style rules. Some will perform utility functions (clearing floats, removing bullets from a list, reseting margins), while others will perform specific functions used only once or twice in a project. Names should reflect this. For commonly used classes, be generic; for unique components be more specific.\n\nIt\u2019s also worth remembering that you can use multiple classes on an element, so combining both generic and specific can give you a powerful modular design system:\n\n\n\tGeneric: list\n\tSpecific: naughty-children\n\tCombined: naughty-children list\n\n\nIf following the BEM methodology, you might use the following classes:\n\n\n\tGeneric: list\n\tSpecific: list\u2013\u2013nice-children\n\tCombined: list list\u2013\u2013nice-children\n\n\nExtensible\n\nGood naming schemes can be extended. One way of achieving this is to use namespaces, which are basically a way of grouping related names under a higher-level term.\n\nMicroformats are a good example of a well-designed naming scheme, with many of its vocabularies taking property names from existing and related specifications (e.g. hCard is a 1:1 representation of vCard). Microformats 2 goes one step further by grouping properties under several namespaces:\n\n\n\th-* for root class names (e.g. h-card)\n\tp-* for simple (text) properties (e.g. p-name)\n\tu-* for URL properties (e.g. u-photo)\n\tdt-* for date/time properties (e.g. dt-bday)\n\te-* for embedded markup properties (e.g. e-note)\n\n\nThe inclusion of namespaces is a massive improvement over the earlier specification, but the downside is that microformats now occupy five separate namespaces. This might be problematic if you are using u-* for your utility classes. While nothing will break, your naming system won\u2019t be as robust, so plan accordingly.\n\n(Note: Microformats perform a very specific function, separate from any presentational concerns. It\u2019s therefore considered best practice to not use microformat classes as styling hooks, but instead use additional classes that relate to the function of the component and adhere to your own naming conventions.)\n\nShort\n\nNames should be as long as required, but no longer. When looking for words to describe a particular function, I try to look for single words where possible. Avoid abbreviations unless they are understood within the contexts described above. rrp is fine if labelling a recommended retail price in an online shop, but not very helpful if used to mean ragged-right paragraph, for example.\n\nFun!\n\nFinally, names can be an opportunity to have some fun! Names can give character to a project, be it by providing an outlet for in-jokes or adding little easter eggs for those inclined to look.\n\nThe copyright statement on Apple\u2019s website has long been named sosumi, a word that has a nice little history inside Apple. Until recently, the hamburger menu icon on the Guardian website was labelled honest-burger, after the developer\u2019s favourite burger restaurant.\n\nA few thoughts on preprocessors\n\nCSS preprocessors have solved a lot of problems, but they have an unfortunate downside: they require you to name yet more things! Whereas we needed to worry only about style rules, now we need names for variables, mixins, functions\u2026 oh my!\n\nA second article could be written about naming these, so for now I\u2019ll offer just a few thoughts. The first is to note that preprocessors make it easier to change things, as they allow for DRYer code. So while the names of variables are important (and the advice in this article still very much applies), you can afford to relax a little.\n\nLooking to name colour variables? If possible, find out if colours have been assigned names in a brand palette. If not, use obvious names (based on appearance or function, depending on your preference) and adapt as the palette grows. If it becomes difficult to name colours that are too similar, I\u2019d venture that the problem lies with the design rather than the naming scheme.\n\nThe same is true for responsive breakpoints. Preprocessors allow you to move awkward naming conventions out of the markup and into the CSS. Although terms like mobile, tablet and desktop are not desirable given the need to think about device-agnostic design, if these terms are widely understood within a product team and among stakeholders, using them will ensure everyone is using the same language (they can always be changed later).\n\nIt still feels like we\u2019re at the very beginning of understanding how preprocessors fit into a development workflow, if at all! I suspect over the next few years, best practices will emerge for all of these considerations. In the meantime, use your brain!\n\n\n\nEven with sensible rules and conventions in place, naming things can remain difficult, but hopefully I\u2019ve made this exercise a little less painful. Christmas is a time of giving, so to the developer reading your code in a year\u2019s time, why not make your gift one of clearer class names.", "year": "2014", "author": "Paul Lloyd", "author_slug": "paulrobertlloyd", "published": "2014-12-21T00:00:00+00:00", "url": "https://24ways.org/2014/naming-things/", "topic": "code"}
{"rowid": 216, "title": "Styling Components - Typed CSS With Stylable", "contents": "There\u2019s been a lot of debate recently about how best to style components for web apps so that styles don\u2019t accidentally \u2018leak\u2019 out of the component they\u2019re meant for, or clash with other styles on the page.\nElaborate CSS conventions have sprung up, such as OOCSS, SMACSS, BEM, ITCSS, and ECSS. These work well, but they are methodologies, and require everyone in the team to know them and follow them, which can be a difficult undertaking across large or distributed teams.\nOthers just give up on CSS and put all their styles in JavaScript. Now, I\u2019m not bashing JS, especially so close to its 22nd birthday, but CSS-in-JS has problems of its own. Browsers have 20 years experience in optimising their CSS engines, so JavaScript won\u2019t be as fast as using real CSS, and in any case, this requires waiting for JS to download, parse, execute then render the styles.\nThere\u2019s another problem with CSS-in-JS, too. Since Responsive Web Design hit the streets, most designers no longer make comps in Photoshop or its equivalents; instead, they write CSS. Why hire an expensive design professional and require them to learn a new way of doing their job? \nA recent thread on Twitter asked \u201cWhat\u2019s your biggest gripe with CSS-in-JS?\u201d, and the replies were illuminating: \u201cAlways having to remember to camelCase properties then spending 10min pulling hair out when you do forget\u201d, \u201cthe cryptic domain-specific languages that each of the frameworks do just ever so slightly differently\u201d, \u201cWhen I test look and feel in browser, then I copy paste from inspector, only to have to re-write it as a JSON object\u201d, \u201cLack of linting, autocomplete, and css plug-ins for colors/ incrementing/ etc\u201d. \nIf you\u2019re a developer, and you\u2019re still unconvinced, I challenge you to let designers change the font in your IDE to Zapf Chancery and choose a new colour scheme, simply because they like it better. Does that sound like fun? Will that boost your productivity? Thought not.\nSome chums at Wix Engineering and I wanted to see if we could square this circle. Wix-hosted sites have always used CSS-in-JS (the concept isn\u2019t new; it was in Netscape 4!) but that was causing performance problems. Could we somehow devise a method of extending CSS (like SASS and LESS do) that gives us styles that are guaranteed not to leak or clash, that is compatible with code editors\u2019 autocompletion, and which could be pre-processed at build time to valid, cross-browser, static CSS?\nAfter a few months and a few proofs of concept later (drumroll), yes \u2013 we could! We call it Stylable.\nIntroducing Stylable\nStylable is a CSS pre-processor, like SASS or LESS. It uses CSS syntax so all your development tools will work. At build time, the Stylable CSS extensions are transpiled to flat, valid, cross-browser vanilla CSS for maximum performance. There\u2019s quite a bit to it, and this is a short article, so let\u2019s look at the basic concepts.\nComponents all the way down\nStylable is designed for component-based systems. Imagine you have a Gallery component. Within that, there is a Navigation component (for example, containing a \u2018next\u2019, \u2018previous\u2019, \u2018show all thumbnails\u2019, and \u2018show all albums\u2019 controls), and within that there are NavButton components. Each component is discrete, used elsewhere in the system in different contexts, perhaps maintained by different team members or even different organisations \u2014 you can use Stylable to add a typed interface to non-Stylable component libraries, as well as using it to build an app from scratch.\nFirstly, Stylable will automatically namespace styles so they only apply inside that component, by rewriting them at build time with a unique (but human-readable) prefix. So, for example,\n<div className=\"jingle bells\" /> might be re-written as <div class=\"header183--jingle header183--bells\"></div>. \nSo far, so BEM-like (albeit without the headache of remembering a convention). But what else can it do?\nCustom pseudo-elements\nAn important feature of Stylable is the ability to reach into a component and style it from the outside, without having to know about its internal structure. Let\u2019s see the guts of a simple JSX button component in the file button.jsx:\nrender () {\n    return (\n        <button>\n            <span className=\"icon\" />\n            <span className=\"label\">Submit</span>\n        </button>\n    );\n}\n(Note:className is the JSX way of setting a class on an element; this example uses React, but Stylable itself is framework-agnostic.)\nI style it using a Stylable stylesheet (the .st.css suffix tells the preprocessor to process this file):\n/* button.st.css */\n\n/* note that the root class is automatically placed on the root HTML \nelement by Stylable React integration */\n.root {\n  background: #b0e0e6;\n}\n\n.icon {\n  display: block; \n  height: 2em;\n  background-image: url('./assets/btnIcon.svg');\n}\n\n.label {\n  font-size: 1.2em;\n  color: rgba(81, 12, 68, 1.0);\n}\nNote that Stylable allows all the CSS that you know and love to be included. As Drew Powers wrote in his review:\n\nwith Stylable, you get CSS, and every part of CSS. This seems like a \u201cduh\u201d observation, but this is significant if you\u2019ve ever battled with a CSS-in-JS framework over a lost or \u201chacky\u201d implementation of a basic CSS feature.\n\nI can import my Button component into another component - this time, panel.jsx:\n/* panel.jsx */\nimport * as React from 'react';\nimport {properties, stylable} from 'wix-react-tools';\nimport {Button} from '../button';\nimport style from './panel.st.css';\n\nexport const Panel = stylable(style)(() => (\n    <div>\n        <Button className=\"cancelBtn\" />\n    </div>\n));\nIn panel.st.css: \n/* panel.st.css */\n:import {\n  -st-from: './button.st.css';\n  -st-default: Button;\n}\n\n/* cancelBtn is of type Button */\n.cancelBtn {\n  -st-extends: Button;\n  background: cornflowerblue;\n}\n\n/* targets the label of <Button className=\"cancelBtn\" /> */\n.cancelBtn::label {\n  color: honeydew;\n  font-weight: bold;\n}\nHere, we\u2019re reaching into the Button component from the Panel component. Buttons that are not inside a Panel won\u2019t be affected.\nWe do this by extending the CSS concept of pseudo-elements. As MDN says \u201cA CSS pseudo-element is a keyword added to a selector that lets you style a specific part of the selected element(s)\u201d. We don\u2019t use a descendant selector because the label isn\u2019t part of the Panel component, it\u2019s part of the Button component. \nThis syntax allows us three important features: \nPiercing the Shadow Boundary\nBecause, like a Matroshka doll of code, you can have components inside components inside components, you can chain pseudo-elements. In Stylable, Gallery::NavigationPanel::Button::Icon is a legitimate selector. We were worried by this (even though all Stylable CSS is transpiled to flat, valid CSS) because it\u2019s not allowed in CSS, albeit with the note \u201cA future version of this specification may allow multiple pseudo-elements per selector\u201d. So I asked the CSS Working Group and was told \u201cwe intend to only allow specific combinations\u201d, so we feel this extension to CSS is in the spirit of the language.\nWhile we\u2019re on the subject of those pesky Web Standards, note that the proposed ::part and ::theme pseudo-elements are meant to fulfil the same function. However, those are coming in two years (YouTube link) and, when they do, Stylable will support them.\nStructure-agnostic\nThe second totez-groovy\u2122 feature of Stylable\u2019s pseudo-element syntax is that you don\u2019t have to care about the internal structure of the component whose boundary you\u2019re piercing. Any element with a class attribute is exposed as a pseudo-element to any component that imports it. It acts as an interface on any component, whether written in-house or by a third party.\nCode completion\nWhen we started writing Stylable, our objective was to do for CSS what TypeScript does for JavaScript. Wikipedia says\n\nChallenges with dealing with complex JavaScript code led to demand for custom tooling to ease developing of components in the language. TypeScript developers sought a solution that would not break compatibility with the standard and its cross-platform support \u2026 [with]  static typing that enables static language analysis, which facilitates tooling and IDE support.\n\nSimilarly, because Stylable knows about components, their stylable parts and states, and how they inter-relate, we can develop language services like code completion and validation. That means we can see our errors at build time or even while working in our IDE. Wave goodbye to silent run-time breakage misery, with the Stylable Intelligence VS Code extension !\nAn action replay of Visual Studio Code offering code completion etc, filmed in super StyloVision.\nPseudo-classes for state\nStylable makes it easy to apply styles to custom states (as well as the usual :active, :checked, :visited etc) by extending the CSS pseudo-class syntax. \nWe do this by declaring the possible custom states on the component:\n/* Gallery.st.css */\n.root {\n  -st-states: toggled, loading;\n}\n\n.root:toggled {\n  color: red;\n}\n\n.root:loading {\n  color: green;\n}\n\n.root:loading:toggled {\n  color: blue;\n}\nThe -st-states \u201cproperty\u201d is actually a directive for the transpiler, so Stylable knows about possible pseudo-elements and can offer code completion etc. It looks like a vendor prefix by design, because it\u2019s therefore valid CSS syntax and IDEs won\u2019t flag it as an error, but is removed at build time. Remember, Stylable resolves to flat, valid, cross-browser CSS.\nAs with plain CSS, it can\u2019t set a state, but can only react to states set externally. In the case of custom pseudo-classes, your JavaScript logic is responsible for maintaining state \u2014 by default, by setting a data-* attribute.\nAnd there\u2019s more!\nHopefully, I\u2019ve shown you how Stylable extends CSS to allow you to style components and sub-components without worrying about that styles will leak, or knowing too much about internal structure. There isn\u2019t time to tell you about mixins (CSS macros in JavaScript), variables or our theming capabilities, because I have wine to wrap and presents to mull.\nWe made Stylable because we \u2665 CSS. But there\u2019s a practical reason, too. As James Kyle, a core team member of Yarn, Babel and TC39 (the JavaScript Standards Technical Committee), said of Styable \u201cpretty sure all the CSS-in-JS libraries just died for me\u201d,\nexplaining\n\nCSS could be perfectly static if given the right tools, that\u2019s exactly what stylable does. It gives you the tools you need in CSS so that you don\u2019t need to do a bunch of dynamic shit in JS.\nMaking it static is a huge performance win.\n\nWix is currently battle-testing Stylable in its back-office systems, before rolling it out to power Wix-hosted sites to make them more performant. There are 110 million Wix-hosted sites, so there will be a lot of Stylable on the web in a few months. And it\u2019s open-sourced so you, dear Reader, can try it out and use it too. There\u2019s a Stylable boilerplate based on create-react-app to get you started (more integrations are in the pipeline).\nHappy Hols \u2018n\u2019 Hugz from the Stylable team: Bruce, Arnon, Tom, Ido.\n\nRead more\n\nStylable documentation centre\nStylable on Twitter\nA nice picture of a hedgehog", "year": "2017", "author": "Bruce Lawson", "author_slug": "brucelawson", "published": "2017-12-09T00:00:00+00:00", "url": "https://24ways.org/2017/styling-components-typed-css-with-stylable/", "topic": "code"}
{"rowid": 314, "title": "Easy Ajax with Prototype", "contents": "There\u2019s little more impressive on the web today than a appropriate touch of Ajax. Used well, Ajax brings a web interface much closer to the experience of a desktop app, and can turn a bear of an task into a pleasurable activity.\n\nBut it\u2019s really hard, right? It involves all the nasty JavaScript that no one ever does often enough to get really good at, and the browser support is patchy, and urgh it\u2019s just so much damn effort. Well, the good news is that \u2013 ta-da \u2013 it doesn\u2019t have to be a headache. But man does it still look impressive. Here\u2019s how to amaze your friends.\n\nIntroducing prototype.js\n\nPrototype is a JavaScript framework by Sam Stephenson designed to help make developing dynamic web apps a whole lot easier. In basic terms, it\u2019s a JavaScript file which you link into your page that then enables you to do cool stuff.\n\nThere\u2019s loads of capability built in, a portion of which covers our beloved Ajax. The whole thing is freely distributable under an MIT-style license, so it\u2019s good to go. What a nice man that Mr Stephenson is \u2013 friends, let us raise a hearty cup of mulled wine to his good name. Cheers! sluurrrrp.\n\nFirst step is to download the latest Prototype and put it somewhere safe. I suggest underneath the Christmas tree.\n\nCutting to the chase\n\nBefore I go on and set up an example of how to use this, let\u2019s just get to the crux. Here\u2019s how Prototype enables you to make a simple Ajax call and dump the results back to the page:\n\nvar url = 'myscript.php';\nvar pars = 'foo=bar';\nvar target = 'output-div';\t\nvar myAjax = new Ajax.Updater(target, url, {method: 'get', parameters: pars});\n\nThis snippet of JavaScript does a GET to myscript.php, with the parameter foo=bar, and when a result is returned, it places it inside the element with the ID output-div on your page.\n\nKnocking up a basic example\n\nSo to get this show on the road, there are three files we need to set up in our site alongside prototype.js. Obviously we need a basic HTML page with prototype.js linked in. This is the page the user interacts with. Secondly, we need our own JavaScript file for the glue between the interface and the stuff Prototype is doing. Lastly, we need the page (a PHP script in my case) that the Ajax is going to make its call too.\n\nSo, to that basic HTML page for the user to interact with. Here\u2019s one I found whilst out carol singing:\n\n<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n    \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n<html xmlns=\"http://www.w3.org/1999/xhtml\" xml:lang=\"en\" lang=\"en\">\n<head>\n    <meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\"/>\n    <title>Easy Ajax</title>\n    <script type=\"text/javascript\" src=\"prototype.js\"></script>\n    <script type=\"text/javascript\" src=\"ajax.js\"></script>\n</head> \n<body>\n    <form method=\"get\" action=\"greeting.php\" id=\"greeting-form\">\n        <div>\n            <label for=\"greeting-name\">Enter your name:</label>\n            <input id=\"greeting-name\" type=\"text\" />\n            <input id=\"greeting-submit\" type=\"submit\" value=\"Greet me!\" />\n        </div>\n        <div id=\"greeting\"></div>\n    </form>\n</body>\n</html>\n\nAs you can see, I\u2019ve linked in prototype.js, and also a file called ajax.js, which is where we\u2019ll be putting our glue. (Careful where you leave your glue, kids.)\n\nOur basic example is just going to take a name and then echo it back in the form of a seasonal greeting. There\u2019s a form with an input field for a name, and crucially a DIV (greeting) for the result of our call. You\u2019ll also notice that the form has a submit button \u2013 this is so that it can function as a regular form when no JavaScript is available. It\u2019s important not to get carried away and forget the basics of accessibility.\n\nMeanwhile, back at the server\n\nSo we need a script at the server which is going to take input from the Ajax call and return some output. This is normally where you\u2019d hook into a database and do whatever transaction you need to before returning a result. To keep this as simple as possible, all this example here will do is take the name the user has given and add it to a greeting message. Not exactly Web 2-point-HoHoHo, but there you have it.\n\nHere\u2019s a quick PHP script \u2013 greeting.php \u2013 that Santa brought me early.\n\n<?php\n     $the_name = htmlspecialchars($_GET['greeting-name']);\n     echo \"<p>Season's Greetings, $the_name!</p>\";\n?>\n\nYou\u2019ll perhaps want to do something a little more complex within your own projects. Just sayin\u2019.\n\nGluing it all together\n\nInside our ajax.js file, we need to hook this all together. We\u2019re going to take advantage of some of the handy listener routines and such that Prototype also makes available. The first task is to attach a listener to set the scene once the window has loaded. He\u2019s how we attach an onload event to the window object and get it to call a function named init():\n\nEvent.observe(window, 'load', init, false);\n\nNow we create our init() function to do our evil bidding. Its first job of the day is to hide the submit button for those with JavaScript enabled. After that, it attaches a listener to watch for the user typing in the name field.\n\nfunction init(){\n     $('greeting-submit').style.display = 'none';\n     Event.observe('greeting-name', 'keyup', greet, false);\n}\n\nAs you can see, this is going to make a call to a function called greet() onkeyup in the greeting-name field. That function looks like this:\n\nfunction greet(){\n     var url = 'greeting.php';\n     var pars = 'greeting-name='+escape($F('greeting-name'));\n     var target = 'greeting';\n     var myAjax = new Ajax.Updater(target, url, {method: 'get', parameters: pars});\n}\n\nThe key points to note here are that any user input needs to be escaped before putting into the parameters so that it\u2019s URL-ready. The target is the ID of the element on the page (a DIV in our case) which will be the recipient of the output from the Ajax call.\n\nThat\u2019s it\n\nNo, seriously. That\u2019s everything. Try the example. Amaze your friends with your 1337 Ajax sk1llz.", "year": "2005", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2005-12-01T00:00:00+00:00", "url": "https://24ways.org/2005/easy-ajax-with-prototype/", "topic": "code"}
{"rowid": 295, "title": "Internet of Stranger Things", "contents": "This year I\u2019ve been running a workshop about using JavaScript and Node.js to work with all different kinds of electronics on the Raspberry Pi. So especially for 24 ways I\u2019m going to show you how I made a very special Raspberry Pi based internet connected project! And nothing says Christmas quite like a set of fairy lights connected to another dimension1.\nWhat you\u2019ll see\nYou can rig up the fairy lights in your home, with the scrawly letters written under each one. The people from the other side (i.e. the internet) will be able to write messages to you from their browser in real time. In fact why not try it now; check this web page. When you click the lights in your browser, my lights (and yours) will turn on and off in real life! (There may be a queue if there are lots of people accessing it, hit the \u201cSend a message\u201d button and wait your turn.)\n\n\n\n\nIt\u2019s all done with JavaScript, using Node.js running on both the Raspberry Pi and on the server. I\u2019m using WebSockets to communicate in real time between the browser, server and Raspberry Pi.\nWhat you\u2019ll need\n\nRaspberry Pi any of the following models: Zero (will need straight male header pins soldered2 and Micro USB OTG adaptor), A+, B+, 2, or 3\nMicro SD card at least 4Gb Class 10 speed3\nMicro USB power supply at least 2A\nUSB Wifi dongle (unless you have a Pi 3 - that has wifi built in). \nAddressable fairy lights\nLogic level shifter (with pins soldered unless you want to do it!)\nBreadboard\nJumper wires (3x male to male and 4x female to male)\n\nOptional but recommended\n\nBase board to hold the Pi and Breadboard (often comes with a breadboard!)\n\nFind links for where to buy all of these items that goes along with this tutorial. The total price should be around $1004.\nSetting up the Raspberry Pi\nYou\u2019ll need to install the SD card for the Raspberry Pi. You\u2019ll find a link to download a disk image on the support document, ready-made with the Raspbian version of Linux, along with Node.js and all the files you need. Download it and write it to the SD card using the fantastic free software Etcher5. \nNext up you have to configure the wifi details on the SD card. If you plug the card into your computer you should see a drive called BOOT. There\u2019s a text file on there called wpa_supplicant.conf. Open it up in your favourite text editor and replace mywifi and mypassword with your wifi details6.\nnetwork={\n   ssid=\"mywifi\"\n   psk=\"mypassword\"\n}\nSave the file, eject the card from your computer and plug it into the Raspberry Pi. \nIf you have a base board or holder for the Raspberry Pi, attach it now. Then connect the wifi USB dongle7 and power supply, but don\u2019t plug it in yet!\nWiring!\nTime to wire everything up! \nFirst of all, push the Logic Level Converter into the middle of the breadboard:\n\nLogic Level Converter\nThe logic level converter may be labelled differently from the one in the diagram but the pins are usually exactly the same internally. I would just make sure the pins marked HV (High Voltage) are on the bottom and LV (Low Voltage) are on the top. \n\nRaspberry Pi pins only output 3.3v but the lights need 5v. That\u2019s why we need the logic level converter in there to boost up the signal.\nConnect the first two wires between the Raspberry Pi pins and the breadboard:\n\nNote that the pins on the Raspberry Pi are male, so you need a female to male jumper wire to connect between them and the breadboard. The colours don\u2019t have to match but it\u2019s easier to follow (and check) if you use the same ones as in the diagram. \n\nThen the next two:\n\nThis is what you should have so far:\n\nLights\nNow to connect the lights! My ones have a connector with three holes in it that I can push jumper wires into, and hopefully yours will too! So I used the male-to-male jumper wires to connect them to the breadboard.\n\n\n\nMake sure that you connect the right end of the lights, mine has a male connector at the wrong end so it\u2019s impossible to do this, but double check.  \nAlso make sure that the holes in the light connector are the same as mine. To do this, follow the wires from the connector to the first light and look at the circuit board inside. You should just about be able to make out the connections labelled + (sometimes 5V, V+ or VCC), GND (or \u2018-\u2019 or G) and DI (sometimes DIN for data in).\n\nYou can just about make out the +, DI and GND on this picture. Note that on the other side of the board there is a DO for data out - that\u2019s what takes the data along to the chip in the next light. Make sure that you\u2019re plugging into the data-in and not the data-out! \nThat\u2019s it! Everything\u2019s plugged in and ready to go! But before you plug power into your Pi, double check all your wires and make sure they\u2019re exactly right! You could damage your Raspberry Pi if it is not wired correctly. So triple check!\n\nThe Moment of Truth!\nPlug in the Raspberry Pi and wait around a minute or two for it to boot up. If all is well, the lights should strobe rainbow colours for one second - that\u2019s your confirmation that it\u2019s connected to my WebSocket server and ready to receive messages from the upside-down! \n\nHowever, if the first light in the string is pulsing red, it means that you\u2019re not connected to the internet. So check the Troubleshooting section of the support document. If it\u2019s pulsing green then you\u2019re connected to the internet but can\u2019t connect to my server. It must have gone down. Sorry! The code will keep trying so leave it running and maybe it\u2019ll come back up.  \nRig up the lights!\nFix the lights up on the wall however you want, pins, nails, tape. I\u2019ve used cable clips. Just be careful! I\u2019m using a 50 light string so I\u2019ve programmed it to use the lights at the end for the letters. That way I have just under half the string to extend down to the floor where I can keep the Raspberry Pi. \nCheck the photo here to see how the lights line up, note that there are spare unused lights in-between each row:\n\nNow visit lights.seb.ly and you\u2019ll see this : \n\nIf you\u2019re the only one online you\u2019ll have direct connection to the lights and any letter you click on will light up both in the browser and in real life. If there are other people there, you\u2019ll need to click the button to join the queue and wait your turn. \nHow it works - the geeky details!\nElectronics:\nThe pins on the Raspberry Pi are known as GPIO pins, general-purpose input/output. You can connect a wide variety of electronic components to them, LED lights, buttons, switches, and sensors. You can turn the power to the pins on and off using Node.js (or Python, if you prefer). \nAddressable LEDs or \u201cNeopixels\u201d\nWe\u2019re only using one GPIO pin on the Raspberry Pi (the other connections are 5V, 3.3V and ground) and that single pin is controlling all of the lights in the string. The code turns the pin on and off really fast in strictly timed morse-code-like dots and dashes to transmit binary data. The chips attached to each LED decode the binary and adjust the output to the LED accordingly. That chip then sends the data on to the next light in the string. \nThe chips on each light are the WS2811, part of the WS281x family that come in a multitude of different form factors and are often packaged with tiny LEDs in a single component. They are commonly referred to as Neopixels8 and I used them on my Laser Light Synths project.\nNeopixels with the chip and the LED all in one - it\u2019s the white square shaped component and the darker square inside is the chip. These are only 5mm wide!\nA Laser Light Synth! Covered with around 800 super bright neopixels!\nLogic Level Converter\nThe logic level converter is a really cheap and easy way to change the level from 3.3v to 5v and back again. You must be careful that you do not connect 5v into a GPIO pin or you will most likely damage the Raspberry Pi processor chip. \nPower\nNeopixels can often draw a lot of current so you need to be careful how you power them. I\u2019ve measured the current draw from the string to be less than 800mA so you should be fine wired directly to the 5V output. But if you use more lights or have them all on really bright at once, you\u2019ll need to use a separate 5V power supply. If you want to learn more, check out Adafruit\u2019s Neopixel Uberguide. \nNode.js\nThere are two Node.js apps running here, one on the Raspberry Pi and one on my server. You can see the code on my GitHub at github.com/sebleedelisle/stranger-lights for the Raspberry Pi and github.com/sebleedelisle/stranger-lights-server for the server.  And they\u2019re hosted on npm as stranger-lights and stranger-lights-server.  \nThe server side code sets up a standard web server to deliver the HTML for the web interface. It also sets up a WebSocket server that allows for real-time communication between the browser and the server. This server code also manages the queue and who is in control of the lights at any given time.\nWebSockets\nI\u2019m using the excellent Socket.io library to manage the WebSocket connection. Both the browser and the Raspberry Pi Node.js app connects to my WebSocket server. \nWhen you click on a letter in the browser, a message is sent to the server, which forwards it to the connected Raspberry Pi clients and also all the web browsers9. \nThe Raspberry Pi code\nThe Node.js app runs automatically on startup, and I made this happen by adding this to the /etc/rc.local file: \nnode /home/pi/strangerthings/client.js > /dev/null &\nAnything in the rc.local file gets executed when the Pi boots up and this line of code runs the Node.js app and routes its output to nowhere (ie /dev/null). The & means that it runs it in the background and doesn\u2019t hold up the boot process. \nWorking with the Raspberry Pi headless\nYou might know that when a computer has no screen or keyboard, you would refer to it as \u201crunning headless\u201d. So just like most web servers, you need to configure it over the network with ssh10. If you\u2019re on a mac you can find your Pi on the network through the name raspberrypi.local11, otherwise you\u2019ll need to find its IP address. There\u2019s more on the guide to Remote Access instructions on the Raspberry Pi website. And if you\u2019re very new to the terminal, I highly recommend this great online Linux command line tutorial.\nImprovements\nThis is quite an early experiment and I\u2019m sure I\u2019ll discover lots of optimisations over the next few weeks, especially if the server gets a proper hammering today! But there are a few things you can do. Obviously I\u2019ve just rigged up my lights with Post-it notes. It\u2019d be a lot nicer to get a paint brush and try to recreate the Winona-in-a-manic-state text style. \nWhere next?\nFinding quality resources about Node.js for electronics on the Pi can be somewhat hit and miss, but this is getting better all the time. Alternatively I am thinking about running some online courses, please let me know if that\u2019s something you\u2019d be interested in, or sign up to my mailing list at st4i.com. \nThere are many many more resources for the Raspberry Pi with Python (gpiozero is a good place to start), so if that language works for you, you\u2019ll be spoilt for choice! \nAlso take a look at Arduino - it\u2019s an incredibly popular platform for electronics and the internet is literally bursting with resources. \nI hope you enjoyed this little foray into the world of JavaScript electronics on the Raspberry Pi! If you get this working at home please let me know! Tweet me at @seb_ly. \n\n\n\n\nNot a particularly original idea, but I don\u2019t think I\u2019ve seen anyone do it quite like this before, ie using WebSockets, and Node.js on a Raspberry Pi. Other examples: Internet of Stranger Things, Strangerlights.com, and loads of examples on Instructables\u00a0\u21a9\ufe0e\n\n\nVideo guide to soldering pins on to a Pi Zero and further soldering advice from Adafruit\u00a0\u21a9\ufe0e\n\n\nSlower cards will work but performance may suffer\u00a0\u21a9\ufe0e\n\n\nOr \u00a35,000 in UK money. Sorry, Brexit joke :)\u00a0\u21a9\ufe0e\n\n\nYou will need a card reader on your computer - most micro SD cards come with an adaptor that fits standard SD slots. \u00a0\u21a9\ufe0e\n\n\nSSID and password should be all that you need but you can see all the config options on this wpa supplicant guide\u00a0\u21a9\ufe0e\n\n\nRaspberry Pi Zero will require the OTG to USB adaptor to attach the wifi dongle\u00a0\u21a9\ufe0e\n\n\nThanks to Adafruit who invented the term neopixels so we don\u2019t have to refer to them as WS281x any more!\u00a0\u21a9\ufe0e\n\n\nSo you can see other people sending messages in the browser\u00a0\u21a9\ufe0e\n\n\nssh is short for Secure Shell and is a way to connect to a remote computer and type in it just like you would in the terminal.\u00a0\u21a9\ufe0e\n\n\nYou can change this default hostname using raspi-config\u00a0\u21a9\ufe0e", "year": "2016", "author": "Seb Lee-Delisle", "author_slug": "sebleedelisle", "published": "2016-12-01T00:00:00+00:00", "url": "https://24ways.org/2016/internet-of-stranger-things/", "topic": "code"}
