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Re: example spec text for longdesc

From: Laura Carlson <laura.lee.carlson@gmail.com>
Date: Mon, 21 Mar 2011 02:59:53 -0500
Message-ID: <AANLkTi=bQEKSQ81PNGw8OyPxidGLiBKpTTcpdda+9m-4@mail.gmail.com>
To: Steve Faulkner <faulkner.steve@gmail.com>
Cc: HTML Accessibility Task Force <public-html-a11y@w3.org>, HTMLWG WG <public-html@w3.org>
Hi Steve and everyone,

I am sorry that I was unable to attend the accessibility task force
face-to-face meeting.

Thank you very, very much for working on spec text to make longdesc
more useful, robust, and encourage better user agent implementation
[1].

Chaals, for the time being I removed your spec text and linked to
Steve's spec text for the details section of the longdesc change
proposal to reinstate longdesc into HTML [2].

It might be good if the spec mentioned something about having
conformance checking tools [3] and authoring tools detect improper
URIs in the final version and of the spec text.

The screenshots of user agent implementations are nice. One of
Patrick’s FireFox extension would be an additional one. But these
should probably be given to the UAWG for inclusion for their docs such
as "Implementing User Agent Accessibility Guidelines" (UAAG 2.0)
document [4] and we could just link to them.

Maybe something like this could work for the spec text:

<draft spec text>

A longdesc attribute may be present. This attribute specifies a link
to a long description of the image. This description should supplement
the short description provided using the alt attribute. If present, it
must contain a valid non-empty URI that references a separate
document, a content fragment in a separate document or content
fragment within the same document as the image.

If a longdesc attribute is present,

* Conformance checkers and authoring tools should inspect the URI and
issue errors if it suspects that the description resource is unlikely
to contain a description of the image (i.e., if the URI is an empty
string, or points to the same URI as the src attribute, or contains a
human-readable description, or if it is indicative of something other
than a URI. Conformance checkers and authoring tools should issue
errors if the longdesc URI has certain file suffixes, such as .gif,
.jpeg, .png etc.)

* User agents should provide the user an option or preference to
access the content via a device independent mechanism. For specific
details consult Implementing User Agent Accessibility Guidelines (UAAG
2.0) [4].

Since an img element may be within the content of an a element, the
user agent's mechanism in the user interface for accessing the
"longdesc" resource of the former must be different than the mechanism
for accessing the href resource of the latter.

</draft spec text>

Ideas for improvement?

I'll try to upload this in a proper document like yours when I'm able.
Or Steve, if you'd like, feel free to update your doc with any of this
text.

Thanks again, I really appreciate your work on this.

Best Regards,
Laura

[1] http://lists.w3.org/Archives/Public/public-html/2011Mar/0295.html
[2] http://www.w3.org/html/wg/wiki/ChangeProposals/InstateLongdesc#Details
[3] http://www.w3.org/Bugs/Public/show_bug.cgi?id=10015
[4] http://www.w3.org/TR/IMPLEMENTING-UAAG20/#gl-access-alternative-content


On 3/20/11, Steve Faulkner <faulkner.steve@gmail.com> wrote:
> hi all,
>
> part of our discussions this weekend at the html accessibility taskforce
> face 2 face has been the improved specification of longdesc, to define what
> the addition of a prescribed method for the addition of long descriptors for
> images in HTML5 may look like.
>
> I have written up example text adding it to the current spec text for image.
> The additional text is identified using the <ins> element and is futher
> differentiated from the current spec text using a background color.
>
> http://www.html5accessibility.com/tests/img-longdesc.html
>
> --
> 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

-- 
Laura L. Carlson
Received on Monday, 21 March 2011 08:01:28 UTC

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