. This is also inaccessible because a screenreader will not pause between adjacent links, and in some configurations will not announce the individual links, but rather all of the tags will be read as just one link containing a whole bunch of words. Markup crime number one. Flickr Ah, Flickr. The darling photo sharing site of the internet, and the biggest blind spot in every standardista’s vision. Forgive it for having atrocious markup and sometimes confusing UI because it’s just so much damn fun to use. Let’s see what they do.

06 africa amsterdam ...

Again we have a simple collection of anchors like del.icio.us, only this time in a paragraph. But rather than using a class to represent the size of the tag they use an inline style. An inline style using a pixel-based font size. That’s so far away from the goal of separating style from content, they might as well use a tag. You could theoretically parse that to extract the information, but you have more work to guess what the pixel sizes represent. Markup crime number two (and extra jail time for using non-breaking spaces purely for visual spacing purposes.) Technorati Ah, now. Here, you’d expect something decent. After all, the Overlord of microformats and King of Semantics Tantek Çelik works there. Surely we’ll see something decent here?

Unfortunately it turns out not to be that decent, and stop calling me Shirley. It’s not exactly terrible code. It does recognise that a tag cloud is a list of links. And, since they’re in alphabetical order, that it’s an ordered list of links. That’s nice. However … fifteen nested tags? FIFTEEN? That’s emphasis for you. Yes, it is parse-able, but it’s also something of a strange way of looking at emphasis. The HTML spec states that is emphasis, and is for stronger emphasis. Nesting tags seems counter to the idea that different tags are used for different levels of emphasis. Plus, if you had a screen reader that stressed the voice for emphasis, what would it do? Shout at you? Markup crime number three. So what should it be? As del.icio.us tells us, a tag cloud is a list of tags where the size that they are rendered at contains extra information. However, by hiding the extra context purely within the CSS or the HTML tags used, you are denying that context to some users. The basic assumption being made is that all users will be able to see the difference between font sizes, and this is demonstrably false. A better way to code a tag cloud is to put the context of the cloud within the content, not the markup or CSS alone. As an example, I’m going to take some of my favourite flickr tags and put them into a cloud which communicates the relative frequency of each tag. To start with a tag cloud in its most basic form is just a list of links. I am going to present them in alphabetical order, so I’ll use an ordered list. Into each list item I add the number of photos I have with that particular tag. The tag itself is linked to the page on flickr which contains those photos. So we end up with this first example. To display this as a traditional tag cloud, we need to alter it in a few ways: The items need to be displayed next to each other, rather than one-per-line The context information should be hidden from display (but not from screen readers) The tag should link to the page of items with that tag Displaying the items next to each other simply means setting the display of the list elements to inline. The context can be hidden by wrapping it in a and then using the off-left method to hide it. And the link just means adding an anchor (with rel=""tag"" for some extra microformats bonus points). So, now we have a simple collection of links in our second example. The last stage is to add the sizes. Since we already have context in our content, the size is purely for visual rendering, so we can just use classes to define the different sizes. For my example, I’ll use a range of class names from not-popular through ultra-popular, in order of smallest to largest, and then use CSS to define different font sizes. If you preferred, you could always use less verbose class names such as size1 through size6. Anyway, adding some classes and CSS gives us our final example, a semantic and more accessible tag cloud.",2006,Mark Norman Francis,marknormanfrancis,2006-12-09T00:00:00+00:00,https://24ways.org/2006/marking-up-a-tag-cloud/,code 134,Photographic Palettes,"How many times have you seen a colour combination that just worked, a match so perfect that it just seems obvious? Now, how many times do you come up with those in your own work? A perfect palette looks easy when it’s done right, but it’s often maddeningly difficult and time-consuming to accomplish. Choosing effective colour schemes will always be more art than science, but there are things you can do that will make coming up with that oh-so-smooth palette just a little a bit easier. A simple trick that can lead to incredibly gratifying results lies in finding a strong photograph and sampling out particularly harmonious colours. Photo Selection Not all photos are created equal. You certainly want to start with imagery that fits the eventual tone you’re attempting to create. A well-lit photo of flowers might lead to a poor colour scheme for a funeral parlour’s