{"rowid": 52, "title": "Git Rebasing: An Elfin Workshop Workflow", "contents": "This year Santa\u2019s helpers have been tasked with making a garland. It\u2019s a pretty simple task: string beads onto yarn in a specific order. When the garland reaches a specific length, add it to the main workshop garland. Each elf has a specific sequence they\u2019re supposed to chain, which is given to them via a work order. (This is starting to sound like one of those horrible calculus problems. I promise it isn\u2019t. It\u2019s worse; it\u2019s about Git.)\nFor the most part, the system works really well. The elves are able to quickly build up a shared chain because each elf specialises on their own bit of garland, and then links the garland together. Because of this they\u2019re able to work independently, but towards the common goal of making a beautiful garland.\nAt first the elves are really careful with each bead they put onto the garland. They check with one another before merging their work, and review each new link carefully. As time crunches on, the elves pour a little more cheer into the eggnog cooler, and the quality of work starts to degrade. Tensions rise as mistakes are made and unkind words are said. The elves quickly realise they\u2019re going to need a system to change the beads out when mistakes are made in the chain.\nThe first common mistake is not looking to see what the latest chain is that\u2019s been added to the main garland. The garland is huge, and it sits on a roll in one of the corners of the workshop. It\u2019s a big workshop, so it is incredibly impractical to walk all the way to the roll to check what the last link is on the chain. The elves, being magical, have set up a monitoring system that allows them to keep a local copy of the main garland at their workstation. It\u2019s an imperfect system though, so the elves have to request a manual refresh to see the latest copy. They can request a new copy by running the command\ngit pull --rebase=preserve\n(They found that if they ran git pull on its own, they ended up with weird loops of extra beads off the main garland, so they\u2019ve opted to use this method.) This keeps the shared garland up to date, which makes things a lot easier. A visualisation of the rebase process is available.\nThe next thing the elves noticed is that if they worked on the main workshop garland, they were always running into problems when they tried to share their work back with the rest of the workshop. It was fine if they were working late at night by themselves, but in the middle of the day, it was horrible. (I\u2019ve been asked not to talk about that time the fight broke out.) Instead of trying to share everything on their local copy of the main garland, the elves have realised it\u2019s a lot easier to work on a new string and then knot this onto the main garland when their pattern repeat is finished. They generate a new string by issuing the following commands:\ngit checkout master\ngit checkout -b 1234_pattern-name\n1234 represents the work order number and pattern-name describes the pattern they\u2019re adding. Each bead is then added to the new link (git add bead.txt) and locked into place (git commit). Each elf repeats this process until the sequence of beads described in the work order has been added to their mini garland.\nTo combine their work with the main garland, the elves need to make a few decisions. If they\u2019re making a single strand, they issue the following commands:\ngit checkout master\ngit merge --ff-only 1234_pattern-name\nTo share their work they publish the new version of the main garland to the workshop spool with the command git push origin master.\nSometimes this fails. Sharing work fails because the workshop spool has gotten new links added since the elf last updated their copy of the main workshop spool. This makes the elves both happy and sad. It makes them happy because it means the other elves have been working too, but it makes them sad because they now need to do a bit of extra work to close their work order. \nTo update the local copy of the workshop spool, the elf first unlinks the chain they just linked by running the command:\ngit reset --merge ORIG_HEAD\nThis works because the garland magic notices when the elves are doing a particularly dangerous thing and places a temporary, invisible bookmark to the last safe bead in the chain before the dangerous thing happened. The garland no longer has the elf\u2019s work, and can be updated safely. The elf runs the command git pull --rebase=preserve and the changes all the other elves have made are applied locally.\nWith these new beads in place, the elf now has to restring their own chain so that it starts at the right place. To do this, the elf turns back to their own chain (git checkout 1234_pattern-name) and runs the command git rebase master. Assuming their bead pattern is completely unique, the process will run and the elf\u2019s beads will be restrung on the tip of the main workshop garland.\nSometimes the magic fails and the elf has to deal with merge conflicts. These are kind of annoying, so the elf uses a special inspector tool to figure things out. The elf opens the inspector by running the command git mergetool to work through places where their beads have been added at the same points as another elf\u2019s beads. Once all the conflicts are resolved, the elf saves their work, and quits the inspector. They might need to do this a few times if there are a lot of new beads, so the elf has learned to follow this update process regularly instead of just waiting until they\u2019re ready to close out their work order.\nOnce their link is up to date, the elf can now reapply their chain as before, publish their work to the main workshop garland, and close their work order:\ngit checkout master\ngit merge --ff-only 1234_pattern-name\ngit push origin master\nGenerally this process works well for the elves. Sometimes, though, when they\u2019re tired or bored or a little drunk on festive cheer, they realise there\u2019s a mistake in their chain of beads. Fortunately they can fix the beads without anyone else knowing. These tools can be applied to the whole workshop chain as well, but it causes problems because the magic assumes that elves are only ever adding to the main chain, not removing or reordering beads on the fly. Depending on where the mistake is, the elf has a few different options.\nLet\u2019s pretend the elf has a sequence of five beads she\u2019s been working on. The work order says the pattern should be red-blue-red-blue-red.\n\nIf the sequence of beads is wrong (for example, blue-blue-red-red-red), the elf can remove the beads from the chain, but keep the beads in her workstation using the command git reset --soft HEAD~5.\n\nIf she\u2019s been using the wrong colours and the wrong pattern (for example, green-green-yellow-yellow-green), she can remove the beads from her chain and discard them from her workstation using the command git reset --hard HEAD~5.\n\nIf one of the beads is missing (for example, red-blue-blue-red), she can restring the beads using the first method, or she can use a bit of magic to add the missing bead into the sequence.\n\nUsing a tool that\u2019s a bit like orthoscopic surgery, she first selects a sequence of beads which contains the problem. A visualisation of this process is available.\nStart the garland surgery process with the command:\ngit rebase --interactive HEAD~4\nA new screen comes up with the following information (the oldest bead is on top):\npick c2e4877 Red bead\npick 9b5555e Blue bead\npick 7afd66b Blue bead\npick e1f2537 Red bead\nThe elf adjusts the list, changing \u201cpick\u201d to \u201cedit\u201d next to the first blue bead:\npick c2e4877 Red bead\nedit 9b5555e Blue bead\npick 7afd66b Blue bead\npick e1f2537 Red bead\nShe then saves her work and quits the editor. The garland magic has placed her back in time at the moment just after she added the first blue bead.\n\nShe needs to manually fix up her garland to add the new red bead. If the beads were files, she might run commands like vim beads.txt and edit the file to make the necessary changes.\nOnce she\u2019s finished her changes, she needs to add her new bead to the garland (git add --all) and lock it into place (git commit). This time she assigns the commit message \u201cRed bead \u2013 added\u201d so she can easily find it.\n\nThe garland magic has replaced the bead, but she still needs to verify the remaining beads on the garland. This is a mostly automatic process which is started by running the command git rebase --continue.\nThe new red bead has been assigned a position formerly held by the blue bead, and so the elf must deal with a merge conflict. She opens up a new program to help resolve the conflict by running git mergetool.\n\nShe knows she wants both of these beads in place, so the elf edits the file to include both the red and blue beads.\n\nWith the conflict resolved, the elf saves her changes and quits the mergetool.\nBack at the command line, the elf checks the status of her work using the command git status.\nrebase in progress; onto 4a9cb9d\nYou are currently rebasing branch '2_RBRBR' on '4a9cb9d'.\n  (all conflicts fixed: run \"git rebase --continue\")\n\nChanges to be committed:\n  (use \"git reset HEAD <file>...\" to unstage)\n\n    modified:   beads.txt\n\nUntracked files:\n  (use \"git add <file>...\" to include in what will be committed)\n\n    beads.txt.orig\nShe removes the file added by the mergetool with the command rm beads.txt.orig and commits the edits she just made to the bead file using the commands:\ngit add beads.txt\ngit commit --message \"Blue bead -- resolved conflict\"\n\nWith the conflict resolved, the elf is able to continue with the rebasing process using the command git rebase --continue. There is one final conflict the elf needs to resolve. Once again, she opens up the visualisation tool and takes a look at the two conflicting files.\n\nShe incorporates the changes from the left and right column to ensure her bead sequence is correct.\n\nOnce the merge conflict is resolved, the elf saves the file and quits the mergetool. Once again, she cleans out the backup file added by the mergetool (rm beads.txt.orig) and commits her changes to the garland:\ngit add beads.txt\ngit commit --message \"Red bead -- resolved conflict\"\nand then runs the final verification steps in the rebase process (git rebase --continue).\n\nThe verification process runs through to the end, and the elf checks her work using the command git log --oneline.\n9269914 Red bead -- resolved conflict\n4916353 Blue bead -- resolved conflict\naef0d5c Red bead -- added\n9b5555e Blue bead\nc2e4877 Red bead\nShe knows she needs to read the sequence from bottom to top (the oldest bead is on the bottom). Reviewing the list she sees that the sequence is now correct.\nSometimes, late at night, the elf makes new copies of the workshop garland so she can play around with the bead sequencer just to see what happens. It\u2019s made her more confident at restringing beads when she\u2019s found real mistakes. And she doesn\u2019t mind helping her fellow elves when they run into trouble with their beads. The sugar cookies they leave her as thanks don\u2019t hurt either. If you would also like to play with the bead sequencer, you can get a copy of the branches the elf worked.\n\nOur lessons from the workshop:\n\nBy using rebase to update your branches, you avoid merge commits and keep a clean commit history.\nIf you make a mistake on one of your local branches, you can use reset to take commits off your branch. If you want to save the work, but uncommit it, add the parameter --soft. If you want to completely discard the work, use the parameter, --hard.\nIf you have merged working branch changes to the local copy of your master branch and it is preventing you from pushing your work to a remote repository, remove these changes using the command reset with the parameter --merge ORIG_HEAD before updating your local copy of the remote master branch.\nIf you want to make a change to work that was committed a little while ago, you can use the command rebase with the parameter --interactive. You will need to include how many commits back in time you want to review.", "year": "2015", "author": "Emma Jane Westby", "author_slug": "emmajanewestby", "published": "2015-12-07T00:00:00+00:00", "url": "https://24ways.org/2015/git-rebasing/", "topic": "code"}
{"rowid": 68, "title": "Grid, Flexbox, Box Alignment: Our New System for Layout", "contents": "Three years ago for 24 ways 2012, I wrote an article about a new CSS layout method I was excited about. A specification had emerged, developed by people from the Internet Explorer team, bringing us a proper grid system for the web. In 2015, that Internet Explorer implementation is still the only public implementation of CSS grid layout. However, in 2016 we should be seeing it in a new improved form ready for our use in browsers.\nGrid layout has developed hidden behind a flag in Blink, and in nightly builds of WebKit and, latterly, Firefox. By being developed in this way, breaking changes could be safely made to the specification as no one was relying on the experimental implementations in production work.\nAnother new layout method has emerged over the past few years in a more public and perhaps more painful way. Shipped prefixed in browsers, The flexible box layout module (flexbox) was far too tempting for developers not to use on production sites. Therefore, as changes were made to the specification, we found ourselves with three different flexboxes, and browser implementations that did not match one another in completeness or in the version of specified features they supported. \nOwing to the different ways these modules have come into being, when I present on grid layout it is often the very first time someone has heard of the specification. A question I keep being asked is whether CSS grid layout and flexbox are competing layout systems, as though it might be possible to back the loser in a CSS layout competition. The reality, however, is that these two methods will sit together as one system for doing layout on the web, each method playing to certain strengths and serving particular layout tasks. \nIf there is to be a loser in the battle of the layouts, my hope is that it will be the layout frameworks that tie our design to our markup. They have been a necessary placeholder while we waited for a true web layout system, but I believe that in a few years time we\u2019ll be easily able to date a website to circa 2015 by seeing <div class=\"row\"> or <div class=\"col-md-3\"> in the markup.\nIn this article, I\u2019m going to take a look at the common features of our new layout systems, along with a couple of examples which serve to highlight the differences between them.\nTo see the grid layout examples you will need to enable grid in your browser. The easiest thing to do is to enable the experimental web platform features flag in Chrome. Details of current browser support can be found here. \nRelationship\nItems only become flex or grid items if they are a direct child of the element that has display:flex, display:grid or display:inline-grid applied. Those direct children then understand themselves in the context of the complete layout. This makes many things possible. It\u2019s the lack of relationship between elements that makes our existing layout methods difficult to use. If we float two columns, left and right, we have no way to tell the shorter column to extend to the height of the taller one. We have expended a lot of effort trying to figure out the best way to make full-height columns work, using techniques that were never really designed for page layout.\nAt a very simple level, the relationship between elements means that we can easily achieve full-height columns. In flexbox:\nSee the Pen Flexbox equal height columns by rachelandrew (@rachelandrew) on CodePen.\n\nAnd in grid layout (requires a CSS grid-supporting browser):\nSee the Pen Grid equal height columns by rachelandrew (@rachelandrew) on CodePen.\n\nAlignment\nFull-height columns rely on our flex and grid items understanding themselves as part of an overall layout. They also draw on a third new specification: the box alignment module. If vertical centring is a gift you\u2019d like to have under your tree this Christmas, then this is the box you\u2019ll want to unwrap first.\nThe box alignment module takes the alignment and space distribution properties from flexbox and applies them to other layout methods. That includes grid layout, but also other layout methods. Once implemented in browsers, this specification will give us true vertical centring of all the things.\nOur examples above achieved full-height columns because the default value of align-items is stretch. The value ensured our columns stretched to the height of the tallest. If we want to use our new vertical centring abilities on all items, we would set align-items:center on the container. To align one flex or grid item, apply the align-self property.\nThe examples below demonstrate these alignment properties in both grid layout and flexbox. The portrait image of Widget the cat is aligned with the default stretch. The other three images are aligned using different values of align-self.\nTake a look at an example in flexbox:\nSee the Pen Flexbox alignment by rachelandrew (@rachelandrew) on CodePen.\n\nAnd also in grid layout (requires a CSS grid-supporting browser):\nSee the Pen Grid alignment by rachelandrew (@rachelandrew) on CodePen.\n\nThe alignment properties used with CSS grid layout.\nFluid grids\nA cornerstone of responsive design is the concept of fluid grids.\n\n\u201c[\u2026]every aspect of the grid\u2014and the elements laid upon it\u2014can be expressed as a proportion relative to its container.\u201d\n\u2014Ethan Marcotte, \u201cFluid Grids\u201d\n\nThe method outlined by Marcotte is to divide the target width by the context, then use that value as a percentage value for the width property on our element.\nh1 {\n  margin-left: 14.575%; /*\u00a0144px / 988px = 0.14575\u00a0*/\n  width: 70.85%; /*\u00a0700px / 988px = 0.7085\u00a0*/\n}\nIn more recent years, we\u2019ve been able to use calc() to simplify this (at least, for those of us able to drop support for Internet Explorer 8). However, flexbox and grid layout make fluid grids simple.\nThe most basic of flexbox demos shows this fluidity in action. The justify-content property \u2013 another property defined in the box alignment module \u2013 can be used to create an equal amount of space between or around items. As the available width increases, more space is assigned in proportion.\nIn this demo, the list items are flex items due to display:flex being added to the ul. I have given them a maximum width of 250 pixels. Any remaining space is distributed equally between the items as the justify-content property has a value of space-between.\nSee the Pen Flexbox: justify-content by rachelandrew (@rachelandrew) on CodePen.\n\nFor true fluid grid-like behaviour, your new flexible friends are flex-grow and flex-shrink. These properties give us the ability to assign space in proportion.\nThe flexbox flex property is a shorthand for:\n\nflex-grow\nflex-shrink\nflex-basis\n\nThe flex-basis property sets the default width for an item. If flex-grow is set to 0, then the item will not grow larger than the flex-basis value; if flex-shrink is 0, the item will not shrink smaller than the flex-basis value.\n\nflex: 1 1 200px: a flexible box that can grow and shrink from a 200px basis.\nflex: 0 0 200px: a box that will be 200px and cannot grow or shrink.\nflex: 1 0 200px: a box that can grow bigger than 200px, but not shrink smaller.\n\nIn this example, I have a set of boxes that can all grow and shrink equally from a 100 pixel basis.\nSee the Pen Flexbox: flex-grow by rachelandrew (@rachelandrew) on CodePen.\n\nWhat I would like to happen is for the first element, containing a portrait image, to take up less width than the landscape images, thus keeping it more in proportion. I can do this by changing the flex-grow value. By giving all the items a value of 1, they all gain an equal amount of the available space after the 100 pixel basis has been worked out.\nIf I give them all a value of 3 and the first box a value of 1, the other boxes will be assigned three parts of the available space while box 1 is assigned only one part. You can see what happens in this demo:\nSee the Pen Flexbox: flex-grow by rachelandrew (@rachelandrew) on CodePen.\n\nOnce you understand flex-grow, you should easily be able to grasp how the new fraction unit (fr, defined in the CSS grid layout specification) works. Like flex-grow, this unit allows us to assign available space in proportion. In this case, we assign the space when defining our track sizes.\nIn this demo (which requires a CSS grid-supporting browser), I create a four-column grid using the fraction unit to define my track sizes. The first track is 1fr in width, and the others 2fr.\ngrid-template-columns: 1fr 2fr 2fr 2fr;\nSee the Pen Grid fraction units by rachelandrew (@rachelandrew) on CodePen.\n\nThe four-track grid.\nSeparation of concerns\nMy younger self petitioned my peers to stop using tables for layout and to move to CSS. One of the rallying cries of that movement was the concept of separating our source and content from how they were displayed. It was something of a failed promise given the tools we had available: the display leaked into the markup with the need for redundant elements to cope with browser bugs, or visual techniques that just could not be achieved without supporting markup.\nBrowsers have improved, but even now we can find ourselves compromising the ideal document structure so we can get the layout we want at various breakpoints. In some ways, the situation has returned to tables-for-layout days. Many of the current grid frameworks rely on describing our layout directly in the markup. We add divs for rows, and classes to describe the number of desired columns. We nest these constructions of divs inside one another.\nHere is a snippet from the Bootstrap grid examples \u2013 two columns with two nested columns:\n<div class=\"row\">\n  <div class=\"col-md-8\">\n    .col-md-8\n    <div class=\"row\">\n      <div class=\"col-md-6\">\n        .col-md-6\n      </div>\n      <div class=\"col-md-6\">\n        .col-md-6\n      </div>\n    </div>\n  </div>\n  <div class=\"col-md-4\">\n    .col-md-4\n  </div>\n</div>\nNot a million miles away from something I might have written in 1999.\n<table>\n  <tr>\n    <td class=\"col-md-8\">\n      .col-md-8\n      <table>\n        <tr>\n          <td class=\"col-md-6\">\n            .col-md-6\n          </td>\n          <td class=\"col-md-6\">\n            .col-md-6\n          </td>\n        </tr>\n      </table>\n    </td>\n    <td class=\"col-md-4\">\n      .col-md-4\n    </td>\n  </tr>\n</table>\nGrid and flexbox layouts do not need to be described in markup. The layout description happens entirely in the CSS, meaning that elements can be moved around from within the presentation layer.\nFlexbox gives us the ability to reverse the flow of elements, but also to set the order of elements with the order property. This is demonstrated here, where Widget the cat is in position 1 in the source, but I have used the order property to display him after the things that are currently unimpressive to him.\nSee the Pen Flexbox: order by rachelandrew (@rachelandrew) on CodePen.\n\nGrid layout takes this a step further. Where flexbox lets us set the order of items in a single dimension, grid layout gives us the ability to position things in two dimensions: both rows and columns. Defined in the CSS, this positioning can be changed at any breakpoint without needing additional markup. Compare the source order with the display order in this example (requires a CSS grid-supporting browser):\nSee the Pen Grid positioning in two dimensions by rachelandrew (@rachelandrew) on CodePen.\n\nLaying out our items in two dimensions using grid layout.\nAs these demos show, a straightforward way to decide if you should use grid layout or flexbox is whether you want to position items in one dimension or two. If two, you want grid layout.\nA note on accessibility and reordering\nThe issues arising from this powerful ability to change the way items are ordered visually from how they appear in the source have been the subject of much discussion. The current flexbox editor\u2019s draft states\n\n\u201cAuthors must use order only for visual, not logical, reordering of content. Style sheets that use order to perform logical reordering are non-conforming.\u201d\n\u2014CSS Flexible Box Layout Module Level 1, Editor\u2019s Draft (3 December 2015)\n\nThis is to ensure that non-visual user agents (a screen reader, for example) can rely on the document source order as being correct. Take care when reordering that you do so from the basis of a sound document that makes sense in terms of source order. Avoid using visual order to convey meaning.\nAutomatic content placement with rules\nHaving control over the order of items, or placing items on a predefined grid, is nice. However, we can often do that already with one method or another and we have frameworks and tools to help us. Tools such as Susy mean we can even get away from stuffing our markup full of grid classes. However, our new layout methods give us some interesting new possibilities.\nSomething that is useful to be able to do when dealing with content coming out of a CMS or being pulled from some other source, is to define a bunch of rules and then say, \u201cDisplay this content, using these rules.\u201d\nAs an example of this, I will leave you with a Christmas poem displayed in a document alongside Widget the cat and some of the decorations that are bringing him no Christmas cheer whatsoever.\nThe poem is displayed first in the source as a set of paragraphs. I\u2019ve added a class identifying each of the four paragraphs but they are displayed in the source as one text. Below that are all my images, some landscape and some portrait; I\u2019ve added a class of landscape to the landscape ones.\nThe mobile-first grid is a single column and I use line-based placement to explicitly position my poem paragraphs. The grid layout auto-placement rules then take over and place the images into the empty cells left in the grid.\nAt wider screen widths, I declare a four-track grid, and position my poem around the grid, keeping it in a readable order.\nI also add rules to my landscape class, stating that these items should span two tracks. Once again the grid layout auto-placement rules position the rest of my images without my needing to position them. You will see that grid layout takes items out of source order to fill gaps in the grid. It does this because I have set the property grid-auto-flow to dense. The default is sparse meaning that grid will not attempt this backfilling behaviour.\nTake a look and play around with the full demo (requires a CSS grid layout-supporting browser):\nSee the Pen Grid auto-flow with rules by rachelandrew (@rachelandrew) on CodePen.\n\nThe final automatic placement example.\nMy wish for 2016\nI really hope that in 2016, we will see CSS grid layout finally emerge from behind browser flags, so that we can start to use these features in production \u2014 that we can start to move away from using the wrong tools for the job.\nHowever, I also hope that we\u2019ll see developers fully embracing these tools as the new system that they are. I want to see people exploring the possibilities they give us, rather than trying to get them to behave like the grid systems of 2015. As you discover these new modules, treat them as the new paradigm that they are, get creative with them. And, as you find the edges of possibility with them, take that feedback to the CSS Working Group. Help improve the layout systems that will shape the look of the future web.\nSome further reading\n\nI maintain a site of grid layout examples and resources at Grid by Example.\nThe three CSS specifications I\u2019ve discussed can be found as editor\u2019s drafts: CSS grid, flexbox, box alignment.\nI wrote about the last three years of my interest in CSS grid layout, which gives something of a history of the specification.\nMore examples of box alignment and grid layout.\nMy presentation at Fronteers earlier this year, in which I explain more about these concepts.", "year": "2015", "author": "Rachel Andrew", "author_slug": "rachelandrew", "published": "2015-12-15T00:00:00+00:00", "url": "https://24ways.org/2015/grid-flexbox-box-alignment-our-new-system-for-layout/", "topic": "code"}
{"rowid": 288, "title": "Displaying Icons with Fonts and Data- Attributes", "contents": "Traditionally, bitmap formats such as PNG have been the standard way of delivering iconography on websites. They\u2019re quick and easy, and it also ensures they\u2019re as pixel crisp as possible. Bitmaps have two drawbacks, however: multiple HTTP requests, affecting the page\u2019s loading performance; and a lack of scalability, noticeable when the page is zoomed or viewed on a screen with a high pixel density, such as the iPhone 4 and 4S.\n\nThe requests problem is normally solved by using CSS sprites, combining the icon set into one (physically) large image file and showing the relevant portion via background-position. While this works well, it can get a bit fiddly to specify all the positions. In particular, scalability is still an issue. A vector-based format such as SVG sounds ideal to solve this, but browser support is still patchy.\n\n\n\nThe rise and adoption of web fonts have given us another alternative. By their very nature, they\u2019re not only scalable, but resolution-independent too. No need to specify higher resolution graphics for high resolution screens! \n\nThat\u2019s not all though:\n\n\n\tBrowser support: Unlike a lot of new shiny techniques, they have been supported by Internet Explorer since version 4, and, of course, by all modern browsers. We do need several different formats, however!\n\tDesign on the fly: The font contains the basic graphic, which can then be coloured easily with CSS \u2013 changing colours for themes or :hover and :focus styles is done with one line of CSS, rather than requiring a new graphic. You can also use CSS3 properties such as text-shadow to add further effects. Using -webkit-background-clip: text;, it\u2019s possible to use gradient and inset shadow effects, although this creates a bitmap mask which spoils the scalability.\n\tSmall file size: specially designed icon fonts, such as Drew Wilson\u2019s Pictos font, can be as little as 12Kb for the .woff font. This is because they contain fewer characters than a fully fledged font. You can see Pictos being used in the wild on sites like Garrett Murray\u2019s Maniacal Rage.\n\n\nAs with all formats though, it\u2019s not without its disadvantages: \n\n\n\tIcons can only be rendered in monochrome or with a gradient fill in browsers that are capable of rendering CSS3 gradients. Specific parts of the icon can\u2019t be a different colour.\n\tIt\u2019s only appropriate when there is an accompanying text to provide meaning. This can be alleviated by wrapping the text label in a tag (I like to use <b> rather than <span>, due to the fact that it\u2019s smaller and isn\u2019 t being used elsewhere) and then hiding it from view with text-indent:-999em.\n\tCreating an icon font can be a complex and time-consuming process. While font editors can carry out hinting automatically, the best results are achieved manually.\n\tUnless you\u2019re adept at creating your own fonts, you\u2019re restricted to what is available in the font. However, fonts like Pictos will cover the most common needs, and icons are most effective when they\u2019re using familiar conventions.\n\n\nThe main complaint about using fonts for icons is that it can mean adding a meaningless character to our markup. The good news is that we can overcome this by using one of two methods \u2013 CSS generated content or the data-icon attribute \u2013 in combination with the :before and :after pseudo-selectors, to keep our markup minimal and meaningful. \n\nOur simple markup looks like this:\n\n<a href=\"/basket\" class=\"icon basket\">View Basket</a>\n\nNote the multiple class attributes. Next, we\u2019ll import the Pictos font using the @font-face web fonts property in CSS:\n\n@font-face {\n    font-family: 'Pictos';\n    src: url('pictos-web.eot');\n    src: local('\u263a'), \n    url('pictos-web.woff') format('woff'), \n    url('pictos-web.ttf') format('truetype'),\n    url('pictos-web.svg#webfontIyfZbseF') format('svg');\n}\n\nThis rather complicated looking set of rules is (at the time of writing) the most bulletproof way of ensuring as many browsers as possible load the font we want.  We\u2019ll now use the content property applied to the :before pseudo-class selector to generate our icon. Once again, we\u2019ll use those multiple class attribute values to set common icon styles, then specific styles for .basket. This helps us avoid repeating styles:\n\n.icon {\n    font-family: 'Pictos';\n    font-size: 22px:\n}\n\n.basket:before {\n    content: \"$\";\n}\n\nWhat does the :before pseudo-class do? It generates the dollar character in a browser, even when it\u2019s not present in the markup. Using the generated content approach means our markup stays simple, but we\u2019ll need a new line of CSS, defining what letter to apply to each class attribute for every icon we add.\n\ndata-icon is a new alternative approach that uses the HTML5 data- attribute in combination with CSS attribute selectors. This new attribute lets us add our own metadata to elements, as long as its prefixed by data- and doesn\u2019t contain any uppercase letters. In this case, we want to use it to provide the letter value for the icon. Look closely at this markup and you\u2019ll see the data-icon attribute.\n\n<a href=\"/basket\" class=\"icon\" data-icon=\"$\">View Basket</a>\n\n\n\nWe could add others, in fact as many as we like.\n\n<a href=\"/\" class=\"icon\" data-icon=\"k\">Favourites</a>\n<a href=\"/\" class=\"icon\" data-icon=\"t\">History</a>\n<a href=\"/\" class=\"icon\" data-icon=\"@\">Location</a>\n\n\n\nThen, we need just one CSS attribute selector to style all our icons in one go:\n\n.icon:before {\n    content: attr(data-icon);\n    /* Insert your fancy colours here */\n    }\n\nBy placing our custom attribute data-icon in the selector in this way, we can enable CSS to read the value of that attribute and display it before the element (in this case, the anchor tag). It saves writing a lot of CSS rules. I can imagine that some may not like the extra attribute, but it does keep it out of the actual content \u2013 generated or not.\n\n\n\n\n\nThis could be used for all manner of tasks, including a media player and large simple illustrations. See the demo for live examples. Go ahead and zoom the page, and the icons will be crisp, with the exception of the examples that use -webkit-background-clip: text as mentioned earlier.\n\nFinally, it\u2019s worth pointing out that with both generated content and the data-icon method, the letter will be announced to people using screen readers. For example, with the shopping basket icon above, the reader will say \u201cdollar sign view basket\u201d. As accessibility issues go, it\u2019s not exactly the worst, but could be confusing. You would need to decide whether this method is appropriate for the audience. Despite the disadvantages, icon fonts have huge potential.", "year": "2011", "author": "Jon Hicks", "author_slug": "jonhicks", "published": "2011-12-12T00:00:00+00:00", "url": "https://24ways.org/2011/displaying-icons-with-fonts-and-data-attributes/", "topic": "code"}
{"rowid": 80, "title": "HTML5 Video Bumpers", "contents": "Video is a bigger part of the web experience than ever before. With native browser support for HTML5 video elements freeing us from the tyranny of plugins, and the availability of faster internet connections to the workplace, home and mobile networks, it\u2019s now pretty straightforward to publish video in a way that can be consumed in all sorts of ways on all sorts of different web devices.\n\nI recently worked on a project where the client had shot some dedicated video shorts to publish on their site. They also had some five-second motion graphics produced to top and tail the videos with context and branding. This pretty common requirement is a great idea on the web, where a user might land at your video having followed a link and be viewing a page without much context.\n\nKnown as bumpers, these short introduction clips help brand a video and make it look a lot more professional.\n\n\n\nAdding bumpers to a video\n\nThe simplest way to add bumpers to a video would be to edit them on to the start and end of the video file itself. Cooking the bumpers into the video file is easy, but should you ever want to update them it can become a real headache. If the branding needs updating, for example, you\u2019d need to re-edit and re-encode all your videos. Not a fun task.\n\nWhat if the bumpers could be added dynamically? That would enable you to use the same bumper for multiple videos (decreasing download time for users who might watch more than one) and to update the bumpers whenever you wanted. You could change them seasonally, update them for special promotions, run different advertising slots, perform multivariate testing, or even target different bumpers to different users.\n\nThe trade-off, of course, is that if you dynamically add your bumpers, there\u2019s a chance that a user in a given circumstance might not see the bumper. For example, if the main video feature was uploaded to YouTube, you\u2019d have no way to control the playback. As always, you need to weigh up the pros and cons and make your choice.\n\nHTML5 bumpers\n\nIf you wanted to dynamically add bumpers to your HTML5 video, how would you go about it? That was the question I found myself needing to answer for this particular client project.\n\nMy initial thought was to treat it just like an image slideshow. If I were building a slideshow that moved between images, I\u2019d use CSS absolute positioning with z-index to stack the images up on top of each other in a pile, with the first image on top. To transition to the second image, I\u2019d use JavaScript to fade the top image out, revealing the second image beneath it.\n\n\n\nNow that video is just a native object in the DOM, just like an image, why not do the same? Stack the videos up with the opening bumper on top, listen for the video\u2019s onended event, and fade it out to reveal the main feature behind. Good idea, right?\n\nWrong\n\nRemember that this is the web. It\u2019s never going to be that easy. The problem here is that many non-desktop devices use native, dedicated video players. Think about watching a video on a mobile phone \u2013 when you play the video, the phone often goes full-screen in its native player, leaving the web page behind. There\u2019s no opportunity to fade or switch z-index, as the video isn\u2019t being viewed in the page. Your page is left powerless. Powerless!\n\n\n\nSo what can we do? What can we control?\n\nThose of us with particularly long memories might recall a time before CSS, when we\u2019d have to use JavaScript to perform image rollovers. As CSS background images weren\u2019t a practical reality, we would use lots of <img> elements, and perform a rollover by modifying the src attribute of the image. \n\nTurns out, this old trick of modifying the source can help us out with video, too. In most cases, modifying the src attribute of a <video> element, or perhaps more likely the src attribute of a source element, will swap from one video to another.\n\nSwappin\u2019 it\n\nLet\u2019s take a deliberately simple example of a super-basic video tag:\n\n<video src=\"mycat.webm\" controls>no fallback coz i is lame, innit.</video>\n\nWe could very simply write a script to find all video tags and give them a new src to show our bumper.\n\n<script>\n\tvar videos, i, l;\n\tvideos = document.getElementsByTagName('video');\n\tfor(i=0, l=videos.length; i<l; i++) {\n\t\tvideos[i].setAttribute('src', 'bumper-in.webm');\n\t}\n</script>\n\nView the example in a browser with WebM support. You\u2019ll see that the video is swapped out for the opening bumper. Great!\n\nBeefing it up\n\nOf course, we can\u2019t just publish video in one format. In practical use, you need a <video> element with multiple <source> elements containing your different source formats.\n\n<video controls>\n    <source src=\"mycat.mp4\" type=\"video/mp4\" />\n    <source src=\"mycat.webm\" type=\"video/webm\" />\n    <source src=\"mycat.ogv\" type=\"video/ogg\" />\n</video>\n\nThis time, our script needs to loop through the sources, not the videos. We\u2019ll use a regular expression replacement to swap out the file name while maintaining the correct file extension.\n\n<script>\n    var sources, i, l, orig;\n    sources = document.getElementsByTagName('source');\n    for(i=0, l=sources.length; i<l; i++) {\n        orig = sources[i].getAttribute('src');\n        sources[i].setAttribute('src', orig.replace(/(w+).(w+)/, 'bumper-in.$2'));\n        // reload the video\n        sources[i].parentNode.load();\n    }\n</script>\n\nThe difference this time is that when changing the src of a <source> we need to call the .load() method on the video to get it to acknowledge the change.\n\nSee the code in action, this time in a wider range of browsers.\n\nBut, my video!\n\nI guess we should get the original video playing again. Keeping the same markup, we need to modify the script to do two things:\n\n\n\tStore the original src in a data- attribute so we can access it later\n\tAdd an event listener so we can detect the end of the bumper playing, and load the original video back in\n\n\nAs we need to loop through the videos this time to add the event listener, I\u2019ve moved the .load() call into that loop. It\u2019s a bit more efficient to call it only once after modifying all the video\u2019s sources.\n\n<script>\nvar videos, sources, i, l, orig;\nsources = document.getElementsByTagName('source');\nfor(i=0, l=sources.length; i<l; i++) {\n    orig = sources[i].getAttribute('src');\n    sources[i].setAttribute('data-orig', orig);\n    sources[i].setAttribute('src', orig.replace(/(w+).(w+)/, 'bumper-in.$2'));\n}\nvideos = document.getElementsByTagName('video');\nfor(i=0, l=videos.length; i<l; i++) {\n    videos[i].load();\n    videos[i].addEventListener('ended', function(){\n        sources = this.getElementsByTagName('source');\n        for(i=0, l=sources.length; i<l; i++) {\n            orig = sources[i].getAttribute('data-orig');\n            if (orig) {\n                sources[i].setAttribute('src', orig);\n            }\n            sources[i].setAttribute('data-orig','');\n        }\n        this.load();\n        this.play();\n    });\n}\n</script>\n\nAgain, view the example to see the bumper play, followed by our spectacular main feature. (That\u2019s my cat, Widget. His interests include sleeping and internet marketing.)\n\nTidying things up\n\nThe final thing to do is add our closing bumper after the main video has played. This involves the following changes:\n\n\n\tWe need to keep track of whether the src has been changed, so we only play the video if it\u2019s changed. I\u2019ve added the modified variable to track this, and it stops us getting into a situation where the video just loops forever.\n\tAdd an else to the event listener, for when the orig is false (so the main feature has been playing) to load in the end bumper. We also check that we\u2019re not already playing the end bumper. Because looping.\n\n\n<script>\nvar videos, sources, i, l, orig, current, modified;\nsources = document.getElementsByTagName('source');\nfor(i=0, l=sources.length; i<l; i++) {\n   orig = sources[i].getAttribute('src');\n   sources[i].setAttribute('data-orig', orig);\n   sources[i].setAttribute('src', orig.replace(/(w+).(w+)/, 'bumper-in.$2'));\n}\nvideos = document.getElementsByTagName('video');\nfor(i=0, l=videos.length; i<l; i++) {\n   videos[i].load();\n   modified = false;\n   videos[i].addEventListener('ended', function(){\n      sources = this.getElementsByTagName('source');\n      for(i=0, l=sources.length; i<l; i++) {\n         orig = sources[i].getAttribute('data-orig');\n         if (orig) {\n            sources[i].setAttribute('src', orig);\n            modified = true;\n         }else{\n            current = sources[i].getAttribute('src');\n            if (current.indexOf('bumper-out')==-1) {\n               sources[i].setAttribute('src', current.replace(/([w]+).(w+)/, 'bumper-out.$2'));\n               modified = true;\n            }else{\n               this.pause();\n               modified = false;\n            }\n         }\n         sources[i].setAttribute('data-orig','');\n      }\n      if (modified) {\n         this.load();\n         this.play();\n      }\n   });\n}\n</script>\n\nYo ho ho, that\u2019s a lot of JavaScript. See it in action \u2013 you should get a bumper, the cat video, and an end bumper.\n\nOf course, this code works fine for demonstrating the principle, but it\u2019s very procedural. Nothing wrong with that, but to do something similar in production, you\u2019d probably want to make the code more modular to ease maintainability. Besides, you may want to use a framework, rather than basic JavaScript. \n\nThe end credits\n\nOne really important principle here is that of progressive enhancement. If the browser doesn\u2019t support JavaScript, the user won\u2019t see your bumper, but they will get the main video. If the browser supports JavaScript but doesn\u2019t allow you to modify the src (as was the case with older versions of iOS), the user won\u2019t see your bumper, but they will get the main video.\n\nIf a search engine or social media bot grabs your page and looks for content, they won\u2019t see your bumper, but they will get the main video \u2013 which is absolutely what you want.\n\nThis means that if the bumper is absolutely crucial, you may still need to cook it into the video. However, for many applications, running it dynamically can work quite well.\n\nAs always, it comes down to three things:\n\n\n\tMeasure your audience: know how people access your site\n\tTest the solution: make sure it works for your audience\n\tPlan for failure: it\u2019s the web and that\u2019s how things work \u2018round these parts\n\n\nBut most of all play around with it, have fun and build something awesome.", "year": "2012", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2012-12-01T00:00:00+00:00", "url": "https://24ways.org/2012/html5-video-bumpers/", "topic": "code"}
