12587 2011-05-03 02:36:15 +0000 AT shouldn't see img@alt="" and img@role=presentation as 100% synonyms 2016-04-07 15:37:06 +0000 1 1 1 Unclassified HTML WG HTML a11y APIs (editor: Steve Faulkner, Cynthia Shelly) unspecified PC All RESOLVED INVALID http://www.w3.org/TR/html-aapi/#api-role a11y, a11ytf P3 normal --- 1 xn--mlform-iua faulkner.steve bhawkeslewis chaals laura.lee.carlson mike public-html-a11y public-html-admin public-html-wg-issue-tracking w3c xn--mlform-iua sideshowbarker+html-a11y-api oldest_to_newest 47859 0 xn--mlform-iua 2011-05-03 02:36:15 +0000 The HTML to Platform Accessibility APIs implementation guide requires AT to treat <img alt="" src=i> as 100% the same as <img role=presentation src=i > But such a change is likely to make many pages less accessible to AT users. Examples: Example 1: In this example, VoiceOver will contstruct a link text from the href URL. <a href="./"> <img src=i role=presentation title="Lorem Ipsum"> </a> Example 2: In this example, VoiceOVer will use @title as link text. <a href="./"> <img src=i title="Lorem Ipsum"> </a> Thus, as you can see, by making the empty img@alt="" a synonym for img@role=presentation, the treatment of existing web pages will be affected. Another problem of seeing them as 100% synonyms is: who wins if both are present and @alt e.g. is non-empty? If they are not 100% synonyms, then it is easier to see why role=presentation wins. Also, I believe there is a usecase for images with non-empty @alt text which nevertheless are presentational. (E.g. the @alt text could be purely decorational - to reflect that the image itself is purely some decorational symbols. ) 47862 1 xn--mlform-iua 2011-05-03 11:18:26 +0000 Example from the wild: Mac OS X told to me to upgrade my printer today. This caused me to find that, on Apple support pages, the link to call the Apple Support Express Lane is an IMG link with a @title attribute in combination with an empty @alt: <a href="[link]"> <img src="http://images.apple.com/support/iknow/images/i_call_adv.png" alt="" title="Apple Support Express Lane"> </a> See the page: http://support.apple.com/kb/HT3669 47865 2 xn--mlform-iua 2011-05-03 13:01:31 +0000 Here is the approach which the 'HTML to Platform Accessibility APIs implementation guide' should take: 1. The AT should first run an algoritm to *calculate* whether the IMG is presentational or non-presentational 2. If it is non-presentational, AT should select the best text substitute When it comes to the algorithm to calculate whether IMG is presentational or not, then I have suggested how it should look in my 'Validity map for <img>': http://lists.w3.org/Archives/Public/public-html/2011Mar/0750 Two examples from that algorithm: * If IMG has non-empty @title, then AT should consider the IMG as non-presentational, regardless of @alt's value. * Ditto if IMG has @aria-labelledby - regardless of @alt's value. 48441 3 w3c 2011-05-10 15:35:41 +0000 Bug-triage sub-team adding the a11yTF keyword because this issue is already discussed in the TF and related to ongoing work regarding @alt validation. 125744 4 chaals 2016-04-07 14:26:51 +0000 With disagreement on how role=presentation should be handled in various cases, on HTML bug triage we agreed that it makes sense to treat these two examples in the same way. 125756 5 chaals 2016-04-07 15:37:06 +0000 With disagreement on how role=presentation should be handled in various cases, on HTML bug triage we agreed that it makes sense to treat alt="" and role=presentation in the same way.