web site, for example. It’s worth thinking about what you’re trying to say in advance, and finding a photo that lends itself to your message. As a general rule of thumb, photos that have a lot of neutral or de-saturated tones with one or two strong colours make for the best palette; bright and multi-coloured photos are harder to derive pleasing results from. Let’s start with a relatively neutral image. Sampling In the above example, I’ve surrounded the photo with three different background colours directly sampled from the photo itself. Moving from left to right, you can see how each of the sampled colours is from an area of increasingly smaller coverage within the photo, and yet there’s still a strong harmony between the photo and the background image. I don’t really need to pick the big obvious colours from the photo to create that match, I can easily concentrate on more interesting colours that might work better for what I intend. Using a similar palette, let’s apply those colour choices to a more interesting layout: In this mini-layout, I’ve re-used the same tan colour from the previous middle image as a background, and sampled out a nicely matching colour for the top and bottom overlays, as well as the two different text colours. Because these colours all fall within a narrow range, the overall balance is harmonious. What if I want to try something a little more daring? I have a photo of stacked chairs of all different colours, and I’d like to use a few more of those. No problem, provided I watch my colour contrast: Though it uses varying shades of red, green, and yellow, this palette actually works because the values are even, and the colours muted. Placing red on top of green is usually a hideous combination of death, but if the green is drab enough and the red contrasts well enough, the result can actually be quite pleasing. I’ve chosen red as my loudest colour in this palette, and left green and yellow to play the quiet supporting roles. Obviously, there are no hard and fast rules here. You might not want to sample absolutely every colour in your scheme from a photo. There are times where you’ll need a variation that’s just a little bit lighter, or a blue that’s not in the photo. You might decide to start from a photo base and tweak, or add in colours of your own. That’s okay too. Tonal Variations I’ll leave you with a final trick I’ve been using lately, a way to bring a bit more of a formula into the equation and save some steps. Starting with the same base palette I sampled from the chairs, in the above image I’ve added a pair of overlaying squares that produce tonal variations of each primary. The lighter variation is simply a solid white square set to 40% opacity, the darker one is a black square at 20%. That gives me a highlight and shadow for each colour, which would prove handy if I had to adapt this colour scheme to a larger layout. I could add a few more squares of varying opacities, or adjust the layer blending modes for different effects, but as this looks like a great place to end, I’ll leave that up to your experimental whims. Happy colouring!",2006,Dave Shea,daveshea,2006-12-22T00:00:00+00:00,https://24ways.org/2006/photographic-palettes/,design 131,Random Lines Made With Mesh,"I know that Adobe Illustrator can be a bit daunting for people who aren’t really advanced users of the program, but you would be amazed by how easy you can create cool effects or backgrounds. In this short tutorial I show you how to create a cool looking background only in 5 steps. Step 1 – Create Lines Create lines using random widths and harmonious suitable colors. If you get stuck on finding the right colors, check out Adobe’s Kuler and start experimenting. Step 2 – Convert Strokes to Fills Select all lines and convert them to fills. Go to the Object menu, select Path > Outline Stroke. Select the Rectangle tool and draw 1 big rectangle on top the lines. Give the rectangle a suitable color. With the rectangle still selected, go to the Object menu, select Arrange > Send to Back. Step 3 – Convert to Mesh Select all objects by pressing the command key (for Mac users), control key (for Windows users) + the “a” key. Go to the Object menu and select the Envelope Distort > Make with Mesh option. Enter 2 rows and 2 columns. Check the preview box to see what happens and click the OK button. Step 4 – Play Around with The Mesh Points Play around with the points of the mesh using the Direct Selection tool (the white arrow in the Toolbox). Click on the top right point of the mesh. Once you’re starting to drag hold down the shift key and move the point upwards. Now start dragging the bezier handles on the mesh to achieve the effect as shown in the above picture. Of course you can try out all kind of different effects here. The Final Result This is an example of how the final result can look. You can try out all kinds of different shapes dragging the handles of the mesh points. This is just one of the many results you can get. So next time you haven’t got inspiration for a background of a header, a banner or whatever, just experiment with a few basic shapes such as lines and try out the ‘Envelope Distort’ options in Illustrator or the ‘Make with Mesh’ option and experiment, you’ll be amazed