{"rowid": 264, "title": "Dynamic Social Sharing Images", "contents": "Way back when social media was new, you could be pretty sure that whatever you posted would be read by those who follow you. If you\u2019d written a blog post and you wanted to share it with those who follow you, you could post a link and your followers would see it in their streams. Oh heady days! \nWith so many social channels and a proliferation of content and promotions flying past in everyone\u2019s streams, it\u2019s no longer enough to share content on social media, you have to actively sell it if you want it to be seen. You really need to make the most of every opportunity to catch a reader\u2019s attention if you\u2019re trying to get as many eyes as possible on that sweet, sweet social content.\nOne of the best ways to grab attention with your posts or tweets is to include an image. There\u2019s heaps of research that says that having images in your posts helps them stand out to followers. Reports I found showed figures from anything from 35% to 150% improvement from just having image in a post. Unfortunately, the details were surrounded with gross words like engagement and visual marketing assets and so I had to close the page before I started to hate myself too much.\nSo without hard stats to quote, we\u2019ll call it a rule of thumb. The rule of thumb is that posts with images will grab more attention than those without, so it makes sense that when adding pages to a website, you should make sure that they have social media sharing images associated with them.\nAdding sharing images\nThe process for declaring an image to be used in places like Facebook and Twitter is very simple, and at this point is familiar to many of us. You add a meta tag to the head of the page to point to the location of the image to use. When a link to the page is added to a post, the social network will fetch the page, look for the meta tag and then use the image you specified.\n<meta property=\"og:image\" content=\"https://example.com/my_image.jpg\">\nThere\u2019s a good post on this over at CSS-Tricks if you need to bone up on the details of this and other similar meta tags for social media sharing.\nThis is all fine and well for content that has a very obvious choice of image to go along with it, but what if you don\u2019t necessarily have an image? One approach is to use stock photography, but that\u2019s not going to be right for every situation.\nThis was something we faced with 24 ways in 2017. We wanted to add images to the tweets we post each day announcing a new article. Some articles have images, but not all, and there tended not to be any consistency in terms of imagery from one article to the next. We always have an author photograph, but those don\u2019t usually lend themselves directly to being the main \u2018hero\u2019 image for an article.\nPutting his thinking cap on, Paul came up with a design for an image that used the author photo along with a quote extracted from the article.\nOne of the hand-made sharing images from 2017\nEach day we would pick a quote from the article, and Paul would manually compose an image to be uploaded to the site. The results were great, but the whole process was a bit too labour intensive and relied on an individual (Paul) being available each day to do the work. I thought we could probably improve this.\nHatching a new plan\nOne initial idea I came up with was to script the image editor to dynamically build a new image by pulling content from our database. Sketch has plugins available to pull JSON content into a design, and our CMS can easily output JSON data, so that was one possibility.\nThe more I thought about this and how much I wish graphic design tools worked just a little bit more like CSS, the obvious solution hit me. We should just build it with CSS!\nIn fact, as the author name and image already exist in our CMS, and the visual styling is based on the design of the website, couldn\u2019t this just be another page on the site generated by the CMS?\nBreaking it down, I figured the steps needed would be something like:\n\nCreate the CSS to lay out a component that could be turned into an image\nAdd a new field to articles in the CMS to hold a handpicked quote\nBuild a new article template in the CMS to output the author name and quote dynamically for any article\n\u2026 um \u2026 screenshot?\n\nI thought I\u2019d get cracking and see if I could figure out the final steps later.\nBuilding the page\nThe first thing to tackle was the basic HTML and CSS to lay out the components for our image. That bit was really easy, as I just asked Paul to do it. Everyone should have a Paul.\nPaul\u2019s code uses a fixed dimension container in the HTML, set to 600 \u00d7 315px. This is to make it the correct aspect ratio for Facebook\u2019s recommended image size. It\u2019s useful to remember here that it doesn\u2019t need to be responsive or robust, as the page only needs to lay out correctly for a screenshot and a fixed size in a known browser.\nWith the markup and CSS in place, I turned this into a new template. Our CMS can easily display content through any number of templates, so I created a version of the article template that was totally stripped down. It only included the author details and the quote, along with Paul\u2019s markup.\nI also added the quote as a new field on the article in the CMS, so each \u2018image\u2019 could be quickly and easily customised in the editing process.\nI added a new field to the article template to capture the quote.\nWith very little effort, we quickly had a page to dynamically generate our \u2018image\u2019 right from the CMS. You can see any of them by adding /sharing onto the end of an article URL for any 2018 article.\nOur automatically generated layout direct from the CMS\nIt soon became clear that the elusive Step 4 was going to be the tricky part. I can create a small page on the site that looks like an image, but how should I go about turning it into one? An obvious route is to screenshot the page by hand, but that\u2019s going back to some of the manual steps I was trying to eliminate, and also opens up a possibility for errors to be made. But it did lead me to the thought\u2026 how could I automatically take a screenshot?\nEnter Puppeteer\nPuppeteer is a Node.js library that provides a nice API onto Headless Chrome. What is Headless Chrome, you ask? It\u2019s just a version of the Chrome browser than runs from the command line without ever drawing anything to a user interface window. It loads pages, renders CSS, runs JavaScript, pretty much every normal thing that Chrome on the desktop does, but without a clicky user interface.\nHeadless Chrome can be used for all sorts of things such as running automated tests on front-end code after making changes, or\u2026 get this\u2026 rendering pages that can be used for screenshots. The actual process of writing some code to control Chrome and to take the screenshot is where Puppeteer comes in. Puppeteer puts a friendly layer in front of big old scary Chrome to enable us to interact with it using simple JavaScript code running in Node.\nUsing Puppeteer, I can write a small script that will repeatably turn a URL into an image. So simple is it to do this, that\u2019s it\u2019s actually Puppeteer\u2019s \u2018hello world\u2019 example.\nFirst you install Puppeteer. It downloads a compatible headless browser (actually Chromium) as a dependancy, so you don\u2019t need to worry about installing that. At the command line:\nnpm i puppeteer\nThen save a new file as example.js with this code:\nconst puppeteer = require('puppeteer');\n\n(async () => {\n  const browser = await puppeteer.launch();\n  const page = await browser.newPage();\n  await page.goto('https://example.com');\n  await page.screenshot({path: 'example.png'});\n  await browser.close();\n})();\nand then run it using Node:\nnode example.js\nThis will output an image file example.png to disk, which contains a screenshot of, in this case https://example.com. The logic of the code is reasonably easy to follow:\n\nLaunch a browser\nOpen up a new page\nGoto a URL\nTake a screenshot\nClose the browser\n\nThe async function and await keywords are a way to have the script pause and wait for normally asynchronous code to return before proceeding. That\u2019s useful with actions like loading a web page that might take some time to complete. They\u2019re used with Promises, and the effect is to make asynchronous code behave as if it\u2019s synchronous. You can read more about async and await at MDN if you\u2019re interested.\nThat\u2019s a good proof-of-concept using the basic Puppeteer example. I can take a screenshot of a URL! But what happens if I put the URL of my new special page in there?\nOur content is up in the corner of the image with lots of empty space.\nThat\u2019s not great. It\u2019s okay, but not great. It looks like that, by default, Puppeteer takes a screenshot with a resolution of 800 \u00d7 600, so we need to find out how to adjust that. Fortunately, the docs aren\u2019t the worst and I was able to find the page.setViewport() method pretty easily.\nconst puppeteer = require('puppeteer');\n\n(async () => {\n  const browser = await puppeteer.launch();\n  const page = await browser.newPage();\n  await page.goto('https://24ways.org/2018/clip-paths-know-no-bounds/sharing');\n  await page.setViewport({\n    width: 600,\n    height: 315\n  });\n  await page.screenshot({path: 'example.png'});\n  await browser.close();\n})();\nThis worked! The screenshot is now 600 \u00d7 315 as expected. That\u2019s exactly what we asked for. Trouble is, that\u2019s a bit low res and it is nearly 2019 after all. While in those docs, I noticed the deviceScaleFactor option that can be passed to page.setViewport(). Setting that to 2 gives us an image of the same area of the screen, but with twice as many pixels.\n  await page.setViewport({\n    width: 600,\n    height: 315,\n    deviceScaleFactor: 2\n  });\nPerfect! We now have a programmatic way of turning a URL into an image.\nImproving the script\nRather than having a script with a fixed URL in it that outputs an image called example.png, the next step is to make that a bit more dynamic. The aim here is to have a script that we can run with a URL as an argument and have it output an image for that one page. That way we can run it manually, or hook it into part of our site\u2019s build process to automate the generation of the image.\nOur goal is to call the script like this:\nnode shoot-sharing-image.js https://24ways.org/2018/clip-paths-know-no-bounds/\nAnd I want the image to come out with the name clip-paths-know-no-bounds.png. To do that, I need to have my script look for command arguments, and then to split the URL up to grab the slug from it.\n// Get the URL and the slug segment from it\nconst url = process.argv[2];\nconst segments = url.split('/');\n// Get the second-to-last segment (the slug)\nconst slug = segments[segments.length-2];\nWe can then use these variables later in the script, remembering to add sharing back onto the end of the URL to get our dedicated page.\n(async () => {\n  const browser = await puppeteer.launch();\n  const page = await browser.newPage();\n  await page.goto(url + 'sharing');\n  await page.setViewport({\n    width: 600,\n    height: 315,\n    deviceScaleFactor: 2\n  });\n  await page.screenshot({path: slug + '.png'});\n  await browser.close();\n})();\nOnce you\u2019re generating the image with Node, there\u2019s all sorts of things you can do with it. An obvious step is to move it to the correct location within your site or project.\nYou can also run optimisations on the file. I\u2019m using imagemin with pngquant to reduce the file size a little.\nconst imagemin = require('imagemin');\nconst imageminPngquant = require('imagemin-pngquant');\n\nawait imagemin([slug + '.png'], 'build', {\n  plugins: [\n    imageminPngquant({quality: '75-90'})\n  ]\n});\n\nYou can see the completed example as a gist.\nIntegrating it with your CMS\nSo we now have a command we can run to take a URL and generate a custom image for that URL. It\u2019s in a format that can be called by any sort of build script, or triggered from a publishing hook in a CMS. Exactly how you do that is going to depend on the way your site is built and the technology stack you\u2019re using, but it\u2019s likely not too hard as long as you can run a command as part of the process.\nFor 24 ways this year, I\u2019ve been running the script by hand once each article is ready. My script adds the file to a git repo and pushes to a deployment remote that is configured to automatically deploy static assets to our server. Along with our theme of making incremental improvements, next year I\u2019ll look to automate this one step further.\nWe may also look at having a few slightly different layouts to choose from, so that each day isn\u2019t exactly the same as the last. Interestingly, we could even try some A/B tests to see if there\u2019s any particular format of image or type of quote that does a better job of grabbing attention. There are lots of possibilities!\n\nBy using a bit of ingenuity, some custom CMS templates, and the very useful Puppeteer project, we\u2019ve been able to reliably produce dynamic social media sharing images for all of our articles. In doing so, we reduced the dependancy on any individual for producing those images, and opened up a world of possibilities in how we use those images.\nI hope you\u2019ll give it a try!", "year": "2018", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2018-12-24T00:00:00+00:00", "url": "https://24ways.org/2018/dynamic-social-sharing-images/", "topic": "code"}
{"rowid": 135, "title": "A Scripting Carol", "contents": "We all know the stories of the Ghost of Scripting Past \u2013 a time when the web was young and littered with nefarious scripting, designed to bestow ultimate control upon the developer, to pollute markup with event handler after event handler, and to entrench advertising in the minds of all that gazed upon her.\n\nAnd so it came to be that JavaScript became a dirty word, thrown out of solutions by many a Scrooge without regard to the enhancements that JavaScript could bring to any web page. JavaScript, as it was, was dead as a door-nail.\n\nWith the arrival of our core philosophy that all standardistas hold to be true: \u201cseparate your concerns \u2013 content, presentation and behaviour,\u201d we are in a new era of responsible development the Web Standards Way\u2122. Or are we? Have we learned from the Ghosts of Scripting Past? Or are we now faced with new problems that come with new ways of implementing our solutions?\n\nThe Ghost of Scripting Past\n\nIf the Ghost of Scripting Past were with us it would probably say: \n\n\n\tYou must remember your roots and where you came from, and realize the misguided nature of your early attempts for control. That person you see down there, is real and they are the reason you exist in the first place\u2026 without them, you are nothing.\n\n\nIn many ways we\u2019ve moved beyond the era of control and we do take into account the user, or at least much more so than we used to. Sadly \u2013 there is one advantage that old school inline event handlers had where we assigned and reassigned CSS style property values on the fly \u2013 we knew that if JavaScript wasn\u2019t supported, the styles wouldn\u2019t be added because we ended up doing them at the same time.\n\nIf anything, we need to have learned from the past that just because it works for us doesn\u2019t mean it is going to work for anyone else \u2013 we need to test more scenarios than ever to observe the multitude of browsing arrangements we\u2019ll observe: CSS on with JavaScript off, CSS off/overridden with JavaScript on, both on, both off/not supported. It is a situation that is ripe for conflict.\n\nThis may shock some of you, but there was a time when testing was actually easier: back in the day when Netscape 4 was king. Yes, that\u2019s right. I actually kind of enjoyed Netscape 4 (hear me out, please). With NS4\u2019s CSS implementation known as JavaScript Style Sheets, you knew that if JavaScript was off the styles were off too.\n\nThe Ghost of Scripting Present\n\nWith current best practice \u2013 we keep our CSS and JavaScript separate from each other. So what happens when some of our fancy, unobtrusive DOM Scripting doesn\u2019t play nicely with our wonderfully defined style rules?\n\nLets look at one example of a collapsing and expanding menu to illustrate where we are now:\n\nSimple Collapsing/Expanding Menu Example\n\nWe\u2019re using some simple JavaScript (I\u2019m using jquery in this case) to toggle between a CSS state for expanded and not expanded:\n\nJavaScript\n\n$(document).ready(function(){\n\tTWOFOURWAYS.enableTree();\n});\nvar TWOFOURWAYS = new Object();\nTWOFOURWAYS.enableTree = function ()\n{\n\t$(\"ul li a\").toggle(function(){\n\t\t$(this.parentNode).addClass(\"expanded\");\n\t}, function() {\n\t\t$(this.parentNode).removeClass(\"expanded\");\n\t});\n\treturn false;\t\n}\n\nCSS\n\nul li ul {\n\tdisplay: none;\n}\nul li.expanded ul {\n\tdisplay: block;\n}\n\nAt this point we\u2019ve separated our presentation from our content and behaviour, and all is well, right?\n\nNot quite.\n\nHere\u2019s where I typically see failures in the assessment work that I do on web sites and applications (Yes, call me Scrooge \u2013 I don\u2019t care!). We know our page needs to work with or without scripting, and we know it needs to work with or without CSS. All too often the testing scenarios don\u2019t take into account combinations.\n\nTesting it out\n\nSo what happens when we test this? Make sure you test with:\n\n\n\tCSS off\n\tJavaScript off\n\n\nUse the simple example again.\n\nWith CSS off, we revert to a simple nested list of links and all functionality is maintained. With JavaScript off, however, we run into a problem \u2013 we have now removed the ability to expand the menu using the JavaScript triggered CSS change.\n\nHopefully you see the problem \u2013 we have a JavaScript and CSS dependency that is critical to the functionality of the page. Unobtrusive scripting and binary on/off tests aren\u2019t enough. We need more.\n\nThis Ghost of Scripting Present sighting is seen all too often.\n\nLets examine the JavaScript off scenario a bit further \u2013 if we require JavaScript to expand/show the branch of the tree we should use JavaScript to hide them in the first place. That way we guarantee functionality in all scenarios, and have achieved our baseline level of interoperability. \n\nTo revise this then, we\u2019ll start with the sub items expanded, use JavaScript to collapse them, and then use the same JavaScript to expand them.\n\nHTML\n\n<ul>\n\t<li><a href=\"#\">Main Item</a>\n\t\t<ul class=\"collapseme\">\n\t\t\t<li><a href=\"#\">Sub item 1</a></li>\n\t\t\t<li><a href=\"#\">Sub item 2</a></li>\n\t\t\t<li><a href=\"#\">Sub item 3</a></li>\n\t\t</ul>\n\t</li>\n</ul>\n\nCSS\n\n/* initial style is expanded */\nul li ul.collapseme {\n\tdisplay: block;\n}\n\nJavaScript\n\n// remove the class collapseme after the page loads\n$(\"ul ul.collapseme\").removeClass(\"collapseme\");\n\nAnd there you have it \u2013 a revised example with better interoperability.\n\nThis isn\u2019t rocket surgery by any means. It is a simple solution to a ghostly problem that is too easily overlooked (and often is).\n\nThe Ghost of Scripting Future\n\nWell, I\u2019m not so sure about this one, but I\u2019m guessing that in a few years\u2019 time, we\u2019ll all have seen a few more apparitions and have a few more tales to tell. And hopefully we\u2019ll be able to share them on 24 ways.\n\nThanks to Drew for the invitation to contribute and thanks to everyone else out there for making this a great (and haunting) year on the web!", "year": "2006", "author": "Derek Featherstone", "author_slug": "derekfeatherstone", "published": "2006-12-21T00:00:00+00:00", "url": "https://24ways.org/2006/a-scripting-carol/", "topic": "code"}
{"rowid": 293, "title": "A Favor for Your Future Self", "contents": "We tend to think about the future when we build things. What might we want to be able to add later? How can we refactor this down the road? Will this be easy to maintain in six months, a year, two years? As best we can, we try to think about the what-ifs, and build our websites, systems, and applications with this lens. \nWe comment our code to explain what we knew at the time and how that impacted how we built something. We add to-dos to the things we want to change. These are all great things! Whether or not we come back to those to-dos, refactor that one thing, or add new features, we put in a bit of effort up front just in case to give us a bit of safety later.\nI want to talk about a situation that Past Alicia and Team couldn\u2019t even foresee or plan for. Recently, the startup I was a part of had to remove large sections of our website. Not just content, but entire pages and functionality. It wasn\u2019t a very pleasant experience, not only for the reason why we had to remove so much of what we had built, but also because it\u2019s the ultimate \u201cI really hope this doesn\u2019t break something else\u201d situation. It was a stressful and tedious effort of triple checking that the things we were removing weren\u2019t dependencies elsewhere. To be honest, we wouldn\u2019t have been able to do this with any amount of success or confidence without our test suite.\nWriting tests for code is one of those things that developers really, really don\u2019t want to do. It\u2019s one of the easiest things to cut in the development process, and there\u2019s often a struggle to have developers start writing tests in the first place. One of the best lessons the web has taught us is that we can\u2019t, in good faith, trust the happy path. We must make sure ourselves, and our users, aren\u2019t in a tough spot later on because we only thought of the best case scenarios.\nJavaScript\nRegardless of your opinion on whether or not everything needs to be built primarily with JavaScript, if you\u2019re choosing to build a JavaScript heavy app, you absolutely should be writing some combination of unit and integration tests.\nUnit tests are for testing extremely isolated and small pieces of code, which we refer to as the units themselves. Great for reused functions and small, scoped areas, this is the closest you examine your code with the testing microscope. For example, if we were to build a calculator, the most minute piece we could test could be the basic operations.\n/*\n * This example uses a test framework called Jasmine\n */\n\ndescribe(\"Calculator Operations\", function () {\n\n    it(\"Should add two numbers\", function () {\n\n    // Say we have a calculator\n        Calculator.init();\n\n    // We can run the function that does our addition calculation...\n        var result = Calculator.addNumbers(7,3);\n\n    // ...and ensure we're getting the right output\n        expect(result).toBe(10);\n\n    });\n});\nEven though these teeny bits work in isolation, we should ensure that connecting the large pieces work, as well. This is where integration tests excel. These tests ensure that two or more different areas of code, that may not directly know about each other, still behave in expected ways. Let\u2019s build upon our calculator - we may want the operations to be saved in memory after a calculation runs. This isn\u2019t as suited for a unit test because there are a few other moving pieces involved in the process (the calculations, checking if the result was an error, etc.).\n    it(\u201cShould remember the last calculation\u201d, function () {\n\n    // Run an operation\n        Calculator.addNumbers(7,10);\n\n    // Expect something else to have happened as a result\n        expect(Calculator.updateCurrentValue).toHaveBeenCalled();\n        expect(Calculator.currentValue).toBe(17);\n    });\nUnit and integration tests provide assurance that your hand-rolled JavaScript should, for the most part, never fail in a grand fashion. Although it still might happen, you could be able to catch problems way sooner than without a test suite, and hopefully never push those failures to your production environment.\nInterfaces\nRegardless of how you\u2019re building something, it most definitely has some kind of interface. Whether you\u2019re using a very barebones structure, or you\u2019re leveraging a whole design system, these things can be tested as well.\nAcceptance testing helps us ensure that users can get from point A to point B within our web things, which can provide assurance that major features are always functioning properly. By simulating user input and data entry, we can go through whole user workflows to test for both success and failure scenarios. These are not necessarily for simulating edge-case scenarios, but rather ensuring that our core offerings are stable.\nFor example, if your site requires signup, you want to make sure the workflow is behaving as expected - allowing valid information to go through signup, while invalid information does not let you progress.\n/*\n * This example uses Jasmine along with an add-on called jasmine-integration\n */\n\ndescribe(\"Acceptance tests\", function () {\n\n  // Go to our signup page\n  var page = visit(\"/signup\");\n\n  // Fill our signup form with invalid information\n  page.fill_in(\"input[name='email']\", \"Not An Email\");\n  page.fill_in(\"input[name='name']\", \"Alicia\");\n  page.click(\"button[type=submit]\");\n\n  // Check that we get an expected error message\n  it(\"Shouldn't allow signup with invalid information\", function () {\n    expect(page.find(\"#signupError\").hasClass(\"hidden\")).toBeFalsy();\n  });\n\n  // Now, fill our signup form with valid information\n  page.fill_in(\"input[name='email']\", \"thisismyemail@gmail.com\");\n  page.fill_in(\"input[name='name']\", \"Gerry\");\n  page.click(\"button[type=submit]\");\n\n  // Check that we get an expected success message and the error message is hidden\n  it(\"Should allow signup with valid information\", function () {\n    expect(page.find(\"#signupError\").hasClass(\"hidden\")).toBeTruthy();\n    expect(page.find(\"#thankYouMessage\").hasClass(\"hidden\")).toBeFalsy();\n  });\n});\nIn terms of visual design, we\u2019re now able to take snapshots of what our interfaces look like before and after any code changes to see what has changed. We call this visual regression testing. Rather than being a pass or fail test like our other examples thus far, this is more of an awareness test, intended to inform developers of all the visual differences that have occurred, intentional or not. Developers may accidentally introduce a styling change or fix that has unintended side effects on other areas of a website - visual regression testing helps us catch these sooner rather than later. These do require a bit more consistent grooming than other tests, but can be valuable in major CSS refactors or if your CSS is generally a bit like Jenga.\nTools like PhantomCSS will take screenshots of your pages, and do a visual comparison to check what has changed between two sets of images. The code would look something like this:\n/*\n * This example uses PhantomCSS\n */\n\ncasper.start(\"/home\").then(function(){\n\n  // Initial state of form\n  phantomcss.screenshot(\"#signUpForm\", \"sign up form\");\n\n  // Hit the sign up button (should trigger error)\n  casper.click(\"button#signUp\");\n\n  // Take a screenshot of the UI component\n  phantomcss.screenshot(\"#signUpForm\", \"sign up form error\");\n\n  // Fill in form by name attributes & submit\n  casper.fill(\"#signUpForm\", {\n    name: \"Alicia Sedlock\",\n    email: \"alicia@example.com\"\n  }, true);\n\n  // Take a second screenshot of success state\n  phantomcss.screenshot(\"#signUpForm\", \"sign up form success\");\n});\nYou run this code before starting any development, to create your baseline set of screen captures. After you\u2019ve completed a batch of work, you run PhantomCSS again. This will create a second batch of screenshots, which are then put through an image comparison tool to display any differences that occurred. Say you changed your margins on our form elements \u2013 your image diff would look something like this:\n\nThis is a great tool for ensuring not just your site retains its expected styling, but it\u2019s also great for ensuring nothing accidentally changes in the living style guide or modular components you may have developed. It\u2019s hard to keep eagle eyes on every visual aspect of your site or app, so visual regression testing helps to keep these things monitored.\nConclusion\nThe shape and size of what you\u2019re testing for your site or app will vary. You may not need lots of unit or integration tests if you don\u2019t write a lot of JavaScript. You may not need visual regression testing for a one page site. It\u2019s important to assess your codebase to see which tests would provide the most benefit for you and your team.\nWriting tests isn\u2019t a joy for most developers, myself included. But I end up thanking Past Alicia a lot when there are tests, because otherwise I would have introduced a lot of issues into codebases. Shipping code that\u2019s broken breaks trust with our users, and it\u2019s our responsibility as developers to make sure that trust isn\u2019t broken. Testing shouldn\u2019t be considered a \u201cnice to have\u201d - it should be an integral piece of our workflow and our day-to-day job.", "year": "2016", "author": "Alicia Sedlock", "author_slug": "aliciasedlock", "published": "2016-12-03T00:00:00+00:00", "url": "https://24ways.org/2016/a-favor-for-your-future-self/", "topic": "code"}
{"rowid": 335, "title": "Naughty or Nice? CSS Background Images", "contents": "Web Standards based development involves many things \u2013 using semantically sound HTML to provide structure to our documents or web applications, using CSS for presentation and layout, using JavaScript responsibly, and of course, ensuring that all that we do is accessible and interoperable to as many people and user agents as we can.\n\nThis we understand to be good. \n\nAnd it is good. \n\nExcept when we don\u2019t clearly think through the full implications of using those techniques.\n\nWhich often happens when time is short and we need to get things done.\n\nHere are some naughty examples of CSS background images with their nicer, more accessible counterparts.\n\nTransaction related messages\n\nI\u2019m as guilty of this as others (or, perhaps, I\u2019m the only one that has done this, in which case this can serve as my holiday season confessional)  We use lovely little icons to show status messages for a transaction to indicate if the action was successful, or was there a warning or error? For example:\n\n\u201cYour postal/zip code was not in the correct format.\u201d\n\nNotice that we place a nice little icon there, and use background colours and borders to convey a specific message: there was a problem that needs to be fixed. Notice that all of this visual information is now contained in the CSS rules for that div:\n\n<div class=\"error\">\n     <p>Your postal/zip code was not in the correct format.</p>\n </div>\n\n div.error {\n     background: #ffcccc url(../images/error_small.png) no-repeat 5px 4px;\n     color: #900;\n     border-top: 1px solid #c00;\n     border-bottom: 1px solid #c00;\n     padding: 0.25em 0.5em 0.25em 2.5em;\n     font-weight: bold;\n }\n\nUsing this approach also makes it very easy to create a div.success and div.warning CSS rules meaning we have less to change in our HTML.\n\nNice, right?\n\nNo. Naughty. \n\nVisual design communicates\n\nThe CSS is being used to convey very specific information. The choice of icon, the choice of background colour and borders tell us visually that there is something wrong. \n\nWith the icon as a background image \u2013 there is no way to specify any alt text for the icon, and significant meaning is lost. A screen reader user, for example, misses the fact that it is an \u201cerror.\u201d \n\nThe solution? Ask yourself: what is the bare minimum needed to indicate there was an error? Currently in the absence of CSS there will be no icon \u2013 which (I\u2019m hoping you agree) is critical to communicating there was an error.\n\nThe icon should be considered content and not simply presentational.\n\nThe borders and background colour are certainly much less critical \u2013 they belong in the CSS.\n\nLets change the code to place the image directly in the HTML and using appropriate alt text to better communicate the meaning of the icon to all users:\n\n<div class=\"bettererror\">\n     <img src=\"images/error_small.png\" alt=\"Error\" />\n     <p>Your postal/zip code was not in the correct format.</p>\n </div>\n\n div.bettererror {\n     background-color: #ffcccc;\n     color: #900;\n     border-top: 1px solid #c00;\n     border-bottom: 1px solid #c00;\n     padding: 0.25em 0.5em 0.25em 2.5em;\n     font-weight: bold;\n     position: relative;\n     min-height: 1.25em;\n }\n\n div.bettererror img {\n     display: block;\n     position: absolute;\n     left: 0.25em;\n     top: 0.25em;\n     padding: 0;\n     margin: 0;\n }\n\n div.bettererror p {\n     position: absolute;\n     left: 2.5em;\n     padding: 0;\n     margin: 0;\n }\n\nCompare these two examples of transactional messages\n\nStatus of a Record\n\nThis example is pretty straightforward. Consider the following: a real estate listing on a web site. There are three \u201cstates\u201d for a listing: new, normal, and sold. Here\u2019s how they look:\n\nExample of a New Listing\n\nExample of A Sold Listing\n\nIf we (forgive the pun) blindly apply the \u201cuse a CSS background image\u201d technique we clearly run into problems with the new and sold images \u2013 they actually contain content with no way to specify an alternative when placed in the CSS.\n\nIn this case of the \u201cnew\u201d image, we can use the same strategy as we used in the first example (the transaction result). The \u201cnew\u201d image should be considered content and is placed in the HTML as part of the <h2>...</h2> that identifies the listing.\n\nHowever when considering the \u201csold\u201d listing, there are less changes to be made to keep the same look by leaving the \u201cSOLD\u201d image as a background image and providing the equivalent information elsewhere in the listing \u2013 namely, right in the heading.\n\nFor those that can\u2019t see the background image, the status is communicated clearly and right away. A screen reader user that is navigating by heading or viewing a listing will know right away that a particular property is sold.\n\nOf note here is that in both cases (new and sold) placing the status near the beginning of the record helps with a zoom layout as well.\n\nBetter Example of A Sold Listing\n\nSummary\n\nRemember: in the holiday season, its what you give that counts!! Using CSS background images is easy and saves time for you but think of the children. And everyone else for that matter\u2026 \n\nCSS background images should only be used for presentational images, not for those that contain content (unless that content is already represented and readily available elsewhere).", "year": "2005", "author": "Derek Featherstone", "author_slug": "derekfeatherstone", "published": "2005-12-20T00:00:00+00:00", "url": "https://24ways.org/2005/naughty-or-nice-css-background-images/", "topic": "code"}
{"rowid": 239, "title": "Using the WebFont Loader to Make Browsers Behave the Same", "contents": "Web fonts give us designers a whole new typographic palette with which to work. However, browsers handle the loading of web fonts in different ways, and this can lead to inconsistent user experiences.\n\nSafari, Chrome and Internet Explorer leave a blank space in place of the styled text while the web font is loading. Opera and Firefox show text with the default font which switches over when the web font has loaded, resulting in the so-called Flash of Unstyled Text (aka FOUT). Some people prefer Safari\u2019s approach as it eliminates FOUT, others think the Firefox way is more appropriate as content can be read whilst fonts download. Whatever your preference, the WebFont Loader can make all browsers behave the same way.\n\nThe WebFont Loader is a JavaScript library that gives you extra control over font loading. It was co-developed by Google and Typekit, and released as open source. The WebFont Loader works with most web font services as well as with self-hosted fonts.\n\nThe WebFont Loader tells you when the following events happen as a browser downloads web fonts (or loads them from cache):\n\n\n\twhen fonts start to download (\u2018loading\u2019)\n\twhen fonts finish loading (\u2018active\u2019)\n\tif fonts fail to load (\u2018inactive\u2019)\n\n\nIf your web page requires more than one font, the WebFont Loader will trigger events for individual fonts, and for all the fonts as a whole. This means you can find out when any single font has loaded, and when all the fonts have loaded (or failed to do so).\n\nThe WebFont Loader notifies you of these events in two ways: by applying special CSS classes when each event happens; and by firing JavaScript events. For our purposes, we\u2019ll be using just the CSS classes.\n\nImplementing the WebFont Loader\n\nAs stated above, the WebFont Loader works with most web font services as well as with self-hosted fonts.\n\nSelf-hosted fonts\n\nTo use the WebFont Loader when you are hosting the font files on your own server, paste the following code into your web page:\n\n<script type=\"text/javascript\">\nWebFontConfig = {\n\tcustom: { families: ['Font Family Name', 'Another Font Family'],\n\turls: [ 'http://yourwebsite.com/styles.css' ] }\n};\n(function() {\n\tvar wf = document.createElement('script');\n\twf.src = ('https:' == document.location.protocol ? 'https' : 'http') + '://ajax.googleapis.com/ajax/libs/webfont/1/webfont.js';\n\twf.type = 'text/javascript';\n\twf.async = 'true';\n\tvar s = document.getElementsByTagName('script')[0];\n\ts.parentNode.insertBefore(wf, s);\n})();\n</script>\n\nReplace Font Family Name and Another Font Family with a comma-separated list of the font families you want to check against, and replace http://yourwebsite.com/styles.css with the URL of the style sheet where your @font-face rules reside.\n\nFontdeck\n\nAssuming you have added some fonts to a website project in Fontdeck, use the afore-mentioned code for self-hosted solutions and replace http://yourwebsite.com/styles.css with the URL of the <link> tag in your Fontdeck website settings page. It will look something like http://f.fontdeck.com/s/css/xxxx/domain/nnnn.css.\n\nTypekit\n\nTypekit\u2019s JavaScript-based implementation incorporates the WebFont Loader events by default, so you won\u2019t need to include any WebFont Loader code.\n\nMaking all browsers behave like Safari\n\nTo make Firefox and Opera work in the same way as WebKit browsers (Safari, Chrome, etc.) and Internet Explorer, and thus minimise FOUT, you need to hide the text while the fonts are loading.\n\nWhile fonts are loading, the WebFont Loader adds a class of wf-loading to the <html> element. Once the fonts have loaded, the wf-loading class is removed and replaced with a class of wf-active (or wf-inactive if all of the fonts failed to load). This means you can style elements on the page while the fonts are loading and then style them differently when the fonts have finished loading.\n\nSo, let\u2019s say the text you need to hide while fonts are loading is contained in all paragraphs and top-level headings. By writing the following style rule into your CSS, you can hide the text while the fonts are loading:\n\n.wf-loading h1, .wf-loading p {\n\tvisibility:hidden;\n}\n\nBecause the wf-loading class is removed once the the fonts have loaded, the visibility:hidden rule will stop being applied, and the text revealed. You can see this in action on this simple example page.\n\nThat works nicely across the board, but the situation is slightly more complicated. WebKit doesn\u2019t wait for all fonts to load before displaying text: it displays text elements as soon as the relevant font is loaded. \n\nTo emulate WebKit more accurately, we need to know when individual fonts have loaded, and apply styles accordingly. Fortunately, as mentioned earlier, the WebFont Loader has events for individual fonts too.\n\nWhen a specific font is loading, a class of the form wf-fontfamilyname-n4-loading is applied. Assuming headings and paragraphs are styled in different fonts, we can make our CSS more specific as follows:\n\n.wf-fontfamilyname-n4-loading h1, \n.wf-anotherfontfamily-n4-loading p {\n\tvisibility:hidden;\n}\n\nNote that the font family name is transformed to lower case, with all spaces removed. The n4 is a shorthand for the weight and style of the font family. In most circumstances you\u2019ll use n4 but refer to the WebFont Loader documentation for exceptions.\n\nYou can see it in action on this Safari example page (you\u2019ll probably need to disable your cache to see any change occur).\n\nMaking all browsers behave like Firefox\n\nTo make WebKit browsers and Internet Explorer work like Firefox and Opera, you need to explicitly show text while the fonts are loading. In order to make this happen, you need to specify a font family which is not a web font while the fonts load, like this:\n\n.wf-fontfamilyname-n4-loading h1 { \n    font-family: 'arial narrow', sans-serif; \n}\n.wf-anotherfontfamily-n4-loading p { \n    font-family: arial, sans-serif; \n}\n\nYou can see this in action on the Firefox example page (again you\u2019ll probably need to disable your cache to see any change occur).\n\nAnd there\u2019s more\n\nThat\u2019s just the start of what can be done with the WebFont Loader. More areas to explore would be tweaking font sizes to reduce the impact of reflowing text and to better cater for very narrow fonts. By using the JavaScript events much more can be achieved too, such as fading in text as the fonts load.", "year": "2010", "author": "Richard Rutter", "author_slug": "richardrutter", "published": "2010-12-02T00:00:00+00:00", "url": "https://24ways.org/2010/using-the-webfont-loader-to-make-browsers-behave-the-same/", "topic": "code"}
