- From: Steve Faulkner <faulkner.steve@gmail.com>
- Date: Tue, 10 May 2011 22:13:23 +0100
- To: James Craig <jcraig@apple.com>
- Cc: W3C WAI-XTECH <wai-xtech@w3.org>
- Message-ID: <BANLkTinNeCZ+kquFsBtrCpsbC5826UxMOA@mail.gmail.com>
HI james, a related question: is <img> being special cased here or should a title on an element with role=presentation mean that role=presentaion is overriden on the element? regards steve On 10 May 2011 18:54, James Craig <jcraig@apple.com> wrote: > On May 10, 2011, at 7:16 AM, Leif Halvard Silli wrote: > > > as VoiceOver developer and as WAI-ARIA editor, > > Well, since you asked it like that: The following opinions are my own and > do not necessary represent the views of my employer, nor do they represent > group consensus within the ARIA subteam of the PFWG. > > > is it in your view > > correct to treat the following image as non-presentational? > > > > <img alt="" title="Advicory text" src="i" /> > > > > VoiceOver currently does treat it as non-presentational and reads the > > @title to the user. Ahis seems correct to do, from my POV. The > > background for my question is found int Bug 12587 against HTML5. [1] > > > > [1] http://www.w3.org/Bugs/Public/show_bug.cgi?id=12587 > > In my opinion, the presentation state would only apply if one of the > following were true: > > • the author explicitly provided a role of presentation on the img tag, > <img role="presentation"> > • the host language labeling mechanism (in this case @alt) equaled an empty > string, *AND* the ARIA text alternative computation [1] equaled an empty > string. > > The ARIA spec does *NOT* limit the ability of assistive technologies to use > heuristic to determine the text alternative of an image with missing > alternative text. Sometimes these heuristics fall back to image file name > substrings on standalone images, or link path substring on linked images. > For example, some assistive technologies will determine the following > alternative text from the following markup (that is invalid in HTML4 b/c of > the missing @alt)… > > "contact": <img src="contact.png"> > "about us": <a href="/path/about_us.html"><img src="contact.png"></a> > > Perhaps if the HTML editors were to standardize the heuristic mechanism > above, the accessibility advocates in the HTML group would be appeased. As > is, it's unacceptable to state that these images are presentational, because > it is in the best interest of the spec editors, browser vendors, AT users, > and AT vendors to make sure rendering engines provide the most accessible > output, even with the worst possible markup: > > <img src="asdfhjklafds_gibberish_12347612394786.png"> > > W3C process requires that, in order for HTML 5 to reach Candidate > Recommendation phase, the Working Group will have to prove on each part of > the spec, that two rendering engines have implemented the requirement. > Despite what is currently in the HTML 5 spec, I don't believe any of the > major browser vendors will decrease the accessibility of their rendering > engines in order to make <img src="contact.png"> presentational, because it > would be a user interface regression. > > And again, these opinions are my own and do not necessary represent the > views of my employer, nor do they represent group consensus within the ARIA > subteam of the PFWG. > > Cheers, > James > > 1. ARIA text alternative computation: > http://www.w3.org/TR/wai-aria/complete#textalternativecomputation > > > -- with regards Steve Faulkner Technical Director - TPG www.paciellogroup.com | www.HTML5accessibility.com | www.twitter.com/stevefaulkner HTML5: Techniques for providing useful text alternatives - dev.w3.org/html5/alt-techniques/ Web Accessibility Toolbar - www.paciellogroup.com/resources/wat-ie-about.html
Received on Tuesday, 10 May 2011 21:14:10 UTC