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Sandra Earl

WebAIM: Accessibility of AJAX Applications - Accessibility Issues - 0 views

  • AJAX is
  • a smorgasbord of web technologies put together to allow dynamic client-server interactions to occur in web applications without requiring pages to reload or refresh.
  • AJAX uses the following:
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  • The XHTML and CSS elements can be dynamically modified to display new information or styling. These changes are typically done using the Document Object Model.
  • XHTML (or HTML) and CSS to create an interface and visually style information.
  • JavaScript is used to manipulate the interface elements and is also used to establish a communication with a web server through XMLHttpRequest. This allows data (typically in XML format) to be transmitted between the client and the web server without requiring page reloads or refreshes.
  • standard type of client-server interaction
  • A web page interface is presented. User information is collected (via forms, links, etc.). The user submits information (submits form, activates link, etc.). The server processes submitted information. A new web page interface is sent to the user.
  • With AJAX, all of these steps can be handled in one interface.
  • The types of web applications and interactions allowed by using AJAX has given rise to the term "Web 2.0"
  • AJAX allows feature-rich, dynamic web applications which use server-side processing without requiring the traditional "submit data — retrieve web page"
  • allows more streamlined applications that require less processing and data transmission
  • higher levels of interactivity
  • current solution to these problems is to either provide a non-AJAX alternative to your application or to allow your AJAX application to continue to function if JavaScript and XMLHttpRequest are not supported. Such a requirement may be very difficult to achieve
  • Another issue with AJAX is how the application interface is updated. When updates to the interface occur, it may not be visually apparent that a change has occurred. The problem is even more troublesome for screen reader users. Screen readers typically read in a linear fashion. When changes happen in the interface, the screen reader user may not be aware of the change and the new content will likely not be read.
  • to allow dynamic interface changes to be accessible, the application must alert the user that a change has occurred, allow direct access to the new content, and then allow continued functionality of the web application. This process, while difficult to achieve, especially for screen reader users, is possible to achieve in many AJAX applications.
Vernon Fowler

Accessible forms using WCAG 2.0 | Web Usability - 0 views

  • The label element is not used for the following because labels for these elements are provided via the value attribute
  • This technique inserts new content into the DOM immediately following the element that was activated to trigger the script. The triggering element must be a link or a button, and the script must be called from its onclick event. These elements are natively focusable, and their onclick event is device independent. Focus remains on the activated element and the new content, inserted after it, becomes the next thing in both the tab order and screen-reader reading order. Note that this technique works for synchronous updates. For asynchronous updates (sometimes called AJAX), an additional technique is needed to inform the assistive technology that the asynchronous content has been inserted.
Sandra Earl

Designing and Developing mobile web sites in the real world, part 2 - Opera Developer C... - 0 views

  • In tandem with the launch of their 3G mobile website, Siminn also launched a slightly lighter version of the same site - a 2G-optimized mobile presence to serve less powerful phones. Both sites are anchored to the same reservoir of information, but the 3G site makes less-restricted use of CSS, images, and other coding ornamentations.
  • The only distinction Siminn makes concerning the dimensionality of the user-experience is whether the device is 2G or 3G enabled. As stated before, 2G devices are sent to a slightly lighter version of the 3G site
  • This is exactly what Siminn are doing. By detecting the type of phone, they are presenting the customer with the most appropriate version of the page – either the 3G enhanced or the more basic design.
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  • e chose not to try and replicate the entire Icelandair website, but rather to cleave from it four or five of its most crucial elements.
  • This page contains the only form on the mobile site. In general, forms should be avoided because form input via a mobile device can be a tricky endeavor. However, there are certain coding practices that can simplify form input. For example, if your form field should only accept numeric input, then you should make use of the -wap-input-format property of WAP CSS. The Apple iPhone will automatically set the input to numeric if the name of the input element is set to certain values - phone or zip for example.
  • Mobile users only need to be shown news items that have some inherent urgency.
  • Much like your desktop browser recognizes a mailto: link as an email address, mobile devices recognize tel: links and phone numbers.
  • Do not assume that just because the UA string is not in your enumerated list of “Accepted strings”, it is not possible to view the site.
  • This is where you build in progressive enhancements to the website experience.
  • WURFL is an open source list of known phones and their capabilities. This can be put into a database and when a mobile device visits the your site you can sniff the UA, look-up the capabilities of that device (including screen-dimensions, default browser, etc) and serve them the best possible experience.
  • The RDF vocabulary is a standard across many mobile devices. Vendors that use this approach allow mobile sites to keep up-to-date with any new devices, without having to keep their own database of device types.
  • ou can find more details about standards support in Opera Mini/Mobile 4 here: Designing with Opera Mini 4 in mind JavaScript support in Opera Mini 4
  • There are a few basic coding items to avoid in the mobile web space. Chief among these, at least for now (now being 10/2007), is client-side scripting.
  • While it's tempting to try and port that elegant bit of AJAX from your conventional web to your mobile web, you will only create headaches for yourself.
  • ome browsers do support various levels of JavaScript, but as a developer you should not expect it to work across all devices.
  • retty heavy processor hog, so continuous scripting can drain a battery fast
  • mobile browser support for stylesheets varies greatly.
  • keep things simple.
  • most mobile devices default to their own font sizes and families regardless of styling. Thus, when working on the Siminn project we made no attempt to influence font size or family. In cases where we wanted a larger font, we simply relied on the generic XHTML heading elements.
  • he inclusion of font-size=smaller in the body tag worked as a kind of global reset for font sizes in every device we tested. With this little bit of code we were able to sufficiently reduce the default font size and thus more faithfully reproduce the design that we had been tasked with coding.
  • XHTML-MP - the mobile web subset of XHTML - is fully supported on most modern devices.
  • You can't read 2 books and several articles about mobile web development and cover everything. Much of the effort is trial and error. When starting out, emulators are a good way to get a rough idea of how the site will work. It gives you some feel for the navigation, architecture and flow of the site, but the look and feel varies from the emulator to the real device. The best thing you can do is get a few real phones to test on. I'm sure between yourself, co-workers and a few friends, you can manage to test your site on a good cross-section of the phones out there. Finally, there is some help. The W3C mobile web initiative does have a checklist to see how well your site is doing and so does dev.mobi - if you take heed of these two lists, your site should give a quality experience to most customers.
Sandra Earl

