|
AJAX is a great tool for creating rich internet applications, however, when improperly implemented it can cause huge accessibility issues. The good news is that most of these issues can be fixed so your websites are viewable by a much wider audience. Great resources on accessibility have been around for years, however, many web 2.0 and AJAX websites ignore all of the research that went into turning website accessibility into a movement followed by most professional web developers. Below you‘ll find a list of 40 best AJAX accessibility tutorials and articles that I have found on the web in the last year. As always thanks to all of the developers and accessibility experts who made all of the information below available to us. Also, if you know of any other AJAX accessibility resources please add them to this post via my comments area. 3 Myths of Ajax and Accessibility I‘ve seen quite a few ideas and bits of policy writing about accessiblity that could probably do with some updating. These are the 3 most common. Accessibility of AJAX Applications AJAX will not work in all web browsers. As its name suggests, AJAX requires JavaScript. This alone means that AJAX applications will not work in web browsers and devices that do not support JavaScript. For this reason it is not accessible to many typical Web users. The Web Content Accessibility Guidelines also require that web applications function when JavaScript is disabled or not supported. AJAX also requires that XMLHttpRequest be supported, which many browsers do not. Accessible DHTML DHTML accessibility allows desktop-style widgets such as tree views, menu bars and spreadsheets which are accessible both with the keyboard and assistive technologies such as screen readers, screen magnifiers and alternative input devices. Accessible JavaScript Guidelines Use Javascript to enhance the usability features for the majority of users, without negatively affecting the accessibility for the minority of users. You can almost always fall back on a plain HTML or server-side solution for the benefit JavaScript provides. Accessible Pop-up Links Sometimes we have to use pop-ups -- so we might as well do them right. This article will show you how to make them more accessible and reliable while simplifying their implementation. AJAX Accessibility Overview Asynchronous JavaScript and XML (AJAX) is a hot new technology on the Internet that allows the incremental update of portions of a Web page without reloading the entire page. This has great performance benefits and provides a medium for developing rich Internet applications. Accessibility concerns have arisen with the increased use of JavaScript and AJAX on the Web. This article introduces AJAX and discusses some of the accessibility issues and best practices. AJAX and Accessibility In this article we will have a look at the implications for accessibility and usability when using Javascript to dynamically update a web page. I will also show how you can increase accessibility for AJAX-based forms Ajax, accessibility and Assistive Technology I‘ve been worrying about Ajax accessibility for a while now, so I was delighted to read two very interesting items of research on Ajax accessibility which were published last week. Ajax Accessibility Revisited The incredible flexibility provided by Ajax technologies is a big frustration to the accessible design community. Speaking for myself, I‘d LOVE to feel comfortable using these powerful tools to create accessible tools. But the situation continues to be limiting. AJAX and Accessibility With DOM Scripting and Remote Scripting making their way into standards-compliant web development, people are beginning to wonder what the effect of these techniques is in screenreaders and other assistive technologies. Kevin Leitch asked me and some others about AJAX and Accessibility. AJAX and Screenreaders: When Can it Work? We‘ve all heard a great deal of buzz about AJAX in the last few months, and with this talk has come a legion of articles, tips, presentations and practical APIs designed to explore the possibilities and try to arrive at best-practice techniques. But, for all of the excitement and hype, still very little has been said on the subject of AJAX and accessibility. Ajax, Hijax and accessibility The main aim of Keith‘s Hijax methodology is a model of Web Standards "Progressive Enhancement" lovliness, which ensures the degradability of the web page/ web app (call it what you will). It is basically the principle of unobtrusive JavaScript applied to Ajax. AJAX, JavaScript and accessibility With the advent of mass-hype for building AJAX solutions, I find it necessary to shed some light of AJAX and JavaScript implementations and how they relate to and affect accessibility, and to explain how they can both co-exist; that one doesn‘t exclude the other. AJAX: Usable