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Help with text alternative bugs related to HTML5 Change Proposal: "Replace img Guidance for Conformance Checkers"

From: Laura Carlson <laura.lee.carlson@gmail.com>
Date: Mon, 1 Mar 2010 13:44:40 -0600
Message-ID: <1c8dbcaa1003011144j108bd1e3ifd1e4b45c774b958@mail.gmail.com>
To: HTML Accessibility Task Force <public-html-a11y@w3.org>
Cc: Steve Faulkner <sfaulkner@paciellogroup.com>, Gez Lemon <gez.lemon@gmail.com>, Matt Morgan-May <mattmay@adobe.com>, "Gregory J. Rosmaita" <oedipus@hicom.net>, Janina Sajka <janina@rednote.net>, Maciej Stachowiak <mjs@apple.com>
Hi All,

Maciej has asked me [1] to provided bugs for the differences between
Ian's draft and the text in the Change Proposal that I drafted to
implement WAI  CG’s text alternative consensus document.
http://www.w3.org/html/wg/wiki/ChangeProposals/ImgElement20090126

Providing bugs for these is probably not required as Issue 31 predates
the HTML WG decision policy. And bugs were never filed for similar
accessibility issues. But I think it is good to do it anyway to give
Ian the complete opportunity to address and fix the problems.

So I’ve been working on drafting bugs and need your help and
expertise.  When you get a chance could you please give me advice on
the following?  Many thanks to Gez for already doing so. He provided
great input.

Background info:

Ian recently changed the conformance section for images in the HTML5
draft to the following (I replaced the * bullets with numbers for
easier referencing):

<q cite="http://dev.w3.org/html5/spec/text-level-semantics.html#guidance-for-conformance>

4.8.1.1.14 Guidance for conformance checkers

A conformance checker must report the lack of an alt attribute as an
error unless one of the conditions listed below applies:

1. The title attribute is present and has a non-empty value (as
described above).

2. The img element is in a figure element that contains a figcaption
element that contains content other than inter-element whitespace (as
described above).

3. The img element is part of the only paragraph directly in its
section, and is the only img element without an alt attribute in its
section, and its section has an associated heading (as described
above).

4. The conformance checker has been configured to assume that the
document is an e-mail or document intended for a specific person who
is known to be able to view images.

5. The document has a meta element with a name attribute whose value
is an ASCII case-insensitive match for the string "generator". (This
case does not represent a case where the document is conforming, only
that the generator could not determine appropriate alternative text -
validators are required to not show an error in this case to
discourage markup generators from including bogus alternative text
purely in an attempt to silence validators.)

</q>

The change proposal that I drafted to implement WAI CG's advice [3]
"Replace img Guidance for Conformance Checkers" says:

<q cite="http://www.w3.org/html/wg/wiki/ChangeProposals/ImgElement20090126">

A conformance checker must report the lack of a text alternative as an
error. The img element is only valid when at least one of the
following is true:

*  alt is present (empty or non-empty) OR
* @aria-labelledby is present (non-empty only) OR
* the <img> is located within a <figure> that has a non-empty <figcaption> OR
* @role="presentation" OR
* <img> has an attribute other than alt whose value is an ASCII
case-insensitive match for the string "generator" OR
* <img> has a "missing" attribute.

</q>

The other relevant section of the HTML5 spec is "Images whose contents
are not known"
http://dev.w3.org/html5/spec/text-level-semantics.html#unknown-images

Current Status and Advice Needed From A11y Task Force Members:

There are some bugs in various stages and some may need to be created.

1. Steve has a WONTFIX bug for title, so we already have a bug for this item:
http://www.w3.org/Bugs/Public/show_bug.cgi?id=7362

2. Simon Pieters has a CLOSED (duplicate) bug for <img
aria-labelledby>, so a bug exists for this item. The duplicate Bug
8171 is in the NEEDSINFO state. I provided a general comment (4). Does
anything more need to be provided for img aria-labelledby?
http://www.w3.org/Bugs/Public/show_bug.cgi?id=6496
http://www.w3.org/Bugs/Public/show_bug.cgi?id=8171

3. Gez has a WONTFIX bug for the e-mail issue, so we already have a
bug for this item:
http://www.w3.org/Bugs/Public/show_bug.cgi?id=8646

4. I think figcaption is okay and probably doesn't need a bug unless
anyone thinks differently.

5. Do we want a bug for Ian's number 3 "img element is part of the
only paragraph..."?  Gez recommended we do, as he is not sure how a
conformance checker would find that, and doesn’t follow the rationale
that the alt text is presentational and the paragraph provides the
context for it. Any suggestions for bug text?

6. Although I personally disagree with it being a valid option, I've
drafted bug for the generator mechanism for img from document level to
element level as WAI CG said that they would condone it:
http://www.w3.org/WAI/PF/HTML/wiki/Bugs/Generator
Any suggested text or ideas to improve the bug text?

7. Although I personally disagree with it being a valid option, I've
drafted bug for a missing attribute, as WAI CG said that they would
condone it. Matt’s crowdsourcing idea is intriguing if it could be
implemented it would be great.  The bug is at:
http://www.w3.org/WAI/PF/HTML/wiki/Bugs/Missing
Any suggested text or ideas to improve the bug text?

8. I've drafted bug to enable automatic validators to programmatically
determine the presence or absence of a set of text alternatives as
HTML4 did with alt:
http://www.w3.org/WAI/PF/HTML/wiki/Bugs/ProgrammaticallyDetermineTextAlternatives
Any suggested text or ideas to improve the bug text?

9. I've drafted bug for role="presentation" on img.
http://www.w3.org/WAI/PF/HTML/wiki/Bugs/role=%22presentation%22
Any suggested text or ideas to improve the bug text?

10. I've drafted bug for CAPTCHAs
http://www.w3.org/WAI/PF/HTML/wiki/Bugs/CAPTCHA
Any suggested text or ideas to improve it?
I have also filed a bug with Steve (and he agreed) to provide and
example in his document.
http://www.w3.org/Bugs/Public/show_bug.cgi?id=9169

11. I've drafted bug for Webcams
http://www.w3.org/WAI/PF/HTML/wiki/Bugs/Webcam
Any suggested text or ideas to improve it?
I have also asked Steve to provide and example in his document.
http://www.w3.org/Bugs/Public/show_bug.cgi?id=9174

If you have suggested text or ideas for improvement on these bugs,
please let me know soon, as I would like to file them mid-week.

Thank you very much.

Kindest Regards,
Laura

[1] http://lists.w3.org/Archives/Public/public-html/2010Feb/0803.html
[2] Thread HTML5 Change Proposal to "Replace img Guidance for
Conformance Checkers"
[3] http://www.w3.org/2009/06/Text-Alternatives-in-HTML5
Directly Related Bug "implement the text alternatives proposal from
WAI":
http://www.w3.org/Bugs/Public/show_bug.cgi?id=8171

-- 
Laura L. Carlson
Received on Monday, 1 March 2010 19:45:14 GMT

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