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Re: H43 and header cell relationships

From: Pierre Dubois <duboisp2@gmail.com>
Date: Thu, 20 Feb 2014 11:25:47 -0500
Message-ID: <CAPGwD7i4f5iKdR9i4Kaa70NzD0e=f+JDjSvxcdRch6ccR50ExQ@mail.gmail.com>
To: Jonathan Avila <jon.avila@ssbbartgroup.com>
Cc: W3C WAI ig <w3c-wai-ig@w3.org>
Jonathan, I agree with you that id and header attributes should not be
mixed with the scope technique.

My question is regarding if the following 3 tables would be supported in an
equivalent way for AT? What are the major difference the AT user would
perceive?

<table>
    <caption>Implicit headers to define cells relationship</caption>
    <tr>
        <th id="ta1" colspan="2">Section</th>
    </tr>
    <tr>
        <th id="ta2" headers="ta1">Group 1</th>
        <td headers="ta2">Group Data</td>
    </tr>
    <tr>
        <th id="ta3" headers="ta2">Title</th>
        <td headers="ta3">Data</td>
    </tr>
    <tr>
        <th id="ta4" headers="ta1">Group 2</th>
        <td headers="ta4">Group Data</td>
    </tr>
    <tr>
        <th id="ta5" headers="ta4">Title</th>
        <td headers="ta5">Data</td>
    </tr>
    <tr>
        <th id="ta6" headers="ta4">Title</th>
        <td headers="ta6">Data</td>
    </tr>
</table>

<table>
    <caption>Explicit headers to define cells relationship</caption>
    <tr>
        <th id="tb1" colspan="2">Section</th>
    </tr>
    <tr>
        <th id="tb2" headers="tb1">Group</th>
        <td headers="tb1 tb2">Group Data</td>
    </tr>
    <tr>
        <th id="tb3" headers="tb2">Title</th>
        <td headers="tb1 tb2 tb3">Data</td>
    </tr>
    <tr>
        <th id="tb4" headers="tb1">Group 2</th>
        <td headers="tb1 tb4">Group Data</td>
    </tr>
    <tr>
        <th id="tb5" headers="tb4">Title</th>
        <td headers="tb1 tb4 tb5">Data</td>
    </tr>
    <tr>
        <th id="tb6" headers="tb4">Title</th>
        <td headers="tb1 tb4 tb6">Data</td>
    </tr>
</table>

<table>
    <caption>Mix of implicit headers with default behaviour to define cells
relationship</caption>
    <tr>
        <th id="tc1" colspan="2">Section</th>
    </tr>
    <tr>
        <th id="tc2" headers="tc1">Group</th>
        <td>Group Data</td>
    </tr>
    <tr>
        <th id="tc3" headers="tc2">Title</th>
        <td>Data</td>
    </tr>
    <tr>
        <th id="tc4" headers="tc1">Group 2</th>
        <td>Group Data</td>
    </tr>
    <tr>
        <th id="tc5" headers="tc4">Title</th>
        <td>Data</td>
    </tr>
    <tr>
        <th id="tc6" headers="tc4">Title</th>
        <td>Data</td>
    </tr>
</table>


Thanks

:-)

Pierre Dubois


On Thu, Feb 20, 2014 at 9:43 AM, Jonathan Avila
<jon.avila@ssbbartgroup.com>wrote:

> Pierre,
>
> I’m always concerned when I see id and header attributes combined with the
> scope technique.  I don’t have data on this but I feel like the combining
> of techniques could be confusing for AT to interpret.   If people think
> it’s a valid method and AT supported then it would be great to have a
> sufficient technique created documenting the support.
>
>
>
> Jonathan
>
>
>
> *From:* Pierre Dubois [mailto:duboisp2@gmail.com]
> *Sent:* Thursday, February 20, 2014 9:32 AM
> *To:* W3C WAI ig
>
> *Subject:* Re: H43 and header cell relationships
>
>
>
> Does someone has completed recent test whether the implicit header are
> supported by AT?
>
> It seems to be allowed within the HTML5 spec. [1]
>
> ---
> [1]
> On Tue Nov 6 2012, Ian Hickson wrote:
> > > About "headers" I wonder if this would be acceptable:
> > >
> > > <tr><th id="th1" colspan="2">MySection</th></tr>
> > > <tr><th id="th2" headers="th1"
> scope="row">MyName</th><td>MyData</td></tr>
> > > <tr><th id="th3" headers="th2" scope="row">+
> MySubName</th><td>MySubData</td></tr>
> > >
> > > as for the third row, the th1 header is implicit from the th2 declared
> header
> >
> > Yup, that is allowed and is defined to work as you'd expect.
> (source:
> http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2012-November/037791.html
> )
>
>
> :-)
>
> Pierre Dubois
>
>
>
> On Thu, Feb 20, 2014 at 8:51 AM, Jonathan Avila <
> jon.avila@ssbbartgroup.com> wrote:
>
> Olaf, the first step I would do is to try to validate or disprove the
> possibility of a nesting/serial access approach.  Is it possible to design
> a table where a references b and b references c but a should not reference
> c?  If that's possible then you can't rely on this serial type approach.
>
> Jonathan
>
>
> -----Original Message-----
> From: Olaf Drümmer [mailto:olaf@druemmer.com]
>
> Sent: Wednesday, February 19, 2014 5:19 PM
> To: W3C WAI ig; Matt Tongue
> Cc: Olaf Drümmer
> Subject: Re: H43 and header cell relationships
>
> I think I have to correct my statement:
> HTML seems to require (as Sailesh points out) that indeed the headers
> attribute of table cell has to list the ids of all the header cells with
> which it is associated.
>
> Sorry for any confusion my statement might have caused.
>
> I nevertheless would like to add that I think that this approach is
> conceptually wrong - nested semantic structure should be expressed via
> nested representation of pertinent data / attributes. Even if one were to
> agree though with my reasoning it's probably a bit late in the game to
>
> have this addressed...
>
>
>
> Olaf
>
>
>
> On 19 Feb 2014, at 22:46, Olaf Drümmer <olaf@druemmer.com> wrote:
>
> > As far as I can tell, any cell should identify only its direct header
> cell parents. Nested header cell relationships would then be represented
> by nested use of the headers attribute.
> >
> > Olaf
> >
> > On 19 Feb 2014, at 22:09, "Tongue, Matt" <Matt.Tongue@nrc-cnrc.gc.ca>
> wrote:
> >
> >> When marking up a table with multiple levels of headings, is it
> mandatory to always put all header cell IDs into the headers attribute of
> a cell?
> >>
> >> For example, if a data cell has 3 header cells, but the 2nd header
> cell's headers attribute references the 1st header's ID, would it not
> suffice for the data cell to just reference header cells 2 and 3, since
> header cell 2 references header cell 1 (thus creating a relationship
> already)? Or must every header always be identified for every cell, no
> matter what?
> >>
> >> Reference: http://www.w3.org/TR/2013/NOTE-WCAG20-TECHS-20130905/H43
> >>
> >
> >
>
>
>
Received on Thursday, 20 February 2014 16:26:15 UTC

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