- From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
- Date: Thu, 16 Feb 2012 01:32:00 +0100
- To: Richard Schwerdtfeger <schwer@us.ibm.com>
- Cc: Joseph Scheuhammer <clown@alum.mit.edu>, Janina Sajka <janina@rednote.net>, "wai-xtech@w3.org" <wai-xtech@w3.org>
Some comments, to - perhaps - clarify that we are on the same page in this dbate - see below. Richard Schwerdtfeger, Wed, 15 Feb 2012 15:59:04 -0600: > Joseph Scheuhammer wrote on 02/15/2012 10:25:06 AM: >> 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> >> and forces the rendering of the hidden element. No. Not rendering. It is just included in the 'accessible name' - like @alt text. ISSUE-204 is about making it possible to 'render' it as a shadow DOM 'thingy' to AT. It would be hidden to AT too, except when the AT presents an element's ARIA-describedby references to the user. >> It goes further, and requires that elements hidden via >> CSS must be exposed if they are referenced by some aria-* attribute: In ARIA 1.0, 'hidden' covers 'hidden via CSS' > I doubt CSS is going to change that any time soon. However, if this goes > through it will break a lot of code where the text is *intentionally* > hidden where CSS is used to hide content. For example, companies do provide > additional help text for form entries and other forms of interactive > components to assist in performing a task. This is there to help people > with disabilities but the author does NOT want to that help information to > be visually exposed such that it clutters up the user interface. Rich, before you conclude: ISSUE-204 does not touch the way in which aria-describedby 'trumps aria-hidden'. *That* is described in ARIA 1.0. ISSUE-204 is instead about HTML5's @hidden. And even though @hidden implies @aria-hidden, they are different things. First and foremost - whether the idea is good or bad - the intention is *not* that @hidden content gets 'rendered' - to all users, in a visual way. The idea is only that, instead of being presented as a text string - to AT [as *required* by ARIA] - the @hidden content is instead presented to AT with *full semantics [as *recommended* by ARIA]. ISSUE-204 in a summary: @aria-describedby 'flattens' semantics such as links. @longdesc does not have this problem. Jonas Sicking is therefore suggesting that when aria-describedby points to content that has the HTML5 @hidden attribute, *then* its content will be 'rendered' with full semantics - to the AT user and AT users alone. That way, @longdesc will loose this advantage. And the case for deprecation of @longdesc gets - to put it bluntly - stronger. [At least to the degree that the chairs is looking for @longdesc to be very different from @aria-describedby.] Of course, I think that Jonas' motivation is not deprecation in itself, but to improve the AT presentation. And Maciej hinted in one of his letters last week, that making @hidden content visible to AT users in this way, is technically similar to making the shadow DOM of <canvas> work. <http://www.w3.org/mid/F3A95E6A-05EE-488A-A4F0-0E279B11117B@apple.com> Here is hoping that we, in the same go, could make AT read the fallback of <object> - which AT currently has problems with. So, when aria-describedby points to an aria-hidden=true section, then ISSUE-204 promises the following: * When the aria-hidden=true section is visually visible [as permitted with a MAY by ARIA 1.0], then it sounds simple to render it with 'full semantics', if the AT is capable of doing that. * When the aria-hidden=true section has display:none, then it looks like ISSUE-204 has nothing to offer - it seems likely that the @aria-describedby content in that case will be presented as string. * When the aria-hidden=true is implied via the presence of @hidden, *then* ISSUE-204 suggest that the the UA should render some kind of accessible shadow down [see the link to Macie's letter above]. So, there is nothing in ISSUE-204 that would make anything visible *to all*. -- Leif Halvard Silli
Received on Thursday, 16 February 2012 00:32:37 UTC