{"rowid": 256, "title": "Develop Your Naturalist Superpowers with Observable Notebooks and iNaturalist", "contents": "We\u2019re going to level up your knowledge of what animals you might see in an area at a particular time of year - a skill every naturalist* strives for -  using technology! Using iNaturalist and Observable Notebooks we\u2019re going to prototype seasonality graphs for particular species in an area, and automatically create a guide to what animals you might see in each month.\n*(a Naturalist is someone who likes learning about nature, not someone who\u2019s a fan of being naked, that\u2019s a \u2018Naturist\u2019\u2026 different thing!)\nLooking for critters in rocky intertidal habitats\nOne of my favourite things to do is going rockpooling, or as we call it over here in California, \u2018tidepooling\u2019. Amounting to the same thing, it\u2019s going to a beach that has rocks where the tide covers then uncovers little pools of water at different times of the day. All sorts of fun creatures and life can be found in this \u2018rocky intertidal habitat\u2019\nA particularly exciting creature that lives here is the Nudibranch, a type of super colourful \u2018sea slug\u2019. There are over 3000 species of Nudibranch worldwide. (The word \u201cnudibranch\u201d comes from the Latin nudus, naked, and the Greek \u03b2\u03c1\u03b1\u03bd\u03c7\u03b9\u03b1 / brankhia, gills.)\n\u200b\n\nThey are however quite tricky to find! Even though they are often brightly coloured and interestingly shaped, some of them are very small, and in our part of the world in the Bay Area in California their appearance in our rockpools is seasonal. We see them more often in Summer months, despite the not-as-low tides as in our Winter and Spring seasons.\nMy favourite place to go tidepooling here is Pillar Point in Half Moon bay (at other times of the year more famously known for the surf competition \u2018Mavericks\u2019). The rockpools there are rich in species diversity, of varied types and water-coverage habitat zones as well as being relatively accessible.\n\u200b\n\nI was rockpooling at Pillar Point recently with my parents and we talked to a lady who remarked that she hadn\u2019t seen any Nudibranchs on her visit this time. I realised that having an idea of what species to find where, and at what time of year is one of the many superpower goals of every budding Naturalist. \nUsing technology and the croudsourced species observations of the iNaturalist community we can shortcut our way to this superpower!\nFinding nearby animals with iNaturalist\nWe\u2019re going to be getting our information about what animals you can see in Pillar Point using iNaturalist. iNaturalist is a really fun platform that helps connect people to nature and report their findings of life in the outdoors. It is also a community of nature-loving people who help each other identify and confirm those observations. iNaturalist is a project run as a joint initiative by the California Academy of Sciences and the National Geographic Society.\nI\u2019ve been using iNaturalist for over two years to record and identify plants and animals that I\u2019ve found in the outdoors. I use their iPhone app to upload my pictures, which then uses machine learning algorithms to make an initial guess at what it is I\u2019ve seen. The community is really active, and I often find someone else has verified or updated my species guess pretty soon after posting. \nThis process is great because once an observation has been identified by at least two people it becomes \u2018verified\u2019 and is considered research grade. Research grade observations get exported and used by scientists, as well as being indexed by the Global Biodiversity Information Facility, GBIF.\n\u200b\n\niNaturalist has a great API and API explorer, which makes interacting and prototyping using iNaturalist data really fun. For example, if you go to the API explorer and expand the Observations : Search and fetch section and then the GET /observations API, you get a selection of input boxes that allow you to play with options that you can then pass to the API when you click the \u2018Try it out\u2019 button.\n\u200b\n\nYou\u2019ll then get a URL that looks a bit like\nhttps://api.inaturalist.org/v1/observations?captive=false &geo=true&verifiable=true&taxon_id=47113&lat=37.495461&lng=-122.499584 &radius=5&order=desc&order_by=created_at \nwhich you can call and interrrogate using a programming language of your choice.\nIf you would like to see an all-JavaScript application that uses the iNaturalist API, take a look at OwlsNearMe.com which Simon and I built one weekend earlier this year. It gets your location and shows you all iNaturalist observations of owls near you and lists which species you are likely to see (not adjusted for season).\nRapid development using Observable Notebooks\nWe\u2019re going to be using Observable Notebooks to prototype our examples, pulling data down from iNaturalist. I really like using visual notebooks like Observable, they are great for learning and building things quickly. You may be familiar with Jupyter notebooks for Python which is similar but takes a bit of setup to get going - I often use these for prototyping too. Observable is amazing for querying and visualising data with JavaScript and since it is a hosted product it doesn\u2019t require any setup at all.\nYou can follow along and play with this example on my Observable notebook. If you create an account there you can fork my notebook and create your own version of this example. \nEach \u2018notebook\u2019 consists of a page with a column of \u2018cells\u2019, similar to what you get in a spreadsheet. A cell can contain Markdown text or JavaScript code and the output of evaluating the cell appears above the code that generated it. There are lots of tutorials out there on Observable Notebooks, I like this code introduction one from Observable (and D3) creator Mike Bostock.\nDeveloping your Naturalist superpowers\nIf you have an idea of what plants and critters you might see in a place at the time you visit, you can hone in on what you want to study and train your Naturalist eye to better identify the life around you.\nFor our example, we care about wildlife we can see at Pillar Point, so we need a way of letting the iNaturalist API know which area we are interested in.\nWe could use a latitide, longitude and radius for this, but a rectangular bounding box is a better shape for the reef. We can use this tool to draw the area we want to search within: boundingbox.klokantech.com\n\u200b\n\nThe tool lets you export the bounding box in several forms using the dropdown at the bottom left under the map givese We are going to use the \u2018DublinCore\u2019 format as it\u2019s closest to the format needed by the iNaturalist API.\n westlimit=-122.50542; southlimit=37.492805; eastlimit=-122.492738; northlimit=37.499811\nA quick map primer:\nThe higher the latitude the more north it is\nThe lower the latitude the more south it is\nLatitude 0 = the equator\n\nThe higher the longitude the more east it is of Greenwich\nThe lower the longitude the more west it is of Greenwich\nLongitude 0 = Greenwich\nIn the iNaturalst API we want to use the parameters nelat, nelng, swlat, swlng to create a query that looks inside a bounding box of Pillar Point near Half Moon Bay in California:\nnelat = highest latitude = north limit = 37.499811\nnelng = highest longitude = east limit = -122.492738\nswlat = smallest latitude = south limit = 37.492805\nswlng = smallest longitude = west limit = 122.50542\nAs API parameters these look like this:\n?nelat=37.499811&nelng=-122.492738&swlat=37.492805&swlng=122.50542\nThese parameters in this format can be used for most of the iNaturalist API methods.\nNudibranch seasonality in Pillar Point\nWe can use the iNaturalist observation_histogram API to get a count of Nudibranch observations per week-of-year across all time and within our Pillar Point bounding box.\nIn addition to the geographic parameters that we just worked out, we are also sending the taxon_id of 47113, which is iNaturalists internal number associated with the Nudibranch taxon. By using this we can get all species which are under the parent \u2018Order Nudibranchia\u2019. \nAnother useful piece of naturalist knowledge is understanding the biological classification scheme of Taxanomic Rank - roughly, when a species has a Latin name of two words eg \u2018Glaucus Atlanticus\u2019 the first Latin word is the \u2018Genus\u2019 like a family name \u2018Glaucus\u2019, and the second word identifies that particular species, like a given name \u2018Atlanticus\u2019. \nThe two Latin words together indicate a specific species, the term we use colloquially to refer to a type of animal often differs wildly region to region, and sometimes the same common name in two countries can refer to two different species. The common names for the Glaucus Atlanticus (which incidentally is my favourite sea slug) include: sea swallow, blue angel, blue glaucus, blue dragon, blue sea slug and blue ocean slug! Because this gets super confusing, Scientists like using this Latin name format instead.\nThe following piece of code asks the iNaturalist Histogram API to return per-week counts for verified observations of Nudibranchs within our Pillar Point bounding box:\npillar_point_counts_per_week = fetch(\n  \"https://api.inaturalist.org/v1/observations/histogram?taxon_id=47113&nelat=37.499811&nelng=-122.492738&swlat=37.492805&swlng=-122.50542&date_field=observed&interval=week_of_year&verifiable=true\"\n  ).then(response => {\n  return response.json();\n})\nOur next step is to take this data and draw a graph! We\u2019ll be using Vega-Lite for this, which is a fab JavaScript graphing libary that is also easy and fun to use with Observable Notebooks. \n(Here is a great tutorial on exploring data and drawing graphs with Observable and Vega-Lite)\nThe iNaturalist API returns data that looks like this:\n{\n  \"total_results\": 53,\n  \"page\": 1,\n  \"per_page\": 53,\n  \"results\": {\n    \"week_of_year\": {\n      \"1\": 136,\n      \"2\": 20,\n      \"3\": 150,\n      \"4\": 65,\n      \"5\": 186,\n      \"6\": 74,\n      \"7\": 47,\n      \"8\": 87,\n      \"9\": 64,\n      \"10\": 56,\nBut for our Vega-Lite graph we need data that looks like this:\n[{\n  \"week\": \"01\",\n  \"value\": 136\n}, {\n  \"week\": \"02\",\n  \"value\": 20\n}, ...]\nWe can convert what we get back from the API to the second format using a loop that iterates over the object keys:\nobjects_to_plot = {\n  let objects = [];\n  Object.keys(pillar_point_counts_per_week.results.week_of_year).map(function(week_index) {\n    objects.push({\n      week: `Wk ${week_index.toString()}`,\n      observations: pillar_point_counts_per_week.results.week_of_year[week_index]\n    });\n  })\n  return objects;\n}\nWe can then plug this into Vega-Lite to draw us a graph:\nvegalite({\n  data: {values: objects_to_plot},\n  mark: \"bar\",\n  encoding: {\n    x: {field: \"week\", type: \"nominal\", sort: null},\n    y: {field: \"observations\", type: \"quantitative\"}\n  },\n  width: width * 0.9\n})\n\nIt\u2019s worth noting that we have a lot of observations of Nudibranchs particularly at Pillar Point due in no small part to the intertidal monitoring research that Alison Young and Rebecca Johnson facilitate for the California Achademy of Sciences. \nSo, what if we want to look for the seasonality of observations of a particular species of adorable sea slug? We want our interface to have a select box with a list of all the species you might find at any time of year. We can do this using the species_counts API to create us an object with the iNaturalist species ID and common & Latin names.\npillar_point_nudibranches = {\n  let api_results = await fetch(\n  \"https://api.inaturalist.org/v1/observations/species_counts?taxon_id=47113&nelat=37.499811&nelng=-122.492738&swlat=37.492805&swlng=-122.50542&date_field=observed&verifiable=true\"\n  ).then(r => r.json())\n\n  let species_list = api_results.results.map(i => ({\n      value: i.taxon.id,\n      label: `${i.taxon.preferred_common_name} (${i.taxon.name})`\n  }));\n\n  return species_list\n}\nWe can create an interactive select box by importing code from Jeremy Ashkanas\u2019 Observable Notebook: add import {select} from \"@jashkenas/inputs\" to a cell anywhere in our notebook. Observable is magic: like a spreadsheet, the order of the cells doesn\u2019t matter - if one cell is referenced by any other cell then when that cell updates all the other cells refresh themselves. You can also import and reference one notebook from another!\nviewof select_species = select({\n    title: \"Which Nudibranch do you want to see seasonality for?\",\n    options: [{value: \"\", label: \"All the Nudibranchs!\"}, ...pillar_point_nudibranches],\n    value: \"\"\n})\nThen we go back to our old favourite, the histogram API just like before, only this time we are calling it with the value created by our select box ${select_species} as taxon_id instead of the number 47113.\npillar_point_counts_per_month_per_species = fetch(\n  `https://api.inaturalist.org/v1/observations/histogram?taxon_id=${select_species}&nelat=37.499811&nelng=-122.492738&swlat=37.492805&swlng=-122.50542&date_field=observed&interval=month_of_year&verifiable=true`\n).then(r => r.json())\nNow for the fun graph bit! As we did before, we re-format the result of the API into a format compatible with Vega-Lite:\nobjects_to_plot_species_month = {\n  let objects = [];\n  Object.keys(pillar_point_counts_per_month_per_species.results.month_of_year).map(function(month_index) {\n    objects.push({\n      month: (new Date(2018, (month_index - 1), 1)).toLocaleString(\"en\", {month: \"long\"}),\n      observations: pillar_point_counts_per_month_per_species.results.month_of_year[month_index]\n    });\n  })\n  return objects;\n}\n(Note that in the above code we are creating a date object with our specific month in, and using toLocalString() to get the longer English name for the month. Because the JavaScript Date object counts January as 0, we use month_index -1 to get the correct month)\nAnd we draw the graph as we did before, only now if you interact with the select box in Observable the graph will dynamically update!\nvegalite({\n  data: {values: objects_to_plot_species_month},\n  mark: \"bar\",\n  encoding: {\n    x: {field: \"month\", type: \"nominal\", sort:null},\n    y: {field: \"observations\", type: \"quantitative\"}\n  },\n  width: width * 0.9\n})\nNow we can see when is the best time of year to plan to go tidepooling in Pillar Point if we want to find a specific species of Nudibranch.\n\u200b\n\nThis tool is great for planning when we to go rockpooling at Pillar Point, but what about if you are going this month and want to pre-train your eye with what to look for in order to impress your friends with your knowledge of Nudibranchs?\nWell\u2026 we can create ourselves a dynamic guide that you can with a list of the species, their photo, name and how many times they have been observed in that month of the year!\nOur select box this time looks as follows, simpler than before but assigning the month value to the variable selected_month.\nviewof selected_month = select({\n    title: \"When do you want to see Nudibranchs?\",\n    options: [\n      { label: \"Whenever\", value: \"\" },\n      { label: \"January\", value: \"1\" },\n      { label: \"February\", value: \"2\" },\n      { label: \"March\", value: \"3\" },\n      { label: \"April\", value: \"4\" },\n      { label: \"May\", value: \"5\" },\n      { label: \"June\", value: \"6\" },\n      { label: \"July\", value: \"7\" },\n      { label: \"August\", value: \"8\" },\n      { label: \"September\", value: \"9\" },\n      { label: \"October\", value: \"10\" },\n      { label: \"November\", value: \"11\" },\n      { label: \"December\", value: \"12\" },\n    ],\n    value: \"\"\n })\nWe then can use the species_counts API to get all the relevant information about which species we can see in month=${selected_month}. We\u2019ll be able to reference this response object and its values later with the variable we just created, eg: all_species_data.results[0].taxon.name.\nall_species_data = fetch(\n    `https://api.inaturalist.org/v1/observations/species_counts?taxon_id=47113&month=${selected_month}&nelat=37.499811&nelng=-122.492738&swlat=37.492805&swlng=-122.50542&verifiable=true`\n).then(r => r.json())\nYou can render HTML directly in a notebook cell using Observable\u2019s html tagged template literal:\n<style> \n.collection { margin-top: 2em }\n.collection .species { display: inline-block; width: 9em; margin-bottom: 2em; }\n.collection .species-name { font-size: 1em; margin: 0; padding: 0 } \n.collection .species-count { margin: 0 0 0.3em 0; padding: 0; font-size: 0.75em; color: #999; font-style: italic; }\n.collection img { display: block; width: 100% }\n.collection select { font-size: 1.5em; }\n</style>\n\n<h2>If you go to Pillar Point ${\n  {\"\": \"\",\n   \"1\":\"in January\",\n   \"2\":\"in Febrary\",\n   \"3\":\"in March\",\n   \"4\":\"in April\",\n   \"5\":\"in May\",\n   \"6\":\"in June\",\n   \"7\":\"in July\",\n   \"8\":\"in August\",\n   \"9\":\"in September\",\n   \"10\":\"in October\",\n   \"11\":\"in November\",\n   \"12\":\"in December\",\n  }[selected_month]\n } you might see\u2026</h2>\n\n<div class=\"collection\">\n${all_species_data.results.map(s => `<div class=\"species\"><h3 class=\"species-name\">${s.taxon.name}</h3>\n  <p class=\"species-count\">Seen ${s.count} times</p>\n  <img src=\"${s.taxon.default_photo.medium_url}\"></div>\n`)}\n</div>\nThese few lines of HTML are all you need to get this exciting dynamic guide to what Nudibranchs you will see in each month!\n\u200b\n\nPlay with it yourself in this Observable Notebook.\nConclusion\nI hope by playing with these examples you have an idea of how powerful it can be to prototype using Observable Notebooks and how you can use the incredible crowdsourced community data and APIs from iNaturalist to augment your naturalist skills and impress your friends with your new \u2018knowledge of nature\u2019 superpower.\nLastly I strongly encourage you to get outside on a low tide to explore your local rocky intertidal habitat, and all the amazing critters that live there.\nHere is a great introduction video to tidepooling / rockpooling, by Rebecca Johnson and Alison Young from the California Academy of Sciences.", "year": "2018", "author": "Natalie Downe", "author_slug": "nataliedowne", "published": "2018-12-18T00:00:00+00:00", "url": "https://24ways.org/2018/observable-notebooks-and-inaturalist/", "topic": "code"}
{"rowid": 71, "title": "Upping Your Web Security Game", "contents": "When I started working in web security fifteen years ago, web development looked very different. The few non-static web applications were built using a waterfall process and shipped quarterly at best, making it possible to add security audits before every release; applications were deployed exclusively on in-house servers, allowing Info Sec to inspect their configuration and setup; and the few third-party components used came from a small set of well-known and trusted providers. And yet, even with these favourable conditions, security teams were quickly overwhelmed and called for developers to build security in.\nIf the web security game was hard to win before, it\u2019s doomed to fail now. In today\u2019s web development, every other page is an application, accepting inputs and private data from users; software is built continuously, designed to eliminate manual gates, including security gates; infrastructure is code, with servers spawned with little effort and even less security scrutiny; and most of the code in a typical application is third-party code, pulled in through open source repositories with rarely a glance at who provided them.\nSecurity teams, when they exist at all, cannot solve this problem. They are vastly outnumbered by developers, and cannot keep up with the application\u2019s pace of change. For us to have a shot at making the web secure, we must bring security into the core. We need to give it no less attention than that we give browser compatibility, mobile design or web page load times. More broadly, we should see security as an aspect of quality, expecting both ourselves and our peers to address it, and taking pride when we do it well.\nWhere To Start?\nEmbracing security isn\u2019t something you do overnight.\nA good place to start is by reviewing things you\u2019re already doing \u2013 and trying to make them more secure. Here are three concrete steps you can take to get going.\nHTTPS\nThreats begin when your system interacts with the outside world, which often means HTTP. As is, HTTP is painfully insecure, allowing attackers to easily steal and manipulate data going to or from the server. HTTPS adds a layer of crypto that ensures the parties know who they\u2019re talking to, and that the information exchanged can be neither modified nor sniffed.\nHTTPS is relevant to any site. If your non-HTTPS site holds opinions, reading it may get your users in trouble with employers or governments. If your users believe what you say, attackers can modify your non-HTTPS to take advantage of and abuse that trust. If you want to use new browser technologies like HTTP2 and service workers, your site will need to be HTTPS. And if you want to be discovered on the web, using HTTPS can help your Google ranking. For more details on why I think you should make the switch to HTTPS, check out this post, these slides and this video.\nUsing HTTPS is becoming easier and cheaper. Here are a few free tools that can help:\n\nGet free and easy HTTPS delivery from Cloudflare (be sure to use \u201cFull SSL\u201d!)\nGet a free and automation-friendly certificate from Let\u2019s Encrypt (now in open beta).\nTest how well your HTTPS is set up using SSLTest.\n\nOther vendors and platforms are rapidly simplifying and reducing the cost of their HTTPS offering, as demand and importance grows.\nTwo-Factor Authentication\nThe most sensitive data is usually stored behind a login, and the authentication process is the primary gate in front of this data. Making this process secure has many aspects, including using HTTPS when accepting credentials, having a strong password policy, never storing the password, and more.\nAll of these are important, but the best single step to boost your authentication security is to introduce two-factor authentication (2FA). Adding 2FA usually means prompting users for an additional one-time code when logging in, which they get via SMS or a mobile app (e.g. Google Authenticator). This code is short-lived and is extremely hard for a remote attacker to guess, thus vastly reducing the risk a leaked or easily guessed password presents.\nThe typical algorithm for 2FA is based on an IETF standard called the time-based one-time password (TOTP) algorithm, and it isn\u2019t that hard to implement. Joel Franusic wrote a great post on implementing 2FA; modules like speakeasy make it even easier; and you can swap SMS with Google Authenticator or your own app if you prefer. If you don\u2019t want to build 2FA support yourself, you can purchase two/multi-factor authentication services from vendors such as DuoSecurity, Auth0, Clef, Hypr and others.\nIf implementing 2FA still feels like too much work, you can also choose to offload your entire authentication process to an OAuth-based federated login. Many companies offer this today, including Facebook, Google, Twitter, GitHub and others. These bigger players tend to do authentication well and support 2FA, but you should consider what data you\u2019re sharing with them in the process.\nTracking Known Vulnerabilities\nMost of the code in a modern application was actually written by third parties, and pulled into your app as frameworks, modules and libraries. While using these components makes us much more productive, along with their functionality we also adopt their security flaws. To make things worse, some of these flaws are well-known vulnerabilities, making it easy for hackers to take advantage of them in an attack.\nThis is a real problem and happens on pretty much every platform. Do you develop in Java? In 2014, over 6% of Java modules downloaded from Maven had a known severe security issue, the typical Java applications containing 24 flaws. Are you coding in Node.js? Roughly 14% of npm packages carry a known vulnerability, and over 60% of dev shops find vulnerabilities in their code. 30% of Docker Hub containers include a high priority known security hole, and 60% of the top 100,000 websites use client-side libraries with known security gaps.\nTo find known security issues, take stock of your dependencies and match them against language-specific lists such as Snyk\u2019s vulnerability DB for Node.js, rubysec for Ruby, victims-db for Python and OWASP\u2019s Dependency Check for Java. Once found, you can fix most issues by upgrading the component in question, though that may be tricky for indirect dependencies.  \nThis process is still way too painful, which means most teams don\u2019t do it. The Snyk team and I are hoping to change that by making it as easy as possible to find, fix and monitor known vulnerabilities in your dependencies. Snyk\u2019s wizard will help you find and fix these issues through guided upgrades and patches, and adding Snyk\u2019s test to your continuous integration and deployment (CI/CD) will help you stay secure as your code evolves.\nNote that newly disclosed vulnerabilities usually impact old code \u2013 the one you\u2019re running in production. This means you have to stay alert when new vulnerabilities are disclosed, so you can fix them before attackers can exploit them. You can do so by subscribing to vulnerability lists like US-CERT, OSVDB and NVD. Snyk\u2019s monitor will proactively let you know about new disclosures relevant to your code, but only for Node.js for now \u2013 you can register to get updated when we expand.\nSecuring Yourself\nIn addition to making your application secure, you should make the contributors to that application secure \u2013 including you. Earlier this year we\u2019ve seen attackers target mobile app developers with a malicious Xcode. The real target, however, wasn\u2019t these developers, but rather the users of the apps they create. That you create. Securing your own work environment is a key part of keeping your apps secure, and your users from being compromised.\nThere\u2019s no single step that will make you fully secure, but here are a few steps that can make a big impact:\n\nUse 2FA on all the services related to the application, notably source control (e.g. GitHub), cloud platform (e.g. AWS), CI/CD, CDN, DNS provider and domain registrar. If an attacker compromises any one of those, they could modify or replace your entire application. I\u2019d recommend using 2FA on all your personal services too.\nUse a password manager (e.g. 1Password, LastPass) to ensure you have a separate and complex password for each service. Some of these services will get hacked, and passwords will leak. When that happens, don\u2019t let the attackers access your other systems too.\nSecure your workstation. Be careful what you download, lock your screen when you walk away, change default passwords on services you install, run antivirus software, etc. Malware on your machine can translate to malware in your applications.\nBe very wary of phishing. Smart attackers use \u2018spear phishing\u2019 techniques to gain access to specific systems, and can trick even security savvy users. There are even phishing scams targeting users with 2FA. Be alert to phishy emails.\nDon\u2019t install things through curl <somewhere-on-the-web> | sudo bash, especially if the URL is on GitHub, meaning someone else controls it. Don\u2019t do it on your machines, and definitely don\u2019t do it in your CI/CD systems. Seriously.\n\nStaying secure should be important to you personally, but it\u2019s doubly important when you have privileged access to an application. Such access makes you a way to reach many more users, and therefore a more compelling target for bad actors.\nA Culture of Security\nUsing HTTPS, enabling two-factor authentication and fixing known vulnerabilities are significant steps in building security at your core. As you implement them, remember that these are just a few steps in a longer journey.\nThe end goal is to embrace security as an aspect of quality, and accept we all share the responsibility of keeping ourselves \u2013 and our users \u2013 safe.", "year": "2015", "author": "Guy Podjarny", "author_slug": "guypodjarny", "published": "2015-12-11T00:00:00+00:00", "url": "https://24ways.org/2015/upping-your-web-security-game/", "topic": "code"}
{"rowid": 235, "title": "Real Animation Using JavaScript, CSS3, and HTML5 Video", "contents": "When I was in school to be a 3-D animator, I read a book called Timing for Animation. Though only 152 pages long, it\u2019s essentially the bible for anyone looking to be a great animator. In fact, Pixar chief creative officer John Lasseter used the first edition as a reference when he was an animator at Walt Disney Studios in the early 1980s.\n\nIn the book, authors John Halas and Harold Whitaker advise:\n\n\n\tTiming is the part of animation which gives meaning to movement. Movement can easily be achieved by drawing the same thing in two different positions and inserting a number of other drawings between the two. The result on the screen will be movement; but it will not be animation.\n\n\nBut that\u2019s exactly what we\u2019re doing with CSS3 and JavaScript: we\u2019re moving elements, not animating them. We\u2019re constantly specifying beginning and end states and allowing the technology to interpolate between the two. And yet, it\u2019s the nuances within those middle frames that create the sense of life we\u2019re looking for.\n\nAs bandwidth increases and browser rendering grows more consistent, we can create interactions in different ways than we\u2019ve been able to before. We\u2019re encountering motion more and more on sites we\u2019d generally label \u2018static.\u2019 However, this motion is mostly just movement, not animation. It\u2019s the manipulation of an element\u2019s properties, most commonly width, height, x- and y-coordinates, and opacity.\n\nSo how do we create real animation?\n\nThe metaphor\n\nIn my experience, animation is most believable when it simulates, exaggerates, or defies the real world. A bowling ball falls differently than a racquetball. They each have different weights and sizes, which affect the way they land, bounce, and impact other objects.\n\nThis is a major reason that JavaScript animation frequently feels mechanical; it doesn\u2019t complete a metaphor. Expanding and collapsing a <div> feels very different than a opening a door or unfolding a piece of paper, but it often shouldn\u2019t. The interaction itself should tie directly to the art direction of a page.\n\nPhysics\n\nUnderstanding the physics of a situation is key to creating convincing animation, even if your animation seeks to defy conventional physics. Isaac Newton\u2019s first law of motion\u2019s_laws_of_motion states, \u201cEvery body remains in a state of rest or uniform motion (constant velocity) unless it is acted upon by an external unbalanced force.\u201d Once a force acts upon an object, the object\u2019s shape can change accordingly, depending on the strength of the force and the mass of the object. Another nugget of wisdom from Halas and Whitaker:\n\n\n\tAll objects in nature have their own weight, construction, and degree of flexibility, and therefore each behaves in its own individual way when a force acts upon it. This behavior, a combination of position and timing, is the basis of animation. The basic question which an animator is continually asking himself is this: \u201cWhat will happen to this object when a force acts upon it?\u201d And the success of his animation largely depends on how well he answers this question.\n\n\nIn animating with CSS3 and JavaScript, keep physics in mind. How \u2018heavy\u2019 is the element you\u2019re interacting with? What kind of force created the action? A gentle nudge? A forceful shove? These subtleties will add a sense of realism to your animations and make them much more believable to your users.\n\nMisdirection\n\nMagicians often use misdirection to get their audience to focus on one thing rather than another. They fool us into thinking something happened that actually didn\u2019t.\n\nAnimation is the same, especially on a screen. By changing the arrangement of pixels on screen at a fast enough rate, your eyes fool your mind into thinking an object is actually in motion. \n\nAnother important component of misdirecting in animation is the use of multiple objects. Try to recall a cartoon where a character vanishes. More often, the character makes some sort of exaggerated motion (this is called anticipation) then disappears, and a puff a smoke follows. That smoke is an extra element, but it goes a long way into make you believe that character actually disappeared.\n\nVery rarely does a vanishing character\u2019s opacity simply go from one hundred per cent to zero. That\u2019s not believable. So why do we do it with <div>s?\n\nArmed with the ammunition of metaphors and misdirection, let\u2019s code an example.\n\nShake, rattle, and roll\n\n(These demos require at least a basic understanding of jQuery and CSS3. Run away if your\u2019re afraid, or brush up on CSS animation and resources for learning jQuery. Also, these demos use WebKit-specific features and are best viewed in the latest version of Safari, so performance in other browsers may vary.)\n\nWe often see the design pattern of clicking a link to reveal content. Our \u201cfirst demo\u201d:\u201d/examples/2010/real-animation/demo1/ shows us exactly that. It uses jQuery\u2019s \u201c slideDown()\u201d:http://api.jquery.com/slideDown/ method, as many instances do.\n\nBut what force acted on the <div> that caused it to open? Did pressing the button unlatch some imaginary hook? Did it activate an unlocking sequence with some gears?\n\nTake 2\n\nOur second demo is more explicit about what happens: the button fell on the <div> and shook its content loose. Here\u2019s how it\u2019s done. \n\nfunction clickHandler(){\n\t$('#button').addClass('animate');\n\treturn false;\n}\n\nClicking the link adds a class of animate to our button. That class has the following CSS associated with it:\n\n<style>\n\t.animate {\n\t\t-webkit-animation-name: ANIMATE;\n\t\t-webkit-animation-duration: 0.25s;\n\t\t-webkit-animation-iteration-count: 1;\n\t\t-webkit-animation-timing-function: ease-in;\n\t}\n\t@-webkit-keyframes ANIMATE {\n\t\tfrom {\n\t\ttop: 72px;\n\t\t}\n\t\tto {\n\t\t\ttop: 112px;\n\t\t}\n\t}\n</style>\n\nIn our keyframe definition, we\u2019ve specified from and to states. This is great, because we can be explicit about how an object starts and finishes moving. \n\nWhat\u2019s also extra handy is that these CSS keyframes broadcast events that you can react to with JavaScript. In this example, we\u2019re listening to the webkitAnimationEnd event and opening the <div> only when the sequence is complete. Here\u2019s that code.\n\nfunction attachAnimationEventHandlers(){\n\tvar wrap = document.getElementById('wrap');\n\twrap.addEventListener('webkitAnimationEnd', function($e) {\n\t\tswitch($e.animationName){\n\t\t\tcase \"ANIMATE\" :\n\t\t\topenMain();\n\t\t\tbreak;\n\t\t\tdefault:\n\t\t}\n\t}, false);\n}\nfunction openMain(){\n\t$('#main .inner').slideDown('slow');\n}\n\n(For more info on handling animation events, check out the documentation at the Safari Reference Library.)\n\nTake 3\n\nThe problem with the previous demo is that the subtleties of timing aren\u2019t evident. It still feels a bit choppy.\n\nFor our third demo, we\u2019ll use percentages instead of keywords so that we can insert as many points as we need to communicate more realistic timing. The percentages allow us to add the keys to well-timed animation: anticipation, hold, release, and reaction. \n\n<style>\n\t@-webkit-keyframes ANIMATE {\n\t\t0% {\n\t\t\ttop: 72px;\n\t\t}\n\t\t40% { /* anticipation */\n\t\t\ttop: 57px;\n\t\t}\n\t\t70% { /* hold */\n\t\t\ttop: 56px;\n\t\t}\n\t\t80% { /* release */\n\t\t\ttop: 112px;\n\t\t}\n\t\t100% { /* return */\n\t\t\ttop: 72px;\n\t\t}\n\t}\n</style>\n\nTake 4\n\nThe button animation is starting to feel much better, but the reaction of the <div> opening seems a bit slow.\n\nThis fourth demo uses jQuery\u2019s delay() method to time the opening precisely when we want it. Since we know the button\u2019s animation is one second long and its reaction starts at eighty per cent of that, that puts our delay at 800ms (eighty per cent of one second). However, here\u2019s a little pro tip: let\u2019s start the opening at 750ms instead. The extra fifty milliseconds makes it feel more like the opening is a reaction to the exact hit of the button. Instead of listening for the webkitAnimationEnd event, we can start the opening as soon as the button is clicked, and the movement plays on the specified delay.\n\nfunction clickHandler(){\n\t$('#button').addClass('animate');\n\topenMain();\n\treturn false;\n}\nfunction openMain(){\n\t$('#main .inner').delay(750).slideDown('slow');\n}\n\nTake 5\n\nWe can tweak the timing of that previous animation forever, but that\u2019s probably as close as we\u2019re going to get to realistic animation with CSS and JavaScript. However, for some extra sauce, we could relegate the whole animation in our final demo to a video sequence which includes more nuances and extra elements for misdirection.\n\nHere\u2019s the basis of video replacement. Add a <video> element to the page and adjust its opacity to zero. Once the button is clicked, fade the button out and start playing the video. Once the video is finished playing, fade it out and bring the button back.\n\nfunction clickHandler(){\n\tif($('#main .inner').is(':hidden')){\n\t\t$('#button').fadeTo(100, 0);\n\t\t$('#clickVideo').fadeTo(100, 1, function(){\n\t\t\tvar clickVideo = document.getElementById('clickVideo');\n\t\t\tclickVideo.play();\n\t\t\tsetTimeout(removeVideo, 2400);\n\t\t\topenMain();\n\t\t});\n\t}\n\treturn false;\n}\nfunction removeVideo(){\n\t$('#button').fadeTo(500, 1);\n\t$('#clickVideo').fadeOut('slow');\n}\nfunction openMain(){\n\t$('#main .inner').delay(1100).slideDown('slow');\n}\n\nWrapping up\n\nI\u2019m no JavaScript expert by any stretch. I\u2019m sure a lot of you scripting wizards out there could write much cleaner and more efficient code, but I hope this gives you an idea of the theory behind more realistic motion with the technology we\u2019re using most. This is just one model of creating more convincing animation, but you can create countless variations of this, including\u2026\n\n\n\tExporting <video> animations in 3-D animation tools or 2-D animation tools like Flash or After Effects\n\tUsing <canvas> or SVG instead of <video>\n\tEmploying specific JavaScript animation frameworks\n\tMaking use of all the powerful properties of CSS Transforms and CSS Animation\n\tTrying out emerging CSS3 animation tools like Sencha Animator\n\n\nIf it wasn\u2019t already apparent, these demos show an exaggerated example and probably aren\u2019t practical in a lot of environments. However, there are a handful of great sites out there that honor animation techniques\u2014metaphor, physics, and misdirection, among others\u2014like Benjamin De Cock\u2019s vCard, 20 Things I Learned About Browsers and the Web by Fantasy Interactive, and the Nike Snowboarding site by Ian Coyle and HEGA. They\u2019re wonderful testaments to what you can do to aid interaction for users.\n\nMy goal was to show you the \u2018why\u2019 and the \u2018how.\u2019 Your charge is to discern the \u2018where\u2019 and the \u2018when.\u2019 Happy animating!", "year": "2010", "author": "Dan Mall", "author_slug": "danmall", "published": "2010-12-15T00:00:00+00:00", "url": "https://24ways.org/2010/real-animation-using-javascript-css3-and-html5-video/", "topic": "code"}
