Re: From the HTML-WG about aria-hidden

Hi Joseph, a reply at end of letter:

Joseph Scheuhammer, Thu, 16 Feb 2012 10:05:42 -0500:

> A couple of quick points.  On 12-02-15 7:32 PM, Leif Halvard Silli wrote:
>> ...
>>>> With respect to aria-describedby the above proposes that
>>>> aria-describedby trumps aria-hidden,
>> It is ARIA 1.0 that causes aria-hidden to be trumped:
>> 
>> 'Skip hidden elements unless the author specifies to use them
>>   via an aria-labelledby or aria-describedby.'
>> <http://www.w3.org/TR/wai-aria/roles#namecalculation>
> 
> One distinction here:  I was discussing whether the hidden element is 
> exposed in the a11y tree.  The alternative text computation relates 
> to whether hidden elements are included in the calculation of, well, 
> alternative text.  The two are not the same thing.
> 
> For example:
> <img aria-describedby="desc1" ...>
> <p id="desc1" "aria-hidden="true" style="display:none;">Descriptive text</p>
> 
> There will be one accessible object in the a11y tree corresponding to 
> the image, and that accessible will have a *description property* 
> containing the string "Descriptive text".  That's because the hidden 
> paragraph is not skipped here due to the description relationship, 
> even though it is hidden.
> 
> However, there will be no accessible object in the a11y tree 
> corresponding to the paragraph itself, because it is hidden.  Put 
> another way:  the DOM contains two objects, one for the image and one 
> for the paragraph.  The a11y tree contains only one object, for the 
> image.
> 
> The issue I was exploring was whether the aria-describedby 
> relationship forces an accessible object for the hidden paragraph 
> into the a11y tree, even though it is hidden.

So it seems we are on the same page. I have not explored the 
relationship between DOM and A11Y tree, but what you describe make 
sense to me. I don't think the ISSUE-204 proposal intend to change any 
of this - the calculation of which elements gets included in the 
description property. 

The only thing ISSUE-204 change is this: If you, in your example, 
replace aria-hidden with @hidden and also remove the display:none [*], 
then ISSUE-204 will make UAs present the #desc1 element with 'full 
semantics' - links and other stuff that might be there.

[*] Many details w.r.t. ISSUE-204 seem unclear. Such as the exact 
requirements that needs to be fulfilled before a description property 
presented with 'full semantics'.
-- 
leif halvard silli

Received on Thursday, 16 February 2012 15:50:07 UTC