Requirements for role=presentation

The ARIA draft currently says:

"The user agent MAY choose not to present all structural aspects of the 
element being repurposed. For example, for a table marked as 
presentation, the user agent would remove the table, td, th, tr, etc. 
elements from the accessibility API mapping, while preserving the 
individual text elements within them. Because the user agent knows to 
ignore the structural aspects implied in a table, no harm is done by 
using a table for layout."

This "MAY" level requirement is too weak to ensure interoperable 
behaviour of UAs and too weak to allow authors to code against. Despite 
the example there is no assurance that a conforming UA would indeed 
propagate this role information to the children of the table so a 
careful author would have to write

<table role=presentation>
<tr role=presentation>
<td role=presentation>

Other cases are also unclear; for example it is unclear if the alt text 
in <img role=presentation alt="Holiday photo"> should be read out by a 
conforming UA.

The ARIA spec should tighten up these cases, possibly by explicitly 
deferring to the host language (rather than the user agent) to define 
where the role value is inherited.

Received on Monday, 17 August 2009 14:53:00 UTC