{"rowid": 300, "title": "Taking Device Orientation for a Spin", "contents": "When The Police sang \u201cDon\u2019t Stand So Close To Me\u201d they weren\u2019t talking about using a smartphone to view a panoramic image on Facebook, but they could have been. For years, technology has driven relentlessly towards devices we can carry around in our pockets, and now that we\u2019re there, we\u2019re expected to take the thing out of our pocket and wave it around in front of our faces like a psychotic donkey in search of its own dangly carrot.\nBut if you can\u2019t beat them, join them.\nA brave new world\nA couple of years back all sorts of specs for new HTML5 APIs sprang up much to our collective glee. Emboldened, we ran a few tests and found they basically didn\u2019t work in anything and went off disheartened into the corner for a bit of a sob.\nTurns out, while we were all busy boohooing, those browser boffins have actually being doing some work, and lo and behold, some of these APIs are even half usable. Mostly literally half usable\u2014we\u2019re still talking about browsers, after all.\nNow, of course they\u2019re all a bit JavaScripty and are going to involve complex methods and maths and science and probably about a thousand dependancies from Github that will fall out of fashion while we\u2019re still trying to locate the documentation, right? Well, no! \nSo what if we actually wanted to use one of these APIs, say to impress our friends with our ability to make them wave their phones in front of their faces (because no one enjoys looking hapless more than the easily-technologically-impressed), how could we do something like that? Let\u2019s find out.\nThe Device Orientation API\nThe phone-wavy API is more formally known as the DeviceOrientation Event Specification. It does a bunch of stuff that basically doesn\u2019t work, but also gives us three values that represent orientation of a device (a phone, a tablet, probably not a desktop computer) around its x, y and z axes. You might think of it as pitch, roll and yaw if you like to spend your weekends wearing goggles and a leather hat.\nThe main way we access these values is through an event listener, which can inform our code every time the value changes. Which is constantly, because you try and hold a phone still and then try and hold the Earth still too.\nThe API calls those pitch, roll and yaw values alpha, beta and gamma. Chocks away:\nwindow.addEventListener('deviceorientation', function(e) {\n    console.log(e.alpha);\n    console.log(e.beta);\n    console.log(e.gamma);\n});\nIf you look at this test page on your phone, you should be able to see the numbers change as you twirl the thing around your body like the dance partner you never had. Wrist strap recommended.\nOne important note\nLike may of these newfangled APIs, Device Orientation is only available over HTTPS. We\u2019re not allowed to have too much fun without protection, so make sure that you\u2019re working on a secure line. I\u2019ve found a quick and easy way to share my local dev environment over TLS with my devices is to use an ngrok tunnel.\nngrok http -host-header=rewrite mylocaldevsite.dev:80\nngrok will then set up a tunnel to your dev site with both HTTP and HTTPS URL options. You, of course, want the HTTPS option.\nRight, where were we?\nMake something to look at\nIt\u2019s all well and good having a bunch of numbers, but they\u2019re no use unless we do something with them. Something creative. Something to inspire the generations. Or we could just build that Facebook panoramic image viewer thing (because most of us are familiar with it and we\u2019re not trying to be too clever here). Yeah, let\u2019s just build one of those.\nOur basic framework is going to be similar to that used for an image carousel. We have a container, constrained in size, and CSS overflow property set to hidden. Into this we place our wide content and use positioning to move the content back and  forth behind the \u2018window\u2019 so that the part we want to show is visible.\nHere it is mocked up with a slider to set the position. When you release the slider, the position updates. (This actually tests best on desktop with your window slightly narrowed.)\nThe details of the slider aren\u2019t important (we\u2019re about to replace it with phone-wavy goodness) but the crucial part is that moving the slider results in a function call to position the image. This takes a percentage value (0-100) with 0 being far left and 100 being far right (or \u2018alt-nazi\u2019 or whatever).\nvar position_image = function(percent) {\n    var pos = (img_W / 100)*percent;\n    img.style.transform = 'translate(-'+pos+'px)'; \n};\nAll this does is figure out what that percentage means in terms of the image width, and set the transform: translate(\u2026); CSS property to move the image. (We use translate because it might be a bit faster to animate than left/right positioning.)\nOk. We can now read the orientation values from our device, and we can programatically position the image. What we need to do is figure out how to convert those raw orientation values into a nice tidy percentage to pass to our function and we\u2019re done. (We\u2019re so not done.)\nThe maths bit\nIf we go back to our raw values test page and make-believe that we have a fascinating panoramic image of some far-off beach or historic monument to look at, you\u2019ll note that the main value that is changing as we swing back and forth is the \u2018alpha\u2019 value. That\u2019s the one we want to track.\nAs our goal here is hey, these APIs are interesting and fun and not let\u2019s build the world\u2019s best panoramic image viewer, we\u2019ll start by making a few assumptions and simplifications:\n\nWhen the image loads, we\u2019ll centre the image and take the current nose-forward orientation reading as the middle.\nMoving left, we\u2019ll track to the left of the image (lower percentage).\nMoving right, we\u2019ll track to the right (higher percentage).\nIf the user spins round, does cartwheels or loads the page then hops on a plane and switches earthly hemispheres, they\u2019re on their own.\n\nNose-forward\nWhen the page loads, the initial value of alpha gives us our nose-forward position. In Safari on iOS, this is normalised to always be 0, whereas most everywhere else it tends to be bound to pointy-uppy north. That doesn\u2019t really matter to us, as we don\u2019t know which direction the user might be facing in anyway \u2014 we just need to record that initial state and then use it to compare any new readings.\nvar initial_position = null;\n\nwindow.addEventListener('deviceorientation', function(e) {\n    if (initial_position === null) {\n        initial_position = Math.floor(e.alpha);\n    };\n\n    var current_position = initial_position - Math.floor(e.alpha);\n});\n(I\u2019m rounding down the values with Math.floor() to make debugging easier - we\u2019ll take out the rounding later.)\nWe get our initial position if it\u2019s not yet been set, and then calculate the current position as a difference between the new value and the stored one.\nThese values are weird\nOne thing you need to know about these values, is that they range from 0 to 360 but then you also get weird left-of-zero values like -2 and whatever. And they wrap past 360 back to zero as you\u2019d expect if you do a forward roll.\nWhat I\u2019m interested in is working out my rotation. If 0 is my nose-forward position, I want a positive value as I turn right, and a negative value as I turn left. That puts the awkward 360-tipping point right behind the user where they can\u2019t see it.\nvar rotation  = current_position;\nif (current_position > 180) rotation = current_position-360;\nWhich way up?\nSince we\u2019re talking about orientation, we need to remember that the values are going to be different if the device is held in portrait on landscape mode. See for yourself - wiggle it like a steering wheel and you get different values. That\u2019s easy to account for when you know which way up the device is, but in true browser style, the API for that bit isn\u2019t well supported. The best I can come up with is:\nvar screen_portrait = false;\nif (window.innerWidth < window.innerHeight) {\n    screen_portrait = true;\n}\nIt works. Then we can use screen_portrait to branch our code:\nif (screen_portrait) {\n        if (current_position > 180) rotation = current_position-360;\n} else {\n        if (current_position < -180) rotation = 360+current_position;\n}\nHere\u2019s the code in action so you can see the values for yourself. If you change screen orientation you\u2019ll need to refresh the page (it\u2019s a demo!).\nLimiting rotation\nNow, while the youth of today are rarely seen without a phone in their hands, it would still be unreasonable to ask them to spin through 360\u00b0 to view a photo. Instead, we need to limit the range of movement to something like 60\u00b0-from-nose in either direction and normalise our values to pan the entire image across that 120\u00b0 range. -60 would be full-left (0%) and 60 would be full-right (100%).\nIf we set max_rotation = 60, that code ends up looking like this:\nif (rotation > max_rotation) rotation = max_rotation;\nif (rotation < (0-max_rotation)) rotation = 0-max_rotation;\n\nvar percent = Math.floor(((rotation + max_rotation)/(max_rotation*2))*100);\nWe should now be able to get a rotation from -60\u00b0 to +60\u00b0 expressed as a percentage. Try it for yourself.\nThe big reveal\nAll that\u2019s left to do is pass that percentage to our image positioning function and would you believe it, it might actually work.\nposition_image(percent);\nYou can see the final result and take it for a spin. Literally.\nSo what have we made here? Have we built some highly technical panoramic image viewer to aid surgeons during life-saving operations using only JavaScript and some slightly questionable mathematics? No, my friends, we have not. Far from it. \nWhat we have made is progress. We\u2019ve taken a relatively newly available hardware API and a bit of simple JavaScript and paired it with existing CSS knowledge and made something that we didn\u2019t have this morning. Something we probably didn\u2019t even want this morning. Something that if you take a couple of steps back and squint a bit might be a prototype for something vaguely interesting. But more importantly, we\u2019ve learned that our browsers are just a little bit more capable than we thought.\nThe web platform is maturing rapidly. There are new, relatively unexplored APIs for doing all sorts of crazy thing that are often dismissed as the preserve of native apps. Like some sort of app marmalade. Poppycock. \nThe web is an amazing, exciting place to create things. All it takes is some base knowledge of the fundamentals, a creative mind and a willingness to learn. We have those! So let\u2019s create things.", "year": "2016", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2016-12-24T00:00:00+00:00", "url": "https://24ways.org/2016/taking-device-orientation-for-a-spin/", "topic": "code"}
{"rowid": 181, "title": "Working With RGBA Colour", "contents": "When Tim and I were discussing the redesign of this site last year, one of the clear goals was to have a graphical style without making the pages heavy with a lot of images. When we launched, a lot of people were surprised that the design wasn\u2019t built with PNGs. Instead we\u2019d used RGBA colour values, which is part of the CSS3 specification.\n\nWhat is RGBA Colour?\n\nWe\u2019re all familiar with specifying colours in CSS using by defining the mix of red, green and blue light required to achieve our tone. This is fine and dandy, but whatever values we specify have one thing in common \u2014 the colours are all solid, flat, and well, a bit boring.\n\n Flat RGB colours\n\nCSS3 introduces a couple of new ways to specify colours, and one of those is RGBA. The A stands for Alpha, which refers to the level of opacity of the colour, or to put it another way, the amount of transparency. This means that we can set not only the red, green and blue values, but also control how much of what\u2019s behind the colour shows through. Like with layers in Photoshop.\n\nDon\u2019t We Have Opacity Already?\n\nThe ability to set the opacity on a colour differs subtly from setting the opacity on an element using the CSS opacity property. Let\u2019s look at an example.\n\nHere we have an H1 with foreground and background colours set against a page with a patterned background.\n\n Heading with no transparency applied\n\nh1 {\n\tcolor: rgb(0, 0, 0);\n\tbackground-color: rgb(255, 255, 255);\n}\n\nBy setting the CSS opacity property, we can adjust the transparency of the entire element and its contents:\n\n Heading with 50% opacity on the element\n\nh1 {\n\tcolor: rgb(0, 0, 0);\n\tbackground-color: rgb(255, 255, 255);\n\topacity: 0.5;\n}\n\nRGBA colour gives us something different \u2013 the ability to control the opacity of the individual colours rather than the entire element. So we can set the opacity on just the background:\n\n 50% opacity on just the background colour\n\nh1 {\n\tcolor: rgb(0, 0, 0);\n\tbackground-color: rgba(255, 255, 255, 0.5);\n}\n\nOr leave the background solid and change the opacity on just the text:\n\n 50% opacity on just the foreground colour\n\nh1 {\n\tcolor: rgba(0, 0, 0, 0.5);\n\tbackground-color: rgb(255, 255, 255);\n}\n\nThe How-To\n\nYou\u2019ll notice that above I\u2019ve been using the rgb() syntax for specifying colours. This is a bit less common than the usual hex codes (like #FFF) but it makes sense when starting to use RGBA. As there\u2019s no way to specify opacity with hex codes, we use rgba() like so:\n\ncolor: rgba(255, 255, 255, 0.5);\n\nJust like rgb() the first three values are red, green and blue. You can specify these 0-255 or 0%-100%. The fourth value is the opacity level from 0 (completely transparent) to 1 (completely opaque).\n\nYou can use this anywhere you\u2019d normally set a colour in CSS \u2014 so it\u2019s good for foregrounds and background, borders, outlines and so on. All the transparency effects on this site\u2019s current design are achieved this way.\n\nSupporting All Browsers\n\nLike a lot of the features we\u2019ll be looking at in this year\u2019s 24 ways, RGBA colour is supported by a lot of the newest browsers, but not the rest. Firefox, Safari, Chrome and Opera browsers all support RGBA, but Internet Explorer does not.\n\nFortunately, due to the robust design of CSS as a language, we can specify RGBA colours for browsers that support it and an alternative for browsers that do not.\n\nFalling back to solid colour\n\nThe simplest technique is to allow the browser to fall back to using a solid colour when opacity isn\u2019t available. The CSS parsing rules specify that any unrecognised value should be ignored. We can make use of this because a browser without RGBA support will treat a colour value specified with rgba() as unrecognised and discard it.\n\nSo if we specify the colour first using rgb() for all browsers, we can then overwrite it with an rgba() colour for browsers that understand RGBA.\n\nh1 {\n\tcolor: rgb(127, 127, 127);\n\tcolor: rgba(0, 0, 0, 0.5);\n}\n\nFalling back to a PNG\n\nIn cases where you\u2019re using transparency on a background-color (although not on borders or text) it\u2019s possible to fall back to using a PNG with alpha channel to get the same effect. This is less flexible than using CSS as you\u2019ll need to create a new PNG for each level of transparency required, but it can be a useful solution.\n\nUsing the same principal as before, we can specify the background in a style that all browsers will understand, and then overwrite it in a way that browsers without RGBA support will ignore.\n\nh1 {\n\tbackground: transparent url(black50.png);\n\tbackground: rgba(0, 0, 0, 0.5) none;\n}\n\nIt\u2019s important to note that this works because we\u2019re using the background shorthand property, enabling us to set both the background colour and background image in a single declaration. It\u2019s this that enables us to rely on the browser ignoring the second declaration when it encounters the unknown rgba() value.\n\nNext Steps\n\nThe really great thing about RGBA colour is that it gives us the ability to create far more graphically rich designs without the need to use images. Not only does that make for faster and lighter pages, but sites which are easier and quicker to build and maintain. CSS values can also be changed in response to user interaction or even manipulated with JavaScript in a way that\u2019s just not so easy using images.\n\n Opacity can be changed on :hover or manipulated with JavaScript\n\ndiv {\n\tcolor: rgba(255, 255, 255, 0.8);\n\tbackground-color: rgba(142, 213, 87, 0.3);\n}\ndiv:hover {\n\tcolor: rgba(255, 255, 255, 1);\n\tbackground-color: rgba(142, 213, 87, 0.6);\n}\n\nClever use of transparency in border colours can help ease the transition between overlay items and the page behind.\n\n Borders can receive the RGBA treatment, too\n\ndiv {\n\tcolor: rgb(0, 0, 0);\n\tbackground-color: rgb(255, 255, 255);\n\tborder: 10px solid rgba(255, 255, 255, 0.3);\n}\n\nIn Conclusion\n\n\nThat\u2019s a brief insight into RGBA colour, what it\u2019s good for and how it can be used whilst providing support for older browsers. With the current lack of support in Internet Explorer, it\u2019s probably not a technique that commercial designs will want to heavily rely on right away \u2013 simply because of the overhead of needing to think about fallback all the time. \n\nIt is, however, a useful tool to have for those smaller, less critical touches that can really help to finesse a design. As browser support becomes more mainstream, you\u2019ll already be familiar and practised with RGBA and ready to go.", "year": "2009", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2009-12-01T00:00:00+00:00", "url": "https://24ways.org/2009/working-with-rgba-colour/", "topic": "code"}
{"rowid": 334, "title": "Transitional vs. Strict Markup", "contents": "When promoting web standards, standardistas often talk about XHTML as being more strict than HTML. In a sense it is, since it requires that all elements are properly closed and that attribute values are quoted. But there are two flavours of XHTML 1.0 (three if you count the Frameset DOCTYPE, which is outside the scope of this article), defined by the Transitional and Strict DOCTYPEs. And HTML 4.01 also comes in those flavours.\n\nThe names reveal what they are about: Transitional DOCTYPEs are meant for those making the transition from older markup to modern ways. Strict DOCTYPEs are actually the default \u2013 the way HTML 4.01 and XHTML 1.0 were constructed to be used.\n\nA Transitional DOCTYPE may be used when you have a lot of legacy markup that cannot easily be converted to comply with a Strict DOCTYPE. But Strict is what you should be aiming for. It encourages, and in some cases enforces, the separation of structure and presentation, moving the presentational aspects from markup to CSS. From the HTML 4 Document Type Definition:\n\n\n\tThis is HTML 4.01 Strict DTD, which excludes the presentation attributes and elements that W3C expects to phase out as support for style sheets matures. Authors should use the Strict DTD when possible, but may use the Transitional DTD when support for presentation attribute and elements is required.\n\n\nAn additional benefit of using a Strict DOCTYPE is that doing so will ensure that browsers use their strictest, most standards compliant rendering modes.\n\nTommy Olsson provides a good summary of the benefits of using Strict over Transitional in Ten questions for Tommy Olsson at Web Standards Group:\n\n\n\tIn my opinion, using a Strict DTD, either HTML 4.01 Strict or XHTML 1.0 Strict, is far more important for the quality of the future web than whether or not there is an X in front of the name. The Strict DTD promotes a separation of structure and presentation, which makes a site so much easier to maintain.\n\n\nFor those looking to start using web standards and valid, semantic markup, it is important to understand the difference between Transitional and Strict DOCTYPEs. For complete listings of the differences between Transitional and Strict DOCTYPEs, see XHTML: Differences between Strict & Transitional, Comparison of Strict and Transitional XHTML, and XHTML1.0 Element Attributes by DTD.\n\nSome of the differences are more likely than others to cause problems for developers moving from a Transitional DOCTYPE to a Strict one, and I\u2019d like to mention a few of those.\n\nElements that are not allowed in Strict DOCTYPEs\n\n\n\tcenter\n\tfont\n\tiframe\n\tstrike\n\tu\n\n\nAttributes not allowed in Strict DOCTYPEs\n\n\n\talign (allowed on elements related to tables: col, colgroup, tbody, td, tfoot, th, thead, and tr)\n\tlanguage\n\tbackground\n\tbgcolor\n\tborder (allowed on table)\n\theight (allowed on img and object)\n\thspace\n\tname (allowed in HTML 4.01 Strict, not allowed on form and img in XHTML 1.0 Strict)\n\tnoshade\n\tnowrap\n\ttarget\n\ttext, link, vlink, and alink\n\tvspace\n\twidth (allowed on img, object, table, col, and colgroup)\n\n\nContent model differences\n\nAn element type\u2019s content model describes what may be contained by an instance of the element type. The most important difference in content models between Transitional and Strict is that blockquote, body, and form elements may only contain block level elements. A few examples:\n\n\n\ttext and images are not allowed immediately inside the body element, and need to be contained in a block level element like p or div\n\tinput elements must not be direct descendants of a form element\n\ttext in blockquote elements must be wrapped in a block level element like p or div\n\n\nGo Strict and move all presentation to CSS\n\nSomething that can be helpful when doing the transition from Transitional to Strict DOCTYPEs is to focus on what each element of the page you are working on is instead of how you want it to look.\n\nWorry about looks later and get the structure and semantics right first.", "year": "2005", "author": "Roger Johansson", "author_slug": "rogerjohansson", "published": "2005-12-13T00:00:00+00:00", "url": "https://24ways.org/2005/transitional-vs-strict-markup/", "topic": "code"}
{"rowid": 316, "title": "Have Your DOM and Script It Too", "contents": "When working with the XMLHttpRequest object it appears you can only go one of three ways: \n\n\n\tYou can stay true to the colorful moniker du jour and stick strictly to the responseXML property\n\tYou can play with proprietary \u2013 yet widely supported \u2013 fire and inject the value of responseText property into the innerHTML of an element of your choosing\n\tOr you can be eval() and parse JSON or arbitrary JavaScript delivered via responseText\n\n\nBut did you know that there\u2019s a fourth option giving you the best of the latter two worlds? Mint uses this unmentioned approach to grab fresh HTML and run arbitrary JavaScript simultaneously. Without relying on eval(). \u201cBut wait-\u201d, you might say, \u201cwhen would I need to do this?\u201d Besides the example below this technique is handy for things like tab groups that need initialization onload but miss the main onload event handler by a mile thanks to asynchronous scripting.\n\nConsider the problem\n\nOriginally Mint used option 2 to refresh or load new tabs into individual Pepper panes without requiring a full roundtrip to the server. This was all well and good until I introduced the new Client Mode which when enabled allows anyone to view a Mint installation without being logged in. If voyeurs are afoot as Client Mode is disabled, the next time they refresh a pane the entire login page is inserted into the current document. That\u2019s not very helpful so I needed a way to redirect the current document to the login page.\n\n\n\nEnter the solution\n\nWouldn\u2019t it be cool if browsers interpreted the contents of script tags crammed into innerHTML? Sure, but unfortunately, that just wasn\u2019t meant to be. However like the body element, image elements have an onload event handler. When the image has fully loaded the handler runs the code applied to it. See where I\u2019m going with this?\n\nBy tacking a tiny image (think single pixel, transparent spacer gif \u2013 shudder) onto the end of the HTML returned by our Ajax call, we can smuggle our arbitrary JavaScript into the existing document. The image is added to the DOM, and our stowaway can go to town.\n\n<p>This is the results of our Ajax call.</p>\n <img src=\"../images/loaded.gif\" alt=\"\" onload=\"alert('Now that I have your attention...');\" />\n\nPlease be neat\n\nSo we\u2019ve just jammed some meaningless cruft into our DOM. If our script does anything with images this addition could have some unexpected side effects. (Remember The Fly?) So in order to save that poor, unsuspecting element whose innerHTML we just swapped out from sharing Jeff Goldblum\u2019s terrible fate we should tidy up after ourselves. And by using the removeChild method we do just that.\n\n<p>This is the results of our Ajax call.</p>\n <img src=\"../images/loaded.gif\" alt=\"\" \n     onload=\"alert('Now that I have your attention...');this.parentNode.removeChild(this);\" />", "year": "2005", "author": "Shaun Inman", "author_slug": "shauninman", "published": "2005-12-24T00:00:00+00:00", "url": "https://24ways.org/2005/have-your-dom-and-script-it-too/", "topic": "code"}
{"rowid": 89, "title": "Direction, Distance and Destinations", "contents": "With all these new smartphones in the hands of lost and confused owners, we need a better way to represent distances and directions to destinations. The immediate examples that jump to mind are augmented reality apps which let you see another world through your phone\u2019s camera. While this is interesting, there is a simpler way: letting people know how far away they are and if they are getting warmer or colder. \n\nIn the app world, you can easily tap into the phone\u2019s array of sensors such as the GPS and compass, but what people rarely know is that you can do the same with HTML. The native versus web app debate will never subside, but at least we can show you how to replicate some of the functionality progressively in HTML and JavaScript.\n\nIn this tutorial, we\u2019ll walk through how to create a simple webpage listing distances and directions of a few popular locations around the world. We\u2019ll use JavaScript to access the device\u2019s geolocation API and also attempt to access the compass to get a heading. Both of these APIs are documented, to be included in the W3C geolocation API specification, and can be used on both desktop and mobile devices today.\n\nTo get started, we need a list of a few locations around the world. I have chosen the highest mountain peak on each continent so you can see a diverse set of distances and directions. \n\n\n\t\t\n\t\t\tMountain \n\t\t\t\u00b0Latitude \n\t\t\t\u00b0Longitude \n\t\t\n\t\t\n\t\t\tKilimanjaro\n\t\t\t-3.075833\n\t\t\t37.353333\n\t\t\n\t\t\n\t\t\tVinson Massif\n\t\t\t-78.525483\n\t\t\t-85.617147\n\t\t\n\t\t\n\t\t\tPuncak Jaya\n\t\t\t-4.078889\n\t\t\t137.158333\n\t\t\n\t\t\n\t\t\tEverest\n\t\t\t27.988056\n\t\t\t86.925278\n\t\t\n\t\t\n\t\t\tElbrus\n\t\t\t43.355\n\t\t\t42.439167\n\t\t\n\t\t\n\t\t\tMount McKinley\n\t\t\t63.0695\n\t\t\t-151.0074\n\t\t\n\t\t\n\t\t\tAconcagua\n\t\t\t-32.653431\n\t\t\t-70.011083\n\t\t\n\n\nSource: Wikipedia \n\nWe can put those into an HTML list to be styled and accessed by JavaScript to create some distance and directions calculations.\n\nThe next thing we need to do is check to see if the browser and operating system have geolocation support. To do this we test to see if the function is available or not using a single JavaScript if statement.\n\n<script>\n// If this is true, then the method is supported and we can try to access the location\nif (navigator.geolocation) {\n\tnavigator.geolocation.getCurrentPosition(geo_success, geo_error);\n}\n</script>\n\nThe if statement will be false if geolocation support is not present, and then it is up to you to do something else instead as a fallback. For this example, we\u2019ll do nothing since our page should work as is and only get progressively better if more functionality is available. \n\nThe if statement will be true if there is support and therefore will continue inside the curly brackets to try to get the location. This should prompt the reader to accept or deny the request to get their location. If they say no, the second function callback is processed, in this case a function called geo_error; whereas if the location is available, it fires the geo_success function callback.\n\nThe function geo_error(){ } isn\u2019t that exciting. You can handle this in any way you see fit. The success function is more interesting. We get a position object passed into the function which contains a series of exciting attributes, namely the latitude and longitude of the device\u2019s current location.\n\nfunction geo_success(position){\n\tgLat = position.coords.latitude;\n\tgLon = position.coords.longitude;\n}\n\nNow, in the variables gLat and gLon we have the user\u2019s approximate geographical position. We can use this information to start to calculate some distances between where they are and all the destinations.\n\nAt the time of writing, you can also get position.coords.heading, but on Windows and iOS devices this returned NULL. In the future, if and when this is supported, this is also where you can easily grab the compass information.\n\nInside the geo_success function, we want to loop through the HTML to get all of the mountain peaks\u2019 latitudes and longitudes and compute the distance.\n\n...\n$('.geo').each(function(){\n\t// Get the lat/lon from the HTML\n\ttLat = $(this).find('.lat').html()\n\ttLon = $(this).find('.lon').html()\n\n\t// compute the distances between the current location and this points location\n\tdist = distance(tLat,tLon,gLat,gLon);\n\n\t// set the return values into something useful\n\td = parseInt(dist[0]*10)/10;\n\ta = parseFloat(dist[1]);\n\n\t// display the value in the HTML and style the arrow\n\t$(this).find('.distance').html(d+' km away');\n\t$(this).find('.direction').css('-webkit-transform','rotate(-' + a + 'deg)');\n\n\t// store the arc for later use if compass is available\n\t$(this).attr('data-arc',a);\n}\n\nIn the variable d we have the distance between the current location and the location of the mountain peak based on the Haversine Formula. The variable a is the arc, which has a value from 0 to 359.99. This will be useful later if we have compass support. Given these two values we have a distance and a heading to style the HTML.\n\nThe next thing we want to do is check to see if the device has a compass and then get access to the the current heading. As we\u2019ll see, there are several ways to do this, some of which work on certain devices but not others. The W3C geolocation spec says that, along with the coordinates, there are several other attributes: accuracy; altitude; and heading. Heading is the direction to true north, which is different than magnetic north! WebKit and Windows return NULL for the heading value, but WebKit has an experimental method to fetch the heading. If you get into accessing these sensors, you\u2019ll have to try to catch a few of these methods to finally get a value. Assuming you do, we can move on to the more interesting display opportunities.\n\nIn an ideal world, this would succeed and set a variable we\u2019ll call compassHeading to get a value between 0 and 359.99 degrees. Now we know which direction north is, we also know the direction relative to north of the path to our destination, so we can can subtract the two values to get an arrow to display on the screen. But we\u2019re not finished yet: we also need to get the device\u2019s orientation (landscape or portrait) and subtract the correct amount from the angle for the arrow. Once we have a value, we can use CSS to rotate the arrow the correct number of degrees.\n\n-webkit-transform: rotate(-180deg)\n\nNot all devices support a standard way to access compass information, so in the meantime we need to use a work around. On iOS, you can use the experimental event method e.webkitCompassHeading. We want the compass to update in real time as the device is moved around, so we\u2019ll put this inside an event listener.\n\nwindow.addEventListener('deviceorientation', function(e) {\n\t// Loop through all the locations on the page\n\t$('.geo').each(function(){\n\t\t// get the arc value from north we computed and stored earlier\n\t\tdestination_arc = parseInt($(this).attr('data-arc'))\n\t\tcompassHeading = e.webkitCompassHeading + window.orientation + destination_arc;\n\t\t// find the arrow element and rotate it accordingly\n\t\t$(this).find('.direction').css('-webkit-transform','rotate(-' + compassHeading + 'deg)');\t\t\n\t}\n}\n\nAs the device is rotated, the compass arrow will constantly be updated. If you want to see an example, you can have a look at this page which shows the distances to all the peaks on each continent.\n\nWith progressive enhancement, we slowly layer on additional functionality as we go. The reader will first see the list of locations with a latitude and longitude. If the device is capable and permissions allow, it will then compute the distance. If a compass is available, with the correct permissions it will then add the final layer which is direction.\n\nYou should consider this code a stub for your projects. If you are making a hyperlocal webpage with restaurant locations, for example, then consider adding these features. Knowing not only how far away a place is, but also the direction can be hugely important, and since the compass is always active, it acts as a guide to the location. \n\nFuture developments\n\nImprovements to this could include setting a timer and recalling the navigator.geolocation.getCurrentPosition() function and updating the distances. I chose very distant mountains so kilometres made sense, but you can divide again by 1,000 to convert to metres if you are dealing with much nearer places. Walking or driving would change the distances so the ability to refresh would be important. \n\nIt is outside the scope of this article, but if you manage to get this HTML to work offline, then you can make a nice web app which sits on your devices\u2019 homescreens and works even without an internet connection. This could be ideal for travellers in an unknown city looking for your destination. Just with offline storage, base64 encoding and data URIs, it is possible to embed plenty of design and functionality into a small offline webpage.\n\nNow you know how to use JavaScript to look up a destination\u2019s location and figure out the distance and direction \u2013 never get lost again.", "year": "2012", "author": "Brian Suda", "author_slug": "briansuda", "published": "2012-12-19T00:00:00+00:00", "url": "https://24ways.org/2012/direction-distance-and-destinations/", "topic": "code"}
{"rowid": 30, "title": "Making Sites More Responsive, Responsibly", "contents": "With digital projects we\u2019re used to shifting our thinking to align with our target audience. We may undertake research, create personas, identify key tasks, or observe usage patterns, with our findings helping to refine our ongoing creations.\u00a0A product\u2019s overall experience can make or break its success, and when it comes to defining these experiences our development choices play a huge role alongside more traditional user-focused activities.\n\nThe popularisation of responsive web design is a great example of how we are able to shape the web\u2019s direction through using technology to provide better experiences. If we think back to the move from table-based layouts to CSS, initially our clients often didn\u2019t know or care about the difference in these approaches, but\u00a0we\u00a0did. Responsive design was similar in this respect \u2013 momentum grew through the web industry choosing to use an approach that we felt would give a better experience, and which was more future-friendly.\u00a0\n\nWe tend to think of responsive design as a means of displaying content appropriately across a range of devices, but the technology and our implementation of it can facilitate much more. A responsive layout not only helps your content work when the newest smartphone comes out, but it also ensures your layout suitably adapts if a visually impaired user drastically changes the size of the text.\n\n The 24 ways site at 400% on a Retina MacBook Pro displays a layout more typically used for small screens.\n\nWhen we think more broadly, we realise that our technical choices and approaches to implementation can have knock-on effects for the greater good, and beyond our initial target audiences. We can make our experiences more\u00a0responsive to people\u2019s needs, enhancing their usability and accessibility along the way.\n\nBeing responsibly responsive\n\nOf course, when we think about being more responsive, there\u2019s a fine line between creating useful functionality and becoming intrusive and overly complex. In the excellent Responsible Responsive Design, Scott Jehl states that:\n\n\nA responsible responsive design equally considers the following throughout a project:\n\nUsability: The way a website\u2019s user interface is presented to the user, and how that UI responds to browsing conditions and user interactions.\nAccess: The ability for users of all devices, browsers, and assistive technologies to access and understand a site\u2019s features and content.\nSustainability: The ability for the technology driving a site or application to work for devices that exist today and to continue to be usable and accessible to users, devices, and browsers in the future.\nPerformance: The speed at which a site\u2019s features and content are perceived to be delivered to the user and the efficiency with which they operate within the user interface.\n\n\n\nScott\u2019s book covers these ideas in a lot more detail than I\u2019ll be able to here (put it on your Christmas list if it\u2019s not there already), but for now let\u2019s think a bit more about our roles as digital creators\u00a0and the power this gives us.\n\nOur choices around technology and the decisions we have to make can be extremely wide-ranging. Solutions will vary hugely depending on the needs of each project, though we can further explore the concept of making our creations more responsive through the use of humble web technologies.\n\nThe power of the web\n\nWe all know that under the HTML5 umbrella are some great new capabilities, including a number of JavaScript APIs such as geolocation, web audio, the file API and many more. We often use these to enhance the functionality of our sites and apps, to add in new features, or to facilitate device-specific interactions.\n\nYou\u2019ll have seen articles with flashy titles such as \u201cTop 5 JavaScript APIs You\u2019ve Never Heard Of!\u201d, which you\u2019ll probably read, think \u201cThat\u2019s quite cool\u201d, yet never use in any real work.\n\nThere is great potential for technologies like these\u00a0to be misused, but there are also great prospects for them to be used well to enhance experiences. Let\u2019s have a look at a few\u00a0examples you may not have considered.\n\nOffline first\n\nWhen we make websites, many of us follow a process which involves user stories \u2013 standardised snippets of context explaining who needs what, and why.\n\n\u201cAs a student I want to pay online for my course so I don\u2019t have to visit the college in person.\u201d\n\n\u201cAs a retailer I want to generate unique product codes so I can manage my stock.\u201d\n\nWe very often focus heavily on what\u00a0needs doing, but may not consider carefully how it will be done. As in Scott\u2019s list, accessibility is extremely important, not only in terms of providing a great experience to users of assistive technologies, but also to make your creation more accessible in the general sense \u2013 including under different conditions.\n\nOffline first is yet another \u2018first\u2019 methodology (my personal favourite being \u2018tea first\u2019), which encourages us to develop so that connectivity\u00a0itself is an enhancement \u2013 letting\u00a0users continue with tasks even when they\u2019re offline. Despite the rapid growth in public Wi-Fi, if we consider data costs and connectivity in developing countries, our travel habits with planes, underground trains and roaming (or simply if you live in the UK\u2019s signal-barren East Anglian wilderness as I do), then you\u2019ll realise that connectivity isn\u2019t as ubiquitous as our internet-addled brains would make us believe. Take a scenario that I\u2019m sure we\u2019re all familiar with \u2013 the digital conference. Your venue may be in a city served by high-speed networks, but after overloading capacity with a full house of hashtag-hungry attendees, each carrying several devices, then everyone\u2019s likely to be offline after all. Wouldn\u2019t it be better if we could do something like this instead?\n\n\n\tSomeone visits our conference website.\n\tOn this initial run, some assets may be cached for future use: the conference schedule, the site\u2019s CSS, photos of the speakers.\n\tWhen the attendee revisits the site on the day, the page shell loads up from the cache.\n\tIf we have cached content (our session timetable, speaker photos or anything else), we can load it directly from the cache. We might then try to update this, or get some new content from the internet, but the conference attendee already has a base experience to use.\n\tIf we don\u2019t have something cached already, then we can try\u00a0grabbing it online.\n\tIf for any reason our requests for new content fail (we\u2019re offline), then we can display a pre-cached error message from the initial load, perhaps providing our users with alternative suggestions from what is\u00a0cached.\n\n\nThere are a number of ways we can make something like this, including using the application cache (AppCache) if you\u2019re that way inclined. However, you may want to look into service workers\u00a0instead. There are also some great resources on Offline First!\u00a0if you\u2019d like to find out more about this.\n\nBuilding in offline functionality isn\u2019t necessarily about starting offline first, and it\u2019s also perfectly possible to retrofit sites and apps to catch offline scenarios, but this kind of graceful degradation can end up being more complex than if we\u2019d considered it from the start. By treating connectivity as an enhancement, we can improve the experience and provide better performance than we can when waiting to counter failures. Our websites can respond to connectivity and usage scenarios, on top of adapting how we present our content. Thinking in this way can enhance each point in Scott\u2019s criteria.\n\nAs I mentioned, this isn\u2019t necessarily the kind of development choice that our clients will ask us for, but it\u2019s one we may decide is simply the right way to build based on our project, enhancing the experience we provide to people, and making it more responsive to their situation.\n\nEven more accessible\n\nWe\u2019ve looked at accessibility in terms of broadening when we can interact with a website, but what about how? Our user stories and personas are often of limited use. We refer in very general terms to students, retailers, and sometimes just users. What if we have a student whose needs are very different from another student? Can we make our sites even more usable and accessible through our development choices?\n\nAgain using JavaScript to illustrate this concept, we can do a lot more with the ways people interact with our websites, and with the feedback we provide, than simply accepting keyboard, mouse and touch inputs and displaying output on a screen.\n\nInput\n\nAmbient light detection is one of those features that looks great in simple demos, but which we struggle to put to practical use. It\u2019s not new \u2013 many satnav systems automatically change the contrast for driving at night or in tunnels, and our laptops may alter the screen brightness or keyboard backlighting to better adapt to our surroundings. Using web technologies we can adapt our presentation to be better suited to ambient light levels.\n\nIf our device has an appropriate light sensor and runs a browser that supports the API, we can grab the ambient light in units using ambient light events, in JavaScript. We may then change our presentation based on different bandings, perhaps like this:\n\nwindow.addEventListener('devicelight', function(e) {\n    var lux = e.value;\n\n    if (lux < 50) {\n        //Change things for dim light\n    }\n    if (lux >= 50 && lux <= 10000) {\n        //Change things for normal light\n    }\n    if (lux > 10000) {\n        //Change things for bright light\n    }\n});\n\nLive demo\u00a0(requires light sensor and supported browser).\n\nSoon we may also be able to do such detection through CSS, with light-level being cited in the Media Queries Level 4 specification. If that becomes the case, it\u2019ll probably look something like this:\n\n@media (light-level: dim) {\n  /*Change things for dim light*/\n}\n\n@media (light-level: normal) {\n  /*Change things for normal light*/\n}\n\n@media (light-level: washed) {\n  /*Change things for bright light*/\n}\n\nWhile we may be quick to dismiss this kind of detection as being a gimmick, it\u2019s important to consider that apps such as Light Detector, listed on Apple\u2019s accessibility page, provide important context around exactly this functionality.\n\n\n\t\u201cIf you are blind, Light Detector helps you to be more independent in many daily activities. At home, point your iPhone towards the ceiling to understand where the light fixtures are and whether they are switched on. In a room, move the device along the wall to check if there is a window and where it is. You can find out whether the shades are drawn by moving the device up and down.\u201d\n\n\teverywaretechnologies.com/apps/lightdetector\n\n\nInput can be about so much more than what we enter through keyboards. Both an ever increasing amount of available sensors and more APIs being supported by the major browsers will allow us to cater for more scenarios and respond to them accordingly. This can be as complex or simple as you need; for instance, while x-webkit-speech has been deprecated, the web speech API is available for a number of browsers, and research into sign language detection is also being performed by organisations such as Microsoft.\n\nOutput\n\nWeb technologies give us some great enhancements around input, allowing us to adapt our experiences accordingly. They also provide us with some nice ways to provide feedback to users.\n\nWhen we play video games, many of our modern consoles come with the ability to have rumble effects on our controller pads. These are a great example of an enhancement, as they provide a level of feedback that is entirely optional, but which can give a great deal of extra information to the player in the right circumstances, and broaden the scope of our comprehension beyond what we\u2019re seeing and hearing.\n\nHaptic feedback is possible on the web as well. We could use this in any number of responsible applications, such as alerting a user to changes or using different patterns as a communication mechanism. If you find yourself in a pickle, here\u2019s how to print out SOS in Morse code through the vibration API. The following code indicates the length of vibration in milliseconds, interspersed by pauses in milliseconds.\n\nnavigator.vibrate([100, 300, 100, 300, 100, 300, 600, 300, 600, 300, 600, 300, 100, 300, 100, 300, 100]);\n\nLive demo\u00a0(requires supported browser)\n\nWith great power\u2026\n\nWhat you\u2019ve no doubt come to realise by now is that these are just more examples of progressive enhancement, whose inclusion will provide a better experience if the capabilities are available, but which we should not rely on. This idea isn\u2019t new, but the most important thing to remember, and what I would like you to take away from this article, is that it is up to us to decide to include these kind of approaches within our projects \u2013 if we don\u2019t root for them, they probably won\u2019t happen. This is where our professional responsibility comes in.\n\nWe won\u2019t necessarily be asked to implement solutions for the scenarios above, but they illustrate how we can help to push the boundaries of experiences. Maybe we\u2019ll have to switch our thinking about how we build, but we can create more usable products for a diverse range of people and usage scenarios through the choices we make around technology. Let\u2019s stop thinking simply in terms of features inside a narrow view of our target users, and work out how we can extend these to cater for a wider set of situations.\n\nWhen you plan your next digital project, consider the power of the web and the enhancements we can use, and try to make your projects even more responsive and responsible.", "year": "2014", "author": "Sally Jenkinson", "author_slug": "sallyjenkinson", "published": "2014-12-10T00:00:00+00:00", "url": "https://24ways.org/2014/making-sites-more-responsive-responsibly/", "topic": "code"}