by the unexpected creative results.",2006,Veerle Pieters,veerlepieters,2006-12-08T00:00:00+00:00,https://24ways.org/2006/random-lines-made-with-mesh/,design 142,Revealing Relationships Can Be Good Form,"A few days ago, a colleague of mine – someone I have known for several years, who has been doing web design for several years and harks back from the early days of ZDNet – was running through a prototype I had put together for some user testing. As with a lot of prototypes, there was an element of ‘smoke and mirrors’ to make things look like they were working. One part of the form included a yes/no radio button, and selecting the Yes option would, in the real and final version of the form, reveal some extra content. Rather than put too much JavaScript in the prototype, I took a preverbial shortcut and created a link which I wrapped around the text next to the radio button – clicking on that link would cause the form to mimic a change event on the radio button. But it wasn’t working for him. Why was that? Because whereas I created the form using a tag for each and naturally went to click on the text rather than the form control itself, he was going straight for the control (and missing the sneaky little I’d placed around the text). Bah! There goes my time-saver. So, what did I learn? That a web professional who has used the Internet for years had neither heard of the tag, nor had he ever tried clicking on the text. It just goes to show that despite its obvious uses, the label element is not as well known as it rightfully deserves to be. So, what’s a web-standards-loving guy to do? Make a bit more bleedin’ obvious, that’s what! The Mouse Pointer Trick OK, this is the kind of thing that causes some people outrage. A dead simple way of indicating that the label does something is to use a snippet of CSS to change the default mouse cursor to a hand. It’s derided because the hand icon is usually used for links, and some would argue that using this technique is misleading: label { cursor: pointer; } This is not a new idea, though, and you didn’t come here for this. The point is that with something very simple, you’ve made the label element discoverable. But there are other ways that you can do this that are web standards friendly and won’t upset the purists quite so much as the hand/pointer trick. Time to wheel in the JavaScript trolley jack … Our Old Friend AddEvent First things, first, you’ll need to use the addEvent function (or your favourite variation thereof) that Scott Andrew devised and make that available to the document containing the form: function addEvent(elm, evType, fn, useCapture) { if(elm.addEventListener) { elm.addEventListener(evType, fn, useCapture); return true; } else if (elm.attachEvent) { var r = elm.attachEvent('on' + evType, fn); return r; } else { elm['on' + evType] = fn; } } Finding All Your Labels Once you’ve linked to the addEvent function (or embedded it on the page), you can start to get your JavaScripting fingers a-flexing. Now, what I’m suggesting you do here is: Identify all the label elements on the page by working your way through the DOM Find out the value of the for attribute for each label that you uncover Attach a behaviour or two to each of those label elements – and to the input that the label relates to (identified with the for attribute) Here’s the technobabble version of the steps above: function findLabels() { var el = document.getElementsByTagName(""label""); for (i=0;i Match points Win Draw Lose Played The span inside each legend is because legend elements are highly resistant to styling! Indeed they’re one of the most stubborn elements in the browsers’ vocabulary. Oh man … how I wrestled with the buggers … until this obvious alternative occurred to me! So the legend element itself is just a container, while all the styling is on the inner span. Oh yeah, there was some CSS too I’m not gonna dwell too much on the CSS it took to make this work – this is a short article, and it’s all there in the demo [demo page, style sheet] But I do want to touch on the most interesting bit – where we get from a layout with headers on every row, to one where only the top row has headers – or at least, so it appears to graphical browsers. For screen readers, as we noted, we need those headers on every row, so we should employ some cunning CSS to partly negate their visual presence, without removing them from the output. The core styling for each label span is like this: label span { display:block; padding:5px; line-height:1em; background:#423221; color:#fff; font-weight:bold; } But in the rows below the header they have these additional rules: fieldset.body label span { padding:0 5px; line-height:0; position:relative; top:-10000em; } The rendered width of the element is preserved, ensuring that the surrounding label is still the same width as the one in the header row above, and hence a unified column width is preserved all the way down. But the element effectively has no height, and so it’s effectively invisible. The styling is done this way, rather than just setting the height to zero and using overflow:hidden, because to do that would expose an unrelated quirk with another popular screen reader! (It would hide the output from Window Eyes, as shown