Interactivity with Remote Scripting This article aims to give you an introduction to the foundations of remote scripting, in particular, the emerging XMLHttpRequest protocol. We‘ll then walk through an example application that demonstrates how to implement that protocol, while creating a usable interface. Ajaxessibility Unfortunately for us, it‘s also inaccessible as all getout. Even in 2005, assistive technologies like screen readers get serious heartburn when it comes to just about anything we call "dynamic HTML." It doesn‘t know what of this asynchronous content crossing the transom is relevant to the user, and how to deliver it meaningfully to the user. Do they want to announce every line of a ticker script automatically, while the user is trying to read other content? Nope. An important lesson learned about AJAX and accessibility Yesterday I went to visit some fellow consultants at their assignment for a sub company/department of one of Sweden‘s largest banks. We had a talk about AJAX in general and different ways of how to implement it, and one of them opened his web browser to navigate to some AJAX-based web sites. Build Half a Product: Is Ajax accessible? At all? If you know about WCAG then you know that many parts of it are outdated. And you also know that a lot of people have developed expertise over the years in interpreting WCAG in contemporary ways. Creating Accessible JavaScript JavaScript allows developers to add increased interaction, information processing, and control in web-based content. However, JavaScript can also introduce accessibility issues. Event Handler Accessibility Only use onchange rarely and don‘t alert users of format errors until time for submission. For example, you may want to use it for slight formatting changes of input data. If a user has typed in (555)555-1212 for a phone number format instead of the requested format, you could change it to 555-555-1212 safely without alerting the user. First Framework to Support Accessibility for AJAX and Web 2.0 Applications MB Technologies, developers of Bindows, the leading development framework for AJAX and Web 2.0 applications, announced today the release of Bindows version 2.0 with enhanced support for Section 508 accessibility compliance, an industry first. Fixing the Back Button and Enabling Bookmarking for AJAX Apps Everyone‘s favourite AJAX technology app is Google Maps. Google have done a stunning job... But when I came to try to bookmark a page I had to hunt around for ‘link to this page‘ over on the right hand side. Why have they broken such a basic function of the web? Front-End Architecture: AJAX & DOM Scripting The tipping point that really got me wondering about front-end architecture is AJAX. It‘s unique in that it really crosses the chasm between user experience and the deeper technical bits. On one hand, AJAX is important because it enables us to create exponentially richer user experiences. On the other hand however, its implementation can leave much to be desired if handled incorrectly, and to make matters worse, because of the way it straddles the line between the front and back-end, it‘s difficult to determine how it fits in with everything. How do scripting languages affect accessibility? Scripting languages are becoming increasingly popular on the web, because they can be used to make web pages more dynamic and interactive. There are two types of scripting languages: server-side and client-side. Index of JavaScript tests Some great information about javascript and accessibility Javascript and Accessibility Use of scripts such as Javascript may create barriers to access for some users of adaptive technology. For example, if a script generates content on the "mouseover" event handler, as in the case of "rollovers," anyone who relies on keyboard access will not be able create the event that will cause the browser to generate the text. JavaScript Accessibility Examples Use the event handlers on an anchor element rather than on the image element. An image cannot achieve keyboard focus so it would never be able to use the keyboard events. JavaScript accessibility issues JavaScript is a scripting language used to make HTML documents more dynamic. Oftentimes, user actions trigger scripts which modify the page. Users may not realize a page has changed or may not be ready for the page to change when it does. On the other hand, if done well, JavaScript can enhance the accessibility of pages by allowing users to customize them to their needs. JavaScript and Accessibility here are some pretty serious implications for the AJAX-ification of the web if we want to do it right. I‘m a believer that AJAX is interesting, will become a popular way of building web based applications. I‘m concerned that we‘re going to get people building AJAX type applications that simply won‘t work at all without JavaScript