{"rowid": 221, "title": "\u201cProbably, Maybe, No\u201d: The State of HTML5 Audio", "contents": "With the hype around HTML5 and CSS3 exceeding levels not seen since 2005\u2019s Ajax era, it\u2019s worth noting that the excitement comes with good reason: the two specifications render many years of feature hacks redundant by replacing them with native features. For fun, consider how many CSS2-based rounded corners hacks you\u2019ve probably glossed over, looking for a magic solution. These days, with CSS3, the magic is border-radius (and perhaps some vendor prefixes) followed by a coffee break.\n\nCSS3\u2019s border-radius, box-shadow, text-shadow and gradients, and HTML5\u2019s <canvas>, <audio> and <video> are some of the most anticipated features we\u2019ll see put to creative (ab)use as adoption of the \u2018new shiny\u2019 grows. Developers jumping on the cutting edge are using subsets of these features to little detriment, in most cases. The more popular CSS features are design flourishes that can degrade nicely, but the current audio and video implementations in particular suffer from a number of annoyances.\n\nThe new shiny: how we got here\n\nSound involves one of the five senses, a key part of daily life for most \u2013 and yet it has been strangely absent from HTML and much of the web by default. From a simplistic perspective, it seems odd that HTML did not include support for the full multimedia experience earlier, despite the CD-ROM-based craze of the early 1990s. In truth, standards like HTML can take much longer to bake, but eventually deliver the promise of a lowered barrier to entry, consistent implementations and shiny new features now possible \u2018for free\u2019 just about everywhere.\n\n<img> was introduced early and naturally to HTML, despite having some opponents at the time. Perhaps <audio> and <video> were avoided, given the added technical complexity of decoding various multi-frame formats, plus the hardware and bandwidth limitations of the era. Perhaps there were quarrels about choosing a standard format or \u2013 more simply \u2013 maybe these elements just weren\u2019t considered to be applicable to the HTML-based web at the time. In any event, browser plugins from programs like RealPlayer and QuickTime eventually helped to fill the in-page audio/video gap, handling <object> and <embed> markup which pointed to .wav, .avi, .rm or .mov files. Suffice it to say, the experience was inconsistent at best and, on the standards side of the fence right now, so is HTML5 in terms of audio and video.\n\n: the theory\n\nAs far as HTML goes, the code for <audio> is simple and logical. Just as with <img>, a src attribute specifies the file to load. Pretty straightforward \u2013 sounds easy, right?\n\n<audio src=\"mysong.ogg\" controls>\n\t<!-- alternate content for unsupported case -->\n\tDownload <a href=\"mysong.ogg\">mysong.ogg</a>;\n</audio>\n\nAh, if only it were that simple. The first problem is that the OGG audio format, while \u2018free\u2019, is not supported by some browsers. Conversely, nor is MP3, despite being a de facto standard used in all kinds of desktop software (and hardware). In fact, as of November 2010, no single audio format is commonly supported across all major HTML5-enabled browsers.\n\nWhat you end up writing, then, is something like this:\n\n<audio controls>\n\t<source src=\"mysong.mp3\" />\n\t<source src=\"mysong.ogg\" />\n\t<!-- alternate content for unsupported case, maybe Flash, etc. -->\n\tDownload <a href=\"mysong.ogg\">mysong.ogg</a> or <a href=\"mysong.mp3\">mysong.mp3</a>\n</audio>\n\nKeep in mind, this is only a \u2018first class\u2019 experience for the HTML5 case; also, for non-supported browsers, you may want to look at another inline player (object/embed, or a JavaScript plus Flash API) to have inline audio. You can imagine the added code complexity in the case of supporting \u2018first class\u2019 experiences for older browsers, too.\n\n: the caveats\n\nWith <img>, you typically don\u2019t have to worry about format support \u2013 it just works \u2013 and that\u2019s part of what makes a standard wonderful. JPEG, PNG, BMP, GIF, even TIFF images all render just fine if for no better reason, perhaps, than being implemented during the \u2018wild west\u2019 days of the web. The situation with <audio> today reflects a very different \u2013 read: business-aware \u2013 environment in 2010. (Further subtext: There\u2019s a lot of [potential] money involved.) Regrettably, this is a collision of free and commercial interests, where the casualty is ultimately the user. Second up in the casualty list is you, the developer, who has to write additional code around this fragmented support.\n\nThe HTML5 audio API as implemented in JavaScript has one of the most un-computer-like responses I\u2019ve ever seen, and inspired the title of this post. Calling new Audio().canPlayType('audio/mp3'), which queries the system for format support according to a MIME type, is supposed to return one of \u201cprobably\u201d, \u201cmaybe\u201d, or \u201cno\u201d. Sometimes, you\u2019ll just get a null or empty string, which is also fun. A \u201cmaybe\u201d response does not guarantee that a format will be supported; sometimes audio/mp3 gives \u201cmaybe,\u201d but then audio/mpeg; codecs=\"mp3\" will give a more-solid \u201cprobably\u201d response. This can vary by browser or platform, too, depending on native support \u2013 and finally, the user may also be able to install codecs, extending support to include other formats. (Are you excited yet?)\n\nDamn you, warring formats!\n\nNew market and business opportunities go hand-in-hand with technology developments. What we have here is certainly not failure to communicate; rather, we have competing parties shouting loudly in public in attempts to influence mindshare towards a de facto standard for audio and video. Unfortunately, the current situation means that at least two formats are effectively required to serve the majority of users correctly.\n\nAs it currently stands, we have the free and open source software camp of OGG Vorbis/WebM and its proponents (notably, Mozilla, Google and Opera in terms of browser makers), up against the non-free, proprietary and \u2018closed\u2019 camp of MP3 and MPEG4/HE-AAC/H.264 \u2013 which is where you\u2019ll find commitments from Apple and Microsoft, among others. Apple is likely in with H.264 for the long haul, given its use of the format for its iTunes music store and video offerings.\n\nIt is generally held that H.264 is a technically superior format in terms of file size versus quality, but it involves intellectual property and, in many use cases, requires licensing fees. To be fair, there is a business model with H.264 and much has been invested in its development, but this approach is not often the kind that wins over the web. On that front, OGG/WebM may eventually win for being a \u2018free\u2019 format that does not involve a licensing scheme.\n\nClosed software and tools ideologically clash with the open nature of the web, which exists largely thanks to free and open technology. Because of philosophical and business reasons, support for audio and video is fragmented across browsers adopting HTML5 features. It does not help that a large amount of audio and video currently exists in non-free MP3 and MPEG-4 formats. Adoption of <audio> and <video> may be slowed, since it is more complex than <img> and may feel \u2018broken\u2019 to developers when edge cases are encountered. Furthermore, the HTML5 spec does not mandate a single required format. The end result is that, as a developer, you must currently provide at least both MP3 and OGG, for example, to serve most existing HTML5-based user agents.\n\nTransitioning to \n\n\n\nThere will be some growing pains as developers start to pick up the new HTML5 shiny, while balancing the needs of current and older agents that don\u2019t support either <audio> or the preferred format you may choose (for example, MP3). In either event, Flash or other plugins can be used as done traditionally within HTML4 documents to embed and play the relevant audio.\n\n\n\nThe SoundManager 2 page player demo in action.\n\n\n\nIdeally, HTML5 audio should be used whenever possible with Flash as the backup option. A few JavaScript/Flash-based audio player projects exist which balance the two; in attempting to tackle this problem, I develop and maintain SoundManager 2, a JavaScript sound API which transparently uses HTML5 Audio() and, if needed, Flash for playing audio files. The internals can get somewhat ugly, but the transition between HTML4 and HTML5 is going to be just that \u2013 and even with HTML5, you will need some form of format fall-back in addition to graceful degradation.\n\nIt may be safest to fall back to MP3/MP4 formats for inline playback at this time, given wide support via Flash, some HTML5-based browsers and mobile devices. Considering the amount of MP3/MP4 media currently available, it is wiser to try these before falling through to a traditional file download process.\n\nEarly findings\n\nHere is a brief list of behavioural notes, annoyances, bugs, quirks and general weirdness I have found while playing with HTML5-based audio at time of writing (November 2010):\n\nApple iPad/iPhone (iOS 4, iPad 3.2+)\n\n\n\tOnly one sound can be played at a time. If a second sound starts, the first is stopped.\n\tNo auto-play allowed. Sounds follow the pop-up window security model and can only be started from within a user event handler such as onclick/touch, and so on. Otherwise, playback attempts silently fail.\n\tOnce started, a sequence of sounds can be created or played via the \u2018finish\u2019 event of the previous sound (for example, advancing through a playlist without interaction after first track starts).\n\tiPad, iOS 3.2: Occasional \u2018infinite loop\u2019 bug seen where audio does not complete and stop at a sound\u2019s logical end \u2013 instead, it plays again from the beginning. Might be specific to example file format (HE-AAC) encoded from iTunes.\n\n\nApple Safari, OS X Snow Leopard 10.6.5\n\n\n\tCritical bug: Safari 4 and 5 intermittently fail to load or play HTML5 audio on Snow Leopard due to bug(s) in QuickTime X and/or other underlying frameworks. Known Apple \u2018radar\u2019 bug: bugs.webkit.org #32159 (see also, test case.) Amusing side note: Safari on Windows is fine.\n\n\nApple Safari, Windows\n\n\n\tFood for thought: if you download \u201cSafari\u201d alone on Windows, you will not get HTML5 audio/video support (tested in WinXP). You need to download \u201cSafari + QuickTime\u201d to get HTML5 audio/video support within Safari. (As far as I\u2019m aware, Chrome, Firefox and Opera either include decoders or use system libraries accordingly. Presumably IE 9 will use OS-level APIs.)\n\n\nGeneral Quirks\n\n\n\tSeeking and loading, \u2018progress\u2019 events, and calculating bytes loaded versus bytes total should not be expected to be linear, as users can arbitrarily seek within a sound. It appears that some support for HTTP ranges exists, which adds a bit of logic to UI code. Browsers seem to vary slightly in their current implementations of these features.\n\tThe onload event of a sound may be of little relevance, if non-linear loading is involved (see above note re: seeking).\n\tInterestingly (perhaps I missed it), the current spec does not seem to specify a panning or left/right channel mix option.\n\tThe preload attribute values may vary slightly between browsers at this time.\n\n\nUpcoming shiny: HTML5 Audio Data API\n\n\n\n\n\tWith access to audio data, you can incorporate waveform and spectrum elements that make your designs react to music.\n\n\n\nThe HTML5 audio spec does a good job covering the basics of playback, but did not initially get into manipulation or generation of audio on-the-fly, something Flash has had for a number of years now. What if JavaScript could create, monitor and change audio dynamically, like a sort of audio <canvas> element? With that kind of capability, many dynamic audio processing features become feasible and, when combined with other media, can make for some impressive demos.\n\nWhat started as a small idea among a small group of audio and programming enthusiasts grew to inspire a W3C audio incubator group, and continued to establish the Mozilla Audio Data API. Contributors wrote a patch for Firefox which was reviewed and revised, and is now slated to be in the public release of Firefox 4. Some background and demos are also detailed in an article from the BBC R&D blog.\n\nThere are plenty of live demos to see, which give an impression of the new creative ideas this API enables. Many concepts are not new in themselves, but it is exciting to see this sort of thing happening within the native browser context.\n\nMozilla is not alone in this effort; the WebKit folks are also working on a JavaScriptAudioNode interface, which implements similar audio buffering and sample elements.\n\nThe future?\n\nIt is my hope that we\u2019ll see a common format emerge in terms of support across the major browsers for both audio and video; otherwise, support will continue to be fragmented and mildly frustrating to develop for, and that can impede growth of the feature. It\u2019s a big call, but if <img> had lacked a common format back in the wild west era, I doubt the web would have grown to where it is today.\n\nComplaints and nitpicks aside, HTML5 brings excellent progress on the browser multimedia front, and the first signs of native support are a welcome improvement given all audio and video previously relied on plugins. There is good reason to be excited. While there is room for more, support could certainly be much worse \u2013 and as tends to happen with specifications, the implementations targeting them should improve over time.\n\nNote: Thanks to Nate Koechley, who suggested the Audio().canPlayType() response be part of the article title.", "year": "2010", "author": "Scott Schiller", "author_slug": "scottschiller", "published": "2010-12-08T00:00:00+00:00", "url": "https://24ways.org/2010/the-state-of-html5-audio/", "topic": "code"}
{"rowid": 124, "title": "Writing Responsible JavaScript", "contents": "Without a doubt, JavaScript has been making something of a comeback in the last year. If you\u2019re involved in client-side development in any way at all, chances are that you\u2019re finding yourself writing more JavaScript now than you have in a long time.\n\nIf you learned most of your JavaScript back when DHTML was all the rage and before DOM Scripting was in vogue, there have been some big shifts in the way scripts are written. Most of these are in the way event handlers are assigned and functions declared. Both of these changes are driven by the desire to write scripts that are responsible page citizens, both in not tying behaviour to content and in taking care not to conflict with other scripts. I thought it may be useful to look at some of these more responsible approaches to learn how to best write scripts that are independent of the page content and are safely portable between different applications.\n\nEvent Handling\n\nBack in the heady days of Web 1.0, if you wanted to have an object on the page react to something like a click, you would simply go ahead and attach an onclick attribute. This was easy and understandable, but much like the font tag or the style attribute, it has the downside of mixing behaviour or presentation in with our content. As we\u2019re learned with CSS, there are big benefits in keeping those layers separate. Hey, if it works for CSS, it should work for JavaScript too.\n\nJust like with CSS, instead of adding an attribute to our element within the document, the more responsible way to do that is to look for the item from your script (like CSS does with a selector) and then assign the behaviour to it. To give an example, take this oldskool onclick use case:\n\n<a id=\"anim-link\" href=\"#\" onclick=\"playAnimation()\">Play the animation</a>\n\nThis could be rewritten by removing the onclick attribute, and instead doing the following from within your JavaScript.\n\ndocument.getElementById('anim-link').onclick = playAnimation;\n\nIt\u2019s all in the timing\n\nOf course, it\u2019s never quite that easy. To be able to attach that onclick, the element you\u2019re targeting has to exist in the page, and the page has to have finished loading for the DOM to be available. This is where the onload event is handy, as it fires once everything has finished loading. Common practise is to have a function called something like init() (short for initialise) that sets up all these event handlers as soon as the page is ready.\n\nBack in the day we would have used the onload attibute on the <body> element to do this, but of course what we really want is:\n\nwindow.onload = init;\n\nAs an interesting side note, we\u2019re using init here rather than init() so that the function is assigned to the event. If we used the parentheses, the init function would have been run at that moment, and the result of running the function (rather than the function itself) would be assigned to the event. Subtle, but important.\n\nAs is becoming apparent, nothing is ever simple, and we can\u2019t just go around assigning our initialisation function to window.onload. What if we\u2019re using other scripts in the page that might also want to listen out for that event? Whichever script got there last would overwrite everything that came before it. To manage this, we need a script that checks for any existing event handlers, and adds the new handler to it. Most of the JavaScript libraries have their own systems for doing this. If you\u2019re not using a library, Simon Willison has a good stand-alone example\n\nfunction addLoadEvent(func) {\n\tvar oldonload = window.onload;\n\tif (typeof window.onload != 'function') {\n\t\twindow.onload = func;\n\t} else {\n\t\twindow.onload = function() {\n\t\t\tif (oldonload) {\n\t\t\t\toldonload();\n\t\t\t}\n\t\t\tfunc();\n\t\t}\n\t}\n}\n\nObviously this is just a toe in the events model\u2019s complex waters. Some good further reading is PPK\u2019s Introduction to Events.\n\nCarving out your own space\n\nAnother problem that rears its ugly head when combining multiple scripts on a single page is that of making sure that the scripts don\u2019t conflict. One big part of that is ensuring that no two scripts are trying to create functions or variables with the same names. Reusing a name in JavaScript just over-writes whatever was there before it.\n\nWhen you create a function in JavaScript, you\u2019ll be familiar with doing something like this.\n\nfunction foo() {\n\t... goodness ...\n}\n\nThis is actually just creating a variable called foo and assigning a function to it. It\u2019s essentially the same as the following.\n\nvar foo = function() {\n\t... goodness ...\n}\n\nThis name foo is by default created in what\u2019s known as the \u2018global namespace\u2019 \u2013 the general pool of variables within the page. You can quickly see that if two scripts use foo as a name, they will conflict because they\u2019re both creating those variables in the global namespace.\n\nA good solution to this problem is to add just one name into the global namespace, make that one item either a function or an object, and then add everything else you need inside that. This takes advantage of JavaScript\u2019s variable scoping to contain you mess and stop it interfering with anyone else.\n\nCreating An Object\n\nSay I was wanting to write a bunch of functions specifically for using on a site called \u2018Foo Online\u2019. I\u2019d want to create my own object with a name I think is likely to be unique to me.\n\nvar FOOONLINE = {};\n\nWe can then start assigning functions are variables to it like so:\n\nFOOONLINE.message = 'Merry Christmas!';\nFOOONLINE.showMessage = function() {\n\talert(this.message);\n};\n\nCalling FOOONLINE.showMessage() in this example would alert out our seasonal greeting. The exact same thing could also be expressed in the following way, using the object literal syntax.\n\nvar FOOONLINE = {\n\tmessage: 'Merry Christmas!',\n\tshowMessage: function() {\n\t\talert(this.message);\n\t}\n};\n\nCreating A Function to Create An Object\n\nWe can extend this idea bit further by using a function that we run in place to return an object. The end result is the same, but this time we can use closures to give us something like private methods and properties of our object.\n\nvar FOOONLINE = function(){\n\tvar message = 'Merry Christmas!';\n\treturn {\n\t\tshowMessage: function(){\n\t\t\talert(message);\n\t\t}\n\t}\n}();\n\nThere are two important things to note here. The first is the parentheses at the end of line 10. Just as we saw earlier, this runs the function in place and causes its result to be assigned. In this case the result of our function is the object that is returned at line 4.\n\nThe second important thing to note is the use of the var keyword on line 2. This ensures that the message variable is created inside the scope of the function and not in the global namespace. Because of the way closure works (which if you\u2019re not familiar with, just suspend your disbelief for a moment) that message variable is visible to everything inside the function but not outside. Trying to read FOOONLINE.message from the page would return undefined.\n\nThis is useful for simulating the concept of private class methods and properties that exist in other programming languages. I like to take the approach of making everything private unless I know it\u2019s going to be needed from outside, as it makes the interface into your code a lot clearer for someone else to read. \n\nAll Change, Please\n\nSo that was just a whistle-stop tour of a couple of the bigger changes that can help to make your scripts better page citizens. I hope it makes useful Sunday reading, but obviously this is only the tip of the iceberg when it comes to designing modular, reusable code.\n\nFor some, this is all familiar ground already. If that\u2019s the case, I encourage you to perhaps submit a comment with any useful resources you\u2019ve found that might help others get up to speed. Ultimately it\u2019s in all of our interests to make sure that all our JavaScript interoperates well \u2013 share your tips.", "year": "2006", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2006-12-10T00:00:00+00:00", "url": "https://24ways.org/2006/writing-responsible-javascript/", "topic": "code"}
{"rowid": 213, "title": "Accessibility Through Semantic HTML", "contents": "Working on Better, a tracker blocker, I spend an awful lot of my time with my nose in other people\u2019s page sources. I\u2019m mostly there looking for harmful tracking scripts, but often notice the HTML on some of the world\u2019s most popular sites is in a sad state of neglect.\nWhat does neglected HTML look like? Here\u2019s an example of the markup I found on a news site just yesterday. There\u2019s a bit of text, a few links, and a few images. But mostly it\u2019s div elements.\n<div class=\"block_wrapper\">\n  <div class=\"block_content\">\n    <div class=\"box\">\n      <div id=\"block1242235\">\n        <div class=\"column\">\n          <div class=\"column_content\">\n            <a class=\"close\" href=\"#\"><i class=\"fa\"></i></a>\n          </div>\n          <div class=\"btn account_login\"></div>\n          Some text <span>more text</span>\n        </div>\n      </div>\n    </div>\n  </div>\n</div>\ndivs and spans, why do we use them so much?\nWhile I find tracking scripts completely inexcusable, I do understand why people write HTML like the above. As developers, we like to use divs and spans as they\u2019re generic elements. They come with no associated default browser styles or behaviour except that div displays as a block, and span displays inline. If we make our page up out of divs and spans, we know we\u2019ll have absolute control over styles and behaviour cross-browser, and we won\u2019t need a CSS reset.\nAbsolute control may seem like an advantage, but there\u2019s a greater benefit to less generic, more semantic elements. Browsers render semantic elements with their own distinct styles and behaviours. For example, button looks and behaves differently from a. And ul is different from ol. These defaults are shortcuts to a more usable and accessible web. They provide consistent and well-tested components for common interactions.\nSemantic elements aid usability\nA good example of how browser defaults can benefit the usability of an element is in the <select> option menu. In Safari on the desktop, the browser renders <select> as a popover-style menu. On a touchscreen, Safari overlays the same menu over the lower half of the screen as a \u201cpicker view.\u201d\nOption menu in Safari on macOS.\nOption menu picker in Safari on iOS.\nThe iOS picker is a much better experience than struggling to pick from a complicated interface inside the page. The menu is shown more clearly than in the confined space on the page, which makes the options easier to read. The required swipe and tap gestures are consistent with the rest of the operating system, making the expected interaction easier to understand. The whole menu is scaled up, meaning the gestures don\u2019t need such fine motor control. Good usability is good accessibility.\nWhen we choose to use a div or span over a more semantic HTML element, we\u2019re also doing hard work the browser could be doing for us. We don\u2019t need to tie ourselves in knots making a custom div into a keyboard navigable option menu. Using select passes the bulk of the responsibility over to the browser.\u00a0\nLetting the browser do most of the work is also more future-friendly. More devices, with different expected interactions, will be released in the future. When that happens, the devices\u2019 browsers can adapt our sites according to those interactions. Then we can spend our time doing something more fun than rewriting cross-browser JavaScript for each new device.\nHTML\u2019s impact on accessibility\nAssistive technology also uses semantic HTML to understand how best to convey each element to its user.\nFor screen readers\nSemantic HTML gives context to screen readers. Screen readers are a type of assistive technology that reads the content of the screen to the person using it. All sites have a linear page source. Sighted visitors can use visual cues on the page to navigate to their desired content in a non-linear fashion. As screen readers output audio (and sometimes braille), those visual cues aren\u2019t usable in the same way.\nScreen readers provide alternative means of navigation, enabling people to jump between different types of content, such as links, forms, headings, lists, and paragraphs. If all our content is marked up using divs and spans, we\u2019re not giving screen readers a chance to index the valuable content.\nFor keyboard navigation\nKeyboard-only navigation is also aided by semantic HTML. Forms, option menus, navigation, video, and audio are particularly hard for people relying on a keyboard to access. For instance, option menus and navigation can be very fiddly if you need to use a mouse to hover a menu open and move to select the desired item at the same time.\u00a0\nAgain, we can leave much of the interaction to the browser through semantic HTML. Semantic form elements can convey if a check box has been checked, or which label is associated with which input field. These default behaviours can make the difference between a person being able to use a form or leaving the site out of frustration.\nDid I convince you yet? I hope so. Let\u2019s finish with some easy guidelines to follow.\n1. Use the most semantic HTML element for the job\nWhen you reach for a div, first check if there\u2019s a better element to do the job. What is the role of that element? How should a person be interacting with the element?\nAre you using class names like nav, header, or main? There are HTML5 elements for those sections! Using specific elements can also make writing CSS simpler, and ensure a consistent design with minimal effort.\n2. Separate structure and style\nDon\u2019t choose HTML elements based on how they\u2019re styled in your CSS. Nowadays, common practice is to use class names rather than elements for CSS selectors. You\u2019re unlikely to wrap all your page content in an <h1> element because you want all the text to be big and bold. Still, it can be easy to choose an HTML element because it will be the easiest to style. Focusing on content without style will help us choose the most semantic HTML element without that temptation. For example, you could add a class of .btn to a div to make it look like a button. But we all know that only a button will really behave like a button.\n3. Use progressive enhancement for enhanced functionality\nAirbnb and Groupon recently proved we\u2019re not past the laziness of \u201cthis site only works in X browser.\u201d Baffling disregard for the open web aside, making complex interactive experiences work cross-browser and cross-device is not easy. We can use progressive enhancement to layer fancy or unsupported features on top of a baseline \u201cit works\u201d experience.\u00a0\nWe should build the baseline experience on a foundation of accessible, semantic HTML. Then, if you really want to add a specific feature for a proprietary browser, you can layer that on top, without breaking the underlying experience.\n4. Test your work\nValidators are always valuable for checking the browser will be able to correctly interpret your markup. Document outline checkers can be valuable for testing your structure, but be aware that the HTML5 document outline is not actually implemented in browsers.\nOnce you\u2019ve got something resembling a web page, test the experience! Ensure that semantic HTML element you chose looks and behaves in a predictable manner consistent with its use across the web. Test cross-browser, test cross-device, and test with assistive technology. Testing with assistive technology is not as expensive as it used to be, you can even use your smartphone for testing on iOS and Android. Your visitors will thank you!\nFurther reading\n\nAccessibility For Everyone by Laura Kalbag\nHTML5 Doctor\nHTML5 Accessibility\nAn overview of HTML5 Semantics\nHTML reference on MDN\u00a0\nHeydon Pickering\u2019s Inclusive Design Checklist\nThe Paciello Group\u2019s Inclusive Design Principles", "year": "2017", "author": "Laura Kalbag", "author_slug": "laurakalbag", "published": "2017-12-15T00:00:00+00:00", "url": "https://24ways.org/2017/accessibility-through-semantic-html/", "topic": "code"}
{"rowid": 242, "title": "Creating My First Chrome Extension", "contents": "Writing a Chrome Extension isn\u2019t as scary at it seems!\nNot too long ago, I used a Chrome extension called 20 Cubed. I\u2019m far-sighted, and being a software engineer makes it difficult to maintain distance vision. So I used 20 Cubed to remind myself to look away from my screen and rest my eyes. I loved its simple interface and design. I loved it so much, I often forgot to turn it off in the middle of presentations, where it would take over my entire screen. Oops.\nUnfortunately, the developer stopped updating the extension and removed it from Chrome\u2019s extension library. I was so sad. None of the other eye rest extensions out there matched my design aesthetic, so I decided to create my own! Want to do the same?\nFortunately, Google has some respectable documentation on how to create an extension. And remember, Chrome extensions are just HTML, CSS, and JavaScript. You can add libraries and frameworks, or you can just code the \u201cold-fashioned\u201d way. Sky\u2019s the limit!\nSetup\nBut first, some things you\u2019ll need to know about before getting started:\n\nCallbacks\nTimeouts\nChrome Dev Tools\n\nDeveloping with Chrome extension methods requires a lot of callbacks. If you\u2019ve never experienced the joy of callback hell, creating a Chrome extension will introduce you to this concept. However, things can get confusing pretty quickly. I\u2019d highly recommend brushing up on that subject before getting started.\nHyperbole and a Half\nTimeouts and Intervals are another thing you might want to brush up on. While creating this extension, I didn\u2019t consider the fact that I\u2019d be juggling three timers. And I probably would\u2019ve saved time organizing those and reading up on the Chrome extension Alarms documentation beforehand. But more on that in a bit.\nOn the note of organization, abstraction is important! You might have any combination of the following:\n\nThe Chrome extension options page\nThe popup from the Chrome Menu\nThe windows or tabs you create\nThe background scripts\n\nAnd that can get unwieldy. You might also edit the existing tabs or windows in the browser, which you\u2019ll probably want as a separate script too. Note that this tutorial only covers creating your own customized window rather than editing existing windows or tabs.\nAlright, now that you know all that up front, let\u2019s get going!\nDocumentation\nTL;DR READ THE DOCS.\nA few things to get started:\n\nRead Google\u2019s primer on browser extensions\nHave a look at their Getting started tutorial\nCheck out their overview on Chrome Extensions\n\nThis overview discusses the Chrome extension files, architecture, APIs, and communication between pages. Funnily enough, I only discovered the Overview page after creating my extension.\nThe manifest.json file gives the browser information about the extension, including general information, where to find your extension files and icons, and API permissions required. Here\u2019s what my manifest.json looked like, for example:\nhttps://github.com/jennz0r/eye-rest/blob/master/manifest.json\nBecause I\u2019m a visual learner, I found the images that describe the extension\u2019s architecture most helpful.\n\nTo clarify this diagram, the background.js file is the extension\u2019s event handler. It\u2019s constantly listening for browser events, which you\u2019ll feed to it using the Chrome Extension API. Google says that an effective background script is only loaded when it is needed and unloaded when it goes idle.\nThe Popup is the little window that appears when you click on an extension\u2019s icon in the Chrome Menu. It consists of markup and scripts, and you can tell the browser where to find it in the manifest.json under page_action: { \"default_popup\": FILE_NAME_HERE }.\nThe Options page is exactly as it says. This displays customizable options only visible to the user when they either right-click on the Chrome menu and choose \u201cOptions\u201d under an extension. This also consists of markup and scripts, and you can tell the browser where to find it in the manifest.json under options_page: FILE_NAME_HERE.\nContent scripts are any scripts that will interact with any web windows or tabs that the user has open. These scripts will also interact with any tabs or windows opened by your extension.\nDebugging\nA quick note: don\u2019t forget the debugging tutorial!\nJust like any other Chrome window, every piece of an extension has an inspector and dev tools. If (read: when) you run into errors (as I did), you\u2019re likely to have several inspector windows open \u2013 one for the background script, one for the popup, one for the options, and one for the window or tab the extension is interacting with.\nFor example, I kept seeing the error \u201cThis request exceeds the MAX_WRITE_OPERATIONS_PER_HOUR quota.\u201d Well, it turns out there are limitations on how often you can sync stored information.\nAnother error I kept seeing was \u201cAlarm delay is less than minimum of 1 minutes. In released .crx, alarm \u201cALARM_NAME_HERE\u201d will fire in approximately 1 minutes\u201d. Well, it turns out there are minimum interval times for alarms.\nChrome Extension creation definitely benefits from debugging skills. Especially with callbacks and listeners, good old fashioned console.log can really help!\nMe adding a ton of `console.log`s while trying to debug my alarms.\nEye Rest Functionality\nOk, so what is the extension I created? Again, it\u2019s a way to rest your eyes every twenty minutes for twenty seconds. So, the basic functionality should look like the following:\n\nIf the extension is running AND\nIf the user has not clicked Pause in the Popup HTML AND\nIf the counter in the Popup HTML is down to 00:00 THEN\n\nOpen a new window with Timer HTML AND\nStart a 20 sec countdown in Timer HTML AND\nReset the Popup HTML counter to 20:00\n\nIf the Timer HTML is down to 0 sec THEN\n\nClose that window. Rinse. Repeat.\n\n\nSounds simple enough, but wow, these timers became convoluted! Of all the Chrome extensions I decided to create, I decided to make one that\u2019s heavily dependent on time, intervals, and having those in sync with each other. In other words, I made this unnecessarily complicated and didn\u2019t realize until I started coding.\nFor visual reference of my confusion, check out the GitHub repository for Eye Rest. (And yes, it\u2019s a pun.)\nAPI\nNow let\u2019s discuss the APIs that I used to build this extension.\nAlarms\nWhat even are alarms? I didn\u2019t know either.\nAlarms are basically Chrome\u2019s setTimeout and setInterval. They exist because, as Google says\u2026\n\nDOM-based timers, such as window.setTimeout() or window.setInterval(), are not honored in non-persistent background scripts if they trigger when the event page is dormant.\n\nFor more information, check out this background migration doc.\nOne interesting note about alarms in Chrome extensions is that they are persistent. Garbage collection with Chrome extension alarms seems unreliable at best. I didn\u2019t have much luck using the clearAll method to remove alarms I created on previous extension loads or installs. A workaround (read: hack) is to specify a unique alarm name every time your extension is loaded and clearing any other alarms without that unique name.\nBackground Scripts\nFor Eye Rest, I have two background scripts. One is my actual initializer and event listener, and the other is a helpers file.\nI wanted to share a couple of functions between my Background and Popup scripts. Specifically, the clearAndCreateAlarm function. I wanted my background script to clear any existing alarms, create a new alarm, and add remaining time until the next alarm to local storage immediately upon extension load. To make the function available to the Background script, I added helpers.js as the first item under background > scripts in my manifest.json.\nI also wanted my Popup script to do the same things when the user has unpaused the extension\u2019s functionality. To make the function available to the Popup script, I just include the helpers script in the Popup HTML file.\nOther APIs\nWindows\nI use the Windows API to create the Timer window when the time of my alarm is up. The window creation is initiated by my Background script.\nOne day, while coding late into the evening, I found it very confusing that the window.create method included url as an option. I assumed it was meant to be an external web address. A friend pondered that there must be an option to specify the window\u2019s HTML. Until then, it hadn\u2019t dawned on me that the url could be relative. Duh. I was tired!\nI pass the timer.html as the url option, as well as type, size, position, and other visual options.\nStorage\nMaybe you want to pass information back and forth between the Background script and your Popup script? You can do that using Chrome or local storage. One benefit of using local storage over Chrome\u2019s storage is avoiding quotas and write operation maximums.\nI wanted to pass the time at which the latest alarm was set, the time to the next alarm, and whether or not the timer is paused between the Background and Popup scripts. Because the countdown should change every second, it\u2019s quite complicated and requires lots of writes. That\u2019s why I went with the user\u2019s local storage. You can see me getting and setting those variables in my Background, Helper, and Popup scripts. Just search for date, nextAlarmTime, and isPaused.\nDeclarative Content\nThe Declarative Content API allows you to show your extension\u2019s page action based on several type of matches, without needing to take a host permission or inject a content script. So you\u2019ll need this to get your extension to work in the browser!\nYou can see me set this in my Background script. Because I want my extension\u2019s popup to appear on every page one is browsing, I leave the page matchers empty.\nThere are many more APIs for Chrome apps and extensions, so make sure to surf around and see what features are available!\nThe Extension\nHere\u2019s what my original Popup looked like before I added styles.\nAnd here\u2019s what it looks like with new styles. I guess I\u2019m going for a Nickelodeon feel.\nAnd here\u2019s the Timer window and Popup together! \nPublishing\nPublishing is a cinch. You just zip up your files, create a new or use an existing Google Developer account, upload the files, add some details, and pay a one time $5 fee. That\u2019s all! Then your extension will be available on the Chrome extension store! Neato :D\nMy extension is now available for you to install.\nConclusion\nI thought creating a time based Chrome Extension would be quick and easy. I was wrong. It was more complicated than I thought! But it\u2019s definitely achievable with some time, persistence, and good ole Google searches.\nEventually, I\u2019d like to add more interactive elements to Eye Rest. For example, hitting the YouTube API to grab a silly or cute video as a reward for looking away during the 20 sec countdown and not closing the timer window. This harkens back to one of my first web projects, Toothtimer, from 2012. Or maybe a way to change the background colors of the Timer and Popup!\nEither way, with Eye Rest\u2019s framework built out, I\u2019m feeling fearless about future feature adds! Building this Chrome extension took some broken nails, achy shoulders, and tired eyes, but now Eye Rest can tell me to give my eyes a break every 20 minutes.", "year": "2018", "author": "Jennifer Wong", "author_slug": "jenniferwong", "published": "2018-12-05T00:00:00+00:00", "url": "https://24ways.org/2018/my-first-chrome-extension/", "topic": "code"}
