{"rowid": 278, "title": "Going Both Ways", "contents": "It\u2019s that time of the year again: Santa is getting ready to travel the world. Up until now, girls and boys from all over have sent in letters asking for what they want. I hope that Santa and his elves have\u2014unlike me\u2014learned more than just English.\n\nOn the Internet, those girls and boys want to participate in sharing their stories and videos of opening presents and of being with friends and family. Ah, yes, the wonders of user generated content. But more than that, people also want to be able to use sites in the language they know.\n\nWhile you and I might expect the text to read from left to right, not all languages do. Some go from right to left, such as Arabic and Hebrew. (Some also go from top to bottom, but for now, let\u2019s just worry about those first two directions!)\n\nIf we were building a site for girls and boys to send their letters to Santa, we need to consider having the interface in the language and direction that they prefer. On the elves\u2019 side, they may be viewing the site in one direction but reading the user generated content in the other direction. We need to build a site that supports bidirectional (or bidi) text.\n\nLet\u2019s take a look at some things to be aware of when it comes to building bidi interfaces.\n\nSetting the direction of the interface\n\nRight off the bat, we need to tell the browser what direction the text should be going in. To do this, we add the dir attribute to an HTML element and set it to either LTR (for left to right) or RTL (for right to left).\n\n\n\nYou can add the dir attribute to any element and it will set or change the direction for the content within that element. \n\n\n Here is English Content.\n

\u0627\u0644\u0645\u0648\u0636\u0648\u0639

\n\n\nYou can also set the direction via CSS.\n\n.rtl {\n direction: rtl;\n }\n\nIt\u2019s generally recommended that you don\u2019t use CSS to set the direction of the text. Text direction is an important part of the content that should be retained even in environments where the CSS may not be available or fails to load.\n\nHow things change with the direction attribute\n\nJust adding the dir attribute tells the browser to render the content within it differently. \n\n\n\nThe text aligns to the right of the page and, interestingly, punctuation appears at the left of the sentence. (We\u2019ll get to that in a little bit.) \n\nScrollbars in most browsers will appear on the left instead of the right. Webkit is the notable exception here which always shows the scrollbar on the right, no matter what the text direction is. Avoid having a design that has an expectation that the scrollbar will be in a specific place (and a specific size).\n\nChanging the order of text mid-way\n\nAs we saw in that previous example, the punctuation appeared at the beginning of the sentence instead of the end, even though the text was English. At Yahoo!, we have an interesting dilemma where the company name has punctuation in it. Therefore, when the name appears in the middle of (for example) Arabic text, the exclamation mark appears at the beginning of the word instead of the end.\n\n\n\nThere are two ways in which this problem can be solved:\n\n1. Use HTML around the left-to-right content, or\n\nTo solve the problem of the Yahoo! name in the midst of Arabic text, we can wrap a span around it and change the direction on that element.\n\n\n\n2. Use a text direction mark in the content.\n\nUnicode has two marks, U+200E and U+200F, that tell the browser that the text is in a particular direction. Placing this right after the punctuation will correct the placement.\n\nUsing the HTML entity:\nYahoo!\u200e\n\nTables\n\nThankfully, the cells of a data table also get reordered from right to left. Equally as nice, if you\u2019re using display:table, the content will still get reordered.\n\n\n\nCSS\n\nSo far, we\u2019ve seen that the dir attribute does a pretty decent job of getting content flowing in the direction that we need it. Unfortunately, there are huge swaths of design that is handled by CSS that the handy dir attribute has zero effect over.\n\nMany properties, like float or absolute positioning with left and right values, are unaffected and must be handled manually. Elements that were floated left must now by floated right. Left margins and paddings must now move to the right and the right margins and paddings must now move to the left.\n\nSince the browser won\u2019t handle this for us, we have a couple approaches that we can use:\n\nCSS Only\n\nWe can take advantage of the attribute selector to target CSS to apply in one direction or another.