Accessibility Extensions for Mozilla/Firefox

Campus Information Technologies and Educational Services (CITES) and Disability Resources and Educational Services (DRES)

University of Illinois at Urbana/Champaign

Authoring Accessible DHTML Resources

Using the W3C Role and State properties does not guarantee an accessible web resource. They can provide additional information that can improve navigation, comprehension, and usability if used correctly.


Required Content


Extending Existing Functionality

Legacy Support - HTML 4.01 Workaround

The accessibility people at IBM put together a technique for enabling accessible roles and state properties in HTML. This is needed because the capability to parsing different namespaces is only supported by the newer XHTML standards. Developers may use this to upgrade older pages, especially with informative structural roles, without the additional burden of conversion to XHTML.

The technique uses the styling class attribute to hold keywords that denote the various accessible role and state memberships. A javascript function (provided for the standard roles and states) will then parse the element's styling class properties for these identifiers. The script inserts the corresponding role or state attribute (with the appropriate namespace) into the DOM, where it will be accessible to assistive technologies. Yes, this is a hack, but it does work and it is one of the more respectable hacks floating around on the web, at least!

Helpful Links


W3C Role Taxonomy
Defines standard widgets and RDF taxonomy description
W3C States and Adaptable Properties
Defines the standard states for the standard roles
Stefano's Introduction to the Semantic Web
The clearest short explanation of RDF and related technologies.
W3C OWL Web Ontology Language Guide
An understandable guide to OWL

Authoring Advice

Accessible keyboard events
Mozilla's guidelines for developers on how to use the keyboard in their custom widgets


Mozilla Accessible DHTML
Some overview of DHTML accessibility in Mozilla and several example widgets in HTML and XHTML
Yahoo User Interface Library
At CSUN 2006, Yahoo advertised DHTML accessible widgets in their library