in this test example at access matters.) The finished widget It’s an intricate beast allright! But after all that we do indeed get the widget we want: Demo page Style sheet It’s not perfect, most notably because the legends have to have a fixed width; this can be in em to allow for text scaling, but it still doesn’t allow the content to break into multiple lines. It also doesn’t look quite right in Safari; and some CSS hacking was needed to make it look right in IE6 and IE7. Still it worked well enough for the purpose, and satisfied the client completely. And most of all it re-assured me in my faith – that there’s never any need to abuse tables for layout. (Unless of course you think this content is a table anyway, but that’s another story!)",2006,James Edwards,jamesedwards,2006-12-11T00:00:00+00:00,https://24ways.org/2006/showing-good-form/,ux 140,Styling hCards with CSS,"There are plenty of places online where you can learn about using the hCard microformat to mark up contact details at your site (there are some resources at the end of the article). But there’s not yet been a lot of focus on using microformats with CSS. So in this installment of 24 ways, we’re going to look at just that – how microformats help make CSS based styling simpler and more logical. Being rich, quite complex structures, hCards provide designers with a sophisticated scaffolding for styling them. A recent example of styling hCards I saw, playing on the business card metaphor, was by Andy Hume, at http://thedredge.org/2005/06/using-hcards-in-your-blog/. While his approach uses fixed width cards, let’s take a look at how we might style a variable width business card style for our hCards. Let’s take a common hCard, which includes address, telephone and email details

Web Directions North
1485 Laperrière Avenue Ottawa ON K1Z 7S8 Canada Phone/Fax: Work: 61 2 9365 5007 Email: info@webdirections.org We’ll be using a variation on the now well established “sliding doors” technique (if you create a CSS technique, remember it’s very important to give it a memorable name or acronym, and bonus points if you get your name in there!) by Douglas Bowman, enhanced by Scott Schiller (see http://www.schillmania.com/projects/dialog/,) which will give us a design which looks like this The technique, in a nutshell, uses background images on four elements, two at the top, and two at the bottom, to add each rounded corner. We are going to make this design “fluid” in the sense that it grows and shrinks in proportion with the size of the font that the text of the element is displayed with. This is sometimes referred to as an “em driven design” (we’ll see why in a moment). To see how this works in practice, here’s the same design with the text “zoomed” up in size and the same design again, when we zoom the text size down By the way, the hCard image comes from Chris Messina, and you can download it and other microformat icons from the microformats wiki. Now, with CSS3, this whole task would be considerably easier, because we can add multiple background images to an element, and border images for each edge of an element. Safari, version 1.3 up, actually supports multiple background images, but sadly, it’s not supported in Firefox 1.5, or even Firefox 2.0 (let’s not mention IE7 eh?). So it’s probably too little supported to use now. So instead we’ll use a technique that only involves CSS2, and works in pretty much any browser. Very often, developers add div or span elements as containers for these background images, and in fact, if you visit Scott Shiller’s site, that’s what he has done there. But if at all possible we shouldn’t be adding any HTML simply for presentational purposes, even if the presentation is done via CSS. What we can do is to use the HTML we have already, as much as is possible, to add the style we want. This can take some creative thinking, but once you get the hang of this approach it becomes a more natural way of using HTML compared with simply adding divs and spans at will as hooks for style. Of course, this technique isn’t always simple, and in fact sometimes simply not possible, requiring us to add just a little HTML to provide the “hooks” for CSS. Let’s go to work The first step is to add a background image to the whole vCard element. We make this wide enough (for example 1000 or more pixels) and tall enough that no matter how large the content of the vCard grows, it will never overflow this area. We can’t simply repeat the image, because the top left corner will show when the image repeats. We add this as the background image of the vCard element using CSS. While we are at it, let’s give the text a sans-serif font, some color so that it will be visible, and stop the image repeating. .vcard { background-image: url(images/vcardfill.png); background-repeat: no-repeat; color: #666; font-family: ""Lucida Grande"", Verdana, Helvetica, Arial, sans-serif; } Which in a browser, will look something like this. Next step we need to add the top right hand corner of the hCard. In keeping with our aim of not adding HTML simply for styling purposes, we want to use the existing structure of the page where possible. Here, we’ll use the paragraph of class fn and org, which is the first child element of the vcard element.
