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Re: feedback requested on WAI CG Consensus Resolutions on Text alternatives in HTML 5 document

From: Leif Halvard Silli <lhs@malform.no>
Date: Mon, 17 Aug 2009 23:17:01 +0200
Message-ID: <4A89C8CD.5050305@malform.no>
To: Maciej Stachowiak <mjs@apple.com>
CC: Benjamin Hawkes-Lewis <bhawkeslewis@googlemail.com>, Steven Faulkner <faulkner.steve@gmail.com>, Ian Hickson <ian@hixie.ch>, HTMLWG WG <public-html@w3.org>, W3C WAI-XTECH <wai-xtech@w3.org>
Maciej Stachowiak On 09-08-17 11.05:

> 
> On Aug 17, 2009, at 2:00 AM, Benjamin Hawkes-Lewis wrote:
> 
>> On 17/08/2009 09:42, Maciej Stachowiak wrote:
>>> Would it be appropriate, in light of this, to add a user agent
>>> requirement that an img with empty alt should not be mapped to
>>> accessibility APIs at all?
>>
>> Given the variety of authoring practice around "alt", I don't think 
>> that would be safe.
>>
>> In situations like:
>>
>> <a href="#"><img src="delete.png" alt=""></a>
>>
>> It's useful to AT for the "img" to be exposed and to be able to access 
>> "src" attributes for the purpose of providing a substitute for proper 
>> alternative text.
> 
> If that's so, then wouldn't it be better for authors to use alt="" 
> instead of role="presentation", so that AT can decide whether it needs 
> to expose the image anyway? In particular, if your example was marked up 
> like this:
> 
> <a href="#"><img src="delete.png" role="presentation"></a>
> 
> Then isn't it equally necessary and appropriate for AT to expose that 
> image?
> 
> It seems like, based on this example, images should always be exposed to 
> accessibility APIs, and AT should make the call on whether it needs to 
> override the author-provided semantics.


You say that we have agreement to add ARIA to HTML 5 ... And yet 
you argue for keeping it out of HTML 5 as much as possible? Do you 
simply want to make role="presentation" permitted because you want 
to be polite?

It has been argued that it must not be permitted to use @role in a 
way that conflicts with semantics of the elements in the host 
language.

Just now Anne suggested to add a <main> element based on two 
premises: 1) "main" and "content" are much used as class names. 2) 
  "main" is a role in ARIA. So, by introducing <main> we possibly 
build a bridge to authors and to ARIA. (Though sometimes it is 
probably easier to use role="main".)

Now, it could be argued - perhaps - that the ARIA construct 
<element role="presentation">,  when it comes to images, has an 
equivalent in HTML, namely <img alt="">.

If that is how you view it, then would it not be better to 
completely disallow role="presentation" on IMG?

I would further expect that you would say that an <object> element 
  which has no fallback content, should be considered as having 
role="presentation".
-- 
leif halvard silli
Received on Monday, 17 August 2009 21:17:46 UTC

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