\n\n[dir=ltr] .module {\n\tfloat: left;\n\tmargin: 0 0 0 20px;\n}\n\n[dir=rtl] .module {\n\tfloat: right;\n\tmargin: 0 20px 0 0;\n}\n\nAs you can see from this example, both of the properties have been modified for the flipped interface. If your interface is rather complicated, you will have to create a lot of duplicate rules to have the site looking good in both directions while serving up a single stylesheet.\n\nCSSJanus\n\nGoogle has a tool called CSSJanus. It\u2019s a Python script that runs over the LTR versions of your CSS files and generates RTL versions. For the RTL version of the site, just serve up those CSS files instead of the LTR versions.\n\nThe script looks for keywords and value combinations and automatically swaps them so you don\u2019t have to. \n\nAt Yahoo!, CSSJanus was a huge help in speeding up our development of a bidi interface. We\u2019ve also made a number of improvements to the script to better handle border radius, background positioning, and gradients. We will be pushing those changes back into the CSSJanus project. \n\n\n\nBackground Images\n\nBackground images, especially for things like CSS sprites, also raise an interesting dilemma. Background images are positioned relative to the left of the element. In a flipped interface, however, we need to position it relative to the right. An icon that would be to the left of some text will now need to appear on the right.\n\n\n\nIf the x position of the background is percentage-based, then it\u2019s fairly easy to swap the values. 0 becomes 100%, 10% becomes 90% and so on. If the x position is pixel-based, then we\u2019re in a bit of a pickle. There\u2019s no way to say that the image should be a certain number of pixels from the right.\n\nTherefore, you\u2019ll need to ensure that any background image that needs to be swapped should be percentage-based. (99.9% of the the time, the background position will need to be 0 so that it can be changed to 100% for RTL.)\n\nIf you\u2019re taking an existing implementation, background positioning will likely be the biggest hurdle you\u2019ll have to overcome in swapping your interface around. If you make sure your x position is always percentage-based from the beginning, you\u2019ll have a much smoother process ahead of you!\n\nFlipping Images\n\nThis is a more subtle point and one where you\u2019ll really want an expert with the region to weigh in on. In RTL interfaces, users may expect certain icons to also be flipped. Pencil icons that skew to the right in LTR interfaces might need to be swapped to skew to the left, instead. Chat bubbles that come from the left will need to come from the right.\n\nThe easiest way to handle this is to create new images. Name the LTR versions with -ltr in the name and name the RTL versions with -rtl in the name. CSSJanus will automatically rename all file references from -ltr to -rtl.\n\nThe Future\n\nThankfully, those within the W3C recognize that CSS should be more agnostic. As a result, they\u2019ve begun introducing new properties that allow the browser to manage the swapping from left to right for us.\n\nThe CSS3 specification for backgrounds allows for the background-position to be relative to other corners other than the top left by specifying keywords before each position.\n\nThis will position the background 5px from the bottom right of the element.\n\nbackground-position: right 5px bottom 5px;\n\nOpera 11.60 is currently the only browser that supports this syntax.\n\nFor margin and padding, we have margin-start and margin-end. In LTR interfaces, margin-start would be the same as margin-left and in RTL interfaces, margin-start would be the same as margin-right. \n\nFirefox and Webkit support these but with vendor prefixes right now:\n\n-webkit-margin-start: 20px;\n-moz-margin-start: 20px;\n\nIn the CSS3 Images working draft specification, there\u2019s an image() property that allows us to specify image fallbacks and whether those fallbacks are for LTR or RTL interfaces.\n\nbackground: image('sprite.png' ltr, 'sprite-rtl.png' rtl);\n\nUnfortunately, no browser supports this yet but it\u2019s nice to be able to dream of how much easier this will be in the future!\n\nHo Ho Ho\n\nHopefully, after all of this, you\u2019re full of cheer knowing that you\u2019re well on your way to creating interfaces that can go both ways!", "year": "2011", "author": "Jonathan Snook", "author_slug": "jonathansnook", "published": "2011-12-19T00:00:00+00:00", "url": "https://24ways.org/2011/going-both-ways/", "topic": "ux"}