Re: A presentational img?

Thanks James, I filed the gist of your comment (that part of your reply 
which related to empty @alt in combo with non-empty @title) in the bug:

http://www.w3.org/Bugs/Public/show_bug.cgi?id=12590#c9


Leif


Steve Faulkner, Tue, 10 May 2011 19:20:22 +0100:
> hi james, just a point of clarification:
> 
> an <img> without alt is not mapped to role=presentation in HTML5
> 
> only <img alt="">
> 
> regards
> stevef
> 
> 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 18:38:24 UTC