- From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
- Date: Thu, 16 Feb 2012 16:49:26 +0100
- To: Joseph Scheuhammer <clown@alum.mit.edu>
- Cc: Richard Schwerdtfeger <schwer@us.ibm.com>, Janina Sajka <janina@rednote.net>, "wai-xtech@w3.org" <wai-xtech@w3.org>
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