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Re: Caption@title instead of table@summary?

From: Joshue O Connor <joshue.oconnor@cfit.ie>
Date: Wed, 18 Feb 2009 11:33:02 +0000
Message-ID: <499BF1EE.5020807@cfit.ie>
To: Leif Halvard Silli <lhs@malform.no>
Cc: HTMLWG <public-html@w3.org>
Hi Leif,

Leif Halvard Silli wrote:
> This message investigate the option of replacing table@summary with
> caption@title.
>
> The @title attribute is reserved for advisory information. But what
> @title is supposed to advice about differs a bit from element to
> element. For instance, for an anchor link (<a href="*">), the @title
> attribute advices not on the content of the element, but on the content
> of the link target - usually. For an <img>, the @title might inform on
> who created the image.
>
> Hence, I wonder if the @title of the <caption> would be able to replace
> @summary. After all, it seems reasonable to say that the @title of a
> <caption> advices on what the <caption> is an caption for. Thus, a table
> summary could fit there.

I don't think there is any need to go down this route as @summary could
already provide this kind of additional advisory information if needed.
Also there would be issues around implementing a new attribute in a UA,
backwards compatibility and so on. There is currently nothing to stop an
author putting additional advisory information into the @summary of the
data table, as well as an overview of its structure. It can be as terse
or verbose at the author deems fit and will be accessible by many many
users of Assistive Technology.

Of course this is only possible if @summary is in the spec in the first
place.


> Benefits of using @summary:
> 
>    * All UAs support @title - extremely backwards compatible. Doesn't
>      require any CSS hoolahoops.
>    * Like @summary, @title ensures that the content is purely fast
>      accessible text.
>    * All users can easily view @title content (mouse hovering is the
>      typical way)
>    * Empty <caption> elements are hidden, but still visible in the DOM.
>    * Even empty <caption> elements can be made "visible" through
>      relatively simple CSS and thus become available for hovering even
>      for visuall user agents, so that @title content can be read even
>      when <caption> is empty.
>    * Could promote more use of (non-empty) <caption> elements, which
>      should benefit all users.
>    * The link between table summary and caption becomes clear.
>    * Avoids the problems of the (claimed) misused @summary
>    * Builds on common pattern, namely the use of the @title attribute
> 
> AT software benefits and problems:
> 
>    * Not each and every screen reader support @summary (Or am I wrong
>      there?)

Pretty much all screen readers support @summary, including older
versions which means there is already a vast audience of Assistive
Technology users out there who can avail of it, today.

>    * What about discoverability, eg when <caption> is empty?

If <caption> is empty the @summary contents are announced as soon as a
table had focus. If the <caption> is populated then its contents are
outputted. If both <caption> and @summary are populated the caption is
announced first and the @summary follows. The user can end the
outputting of either by changing focus to another HTML element.

Cheers

Josh
Received on Wednesday, 18 February 2009 11:33:48 GMT

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