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Re: Issue 130

From: Steve Faulkner <faulkner.steve@gmail.com>
Date: Wed, 15 Dec 2010 10:35:06 +0000
Message-ID: <AANLkTik4TieT9_GDsnU6K8YgFnFH9JV5NP4MFpbmwStx@mail.gmail.com>
To: Benjamin Hawkes-Lewis <bhawkeslewis@googlemail.com>
Cc: Richard Schwerdtfeger <schwer@us.ibm.com>, public-html@w3.org, HTML Accessibility Task Force <public-html-a11y@w3.org>, Sam Ruby <rubys@us.ibm.com>
hi benjamin,
>The change proposal claims it is "impractical" for "a user agent
>or an assistive technology to create their own set of heuristics for
>determining if a table is to be used for layout".

It is true that SOME assitive technology have implemented heuristics
to detect what they think are layout tables, this sometimes does not
work correctly (in my experience testing web sites and web
applications) and it also sometimes falsely hides data tables.

you state "Multiple user agents" have heauristics, which of the major
browsers have such heusristics implemented?

regards
Stevef

On 15 December 2010 10:06, Benjamin Hawkes-Lewis
<bhawkeslewis@googlemail.com> wrote:
> On Wed, Dec 15, 2010 at 12:47 AM, Richard Schwerdtfeger
> <schwer@us.ibm.com> wrote:
>> I would like to request the chairs to reopen issue 130. I have a change
>> proposal for it.
>>
>> The proposal is as follows:
>> http://www.w3.org/html/wg/wiki/ChangeProposals/layouttables
>
> Some feedback on the change proposal.
>
>   * "Stating that a table must not be used for layout is impractical"
> is a key claim here, but the only supporting claim is that using
> tables for layout plus role="presentation" makes it much easier for
> "numerous applications, like databases" to conform to HTML5. The
> change proposal could be improved by documenting this supporting claim
> (for example, giving real-world examples of such applications) and by
> providing any other supporting claims. For example, one might want to
> give examples of layouts that cannot be achieved in commonly supported
> browsers without the use of tables, if there are any such layouts.
>
>   * The change proposal claims it is "impractical" for "a user agent
> or an assistive technology to create their own set of heuristics for
> determining if a table is to be used for layout". Multiple user agents
> and assistive technology have created such heuristics. Whatever the
> spec says there will continue to be large swathes of the web corpus
> that use tables for layout without role="presentation", so such
> heuristics will continue to be required. So it would be useful to
> elaborate on what the change proposal means by "impractical" here.
>
>   * Proposed spec text includes: "If a table is to be used for layout
> it must be marked with the attribute role="presentation" for a user
> agent to properly represent the table to an assistive technology and
> to properly convey the intent of the author to tools that wish to
> extract tabular data from the document." Since "presentation"
> essentially nullifies the special tabular semantics of "table", such
> that it might as well be a series of nested "div" elements, should it
> not also a MUST requirement that such tables should make sense when
> linearized as originally recommended by WCAG1?
>
>   http://www.w3.org/TR/WCAG10/#tech-avoid-table-for-layout
>
>   * Proposed spec text includes: "There are a variety of alternatives
> to using HTML tables for layout, primarily using CSS positioning and
> the CSS table model." It might be better to say something like:
> "Applying CSS to structural markup is the preferred alternative to
> using HTML tables for layout.", since authors often use other CSS
> (e.g. floats) as an alternative to tables and since it's not obvious
> what the non-CSS alternatives are.
>
> --
> Benjamin Hawkes-Lewis
>
>



-- 
with regards

Steve Faulkner
Technical Director - TPG Europe
Director - Web Accessibility Tools Consortium

www.paciellogroup.com | www.wat-c.org
Web Accessibility Toolbar -
http://www.paciellogroup.com/resources/wat-ie-about.html
Received on Wednesday, 15 December 2010 10:35:59 GMT

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