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[Bug 10455] Mint a describedby attribute for the img element

From: <bugzilla@jessica.w3.org>
Date: Tue, 31 Aug 2010 01:23:44 +0000
To: public-html-a11y@w3.org
Message-Id: <E1OqFZg-0000Pj-7Q@jessica.w3.org>

--- Comment #44 from Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>  2010-08-31 01:23:43 ---
(In reply to comment #40)
> (In reply to comment #30)
> > Thus it would be interesting to have your comment to rel="longdesc" in
> > combination with image maps: http://malform.no/testing/longdesc/
> Two thoughts:
>    * Testing in Chrome, opening the long description involved moving focus to a
> imperceptible link. I think that contravenes WCAG2's Visible Focus requirement.

Q1: You tested with VoiceOver? Or was it without screenreader? Which of the 5
test pages was it? 
Q2: Please note that I have taken every step to hide the long description URLs
from GUI browsers (media="screen") - only AT and textual browsers are meant to
have access - I suppose this does not break WCAG.  Or,  is the correct way to
read your comment to assume that you would have said the same thing as you said
about (one of) those tests about @longdesc?

>    * Normally, "rel" specifies a relationship between the destination and the
> current document, not a relationship between the destination and a component of
> the current document. So I think you'd need to use some other attribute(s),
> like "resource" from RDFa (something like I suggested above) or "itemprop" from
> Microdata.

Do you have any backup info? I'll note that Julian Reschke of the link type
registry did not express any such reservations when I aired this (2-3 weeks ago
- public-html). Instead it sounded interesting to him, as I perceived it. Also,
when I filed a bug, then Ian accepted the proposal. Perhaps you disagree with
his resolution? [*] 

[*] http://www.w3.org/Bugs/Public/show_bug.cgi?id=10434

I note that what you say, though, seems to be reflected in HTML5:  

]] Links are a conceptual construct, created by a, area, and link elements,
that represent a connection between two resources, one of which is the current
Document. [[
]] In this section, the term referenced document refers to the resource
identified by the element representing the link, and the term current document
refers to the resource within which the element representing the link finds
itself. [[

Whereas HTML4 says that 'source anchor' is not the document itself, but the
anchor element.  From the definition of <a>:

]] href = uri [CT] This attribute specifies the location of a Web resource,
thus defining a link between the current element (the source anchor) and the
destination anchor defined by this attribute. [[

In HTML4, only the link element as draws a link between documents:  ]] The LINK
element defines a relationship between the current document and another
resource. [[

Likewise, the link registry [*] defines the 'alternate' link relation as
follows:  ]] Designates a substitute for the link's context. [[  So what is
the link's context? 'Context' is a least not wider than 'the current document'. 
[*] http://www.iana.org/assignments/link-relations/link-relations.txt

Looking at @longdesc, then it is a link, and its context is very clear: the IMG
element. With help of ARIA, however, we can say <a role="img" href="*" > So,
when I think about it ... One shoudl think that if you have <a role="img"
href="*" aria-labelledby="img" ><img id="img" src="*" alt="Blah blah"></a> then
the @link is related to the img element, and not to the entire document as such

Until I hear from Ian  and/or Julian that @rel="longdesc" with the semantics I
have proposed (and which they both have heard) is a problem, then I choose to
believe that it isn't. Clearly, the current version of HTML - HTML4 - seems to
consider such relations as possible.

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Received on Tuesday, 31 August 2010 01:23:45 UTC

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