{"rowid": 201, "title": "Lint the Web Forward With Sonarwhal", "contents": "Years ago, when I was in a senior in college, much of my web development courses focused on two things: the basics like HTML and CSS (and boy, do I mean basic), and Adobe Flash. I spent many nights writing ActionScript 3.0 to build interactions for the websites that I would add to my portfolio. A few months after graduating, I built one website in Flash for a client, then never again. Flash was dying, and it became obsolete in my r\u00e9sum\u00e9 and portfolio. \nThat was my first lesson in the speed at which things change in technology, and what a daunting realization that was as a new graduate looking to enter the professional world. Now, seven years later, I work on the Microsoft Edge team where I help design and build a tool that would have lessened my early career anxieties: sonarwhal. \nSonarwhal is a linting tool, built by and for the web community. The code is open source and lives under the JS Foundation. It helps web developers and designers like me keep up with the constant change in technology while simultaneously teaching how to code better websites. \nIntroducing sonarwhal\u2019s mascot Nellie\nGood web development is hard. It is more than HTML, CSS, and JavaScript: developers are expected to have a grasp of accessibility, performance, security, emerging standards, and more, all while refreshing this knowledge every few months as the web evolves. It\u2019s a lot to keep track of.\n\u00a0\nWeb development is hard \nStaying up-to-date on all this knowledge is one of the driving forces for developing this scanning tool. Whether you are just starting out, are a student, or you have over a decade of experience, the sonarwhal team wants to help you build better websites for all browsers. \nCurrently sonarwhal checks for best practices in five categories: Accessibility, Interoperability, Performance, PWAs, and Security. Each check is called a \u201crule\u201d. You can configure them and even create your own rules if you need to follow some specific guidelines for your project (e.g. validate analytics attributes, title format of pages, etc.). \nYou can use sonarwhal in two ways:\n\nAn online version, that provides a quick and easy way to scan any public website.\nA command line tool, if you want more control over the configuration, or want to integrate it into your development flow.\n\nThe Online Scanner\nThe online version offers a streamlined way to scan a website; just enter a URL and you will get a web page of scan results with a permalink that you can share and revisit at any time.\nThe online version of sonarwal\nWhen my team works on a new rule, we spend the bulk of our time carefully researching each subject, finding sources, and documenting it rather than writing the rule\u2019s code. Not only is it important that we get you the right results, but we also want you to understand why something is failing. Next to each failing rule you\u2019ll find a link to its detailed documentation, explaining why you should care about it, what exactly we are testing, examples that pass and examples that don\u2019t, and useful links to even more in-depth documentation if you are interested in the subject.\nWe hope that between reading the documentation and continued use of sonarwhal, developers can stay on top of best practices. As devs continue to build sites and identify recurring issues that appear in their results, they will hopefully start to automatically include those missing elements or fix those pieces of code that are producing errors. This also isn\u2019t a one-way communication: the documentation is not only available on the sonarwhal site, but also on GitHub for editing so you can help us make it even better!\nA results report\nThe current configuration for the online scanner is very strict, so it might hurt your feelings (it did when I first tested it on my personal website). But you can configure sonarwhal to any level of strictness as well as customize the command line tool to your needs!  \nSonarwhal\u2019s CLI\u00a0\nThe CLI gives you full control of sonarwhal: what rules to use, tweaks to them, domains that are out of your control, and so on. You will need the latest node LTS (v8) or Stable (v9) and your favorite package manager, such as npm:\nnpm install -g sonarwhal\nYou can now run sonarwhal from anywhere via:\nsonarwhal https://example.com\nUsing the CLI\nThe configuration is done via a .sonarwhalrc file. When analyzing a site, if no file is available, you will be prompted to answer a series of questions:\n\nWhat connector do you want to use? Connectors are what sonarwhal uses to access a website and gather all the information about the requests, resources, HTML, etc. Currently it supports jsdom, Microsoft Edge, and Google Chrome.\nWhat formatter? This is how you want to see the results: summary, stylish, etc. Make sure to look at the full list. Some are concise for, perfect for a quick build assessment, while others are more verbose and informative.\nDo you want to use the recommended rules configuration? Rules are the things we are validating. Unless you\u2019ve read the documentation and know what you are doing, first timers should probably use the recommended configuration.\nWhat browsers are you targeting? One of the best features of sonarwhal is that rules can adapt their feedback depending on your targeted browsers, suggesting to add or remove things. For example, the rule \u201cHighest Document Mode\u201d will tell you to add the \u201cX-UA-Compatible\u201d header if IE10 or lower is targeted or remove if the opposite is true. \n\nsonarwhal configuration generator questions\nOnce you answer all these questions the scan will start and you will have a .sonarwhalrc file similar to the following:\n{\n    \"connector\": {\n        \"name\": \"jsdom\",\n        \"options\": {\n            \"waitFor\": 1000\n        }\n    },\n    \"formatters\": \"stylish\",\n    \"rulesTimeout\": 120000,\n    \"rules\": {\n        \"apple-touch-icons\": \"error\",\n        \"axe\": \"error\",\n        \"content-type\": \"error\",\n        \"disown-opener\": \"error\",\n        \"highest-available-document-mode\": \"error\",\n        \"validate-set-cookie-header\": \"warning\",\n        // ...\n    }\n}\nYou should see the scan initiate in the command line and within a few seconds the results should start to appear. Remember, the scan results will look different depending on which formatter you selected so try each one out to see which one you like best. \nsonarwhal results on my website and hurting my feelings \ud83d\udc94\nNow that you have a list of errors, you can get to work improving the site! Note though, that when you scan your website, it scans all the resources on that page and if you\u2019ve added something like analytics or fonts hosted elsewhere, you are unable to change those files. You can configure the CLI to ignore files from certain domains so that you are only getting results for files you are in control of.\nThe documentation should give enough guidance on how to fix the errors, but if it\u2019s insufficient, please help us and suggest edits or contribute back to it. This is a community effort and chances are someone else will have the same question as you.\nWhen I scanned both my websites, sonarwhal alerted me to not having an Apple Touch Icon. If I search on the web as opposed to using the sonarwhal documentation, the first top 3 results give me outdated information: I need to include many different icon sizes. I don\u2019t need to include all the different size icons that target different devices. Declaring one icon sized 180px x 180px will provide a large enough icon for devices and it will scale down as appropriate for people on older devices. \nThe information at the top of the search results isn\u2019t always the correct answer to an issue and we don\u2019t want you to have to search through outdated documentation. As sonarwhal\u2019s capabilities expand, the goal is for it to be the one stop shop for helping preflight your website. \nThe journey up until now and looking forward\n\nOn the Microsoft Edge team, we\u2019re passionate about empowering developers to build great websites. Every day we see so many sites come through our issue tracker. (Thanks for filing those bugs, they help us make Microsoft Edge better and better!) Some issues we see over and over are honest mistakes or outdated \u2018best practices\u2019 that could be avoided, so we built this tool to help everyone help make the web a better place.\nWhen we decided to create sonarwhal, we wanted to create a tool that would help developers write better and more up-to-date code for their websites. We want sonarwhal to be useful to anyone so, early on, we defined three guiding principles we\u2019ve used along the way:\n\nCommunity Driven. We build for the community\u2019s best interests. The web belongs to everyone and this project should too. Not only is it open source, we\u2019ve also donated it to the JS Foundation and have an inclusive governance model that welcomes the collaboration of anyone, individual or company.\nUser Centric. We want to put the user at the center, making sonarwhal configurable for your needs and easy to use no matter what your skill level is.\nCollaborative. We didn\u2019t want to reinvent the wheel, so we collaborated with existing tools and services that help developers build for the web. Some examples are aXe, snyk.io, Cloudinary, etc.\n\nThis is just the beginning and we still have lots to do. We\u2019re hard at work on a backlog of exciting features for future releases, such as:\n\nNew rules for a variety of areas like\u00a0performance,\u00a0accessibility,\u00a0security,\u00a0progressive web apps, and more.\nA plug-in for Visual Studio Code: we want sonarwhal to help you write better websites, and what better moment than when you are in your editor.\nConfiguration options for the online service: as we fine tune the infrastructure, the rule configuration for our scanner is locked, but we look forward to adding CLI customization options here in the near future.\n\nThis is a tool for the web community by the web community so if you are excited about sonarwhal, making a better web, and want to contribute, we have a\u00a0few issues where you might be able to help. Also, don\u2019t forget to check the rest of the\u00a0sonarwhal GitHub organization. PRs are always welcome and appreciated! \nLet us know what you think about the scanner at @NarwhalNellie on Twitter and we hope you\u2019ll help us lint the web forward!", "year": "2017", "author": "Stephanie Drescher", "author_slug": "stephaniedrescher", "published": "2017-12-02T00:00:00+00:00", "url": "https://24ways.org/2017/lint-the-web-forward-with-sonarwhal/", "topic": "code"}
{"rowid": 15, "title": "Git for Grown-ups", "contents": "You are a clever and talented person. You create beautiful designs, or perhaps you have architected a system that even my cat could use. Your peers adore you. Your clients love you. But, until now, you haven\u2019t *&^#^! been able to make Git work. It makes you angry inside that you have to ask your co-worker, again, for that *&^#^! command to upload your work.\n\nIt\u2019s not you. It\u2019s Git. Promise.\n\nYes, this is an article about the popular version control system, Git. But unlike just about every other article written about Git, I\u2019m not going to give you the top five commands that you need to memorize; and I\u2019m not going to tell you all your problems would be solved if only you were using this GUI wrapper or that particular workflow. You see, I\u2019ve come to a grand realization: when we teach Git, we\u2019re doing it wrong.\n\nLet me back up for a second and tell you a little bit about the field of adult education. (Bear with me, it gets good and will leave you feeling both empowered and righteous.) Andragogy, unlike pedagogy, is a learner-driven educational experience. There are six main tenets to adult education: \n\n\n\tAdults prefer to know why they are learning something.\n\tThe foundation of the learning activities should include experience.\n\tAdults prefer to be able to plan and evaluate their own instruction.\n\tAdults are more interested in learning things which directly impact their daily activities.\n\tAdults prefer learning to be oriented not towards content, but towards problems.\n\tAdults relate more to their own motivators than to external ones.\n\n\nNowhere in this list does it include \u201cmemorize the five most popular Git commands\u201d. And yet this is how we teach version control: init, add, commit, branch, push. You\u2019re an expert! Sound familiar? In the hierarchy of learning, memorizing commands is the lowest, or most basic, form of learning. At the peak of learning you are able to not just analyze and evaluate a problem space, but create your own understanding in relation to your existing body of knowledge.\n\n\u201cFine,\u201d I can hear you saying to yourself. \u201cBut I\u2019m here to learn about version control.\u201d Right you are! So how can we use this knowledge to master Git? First of all: I give you permission to use Git as a tool. A tool which you control and which you assign tasks to. A tool like a hammer, or a saw. Yes, your mastery of your tools will shape the kinds of interactions you have with your work, and your peers. But it\u2019s yours to control. Git was written by kernel developers for kernel development. The web world has adopted Git, but it is not a tool designed for us and by us. It\u2019s no Sass, y\u2019know? Git wasn\u2019t developed out of our frustration with managing CSS files in an increasingly complex ecosystem of components and atomic design. So, as you work through the next part of this article, give yourself a bit of a break. We\u2019re in this together, and it\u2019s going to be OK.\n\nWe\u2019re going to do a little activity. We\u2019re going to create your perfect Git cheatsheet.\n\nI want you to start by writing down a list of all the people on your code team. This list may include:\n\n\n\tdevelopers\n\tdesigners\n\tproject managers\n\tclients\n\n\nNext, I want you to write down a list of all the ways you interact with your team. Maybe you\u2019re a solo developer and you do all the tasks. Maybe you only do a few things. But I want you to write down a list of all the tasks you\u2019re actually responsible for. For example, my list looks like this:\n\n\n\twriting code\n\treviewing code\n\tpublishing tested code to your server(s)\n\ttroubleshooting broken code\n\n\nThe next list will end up being a series of boxes in a diagram. But to start, I want you to write down a list of your tools and constraints. This list potentially has a lot of noun-like items and verb-like items:\n\n\n\tcode hosting system (Bitbucket? GitHub? Unfuddle? self-hosted?)\n\tserver ecosystem (dev/staging/live)\n\tautomated testing systems or review gates\n\tautomated build systems (that Jenkins dude people keep referring to)\n\n\nBrilliant! Now you\u2019ve got your actors and your actions, it\u2019s time to shuffle them into a diagram. There are many popular workflow patterns. None are inherently right or wrong; rather, some are more or less appropriate for what you are trying to accomplish.\n\nCentralized workflow\n\nEveryone saves to a single place. This workflow may mean no version control, or a very rudimentary version control system which only ever has a single copy of the work available to the team at any point in time.\n\n \n\nBranching workflow\n\nEveryone works from a copy of the same place, merging their changes into the main copy as their work is completed. Think of the branches as a motorcycle sidecar: they\u2019re along for the ride and probably cannot exist in isolation of the main project for long without serious danger coming to the either the driver or sidecar passenger. Branches are a fundamental concept in version control \u2014 they allow you to work on new features, bug fixes, and experimental changes within a single repository, but without forcing the changes onto others working from the same branch.\n\n \n\nForking workflow\n\nEveryone works from their own, independent repository. A fork is an exact duplicate of a repository that a developer can make their own changes to. It can be kept up to date with additional changes made in other repositories, but it cannot force its changes onto another\u2019s repository. A fork is a complete repository which can use its own workflow strategies. If developers wish to merge their work with the main project, they must make a request of some kind (submit a patch, or a pull request) which the project collaborators may choose to adopt or reject. This workflow is popular for open source projects as it enforces a review process.\n\n \n\nGitflow workflow\n\nA specific workflow convention which includes five streams of parallel coding efforts: master, development, feature branches, release branches, and hot fixes. This workflow is often simplified down to a few elements by web teams, but may be used wholesale by software product teams. The original article describing this workflow was written by Vincent Driessen back in January 2010.\n\n \n\nBut these workflows aren\u2019t about you yet, are they? So let\u2019s make the connections.\n\nFrom the list of people on your team you identified earlier, draw a little circle. Give each of these circles some eyes and a smile. Now I want you to draw arrows between each of these people in the direction that code (ideally) flows. Does your designer create responsive prototypes which are pushed to the developer? Draw an arrow to represent this.\n\nChances are high that you don\u2019t just have people on your team, but you also have some kind of infrastructure. Hopefully you wrote about it earlier. For each of the servers and code repositories in your infrastructure, draw a square. Now, add to your diagram the relationships between the people and each of the machines in the infrastructure. Who can deploy code to the live server? How does it really get there? I bet it goes through some kind of code hosting system, such as GitHub. Draw in those arrows.\n\nBut wait!\n\nThe code that\u2019s on your development machine isn\u2019t the same as the live code. This is where we introduce the concept of a branch in version control. In Git, a repository contains all of the code (sort of). A branch is a fragment of the code that has been worked on in isolation to the other branches within a repository. Often branches will have elements in common. When we compare two (or more) branches, we are asking about the difference (or diff) between these two slivers. Often the master branch is used on production, and the development branch is used on our dev server. The difference between these two branches is the untested code that is not yet deployed.\n\nOn your diagram, see if you can colour-code according to the branch names at each of the locations within your infrastructure. You might find it useful to make a few different copies of the diagram to isolate each of the tasks you need to perform. For example: our team has a peer review process that each branch must go through before it is merged into the shared development branch.\n\nFinally, we are ready to add the Git commands necessary to make sense of the arrows in our diagram. If we are bringing code to our own workstation we will issue one of the following commands: clone (the first time we bring code to our workstation) or pull. Remembering that a repository contains all branches, we will issue the command checkout to switch from one branch to another within our own workstation. If we want to share a particular branch with one of our team mates, we will push this branch back to the place we retrieved it from (the origin). Along each of the arrows in your diagram, write the name of the command you are are going to use when you perform that particular task.\n\n \n\nFrom here, it\u2019s up to you to be selfish. Before asking Git what command it would like you to use, sketch the diagram of what you want. Git is your tool, you are not Git\u2019s tool. Draw the diagram. Communicate your tasks with your team as explicitly as you can. Insist on being a selfish adult learner \u2014 demand that others explain to you, in ways that are relevant to you, how to do the things you need to do today.", "year": "2013", "author": "Emma Jane Westby", "author_slug": "emmajanewestby", "published": "2013-12-04T00:00:00+00:00", "url": "https://24ways.org/2013/git-for-grownups/", "topic": "code"}
{"rowid": 257, "title": "The (Switch)-Case for State Machines in User Interfaces", "contents": "You\u2019re tasked with creating a login form. Email, password, submit button, done.\n\u201cThis will be easy,\u201d you think to yourself.\nLogin form by Selecto\nYou\u2019ve made similar forms many times in the past; it\u2019s essentially muscle memory at this point. You\u2019re working closely with a designer, who gives you a beautiful, detailed mockup of a login form. Sure, you\u2019ll have to translate the pixels to meaningful, responsive CSS values, but that\u2019s the least of your problems.\nAs you\u2019re writing up the HTML structure and CSS layout and styles for this form, you realize that you don\u2019t know what the successful \u201clogged in\u201d page looks like. You remind the designer, who readily gives it to you. But then you start thinking more and more about how the login form is supposed to work.\n\nWhat if login fails? Where do those errors show up?\nShould we show errors differently if the user forgot to enter their email, or password, or both?\nOr should the submit button be disabled?\nShould we validate the email field?\nWhen should we show validation errors \u2013 as they\u2019re typing their email, or when they move to the password field, or when they click submit? (Note: many, many login forms are guilty of this.)\nWhen should the errors disappear?\nWhat do we show during the login process? Some loading spinner?\nWhat if loading takes too long, or a server error occurs?\n\nMany more questions come up, and you (and your designer) are understandably frustrated. The lack of upfront specification opens the door to scope creep, which readily finds itself at home in all the unexplored edge cases.\nModeling Behavior\nDescribing all the possible user flows and business logic of an application can become tricky. Ironically, user stories might not tell the whole story \u2013 they often leave out potential edge-cases or small yet important bits of information.\nHowever, one important (and very old) mathematical model of computation can be used for describing the behavior and all possible states of a user interface: the finite state machine.\nThe general idea, as it applies to user interfaces, is that all of our applications can be described (at some level of abstraction) as being in one, and only one, of a finite number of states at any given time. For example, we can describe our login form above in these states:\n\nstart - not submitted yet\nloading - submitted and logging in\nsuccess - successfully logged in\nerror - login failed\n\nAdditionally, we can describe an application as accepting a finite number of events \u2013 that is, all the possible events that can be \u201csent\u201d to the application, either from the user or some other external entity:\n\nSUBMIT - pressing the submit button\nRESOLVE - the server responds, indicating that login is successful\nREJECT - the server responds, indicating that login failed\n\nThen, we can combine these states and events to describe the transitions between them. That is, when the application is in one state, an an event occurs, we can specify what the next state should be:\n\nFrom the start state, when the SUBMIT event occurs, the app should be in the loading state.\nFrom the loading state, when the RESOLVE event occurs, login succeeded and the app should be in the success state.\nIf login fails from the loading state (i.e., when the REJECT event occurs), the app should be in the error state.\nFrom the error state, the user should be able to retry login: when the SUBMIT event occurs here, the app should go to the loading state.\nOtherwise, if any other event occurs, don\u2019t do anything and stay in the same state.\n\nThat\u2019s a pretty thorough description, similar to a user story! It\u2019s also a bit more symbolic than a user story (e.g., \u201cwhen the SUBMIT event occurs\u201d instead of \u201cwhen the user presses the submit button\u201d), and that\u2019s for a reason. By representing states, events, and transitions symbolically, we can visualize what this state machine looks like:\n\nEvery state is represented by a box, and every event is connected to a transition arrow that connects two states. This makes it intuitive to follow the flow and understand what the next state should be given the current state and an event.\nFrom Visuals to Code\nDrawing a state machine doesn\u2019t require any special software; in fact, using paper and pencil (in case anything changes!) does the job quite nicely. However, one common problem is handoff: it doesn\u2019t matter how detailed a user story or how well-designed a visualization is, it eventually has to be coded in order for it to become part of a real application.\nWith the state machine model described above, the same visual description can be mapped directly to code. Traditionally, and as the title suggests, this is done using switch/case statements:\nfunction loginMachine(state, event) {\n    switch (state) {\n        case 'start':\n            if (event === 'SUBMIT') {\n                return 'loading';\n            }\n            break;\n        case 'loading':\n            if (event === 'RESOLVE') {\n                return 'success';\n            } else if (event === 'REJECT') {\n                return 'error';\n            }\n            break;\n        case 'success':\n            // Accept no further events\n            break;\n        case 'error':\n            if (event === 'SUBMIT') {\n                return 'loading';\n            }\n            break;\n        default:\n            // This should never occur\n            return undefined;\n    }\n}\n\nconsole.log(loginMachine('start', 'SUBMIT'));\n// => 'loading'\nThis is fine (I suppose) but personally, I find it much easier to use objects:\nconst loginMachine = {\n  initial: \"start\",\n  states: {\n    start: {\n      on: { SUBMIT: 'loading' }\n    },\n    loading: {\n      on: {\n        REJECT: 'error',\n        RESOLVE: 'success'\n      }\n    },\n    error: {\n      on: {\n        SUBMIT: 'loading'\n      }\n    },\n    success: {}\n  }\n};\n\nfunction transition(state, event) {\n  return machine\n    .states[state] // Look up the state\n    .on[event]     // Look up the next state based on the event\n    || state;      // If not found, return the current state\n}\n\nconsole.log(transition('start', 'SUBMIT'));\nAs you might have noticed, the loginMachine is a plain JS object, and can be written in JSON. This is important because it allows the machine to be visualized by a 3rd-party tool, as demonstrated here:\n\nA Common Language Between Designers and Developers\nAlthough finite state machines are a fundamental part of computer science, they have an amazing potential to bridge the application specification gap between designers and developers, as well as project managers, stakeholders, and more. By designing a state machine visually and with code, designers and developers alike can:\n\nidentify all possible states, and potentially missing states\ndescribe exactly what should happen when an event occurs on a given state, and prevent that event from having unintended side-effects in other states (ever click a submit button more than once?)\neliminate impossible states and identify states that are \u201cunreachable\u201d (have no entry transition) or \u201csunken\u201d (have no exit transition)\nadd features with full confidence of knowing what other states it might affect\nsimplify redundant states or complex user flows\ncreate test paths for almost every possible user flow, and easily identify edge cases\ncollaborate better by understanding the entire application model equally.\n\nNot a New Idea\nI\u2019m not the first to suggest that state machines can help bridge the gap between design and development.\n\nVince MingPu Shao wrote an article about designing UI states and communicating with developers effectively with finite state machines\nUser flow diagrams, which visually describe the paths that a user can take through an app to achieve certain goals, are essentially state machines. Numerous tools, from Sketch plugins to standalone apps, exist for creating them.\nIn 1999, Ian Horrocks wrote a book titled \u201cConstructing the User Interface with Statecharts\u201d, which takes state machines to the next level and describes the inherent difficulties (and solutions) with creating complex UIs. The ideas in the book are still relevant today.\nMore than a decade earlier, David Harel published \u201cStatecharts: A Visual Formalism for Complex Systems\u201d, in which the statechart - an extended hierarchical state machine model - is born.\n\nState machines and statecharts have been used for complex systems and user interfaces, both physical and digital, for decades, and are especially prevalent in other industries, such as game development and embedded electronic systems. Even NASA uses statecharts for the Curiosity Rover and more, citing many benefits:\n\nVisualized modeling\nPrecise diagrams\nAutomatic code generation\nComprehensive test coverage\nAccommodation of late-breaking requirements changes\n\nMoving Forward\nIt\u2019s time that we improve how we communicate between designers and developers, much less improve the way we develop UIs to deliver the best, bug-free, optimal user experience. There is so much more to state machines and statecharts than just being a different way of designing and coding. For more resources:\n\nThe World of Statecharts is a comprehensive guide by Erik Mogensen in using statecharts in your applications\nThe Statechart Community on Spectrum is always full of interesting ideas and questions related to state machines, statecharts, and software modeling\nI gave a talk at React Rally over a year ago about how state machines (finite automata) can improve the way we develop applications. The latest one is from Reactive Conf, where I demonstrate how statecharts can be used to automatically generate test cases.\nI have also been working on XState, which is a library for \u201cstate machines and statecharts for the modern web\u201d. You can create and visualize statecharts in JavaScript, and use them in any framework (and soon enough, multiple different languages).\n\nI\u2019m excited about the future of developing web and mobile applications with statecharts, especially with regard to faster design/development cycles, auto-generated testing, better error prevention, comprehensive analytics, and even the use of model-based reinforcement learning and artificial intelligence to greatly improve the user experience.", "year": "2018", "author": "David Khourshid", "author_slug": "davidkhourshid", "published": "2018-12-12T00:00:00+00:00", "url": "https://24ways.org/2018/state-machines-in-user-interfaces/", "topic": "code"}
{"rowid": 336, "title": "Practical Microformats with hCard", "contents": "You\u2019ve probably heard about microformats over the last few months. You may have even read the easily digestible introduction at Digital Web Magazine, but perhaps you\u2019ve not found time to actually implement much yet. That\u2019s understandable, as it can sometimes be difficult to see exactly what you\u2019re adding by applying a microformat to a page. Sure, you\u2019re semantically enhancing the information you\u2019re marking up, and the Semantic Web is a great idea and all, but what benefit is it right now, today? \n\nWell, the answer to that question is simple: you\u2019re adding lots of information that can be and is being used on the web here and now. The big ongoing battle amongst the big web companies if one of territory over information. Everyone\u2019s grasping for as much data as possible. Some of that information many of us are cautious to give away, but a lot of is happy to be freely available. Of the data you\u2019re giving away, it makes sense to give it as much meaning as possible, thus enabling anyone from your friends and family to the giant search company down the road to make the most of it.\n\nOk, enough of the waffle, let\u2019s get working.\n\nIntroducing hCard\n\nYou may have come across hCard. It\u2019s a microformat for describing contact information (or really address book information) from within your HTML. It\u2019s based on the vCard format, which is the format the contacts/address book program on your computer uses. All the usual fields are available \u2013 name, address, town, website, email, you name it.\n\nIf you\u2019re running Firefox and Greasemonkey (or if you can, just to try this out), install this user script. What it does is look for instances of the hCard microformat in a page, and then add in a link to pass any hCards it finds to a web service which will convert it to a vCard. Take a look at the About the author box at the bottom of this article. It\u2019s a hCard, so you should be able to click the icon the user script inserts and add me to your Outlook contacts or OS X Address Book with just a click.\n\nSo microformats are useful after all. Free microformats all round!\n\nImplementing hCard\n\nThis is the really easy bit. All the hCard microformat is, is a bunch of predefined class names that you apply to the markup you\u2019ve probably already got around your contact information. Let\u2019s take the example of the About the author box from this article. Here\u2019s how the markup looks without hCard:\n\n<div class=\"bio\">\n     <h3>About the author</h3>\n     <p>Drew McLellan is a web developer, author and no-good swindler from \n     just outside London, England. At the \n     <a href=\"http://www.webstandards.org/\">Web Standards Project</a> he works \n     on press, strategy and tools. Drew keeps a \n     <a href=\"http://www.allinthehead.com/\">personal weblog</a> covering web \n     development issues and themes.</p>\n</div>\n\nThis is a really simple example because there\u2019s only two key bits of address book information here:- my name and my website address. Let\u2019s push it a little and say that the Web Standards Project is the organisation I work for \u2013 that gives us Name, Company and URL.\n\nTo kick off an hCard, you need a containing object with a class of vcard. The div I already have with a class of bio is perfect for this \u2013 all it needs to do is contain the rest of the contact information.\n\nThe next thing to identify is my name. hCard uses a class of fn (meaning Full Name) to identify a name. As is this case there\u2019s no element surrounding my name, we can just use a span. These changes give us:\n\n<div class=\"bio vcard\">\n     <h3>About the author</h3>\n     <p><span class=\"fn\">Drew McLellan</span> is a web developer...\n\nThe two remaining items are my URL and the organisation I belong to. The class names designated for those are url and org respectively. As both of those items are links in this case, I can apply the classes to those links. So here\u2019s the finished hCard.\n\n<div class=\"bio vcard\">\n     <h3>About the author</h3>\n     <p><span class=\"fn\">Drew McLellan</span> is a web developer, author and \n     no-good swindler from just outside London, England. \n     At the <a class=\"org\" href=\"http://www.webstandards.org/\">Web Standards Project</a> \n     he works on press, strategy and tools. Drew keeps a \n     <a class=\"url\" href=\"http://www.allinthehead.com/\">personal weblog</a> covering web \n     development issues and themes.</p>\n</div>\n\nOK, that was easy. By just applying a few easy class names to the HTML I was already publishing, I\u2019ve implemented an hCard that right now anyone with Greasemonkey can click to add to their address book, that Google and Yahoo! and whoever else can index and work out important things like which websites are associated with my name if they so choose (and boy, will they so choose), and in the future who knows what. In terms of effort, practically nil.\n\nWhere next?\n\nSo that was a trivial example, but to be honest it doesn\u2019t really get much more complex even with the most pernickety permutations. Because hCard is based on vCard (a mature and well thought-out standard), it\u2019s all tried and tested. Here\u2019s some good next steps.\n\n\n\tPlay with the hCard Creator\n\tTake a deep breath and read the spec\n\tStart implementing hCard as you go on your own projects \u2013 it takes very little time\n\n\nhCard is just one of an ever-increasing number of microformats. If this tickled your fancy, I suggest subscribing to the microformats site in your RSS reader to keep in touch with new developments.\n\nWhat\u2019s the take-away?\n\nThe take-away is this. They may sound like just more Web 2-point-HoHoHo hype, but microformats are a well thought-out, and easy to implement way of adding greater depth to the information you publish online. They have some nice benefits right away \u2013 certainly at geek-level \u2013 but in the longer term they become much more significant. We\u2019ve been at this long enough to know that the web has a long, long memory and that what you publish today will likely be around for years. But putting the extra depth of meaning into your documents now you can help guard that they\u2019ll continue to be useful in the future, and not just a bunch of flat ASCII.", "year": "2005", "author": "Drew McLellan", "author_slug": "drewmclellan", "published": "2005-12-06T00:00:00+00:00", "url": "https://24ways.org/2005/practical-microformats-with-hcard/", "topic": "code"}
