Re: A presentational img?

Good summary. Thanks.

On May 10, 2011, at 11:37 AM, Leif Halvard Silli wrote:

> 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 19:00:58 UTC