[Bug 10919] New: Allow role="presentation" to override the default role of any element

http://www.w3.org/Bugs/Public/show_bug.cgi?id=10919

           Summary: Allow role="presentation" to override the default role
                    of any element
           Product: HTML WG
           Version: unspecified
          Platform: All
               URL: http://dev.w3.org/html5/spec/content-models.html#annot
                    ations-for-assistive-technology-products-aria
        OS/Version: All
            Status: NEW
          Keywords: a11y, aria
          Severity: major
          Priority: P2
         Component: HTML5 spec (editor: Ian Hickson)
        AssignedTo: ian@hixie.ch
        ReportedBy: martin.kliehm@namics.com
         QAContact: public-html-bugzilla@w3.org
                CC: mike@w3.org, public-html-wg-issue-tracking@w3.org,
                    public-html@w3.org, public-html-a11y@w3.org


Some HTML elements have native roles that can be overridden by a limited list
of other roles. "presentation" is not in this list, but it should be.

WAI-ARIA [1] defines:

"An element whose implicit native role semantics will not be mapped to the
accessibility API.

"The intended use is when an element is used to change the look of the page but
does not have all the functional, interactive, or structural relevance implied
by the element type [...]

"Example use cases: [...] An element used as an additional markup 'hook' for
CSS"

The following use case can be found at http://bahn.de

<ul role="tablist">
  <li role="presentation">
    <span role="presentation">
      <a role="tab" href="#bahn">Bahn</a>
    </span>
  </li>
</ul>

Some screenreaders don't recognize the tab role when it is not an immediate
child of the tablist role element. In the example above some presentational CSS
is attached to the list item and the span element. The presentation role
removes those elements from the accessibility API such that tab is again a
child of tablist. The anchor is most convenient since it's fragment identifier
is used to update the browser history, and it brings some default behavior like
being included in the taborder and using a pointer cursor.

It may not be a best practice, but it will and does happen. role="presentation"
is more powerful than just an eraser for image elements with empty alt
attributes.

May depend on bug #10066.

[1] http://www.w3.org/TR/2010/WD-wai-aria-20100916/roles#presentation

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Received on Thursday, 30 September 2010 22:54:31 UTC