{"rowid": 153, "title": "JavaScript Internationalisation", "contents": "or:  Why Rudolph Is More Than Just a Shiny Nose\n\nDunder sat, glumly staring at the computer screen.\n\n\u201cWhat\u2019s up, Dunder?\u201d asked Rudolph, entering the stable and shaking off the snow from his antlers.\n\n\u201cWell,\u201d Dunder replied, \u201cI\u2019ve just finished coding the new reindeer intranet Santa Claus asked me to do. You know how he likes to appear to be at the cutting edge, talking incessantly about Web 2.0, AJAX, rounded corners; he even spooked Comet recently by talking about him as if he were some pushy web server.\n\n\u201cI\u2019ve managed to keep him happy, whilst also keeping it usable, accessible, and gleaming \u2014 and I\u2019m still on the back row of the sleigh! But anyway, given the elves will be the ones using the site, and they come from all over the world, the site is in multiple languages. Which is great, except when it comes to the preview JavaScript I\u2019ve written for the reindeer order form. Here, have a look\u2026\u201d\n\nAs he said that, he brought up the textileRef:8234272265470b85d91702:linkStartMarker:\u201corder\n    form in French\u201d:/examples/javascript-internationalisation/initial.fr.html on the screen. (Same in English).\n\n\u201cLooks good,\u201d said Rudolph.\n\n\u201cBut if I add some items,\u201d said Dunder, \u201cthe preview appears in English, as it\u2019s hard-coded in the JavaScript. I don\u2019t want separate code for each language, as that\u2019s just silly \u2014 I thought about just having if statements, but that doesn\u2019t scale at all\u2026\u201d\n\n\u201cAnd there\u2019s more, you aren\u2019t displaying large numbers in French properly, either,\u201d added Rudolph, who had been playing and looking at part of the source code:\n\nfunction update_text() {\n\tvar hay = getValue('hay');\n\tvar carrots = getValue('carrots');\n\tvar bells = getValue('bells');\n\tvar total = 50 * bells + 30 * hay + 10 * carrots;\n\tvar out = 'You are ordering '\n\t\t+ pretty_num(hay) + ' bushel' + pluralise(hay) + ' of hay, '\n\t\t+ pretty_num(carrots) + ' carrot' + pluralise(carrots)\n\t\t+ ', and ' + pretty_num(bells) + ' shiny bell' + pluralise(bells)\n\t\t+ ', at a total cost of <strong>' + pretty_num(total)\n\t\t+ '</strong> gold pieces. Thank you.';\n\tdocument.getElementById('preview').innerHTML = out;\n}\nfunction pretty_num(n) {\n\tn += '';\n\tvar o = '';\n\tfor (i=n.length; i>3; i-=3) {\n\t\to = ',' + n.slice(i-3, i) + o;\n\t}\n\to = n.slice(0, i) + o;\n\treturn o;\n}\nfunction pluralise(n) {\n\tif (n!=1) return 's';\n\treturn '';\n}\n\n\u201cOh, botheration!\u201d cried Dunder. \u201cThis is just so complicated.\u201d\n\n\u201cIt doesn\u2019t have to be,\u201d said Rudolph, \u201cyou just have to think about things in a slightly different way from what you\u2019re used to. As we\u2019re only a simple example, we won\u2019t be able to cover all possibilities, but for starters, we need some way of providing different information to the script dependent on the language. We\u2019ll create a global i18n object, say, and fill it with the correct language information. The first variable we\u2019ll need will be a thousands separator, and then we can change the pretty_num function to use that instead:\n\nfunction pretty_num(n) {\n\tn += '';\n\tvar o = '';\n\tfor (i=n.length; i>3; i-=3) {\n\t\to = i18n.thousands_sep + n.slice(i-3, i) + o;\n\t}\n\to = n.slice(0, i) + o;\n\treturn o;\n}\n\n\u201cThe i18n object will also contain our translations, which we will access through a function called _() \u2014 that\u2019s just an underscore. Other languages have a function of the same name doing the same thing. It\u2019s very simple:\n\nfunction _(s) {\n\tif (typeof(i18n)!='undefined' && i18n[s]) {\n\t\treturn i18n[s];\n\t}\n\treturn s;\n}\n\n\u201cSo if a translation is available and provided, we\u2019ll use that; otherwise we\u2019ll default to the string provided \u2014 which is helpful if the translation begins to lag behind the site\u2019s text at all, as at least something will be output.\u201d\n\n\u201cGot it,\u201d said Dunder. \u201c _('Hello Dunder') will print the translation of that string, if one exists, \u2018Hello Dunder\u2019 if not.\u201d\n\n\u201cExactly. Moving on, your plural function breaks even in English if we have a word where the plural doesn\u2019t add an s \u2014 like \u2018children\u2019.\u201d\n\n\u201cYou\u2019re right,\u201d said Dunder. \u201cHow did I miss that?\u201d\n\n\u201cNo harm done. Better to provide both singular and plural words to the function and let it decide which to use, performing any translation as well:\n\nfunction pluralise(s, p, n) {\n\tif (n != 1) return _(p);\n\treturn _(s);\n}\n\n\u201cWe\u2019d have to provide different functions for different languages as we employed more elves and got more complicated \u2014 for example, in Polish, the word \u2018file\u2019 pluralises like this: 1 plik, 2-4 pliki, 5-21 plik\u00f3w, 22-24 pliki, 25-31 plik\u00f3w, and so on.\u201d (More information on plural forms)\n\n\u201cGosh!\u201d\n\n\u201cNext, as different languages have different word orders, we must stop using concatenation to construct sentences, as it would be impossible for other languages to fit in; we have to keep coherent strings together. Let\u2019s rewrite your update function, and then go through it:\n\nfunction update_text() {\n\tvar hay = getValue('hay');\n\tvar carrots = getValue('carrots');\n\tvar bells = getValue('bells');\n\tvar total = 50 * bells + 30 * hay + 10 * carrots;\n\thay = sprintf(pluralise('%s bushel of hay', '%s bushels of hay', hay), pretty_num(hay));\n\tcarrots = sprintf(pluralise('%s carrot', '%s carrots', carrots), pretty_num(carrots));\n\tbells = sprintf(pluralise('%s shiny bell', '%s shiny bells', bells), pretty_num(bells));\n\tvar list = sprintf(_('%s, %s, and %s'), hay, carrots, bells);\n\tvar out = sprintf(_('You are ordering %s, at a total cost of <strong>%s</strong> gold pieces.'),\n\t\tlist, pretty_num(total));\n\tout += ' ';\n\tout += _('Thank you.');\n\tdocument.getElementById('preview').innerHTML = out;\n}\n\n\u201c sprintf is a function in many other languages that, given a format string and some variables, slots the variables into place within the string. JavaScript doesn\u2019t have such a function, so we\u2019ll write our own. Again, keep it simple for now, only integers and strings; I\u2019m sure more complete ones can be found on the internet.\n\nfunction sprintf(s) {\n\tvar bits = s.split('%');\n\tvar out = bits[0];\n\tvar re = /^([ds])(.*)$/;\n\tfor (var i=1; i<bits.length; i++) {\n\t\tp = re.exec(bits[i]);\n\t\tif (!p || arguments[i]==null) continue;\n\t\tif (p[1] == 'd') {\n\t\t\tout += parseInt(arguments[i], 10);\n\t\t} else if (p[1] == 's') {\n\t\t\tout += arguments[i];\n\t\t}\n\t\tout += p[2];\n\t}\n\treturn out;\n}\n\n\u201cLastly, we need to create one file for each language, containing our i18n object, and then include that from the relevant HTML. Here\u2019s what a blank translation file would look like for your order form:\n\nvar i18n = {\n\tthousands_sep: ',',\n\t\"%s bushel of hay\": '',\n\t\"%s bushels of hay\": '',\n\t\"%s carrot\": '',\n\t\"%s carrots\": '',\n\t\"%s shiny bell\": '',\n\t\"%s shiny bells\": '',\n\t\"%s, %s, and %s\": '',\n\t\"You are ordering %s, at a total cost of <strong>%s</strong> gold pieces.\": '',\n\t\"Thank you.\": ''\n};\n\n\u201cIf you implement this across the intranet, you\u2019ll want to investigate the xgettext program, which can automatically extract all strings that need translating from all sorts of code files into a standard .po file (I think Python mode works best for JavaScript). You can then use a different program to take the translated .po file and automatically create the language-specific JavaScript files for us.\u201d (e.g. German .po file for PledgeBank, mySociety\u2019s .po-.js script, example output)\n\nWith a flourish, Rudolph finished editing. \u201cAnd there we go, localised JavaScript in English, French, or German, all using the same main code.\u201d\n\n\u201cThanks so much, Rudolph!\u201d said Dunder.\n\n\u201cI\u2019m not just a pretty nose!\u201d Rudolph quipped. \u201cOh, and one last thing \u2014 please comment liberally explaining the context of strings you use. Your translator will thank you, probably at the same time as they point out the four hundred places you\u2019ve done something in code that only works in your language and no-one else\u2019s\u2026\u201d\n\nThanks to Tim Morley and Edmund Grimley Evans for the French and German translations respectively.", "year": "2007", "author": "Matthew Somerville", "author_slug": "matthewsomerville", "published": "2007-12-08T00:00:00+00:00", "url": "https://24ways.org/2007/javascript-internationalisation/", "topic": "code"}
{"rowid": 70, "title": "Bringing Your Code to the Streets", "contents": "\u2014 or How to Be a Street VJ\nOur amazing world of web code is escaping out of the browser at an alarming rate and appearing in every aspect of the environment around us. Over the past few years we\u2019ve already seen JavaScript used server-side, hardware coded with JavaScript, a rise of native style and desktop apps created with HTML, CSS and JavaScript, and even virtual reality (VR) is getting its fair share of front-end goodness.\nYou can go ahead and play with JavaScript-powered hardware such as the Tessel or the Espruino to name a couple. Just check out the Tessel project page to see JavaScript in the world of coffee roasting or sleep tracking your pet. With the rise of the internet of things, JavaScript can be seen collecting information on flooding among other things. And if that\u2019s not enough \u2018outside the browser\u2019 implementations, Node.js servers can even be found in aircraft!\nI previously mentioned VR and with three.js\u2019s extra StereoEffect.js module it\u2019s relatively simple to get browser 3D goodness to be Google Cardboard-ready, and thus set the stage for all things JavaScript and VR. It\u2019s been pretty popular in the art world too, with interactive works such as Seb Lee-Delisle\u2019s Lunar Trails installation, featuring the old arcade game Lunar Lander, which you can now play in your browser while others watch (it is the web after all). The Science Museum in London held Chrome Web Lab, an interactive exhibition featuring five experiments, showcasing the magic of the web. And it\u2019s not even the connectivity of the web that\u2019s being showcased; we can even take things offline and use web code for amazing things, such as fighting Ebola.\nOne thing is for sure, JavaScript is awesome. Hell, if you believe those telly programs (as we all do), JavaScript can even take down the stock market, purely through the witchcraft of canvas! Go JavaScript!\nNow it\u2019s our turn\nSo I wanted to create a little project influenced by this theme, and as it\u2019s Christmas, take it to the streets for a little bit of party fun! Something that could take code anywhere. Here\u2019s how I made a portable visual projection pack, a piece of video mixing software and created some web-coded street art.\nStep one: The equipment\nYou will need:\n\nOne laptop: with HDMI output and a modern browser installed, such as Google Chrome.\nOne battery-powered mini projector: I\u2019ve used a Texas Instruments DLP; for its 120 lumens it was the best cost-to-lumens ratio I could find.\nOne MIDI controller (optional): mine is an ICON iDJ as it suits mixing visuals. However, there is more affordable hardware on the market such as an Akai LPD8 or a Korg nanoPAD2. As you\u2019ll see in the article, this is optional as it can be emulated within the software.\nA case to carry it all around in.\n\n\nStep two: The software\nThe projected visuals, I imagined, could be anything you can create within a browser, whether that be simple HTML and CSS, images, videos, SVG or canvas. The only requirement I have is that they move or change with sound and that I can mix any one visual into another.\nYou may remember a couple of years ago I created a demo on this very site, allowing audio-triggered visuals from the ambient sounds your device mic was picking up. That was a great starting point \u2013 I used that exact method to pick up the audio and thus the first requirement was complete. If you want to see some more examples of visuals I\u2019ve put together for this, there\u2019s a showcase on CodePen.\nThe second requirement took a little more thought. I needed two screens, which could at any point show any of the visuals I had coded, but could be mixed from one into the other and back again. So let\u2019s start with two divs, both absolutely positioned so they\u2019re on top of each other, but at the start the second screen\u2019s opacity is set to zero.\nNow all we need is a slider, which when moved from one side to the other slowly sets the second screen\u2019s opacity to 1, thereby fading it in.\nSee the Pen Mixing Screens (Software Version) by Rumyra (@Rumyra) on CodePen.\nMixing Screens (CodePen)\n\nAs you saw above, I have a MIDI controller and although the software method works great, I\u2019d quite like to make use of this nifty piece of kit. That\u2019s easily done with the Web MIDI API. All I need to do is call it, and when I move one of the sliders on the controller (I\u2019ve allocated the big cross fader in the middle for this), pick up on the change of value and use that to control the opacity instead.\nvar midi, data;\n// start talking to MIDI controller\nif (navigator.requestMIDIAccess) {\n  navigator.requestMIDIAccess({\n    sysex: false\n  }).then(onMIDISuccess, onMIDIFailure);\n} else {\n  alert(\u201cNo MIDI support in your browser.\u201d);\n}\n\n// on success\nfunction onMIDISuccess(midiData) {\n  // this is all our MIDI data\n  midi = midiData;\n\n  var allInputs = midi.allInputs.values();\n  // loop over all available inputs and listen for any MIDI input\n  for (var input = allInputs.next(); input && !input.done; input = allInputs.next()) {\n    // when a MIDI value is received call the onMIDIMessage function\n    input.value.onmidimessage = onMIDIMessage;\n  }\n}\n\nfunction onMIDIMessage(message) {\n  // data comes in the form [command/channel, note, velocity]\n  data = message.data;\n\n  // Opacity change for screen. The cross fader values are [176, 8, {0-127}]\n  if ( (data[0] === 176) && (data[1] === 8) ) {\n    // this value will change as the fader is moved\n    var opacity = data[2]/127;\n    screenTwo.style.opacity = opacity;\n  }\n}\n\nThe final code was slightly more complicated than this, as I decided to switch the two screens based on the frequencies of the sound that was playing, and use the cross fader to depict the frequency threshold value. This meant they flickered in and out of each other, rather than just faded. There\u2019s a very rough-and-ready first version of the software on GitHub.\nPhew, Great! Now we need to get all this to the streets!\nStep three: Portable kit\nDid you notice how I mentioned a case to carry it all around in? I wanted the case to be morphable, so I could use the equipment from it too, a sort of bag-to-usherette-tray-type affair. Well, I had an unused laptop bag\u2026\n\nI strengthened it with some MDF, so when I opened the bag it would hold like a tray where the laptop and MIDI controller would sit. The projector was Velcroed to the external pocket of the bag, so when it was a tray it would project from underneath. I added two durable straps, one for my shoulders and one round my waist, both attached to the bag itself. There was a lot of cutting and trimming. As it was a laptop bag it was pretty thick to start and sewing was tricky. However, I only broke one sewing machine needle; I\u2019ve been known to break more working with leather, so I figured I was doing well. By the way, you can actually buy usherette trays, but I just couldn\u2019t resist hacking my own :)\nStep four: Take to the streets\nFirst, make sure everything is charged \u2013 everything \u2013 a lot! The laptop has to power both the MIDI controller and the projector, and although I have a mobile phone battery booster pack, that\u2019ll only charge the projector should it run out. I estimated I could get a good hour of visual artistry before I needed to worry, though.\nI had a couple of ideas about time of day and location. Here in the UK at this time of year, it gets dark around half past four, so I could easily head out in a city around 5pm and it would be dark enough for the projections to be seen pretty well. I chose Bristol, around the waterfront, as there were some interesting locations to try it out in. The best was Millennium Square: busy but not crowded and plenty of surfaces to try projecting on to.\nMy first time out with the portable audio/visual pack (PAVP as it will now be named) was brilliant. I played music and projected visuals, like a one-woman band of A/V!\n\n\nYou might be thinking what the point of this was, besides, of course, it being a bit of fun. Well, this project got me to look at canvas and SVG more closely. The Web MIDI API was really interesting; MIDI as a data format has some great practical uses. I think without our side projects we may not have all these wonderful uses for our everyday code. Not only do they remind us coding can, and should, be fun, they also help us learn and grow as makers.\nMy favourite part? When I was projecting into a water feature in Millennium Square. For those who are familiar, you\u2019ll know it\u2019s like a wall of water so it produced a superb effect. I drew quite a crowd and a kid came to stand next to me and all I could hear him say with enthusiasm was, \u2018Oh wow! That\u2019s so cool!\u2019\nYes\u2026 yes, kid, it was cool. Making things with code is cool.\nMassive thanks to the lovely Drew McLellan for his incredibly well-directed photography, and also Simon Johnson who took a great hand in perfecting the kit while it was attached.", "year": "2015", "author": "Ruth John", "author_slug": "ruthjohn", "published": "2015-12-06T00:00:00+00:00", "url": "https://24ways.org/2015/bringing-your-code-to-the-streets/", "topic": "code"}
{"rowid": 162, "title": "Conditional Love", "contents": "\u201cBrowser.\u201d The four-letter word of web design.\n\nI mean, let\u2019s face it: on the good days, when things just work in your target browsers, it\u2019s marvelous. The air smells sweeter, birds\u2019 songs sound more melodious, and both your design and your code are looking sharp.\n\nBut on the less-than-good days (which is, frankly, most of them), you\u2019re compelled to tie up all your browsers in a sack, heave them into the nearest river, and start designing all-imagemap websites. We all play favorites, after all: some will swear by Firefox, Opera fans are allegedly legion, and others still will frown upon anything less than the latest WebKit nightly.\n\nThankfully, we do have an out for those little inconsistencies that crop up when dealing with cross-browser testing: CSS patches.\n\nSpare the Rod, Hack the Browser\n\nBefore committing browsercide over some rendering bug, a designer will typically reach for a snippet of CSS fix the faulty browser. Historically referred to as \u201chacks,\u201d I prefer Dan Cederholm\u2019s more client-friendly alternative, \u201cpatches\u201d.\n\nBut whatever you call them, CSS patches all work along the same principle: supply the proper property value to the good browsers, while giving higher maintenance other browsers an incorrect value that their frustrating idiosyncratic rendering engine can understand.\n\nTraditionally, this has been done either by exploiting incomplete CSS support:\n\n#content {\n\theight: 1%;\t // Let's force hasLayout for old versions of IE.\n\tline-height: 1.6;\n\tpadding: 1em;\n}\nhtml>body #content {\n\theight: auto; // Modern browsers get a proper height value.\n}\n\nor by exploiting bugs in their rendering engine to deliver alternate style rules:\n\n#content p {\n\tfont-size: .8em;\n\t/* Hide from Mac IE5 \\*/\n\tfont-size: .9em;\n\t/* End hiding from Mac IE5 */\n}\n\nWe\u2019ve even used these exploits to serve up whole stylesheets altogether:\n\n@import url(\"core.css\");\n@media tty {\n\ti{content:\"\\\";/*\" \"*/}} @import 'windows-ie5.css'; /*\";}\n}/* */\n\nThe list goes on, and on, and on. For every browser, for every bug, there\u2019s a patch available to fix some rendering bug.\n\nBut after some time working with standards-based layouts, I\u2019ve found that CSS patches, as we\u2019ve traditionally used them, become increasingly difficult to maintain. As stylesheets are modified over the course of a site\u2019s lifetime, inline fixes we\u2019ve written may become obsolete, making them difficult to find, update, or prune out of our CSS. A good patch requires a constant gardener to ensure that it adds more than just bloat to a stylesheet, and inline patches can be very hard to weed out of a decently sized CSS file.\n\nGiving the Kids Separate Rooms\n\nSince I joined Airbag Industries earlier this year, every project we\u2019ve worked on has this in the head of its templates:\n\n<link rel=\"stylesheet\" href=\"-/css/screen/main.css\" type=\"text/css\" media=\"screen, projection\" />\n<!--[if lt IE 7]>\n<link rel=\"stylesheet\" href=\"-/css/screen/patches/win-ie-old.css\" type=\"text/css\" media=\"screen, projection\" />\n<![endif]-->\n<!--[if gte IE 7]>\n<link rel=\"stylesheet\" href=\"-/css/screen/patches/win-ie7-up.css\" type=\"text/css\" media=\"screen, projection\" />\n<![endif]-->\n\nThe first element is, simply enough, a link element that points to the project\u2019s main CSS file. No patches, no hacks: just pure, modern browser-friendly style rules. Which, nine times out of ten, will net you a design that looks like spilled eggnog in various versions of Internet Explorer.\n\nBut don\u2019t reach for the mulled wine quite yet. Immediately after, we\u2019ve got a brace of conditional comments wrapped around two other link elements. These odd-looking comments allow us to selectively serve up additional stylesheets just to the version of IE that needs them. We\u2019ve got one for IE 6 and below:\n\n<!--[if lt IE 7]>\n<link rel=\"stylesheet\" href=\"-/css/screen/patches/win-ie-old.css\" type=\"text/css\" media=\"screen, projection\" />\n<![endif]-->\n\nAnd another for IE7 and above:\n\n<!--[if gte IE 7]>\n<link rel=\"stylesheet\" href=\"-/css/screen/patches/win-ie7-up.css\" type=\"text/css\" media=\"screen, projection\" />\n<![endif]-->\n\nMicrosoft\u2019s conditional comments aren\u2019t exactly new, but they can be a valuable alternative to cooking CSS patches directly into a master stylesheet. And though they\u2019re not a W3C-approved markup structure, I think they\u2019re just brilliant because they innovate within the spec: non-IE devices will assume that the comments are just that, and ignore the markup altogether.\n\nThis does, of course, mean that there\u2019s a little extra markup in the head of our documents. But this approach can seriously cut down on the unnecessary patches served up to the browsers that don\u2019t need them. Namely, we no longer have to write rules like this in our main stylesheet:\n\n#content {\n\theight: 1%;\t// Let's force hasLayout for old versions of IE.\n\tline-height: 1.6;\n\tpadding: 1em;\n}\nhtml>body #content {\n\theight: auto;\t// Modern browsers get a proper height value.\n}\n\nRather, we can simply write an un-patched rule in our core stylesheet:\n\n#content {\n\tline-height: 1.6;\n\tpadding: 1em;\n}\n\nAnd now, our patch for older versions of IE goes in\u2014you guessed it\u2014the stylesheet for older versions of IE:\n\n#content {\n\theight: 1%;\n}\n\nThe hasLayout patch is applied, our design\u2019s repaired, and\u2014most importantly\u2014the patch is only seen by the browser that needs it. The \u201cgood\u201d browsers don\u2019t have to incur any added stylesheet weight from our IE patches, and Internet Explorer gets the conditional love it deserves.\n\nMost importantly, this \u201ccompartmentalized\u201d approach to CSS patching makes it much easier for me to patch and maintain the fixes applied to a particular browser. If I need to track down a bug for IE7, I don\u2019t need to scroll through dozens or hundreds of rules in my core stylesheet: instead, I just open the considerably slimmer IE7-specific patch file, make my edits, and move right along.\n\nEven Good Children Misbehave\n\nWhile IE may occupy the bulk of our debugging time, there\u2019s no denying that other popular, modern browsers will occasionally disagree on how certain bits of CSS should be rendered. But without something as, well, pimp as conditional comments at our disposal, how do we bring the so-called \u201cgood browsers\u201d back in line with our design?\n\nAssuming you\u2019re loving the \u201cone patch file per browser\u201d model as much as I do, there\u2019s just one alternative: JavaScript.\n\nfunction isSaf() {\n\tvar isSaf = (document.childNodes && !document.all && !navigator.taintEnabled && !navigator.accentColorName) ? true : false;\n\treturn isSaf;\n}\nfunction isOp() {\n\tvar isOp = (window.opera) ? true : false;\n\treturn isOp;\n}\n\nInstead of relying on dotcom-era tactics of parsing the browser\u2019s user-agent string, we\u2019re testing here for support for various DOM objects, whose presence or absence we can use to reasonably infer the browser we\u2019re looking at. So running the isOp() function, for example, will test for Opera\u2019s proprietary window.opera object, and thereby accurately tell you if your user\u2019s running Norway\u2019s finest browser.\n\nWith scripts such as isOp() and isSaf() in place, you can then reasonably test which browser\u2019s viewing your content, and insert additional link elements as needed.\n\nfunction loadPatches(dir) {\n\tif (document.getElementsByTagName() && document.createElement()) {\n\t\tvar head = document.getElementsByTagName(\"head\")[0];\n\t\tif (head) {\n\t\t\tvar css = new Array();\n\t\t\tif (isSaf()) {\n\t\t\t\tcss.push(\"saf.css\");\n\t\t\t} else if (isOp()) {\n\t\t\t\tcss.push(\"opera.css\");\n\t\t\t}\n\t\t\tif (css.length) {\n\t\t\t\tvar link = document.createElement(\"link\");\n\t\t\t\tlink.setAttribute(\"rel\", \"stylesheet\");\n\t\t\t\tlink.setAttribute(\"type\", \"text/css\");\n\t\t\t\tlink.setAttribute(\"media\", \"screen, projection\");\n\t\t\t\tfor (var i = 0; i < css.length; i++) {\n\t\t\t\t\tvar tag = link.cloneNode(true);\n\t\t\t\t\ttag.setAttribute(\"href\", dir + css[0]);\n\t\t\t\t\thead.appendChild(tag);\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t}\n}\n\nHere, we\u2019re testing the results of isSaf() and isOp(), one after the other. For each function that returns true, then the name of a new stylesheet is added to the oh-so-cleverly named css array. Then, for each entry in css, we create a new link element, point it at our patch file, and insert it into the head of our template.\n\nFire it up using your favorite onload or DOMContentLoaded function, and you\u2019re good to go.\n\nScripteat Emptor\n\nAt this point, some of the audience\u2019s more conscientious \u2018scripters may be preparing to lob figgy pudding at this author\u2019s head. And that\u2019s perfectly understandable; relying on JavaScript to patch CSS chafes a bit against the normally clean separation we have between our pages\u2019 content, presentation, and behavior layers.\n\nAnd beyond the philosophical concerns, this approach comes with a few technical caveats attached:\n\nBrowser detection? So un-133t.\n\nBrowser detection is not something I\u2019d typically recommend. Whenever possible, a proper DOM script should check for the support of a given object or method, rather than the device with which your users view your content.\n\nIt\u2019s JavaScript, so don\u2019t count on it being available.\n\nAccording to one site, roughly four percent of Internet users don\u2019t have JavaScript enabled. Your site\u2019s stats might be higher or lower than this number, but still: don\u2019t expect that every member of your audience will see these additional stylesheets, and ensure that your content\u2019s still accessible with JS turned off.\n\nBe a constant gardener.\n\nThe sample isSaf() and isOp() functions I\u2019ve written will tell you if the user\u2019s browser is Safari or Opera. As a result, stylesheets written to patch issues in an old browser may break when later releases repair the relevant CSS bugs.\n\nYou can, of course, add logic to these simple little scripts to serve up version-specific stylesheets, but that way madness may lie. In any event, test your work vigorously, and keep testing it when new versions of the targeted browsers come out. Make sure that a patch written today doesn\u2019t become a bug tomorrow.\n\nPatching Firefox, Opera, and Safari isn\u2019t something I\u2019ve had to do frequently: still, there have been occasions where the above script\u2019s come in handy. Between conditional comments, careful CSS auditing, and some judicious JavaScript, browser-based bugs can be handled with near-surgical precision.\n\nSo pass the \u2018nog. It\u2019s patchin\u2019 time.", "year": "2007", "author": "Ethan Marcotte", "author_slug": "ethanmarcotte", "published": "2007-12-15T00:00:00+00:00", "url": "https://24ways.org/2007/conditional-love/", "topic": "code"}
{"rowid": 8, "title": "Coding Towards Accessibility", "contents": "\u201cCan we make it AAA-compliant?\u201d \u2013 does this question strike fear into your heart? Maybe for no other reason than because you will soon have to wade through the impenetrable WCAG documentation once again, to find out exactly what AAA-compliant means?\n\nI\u2019m not here to talk about that.\n\nThe Web Content Accessibility Guidelines are a comprehensive and peer-reviewed resource which we\u2019re lucky to have at our fingertips. But they are also a pig to read, and they may have contributed to the sense of mystery and dread with which some developers associate the word accessibility.\n\nThis Christmas, I want to share with you some thoughts and some practical tips for building accessible interfaces which you can start using today, without having to do a ton of reading or changing your tools and workflow.\n\nBut first, let\u2019s clear up a couple of misconceptions.\n\nDreary, flat experiences\n\nI recently built a front-end framework for the Post Office. This was a great gig for a developer, but when I found out about my client\u2019s stringent accessibility requirements I was concerned that I\u2019d have to scale back what was quite a complex set of visual designs.\n\nSites like Jakob Neilsen\u2019s old workhorse useit.com and even the pioneering GOV.UK may have to shoulder some of the blame for this. They put a premium on usability and accessibility over visual flourish. (Although, in fairness to Mr Neilsen, his new site nngroup.com is really quite a snazzy affair, comparatively.)\n\nOf course, there are other reasons for these sites\u2019 aesthetics \u2014 and it\u2019s not because of the limitations of the form. You can make an accessible site look as glossy or as plain as you want it to look. It\u2019s always our own ingenuity and attention to detail that are going to be the limiting factors.\n\nSynecdoche\n\nWe must always guard against the tendency to assume that catering to screen readers means we have the whole accessibility ballgame covered. \n\nThere\u2019s so much more to accessibility than assistive technology, as you know. And within the field of assistive technology there are plenty of other devices for us to consider.\n\nPlanning to accommodate all these users and devices can be daunting. When I first started working in this field I thought that the breadth of technology was prohibitive. I didn\u2019t even know what a screen reader looked like. (I assumed they were big and heavy, perhaps like an old typewriter, and certainly they would be expensive and difficult to fathom.) This is nonsense, of course. Screen reader emulators are readily available as browser extensions and can be activated in seconds. Chromevox and Fangs are both excellent and you should download one or the other right now.\n\nBut the really good news is that you can emulate many other types of assistive technology without downloading a byte. And this is where we move from misconceptions into some (hopefully) useful advice.\n\nThe mouse trap\n\nThe simplest and most effective way to improve your abilities as a developer of accessible interfaces is to unplug your mouse.\n\nKeyboard operation has its own WCAG chapter, because most users of assistive technology are navigating the web using only their keyboards. You can go some way towards putting yourself into their shoes so easily \u2014 just by ditching a peripheral.\n\nLearning this was a lightbulb moment for me. When I build interfaces I am constantly flicking between code and the browser, testing or viewing the changes I have made. Now, instead of checking a new element once, I check it twice: once with my mouse and then again without.\n\nDon\u2019t just :hover\n\nThe reality is that when you first start doing this you can find your site becomes unusable straightaway. It\u2019s easy to lose track of which element is in focus as you hit the tab key repeatedly.\n\nOne of the easiest changes you can make to your coding practice is to add :focus and :active pseudo-classes to every hover state that you write. I\u2019m still amazed at how many sites fail to provide a decent focus state for links (and despite previous 24 ways authors in 2007 and 2009 writing on this same issue!).\n\nYou may find that in some cases it makes sense to have something other than, or in addition to, the hover state on focus, but start with the hover state that your designer has taken the time to provide you with. It\u2019s a tiny change and there is no downside. So instead of this:\n\n.my-cool-link:hover {\n\tbackground-color: MistyRose ;\t\n}\n\n\u2026try writing this:\n\n.my-cool-link:hover,\n.my-cool-link:focus,\n.my-cool-link:active {\n\tbackground-color: MistyRose ;\t\n}\n\nI\u2019ve toyed with the idea of making a Sass mixin to take care of this for me, but I haven\u2019t yet. I worry that people reading my code won\u2019t see that I\u2019m explicitly defining my focus and active states so I take the hit and write my hover rules out longhand.\n\nJavaScript can play, too\n\nThis was another revelation for me. Keyboard-only navigation doesn\u2019t necessitate a JavaScript-free experience, and up-to-date screen readers can execute JavaScript. So we\u2019re able to create complex JavaScript-driven interfaces which all users can interact with.\n\nSome of the hard work has already been done for us. First, there are already conventions around keyboard-driven interfaces. Think about the last time you viewed a photo album on Facebook. You can use the arrow keys to switch between photos, and the escape key closes whichever lightbox-y UI thing Facebook is showing its photos in this week. Arrow keys (up/down as well as left/right) for progression through content; Escape to back out of something; Enter or space bar to indicate a positive intention \u2014 these are established keyboard conventions which we can apply to our interfaces to improve their accessiblity. \n\nOf course, by doing so we are improving our interfaces in general, giving all users the option to switch between keyboard and mouse actions as and when it suits them.\n\nSecond, this guy wants to help you out. Hans Hillen is a developer who has done a great deal of work around accessibility and JavaScript-powered interfaces. Along with The Paciello Group he has created a version of the jQuery UI library which has been fully optimised for keyboard navigation and screen reader use. It\u2019s a fantastic reference which I revisit all the time \n\nI\u2019m not a huge fan of the jQuery UI library. It\u2019s a pain to style and the code is a bit bloated. So I\u2019ve not used this demo as a code resource to copy wholesale. I use it by playing with the various components and seeing how they react to keyboard controls. Each component is also fully marked up with the relevant ARIA roles to improve screen reader announcement where possible (more on this below).\n\nCoding for accessibility promotes good habits\n\nThis is a another observation around accessibility and JavaScript. I noticed an improvement in the structure and abstraction of my code when I started adding keyboard controls to my interface elements. \n\nYour code has to become more modular and event-driven, because any number of events could trigger the same interaction. A mouse-click, the Enter key and the space bar could all conceivably trigger the same open function on a collapsed accordion element. (And you want to keep things DRY, don\u2019t you?) \n\nIf you aren\u2019t already in the habit of separating out your interface functionality into discrete functions, you will be soon.\n\nvar doSomethingCool = function(){\n\t// Do something cool here.\n}\n\n// Bind function to a button click - pretty vanilla\n$('.myCoolButton').on('click', function(){\n\tdoSomethingCool();\n\treturn false;\n});\n\n// Bind the same function to a range of keypresses\n$(document).keyup(function(e){\n\tswitch(e.keyCode) {\n\t\tcase 13: // enter\n\t\tcase 32: // spacebar\n\t\t\tdoSomethingCool();\n\t\t\tbreak;\n\t\tcase 27: // escape\n\t\t\tdoSomethingElse();\n\t\t\tbreak;\n\t}\n});\n\nTo be honest, if you\u2019re doing complex UI stuff with JavaScript these days, or if you\u2019ve been building any responsive interfaces which rely on JavaScript, then you are most likely working with an application framework such as Backbone, Angular or Ember, so an abstraced and event-driven application structure will be familar to you. It should be super easy for you to start helping out your keyboard-only users if you aren\u2019t already \u2014 just add a few more event bindings into your UI layer!\n\nManipulating the tab order\n\nSo, you\u2019ve adjusted your mindset and now you test every change to your codebase using a keyboard as well as a mouse. You\u2019ve applied all your hover states to :focus and :active so you can see where you\u2019re tabbing on the page, and your interactive components react seamlessly to a mixture of mouse and keyboard commands. Feels good, right?\n\nThere\u2019s another level of optimisation to consider: manipulating the tab order. Certain DOM elements are naturally part of the tab order, and others are excluded. Links and input elements are the main elements included in the tab order, and static elements like paragraphs and headings are excluded. What if you want to make a static element \u2018tabbable\u2019? \n\nA good example would be in an expandable accordion component. Each section of the accordion should be separated by a heading, and there\u2019s no reason to make that heading into a link simply because it\u2019s interactive.\n\n<div class=\"accordion-widget\">\n\t<h3>Tyrannosaurus</h3>\n\t<p>Tyrannosaurus; meaning \"tyrant lizard\"...<p>\n\n\t<h3>Utahraptor</h3>\n\t<p>Utahraptor is a genus of theropod dinosaurs...<p>\n\n\t<h3>Dromiceiomimus</h3>\n\t<p>Ornithomimus is a genus of ornithomimid dinosaurs...<p>\n</div>\n\nAdding the heading elements to the tab order is trivial. We just set their tabindex attribute to zero. You could do this on the server or the client. I prefer to do it with JavaScript as part of the accordion setup and initialisation process.\n\n$('.accordion-widget h3').attr('tabindex', '0');\n\nYou can apply this trick in reverse and take elements out of the tab order by setting their tabindex attribute to \u22121, or change the tab order completely by using other integers. This should be done with great care, if at all. You have to be sure that the markup you remove from the tab order comes out because it genuinely improves the keyboard interaction experience. This is hard to validate without user testing. The danger is that developers will try to sweep complicated parts of the UI under the carpet by taking them out of the tab order. This would be considered a dark pattern \u2014 at least on my team!\n\nA farewell ARIA\n\nThis is where things can get complex, and I\u2019m no expert on the ARIA specification: I feel like I\u2019ve only dipped my toe into this aspect of coding for accessibility. But, as with WCAG, I\u2019d like to demystify things a little bit to encourage you to look into this area further yourself.\n\nARIA roles are of most benefit to screen reader users, because they modify and augment screen reader announcements. \n\nLet\u2019s take our dinosaur accordion from the previous section. The markup is semantic, so a screen reader that can\u2019t handle JavaScript will announce all the content within the accordion, no problem.\n\nBut modern screen readers can deal with JavaScript, and this means that all the lovely dino information beneath each heading has probably been hidden on document.ready, when the accordion initialised. It might have been hidden using display:none, which prevents a screen reader from announcing content. If that\u2019s as far as you have gone, then you\u2019ve committed an accessibility sin by hiding content from screen readers. Your user will hear a set of headings being announced, with no content in between. It would sound something like this if you were using Chromevox:\n\n> Tyrannosaurus. Heading Three.\n> Utahraptor. Heading Three.\n> Dromiceiomimus. Heading Three.\n\nWe can add some ARIA magic to the markup to improve this, using the tablist role. Start by adding a role of tablist to the widget, and roles of tab and tabpanel to the headings and paragraphs respectively. Set boolean values for aria-selected, aria-hidden and aria-expanded. The markup could end up looking something like this.\n\n<div class=\"accordion-widget\" role=\"tablist\">\n\t<!-- T-rex -->\t\n\t<h3 role=\"tab\" \n\t\ttabindex=\"0\" \n\t\tid=\"tab-2\" \n\t\taria-controls=\"panel-2\" \n\t\taria-selected=\"false\">Utahraptor</h3>\n\t<p\trole=\"tabpanel\" \n\t\tid=\"panel-2\" \n\t\taria-labelledby=\"tab-2\" \n\t\taria-expanded=\"false\" \n\t\taria-hidden=\"true\">Utahraptor is a genus of theropod dinosaurs...</p>\n\t<!-- Dromiceiomimus -->\t\n</div>\n\nNow, if a screen reader user encounters this markup they will hear the following:\n\n> Tyrannosaurus. Tab not selected; one of three.\n> Utahraptor. Tab not selected; two of three.\n> Dromiceiomimus. Tab not selected; three of three.\n\nYou could add arrow key events to help the user browse up and down the tab list items until they find one they like. \n\nYour accordion open() function should update the ARIA boolean values as well as adding whatever classes and animations you have built in as standard. Your users know that unselected tabs are meant to be interacted with, so if a user triggers the open function (say, by hitting Enter or the space bar on the second item) they will hear this:\n\n> Utahraptor. Selected; two of three.\n\nThe paragraph element for the expanded item will not be hidden by your CSS, which means it will be announced as normal by the screen reader.\n\nThis kind of thing makes so much more sense when you have a working example to play with. Again, I refer you to the fantastic resource that Hans Hillen has put together: this is his take on an accessible accordion, on which much of my example is based.\n\nConclusion\n\nGetting complex interfaces right for all of your users can be difficult \u2014 there\u2019s no point pretending otherwise. And there\u2019s no substitute for user testing with real users who navigate the web using assistive technology every day. This kind of testing can be time-consuming to recruit for and to conduct. On top of this, we now have accessibility on mobile devices to contend with. That\u2019s a huge area in itself, and it\u2019s one which I have not yet had a chance to research properly.\n\nSo, there\u2019s lots to learn, and there\u2019s lots to do to get it right. But don\u2019t be disheartened. If you have read this far then I\u2019ll leave you with one final piece of advice: don\u2019t wait.\n\nDon\u2019t wait until you\u2019re building a site which mandates AAA-compliance to try this stuff out. Don\u2019t wait for a client with the will or the budget to conduct the full spectrum of user testing to come along. Unplug your mouse, and start playing with your interfaces in a new way. You\u2019ll be surprised at the things that you learn and the issues you uncover. \n\nAnd the next time an true accessibility project comes along, you will be way ahead of the game.", "year": "2013", "author": "Charlie Perrins", "author_slug": "charlieperrins", "published": "2013-12-03T00:00:00+00:00", "url": "https://24ways.org/2013/coding-towards-accessibility/", "topic": "code"}