[Bug 10614] Clarify what <img role=presentation alt=<not-the-empty-string> > means

http://www.w3.org/Bugs/Public/show_bug.cgi?id=10614





--- Comment #2 from Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>  2010-09-12 20:39:07 ---
3 use cases:

(1) A spacer image could very well contain alt="<space-characters>".  I know
that it is not recommend to place only a space character inside alt=" " - for
one thing, it causes e.g. VoiceOver to treat it as an  element with role="img".
 However, if such an <img> has role="presentation", then it should not pose any
problem for a ARIA supporting user agent.  (Please also note that Lynx treats 
   <img alt="<the-empty-string>">       and  
   <img alt="<a-space-character>">
 the same way - it results in a space character. So, actually, inserting a
space character would be more compatible with how at least Lynx works.)

(2) According to Benjamin Hawkes-Lewis [*] then for a button such as this:
      <button><img role="presentation" src="pencil.png" alt="Edit"></button>
ARIA instructs UAs to use the "Edit" text as the text of the button, despite
that it has role="presentation". (Fails in VoiceOver+Safari on OS X 10.5 -
perhaps improvements in OS X 10.6?)

[*] http://lists.w3.org/Archives/Public/public-html-a11y/2010Sep/0358

(3) When images are used to contain text and logos (ok - a variant of
Benjamin's use case).
     Here is an HTML5 example:
     <header role="banner"><img src=logo alt="ACME corp"
role="presentation"></header>
As long as the user agent supports ARIA, then I don't  see any advantage in
doing this instead:
<header
       ><img src=logo alt="" role="presentation"
       ><span class="use-some-hiding-hack"
       >ACME corp</span>
</header>
And the only alternative to the two alternative above, is to say that the <img>
has role="img". However, that would be identical to the experience that AT
without ARIA support would give, so I see no point it that alternative.

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Received on Sunday, 12 September 2010 20:39:08 UTC