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Re: [Bug 12587] AT shouldn't see img@alt="" and img@role=presentation as 100% synonyms

From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
Date: Tue, 3 May 2011 20:41:15 +0200
To: David Singer <singer@apple.com>
Cc: Richard Schwerdtfeger <schwer@us.ibm.com>, Steve Faulkner <faulkner.steve@gmail.com>, public-html-a11y@w3.org, public-html-a11y-request@w3.org
Message-ID: <20110503204115353450.b0e31d19@xn--mlform-iua.no>
David Singer, Tue, 03 May 2011 11:06:20 -0700:
> 
> On May 3, 2011, at 7:53 , Richard Schwerdtfeger wrote:
>>> 
>>> <a href="green.html"><img role=presentation src="green.jpeg" 
>>> alt="Green"></a>
>>> 
>> In this case it should be invalid to have role="presentation" on an 
>> element that has alt text that is not empty. Here the image is not 
>> presentational. Also, any image with a title attribute should not 
>> have role="presentation" either. 
>> 
>> 
>> The only time role="presentation should be allowed on an image is 
>> when it does not have an form of alternative text such as:
> 
> Flipping this over, you realize that you are saying that I would be 
> prohibited from providing alt text on presentational images, i.e. I 
> am not *allowed* to tell the viewer who does not see images that the 
> page would have been green at this point?  That I do not need to, 
> OK.  That I am not *allowed* to, well, that seems weird.

It probably should be permitted to have role=presentation on an IMG 
with non-empty @alt. 

But note that the particular example above doesn't make any sense: the 
AT use would be told that there is a link, and if AT behaves like 
VoiceOver, then the value of @href will be used to repair for lack of 
accessible text.

An AT user could be interested in accessing the @alt of an IMG with 
role=presentation. But it is another matter whether (s)he would even 
know about the existence of the very IMG. In VoiceOver, such an IMG is 
completely ignored. But there could perhaps be an option in VoiceOver 
to not ignore it.

I can see that Rich has a point, though. And we are here on the 
validity level and not the functional level. And I could certainly live 
with it if it was forbidden to do 
<img src="decorative-separator" alt="--------" role=presentation >
But currently no one has filed such a bug.
-- 
Leif H Silli
Received on Tuesday, 3 May 2011 18:41:45 GMT

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