Web Directions Conference Pty Ltd
Here’s our CSS for this element .fn { background-image: url(images/topright.png); background-repeat: no-repeat; background-position: top right; padding-top: 2em; font-weight: bold; font-size: 1.1em; } Again, we don’t want it to repeat, but this time, we’ve specified a background position for the image. This will make the background image start from the top, but its right edge will be located at the right edge of the element. I also made the font size a little bigger, and the weight bold, to differentiate it from the rest of the text in the hCard. Here’s the image we are adding as the background to this element. So, putting these two CSS statements together we get We specified a padding-top of 2em to give some space between the content of the fn element and the edge of the fn element. Otherwise the top of the hCard image would be hard against the border. To see this in action, just remove the padding-top: 2em; declaration and preview in a browser. So, with just two statements, we are well under way. We’ve not even had to add any HTML so far. Let’s turn to the bottom of the element, and add the bottom border (well, the background image which will serve as that border). Now, which element are we going to use to add this background image to? OK, here I have to admit to a little, teensie bit of cheating. If you look at the HTML of the hCard, I’ve grouped the email and telephone properties into a div, with a class of telecommunications. This grouping is not strictly requred for our hCard.

Phone/Fax: Work: 61 2 9365 5007

Email: info@webdirections.org

Now, I chose that class name because that is what the vCard specification calls this group of properties. And typically, I do tend to group together related elements using divs when I mark up content. I find it makes the page structure more logical and readable. But strictly speaking, this isn’t necessary, so you may consider it cheating. But my lesson in this would be, if you are going to add markup, try to make it as meaningful as possible. As you have probably guessed by now, we are going to add one part of the bottom border image to this element. We’re going to add this image as the background-image. Again, it will be a very wide image, like the top left one, so that no matter how wide the element might get, the background image will still be wide enough. Now, we’ll need to make this image sit in the bottom left of the element we attach it to, so we use a backgound position of left bottom (we put the horizontal position before the vertical). Here’s our CSS statement for this .telecommunications { background-image: url(images/bottom-left.png); background-repeat: no-repeat; background-position: left bottom; margin-bottom: 2em; } And that will look like this Not quite there, but well on the way. Time for the final piece in the puzzle. OK, I admit, I might have cheated just a little bit more in this step. But like the previous step, all valid, and (hopefully) quite justifiable markup. If we look at the HTML again, you’ll find that our email address is marked up like this
Email: info@webdirections.org
Typically, in hCard, the value part of this property isn’t required, and we could get away with info@webdirections.org The form I’ve used, with the span of class value is however, perfectly valid hCard markup (hard allows for multiple email addresses of different types, which is where this typically comes in handy). Why have I gone to all this trouble? Well, when it came to styling the hCard, I realized I needed a block element to attach the background image for the bottom right hand corner to. Typically the last block element in the containing element is the ideal choice (and sometimes it’s possible to take an inline element, for example the link here, and use CSS to make it a block element, and attach it to that, but that really doesn’t work with this design). So, if we are going to use the paragraph which contains the email link, we need a way to select it exclusively, which means that with CSS2 at least, we need a class or id as a hook for our CSS selector (in CSS3 we could use the last-child selector, which selects the last child element of a specified element, but again, as last child is not widely supported, we won’t rely on it here.) So, the least worst thing we could do is take an existing element, and add some reasonably meaningful markup to it. That’s why we gave the paragraph a class of email, and the email address a class of value. Which reminds me a little of a moment in Hamlet The lady doth protest too much, methinks OK, let’s get back to the CSS. We add the bottom right corner image, positioning