Concerns with SC 4.1.2 and dynamic HTML components

4.1.2 The role, state, and value can be programmatically determined for 
every user interface component in the Web content that accepts input from 
the user or changes dynamically in response to user input or external 
events 

I have some concerns with success criterion 4.1.2 and today's dynamic 
HTML.  Using dynamic HTML (without any of the DHTML accessibility roadmap 
enhancements) I can build a tree control using images and links.   This 
tree control will lack any role and state information but is usable from 
the keyboard and via a screen reader.   But, while the screen reader can 
navigate and use this control, there is no role and explicit state 
information to tell them that it is a tree control or that the nodes are 
tree items.   Thus, I think it would fail this level 1 SC.  Or, because 
the tree is built using link elements, and the role and state information 
about the links is available does that meet the requirements of this 
success criterion? I'm not sure, to me, the user interface component is 
the tree, not the individual links. Do we really want to prevent the use 
of dynamic HTML components even though the overall role can not explicitly 
be defined? 

As a proponent of the DHTML Accessibility roadmap [1] I would certainly 
encourage assistive technology vendors, user agent vendors and developers 
to adopt this new standard and am working to make that happen.   But, in 
the interim,  I am concerned that we are preventing dynamic user interface 
elements today with this success criterion. 

I found a relatively good example of this type of tree control on the web 
[2].  It does work with tab key navigation and does work fairly well in 
JAWS. But, the images of the folders and expand / collapse icons are not 
well labeled. So, while this is not a good example, it could be made to 
work better with the screen reader with that addition of proper alt 
attributes.   IBM has similar types of controls but there are not external 
examples that I can provide a public link to. 

comments? 

Note: I am not trying to make any kind of statement about the code example 
at [2].  I have just used it as a fairly accessible example of an HTML 
tree control that is publically available on the Web. 

[1] http://www.w3.org/WAI/PF/roadmap/DHTMLRoadmap110505.html
[2] http://www.treemenu.net/treeviewfiles/demoFrameless.html



Becky Gibson
Web Accessibility Architect
                                                       
IBM Emerging Internet Technologies
5 Technology Park Drive
Westford, MA 01886
Voice: 978 399-6101; t/l 333-6101
Email: gibsonb@us.ibm.com

Received on Friday, 20 January 2006 21:31:48 UTC