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ACTION-790 Produce some text around accessibility of Javascript for Web Application Best Practices

From: Alan Chuter <achuter@technosite.es>
Date: Mon, 22 Sep 2008 12:32:48 +0200
Message-ID: <48D77450.1070202@technosite.es>
To: MWI BPWG Public <public-bpwg@w3.org>

Here are some suggestions for incorporating accessibility concepts into 
the BP2 document. I think it could be put under "User Interface" rather 
than in a separate section. I think that perhaps investigating 
accessibility may help identify new BPs that will benefit all mobile users.

3.6 User Interface

Add a new BP. "For dynamic rich user interfaces, follow WAI-ARIA Best 
Practices, for accessibility"

The BP title should not imply that ARIA [1] will make the interface 
accessible, as this is covered by WCAG. Rather ARIA is a set of 
technologies that are very relevant to mobile Web applications. Indeed, 
if there is device support, some of ARIA has the potential to make 
dynamic content more usable. For example it may make it possible to 
indicate to the user what part of the page has or may be updated, and a 
way to jump to that content.

It would be useful to consult with the ARIA WG to identify different 
ways that ARIA could improve usability for all on mobile devices. ARIA 
could transform the way Web applications are used on mobile devices. For 
example, I can imagine displaying DHTML menus as GUI widget menus if 
they were marked up with ARIA.

This document should mention ARIA and explain its importance for users 
with disabilities and all mobile users. I suggest including text 
something like this: "Be aware of the difficulties caused by dynamic 
content for users with special accessibility needs. Users may be unaware 
that content has been updated or where the updated content is located in 
the page. Users may be unaware of special behaviour assigned to standard 
HTML elements using script (for example lists used as menus, buttons 
used as slider controls). WAI ARIA provides a means to ensure 
interoperability with assistive technologies by incorporating the 
appropriate metadata into HTML and XHTML markup to support 
platform-specific accessibility APIs." This could even be a separate BP.

3.6.3 Don't Move the Focus on Updates

I would suggest expanding this to say "ensure the user is aware which 
parts of the page may be updated dynamically." Like blind and low-vision 
users, the mobile user may not see the content update if it is outside 
the current viewport.

3.6.4 Group Closely Coupled Views onto the Same Page

It would be useful to mention that hiding content with CSS is a purely 
visual thing. Users of voice synthesis will still "see" (hear) all the 
hidden content as if no CSS had been applied. Using display:none does 
generally hide the content from screen readers too (but not always, see 
[2]). If "Script can be used to show and hide the relevant views and 
their content updated with a background server request" perhaps it would 
be better to insert and remove the entire section using script.

regards,

Alan



[1] http://www.w3.org/TR/wai-aria/
[2] http://juicystudio.com/article/screen-readers-display-none.php

-- 
Alan Chuter
Senior Web Accessibility Consultant, Technosite
Researcher, Inredis Project (www.inredis.es/)
achuter@technosite.es
http://www.technosite.es
Received on Monday, 22 September 2008 10:34:35 GMT

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