it in the bottom right of the element, and making sure it doesn’t repeat. We also add some padding to the bottom, to balance out the padding we added to the top of the hCard. p.email { background-image: url(images/bottom-right.png); background-position: right bottom; background-repeat: no-repeat; padding-bottom: 2em; } Which all goes to make our hCard look like this It just remains for us to clean up a little. Let’s start from the top. We’ll float the download image to the right like this .vcard img { float: right; padding-right: 1em; margin-top: -1em } See how we didn’t have to add a class to style the image, we used the fact that the image is a descendent of the vcard element, and a descendent selector. In my experience, the very widely supported, powerful descendent selector is one of the most underused aspects of CSS. So if you don’t use it frequently, look into it in more detail. We added some space to the right of the image, and pulled it up a bit closer to the top of the hCard, like this We also want to add some whitespace between the edge of the hCard and the text. We would typically add padding to the left of the containing element, (in this case the vcard element) but this would break our bottom left hand corner, like this That’s because the div element we added this bottom left background image to would be moved in by the padding on its containing element. So instead, we add left margin to all the paragraphs in the hCard .vcard p { margin-left: 1em; } (there is the descendent selector again – it is the swiss army knife of CSS) Now, we’ve not yet made the width of the hCard a function of the size of the text inside it (or “em driven” as we described it earlier). We do this by giving the hCard a width that is specified in em units. Here we’ll set a width of say 28em, which makes the hCard always roughly as wide as 28 characters (strictly speaking 28 times the width of the letter capital M). So the statement for our containing vcard element becomes .vcard { background-image: url(images/vcardfill.png); background-repeat: no-repeat; color: #666; font-family: ""Lucida Grande"", Verdana, Helvetica, Arial, sans-serif; width: 28em; } and now our element will look like this We’ve used almost entirely the existing HTML from our original hCard (adding just a little, and trying as much as possible to keep that additional markup meaningful), and just 6 CSS statements. Holiday Bonus – a downloadable vCard Did you notice this part of the HTML What’s with the odd looking url -1){ chunks.push({ ref: everything[i], original: everything[i].innerHTML }); } } }; The variable chunks is stored outside of this function so that we can access it from our next core function, which is doTrim. var doTrim = function(interval) { if (!chunks) loadChunks(); var i, l; for (i=0, l=chunks.length; i As for MIME type, Open Mobile Alliance (OMA) specifies using the MIME type application/vnd.wap.xhtml+xml, but ultimately you need to ensure the server delivering your mobile content is configured properly for the MIME type you choose to use, as there are other options (see Setting up WAP Servers). Once you’ve made it to the body, the XHTML-MP markup is not unlike what you’re already used to. A few resources worth skimming: Developers Home XHTML-MP Tutorial – An impressively replete resource for all things XHTML-MP XHTML-MP Tags List – A complete list of XHTML-MP elements and accompanying attributes And last but certainly not least, CSS. There exists WAP CSS, which is essentially a subset of CSS2 with WAP-specific extensions. For all intents and purposes, much of the CSS you’re already comfortable using will be transferrable to mobile. As for including CSS in your pages, your options are the same as for desktop sites: external, embedded, and inline. Some experts will argue embedded or inline over external in favor of reducing the number of HTTP connections per page request, yet many popular mobilized sites and apps employ external linking without issue. Stocking stuffers: Flickr Mobile, Fandango Mobile, and Popurls Mobile. A few sites with whom you can do the View Source song and dance for further study. 