E-Access Blog » Blog Archive » Organisation in the Spotlight - W3C: Global St... - 0 views

  • One major new piece of work undertaken by WAI is the EC-funded WAI-AGE Project (http://www.w3.org/WAI/WAI-AGE/), a look at the implications of an ageing population for web access, given the older people are more likely to have disabilities and may also be less familiar with new technologies. “Demographics worldwide are dramatically changing at the moment,” says Andrew Arch, who works with Abou-Zahra on WAI-AGE. “The proportions of older to younger people are changing as well as the numbers. We’re living longer, and we haven’t got the support behind us. “Lots of things have got to change in governments and organisations - with an ageing workforce, you have to keep learning to stay accessible.”
  • The WAI-AGE project is partly aimed at finding out whether there are any significant new pieces of work needed to ensure web accessibility for an older population, Arch says. “We’ve looked at what research and user observation has gone on over the decade. There is a pretty big overlap between older people and others with disabilities - sight starts to decline, motor dexterity - and individually these overlap. But with older people there is often a lack of recognition that there is a disability there. For example some people might just say they can’t remember so well, rather than that they have a cognitive impairment. Or people won’t see failing eye-sight as a disability, it’s just ‘part of growing old’. But they are disabilities, and often multiple disabilities.”
  • Having gained a grasp of current research the project returned to guidelines such as WCAG 2.0 to see if any changes might be needed. “A large proportion of the needs of older people are met by the new guidelines, but other things might need to feed into the guidance we will issue on implementing the guidelines, for example guidance on how people prepare content for older people.,” said Arch. “Many older people have not grown up with computers, and may not realise their capabilities, for example that you can magnify text in your browser.”
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  • This argument is a development of the age-old mantra from the accessibility sector that people with disabilities want to use the web in the same way as everybody else - “it is a human right recognised by the UN,” says Abou-Zahra. But he recognizes that businesses in particular will also  be interested in the additional business benefits, especially in the current financial climate.
  • “With commercial organisations the return on investment is often an important argument. Well, a few years ago, companies might have said ‘how many older people are online?’ but with demographics changing they know the answer. And with the current surge in mobile phone use there is another incentive, since accessible sites work better on mobile phones.”
  • Another change of style will be a greater separation between the core guidelines and references to specific technologies such as Javascript or browser types, Abou-Zahra says.
  • “WCAG 1.0 was too  technology-specific. Back then HTML was more dominant, and there was less use of multimedia, but today we have a flurry of technologies such as Ajax, so the first lesson we learned is don’t write for a specific technology. Also, in the days of WCAG 1.0 we had to exclude Javascript because it was not sufficiently standardised and  assistive technology could not handle it consistently, but now that has largely changed so you need to include it, to look at how any technology should be accessible. The requirements - such as tagging images with text - needs to apply to any technology you are using.
Sandra Earl

WebAIM: Accessibility of Rich Internet Applications - 0 views

  • WAI-ARIA (Accessible Rich Internet Applications or ARIA) is a W3C protocol for enhancing and supporting accessibility of scripted and dynamic content.
  • ARIA provides accessible interactive controls (such as tree menus, drag and drop, sliders, sort controls, etc.), content roles for identifying page structure (navigation, search, main content, etc.), areas that can be dynamically updated (called "live regions" in ARIA), better support for keyboard accessibility and interactivity, and much more.
  • accessibility issues with rich internet applications can be characterized as: Providing the semantic structure of page areas and functionality (e.g., navigation, main content, search, etc.) Maintaining accessibility of content that is dynamic and may change within the page (e.g., AJAX content updates) Allowing certain non-focusable page elements to receive keyboard focus (e.g., setting focus to an error message within the page) Providing keyboard and screen reader accessibility with complex widgets and navigation elements (e.g., sliders, menu trees, etc.)
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  • WAI-ARIA provides the ability for developers to specify roles for document areas (and many other things).
  • ARIA is being implemented into many scripting libraries (such as jQuery, Dojo, YUI, and GWT). While developers can certainly implement ARIA into their advanced widgets and applications, using ARIA-supported libraries greatly simplifies the process of providing this level of accessibility.
Sandra Earl

InformIT: The Adobe AIR Platform: Software Revolution or Evolution? > The Adobe AIR Pla... - 0 views

  • Adobe AIR is a cross-operating system platform that allows developers to leverage their existing web development skills in HTML, Ajax, XML, Flash and Flex to build and deploy Rich Internet Applications for the desktop.
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