on. Making Ajax Work with Screen Readers The accessibility community is understandably concerned about the accessibility of client-side scripting, in particular using Asynchronous JavaScript and XML (Ajax) to produce Rich Internet Applications. Steve Faulkner of Vision Australia and founder member of the Web Accessibility Tools Consortium (WAT-C) and myself on behalf of The Paciello Group (TPG) have collaborated in an effort to come up with techniques to make Ajax and other client-side scripting techniques accessible to assistive technology. Progressive enhancement with Ajax It would be nice if Google Maps were accessible by non-JavaScript enabled user agents, but in practice this must be weighed up against market forces - is an acceptable proportion of your target market likely to have JavaScript enabled, or is your service so useful that people will go out of their way to acquire JavaScript capabilities to use it Responsible Asynchronous Scripting AJAX and its kin are empowering developers, but with great power comes great responsibility. Asynchronous or remote scripting has been lurking in the background of web app development for quite some time now. Rich Accessibility I think accessibility issues have always been an abstract concept to me. It usually was an afterthought, something that the usability folks dinged us for. You know the text wasn‘t dark enough or the font was too small. It seemed to me that every experience I had with accessibility was from the negative perspective. Same Language, New Dialect First, accessibility: Advanced interactions and behavior provided via JavaScript must be enhancements, not the sole way to accomplish a task. In desktop cut-and-paste, there are at least three ways: keyboard shortcuts; "Edit" menu options; and drag and drop. Accessibility isn‘t an optional characteristic of the Web. The Hows and Whys of Degradable Ajax While working on Particletree‘s shopping cart system for our magazine, we decided that we wanted to create a flawless user experience for all users without having to sacrifice the added user interface benefits provided by Ajax goodness. A lot of places will tell you that it is ok to use JavaScript and Ajax as long as it‘s not mission critical. Well, we don‘t think web apps have to be boring to be reliable. Usable XMLHttpRequest in Practice One of the great benefits of XMLHttpRequest is that you can use it to make complex WYSIWYG. This has previously been hard to do on the web. Take a "build your car" feature that you often find on sites of car manufacturers. This could be greatly enhanced by the use of XMLHttpRequest. When the buyer selects something, you can connect to the database, recalculate prices, change the image or change other options - without reloading the page, on the fly. This is great! But... remember the 4 points above. XMLHttpRequest do not support any of them by default, if you want to keep your web application usable - you have to reinvent them. Usability and accessibility with Ajax The Ajax express train rumbles on, threatening to crush anything in its path. Recent discussion has turned to those critical elements of good web development, usability and accessibility. Accessibility is a major issue with Ajax, mainly because anything that relies on JavaScript to function is inaccessible pretty much by default. There are two solutions: either provide a fall-back system where the site remains useful without its Ajax enhancements, or provide a whole separate interface that works without scripting. XMLHttpRequest Usability Guidelines XMLHttpRequest is becoming more and more popular, and many people are currently exploring what we could do with it. Unfortunately this also causes people to reinvent old and forgotten usability problems. Web 2.0 and accessibility Web 2.0 is the hottest buzzword since Ajax, and I‘m glad to see that I‘m not the only one worried about what thoughtless implementation of everything that fits in "Web 2.0" could mean for accessibility and device independence on the web. Important Note: The post that was here Why Ajax Sucks (Most of the Time) has been removed as it was not a legitimate article about AJAX. It was a fraud, and it was not written by Jakob Nielsen. Very sorry Jakob. Why Ajax Sucks (Most of the Time) With respect to the use of ajax by highly skilled Web designers, I have changed my opinion somewhat: people who really know what they are doing can sometimes use ajax to good effect, though even experienced designers are advised to use ajax as sparingly as possible. You should‘ve been @media What we basically agreed on is that we need to get the word out. JavaScript is ready for its proper role in modern, standards based websites. During the conference we found plenty of evidence that there is much interest in JavaScript, if only people could get more help and more explanations. |
|
|