4. “Cell phone” is so DynaTAC If you’re a U.S. resident, listen up: You must rid your vocabulary of the term “cell phone”. We’re one of the few economies on the planet to refer to a mobile phone accordingly. If you care to find yourself in any of the worthwhile mobile development circles, begin using terms more widely accepted: “mobile” or “mobile phone” or “handset” or “handy”. If you’re not sure which, go for “mobile”. Such as, “Yo dog, check out my new mobile.” More importantly, however, is overcoming the mentality that access to the mobile web can be done only with a phone. Instead, “device” encourages us to think phone, handheld computer, watch, Nintendo DS, car, you name it. Simple enough?",2006,Cameron Moll,cameronmoll,2006-12-19T00:00:00+00:00,https://24ways.org/2006/the-mobile-web-simplified/,ux 124,Writing Responsible JavaScript,"Without a doubt, JavaScript has been making something of a comeback in the last year. If you’re involved in client-side development in any way at all, chances are that you’re finding yourself writing more JavaScript now than you have in a long time. If 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. Event Handling Back 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’re learned with CSS, there are big benefits in keeping those layers separate. Hey, if it works for CSS, it should work for JavaScript too. Just 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: Play the animation This could be rewritten by removing the onclick attribute, and instead doing the following from within your JavaScript. document.getElementById('anim-link').onclick = playAnimation; It’s all in the timing Of course, it’s never quite that easy. To be able to attach that onclick, the element you’re 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. Back in the day we would have used the onload attibute on the element to do this, but of course what we really want is: window.onload = init; As an interesting side note, we’re 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. As is becoming apparent, nothing is ever simple, and we can’t just go around assigning our initialisation function to window.onload. What if we’re 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’re not using a library, Simon Willison has a good stand-alone example function addLoadEvent(func) { var oldonload = window.onload; if (typeof window.onload != 'function') { window.onload = func; } else { window.onload = function() { if (oldonload) { oldonload(); } func(); } } } Obviously this is just a toe in the events model’s complex waters. Some good further reading is PPK’s Introduction to Events. Carving out your own space Another problem that rears its ugly head when combining multiple scripts on a single page is that of making sure that the scripts don’t 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. When you create a function in JavaScript, you’ll be familiar with doing something like this. function foo() { ... goodness ... } This is actually just creating a variable called foo and assigning a function to it. It’s essentially the same as the following. var foo = function() { ... goodness ... } This name foo is by default created in what’s known as the ‘global namespace’ – 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’re both creating those variables in the global namespace. A 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’s variable scoping to contain you mess and stop it interfering with anyone else. Creating An Object Say I was wanting to write a bunch of functions specifically for using on a site called ‘Foo Online’. I’d want to create my own object with a name I think is likely to be unique to me. var FOOONLINE = {}; We can then start assigning functions are variables to it like so: FOOONLINE.message = 'Merry Christmas!'; FOOONLINE.showMessage = function() { alert(this.message); }; Calling 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. var FOOONLINE = { message: 'Merry Christmas!', showMessage: function() { alert(this.message); } }; Creating A Function to Create An Object We 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. var FOOONLINE = function(){ var message = 'Merry Christmas!'; return { showMessage: function(){ alert(message); } } }(); There 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. The 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’re 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. This 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’s going to be needed from outside, as it makes the interface into your code a lot clearer for someone else to read. All Change, Please So 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. For some, this is all familiar ground already. If that’s the case, I encourage you to perhaps submit a comment with any useful resources you’ve found that might help others get up to speed. Ultimately it’s in all of our interests to make sure that all our JavaScript interoperates well – share your tips.",2006,Drew McLellan,drewmclellan,2006-12-10T00:00:00+00:00,https://24ways.org/2006/writing-responsible-javascript/,code

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