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Re: Expressions in DISelect versus MQ

From: Anne van Kesteren <annevk@opera.com>
Date: Fri, 26 May 2006 20:05:00 +0200
To: Max Froumentin <mf@w3.org>
Cc: www-di@w3.org
Message-id: <op.s9566mjt64w2qv@id-c0020.oslo.opera.com>

On Wed, 17 May 2006 15:18:13 +0200, Max Froumentin <mf@w3.org> wrote:
>>> You've almost answered your own question: the media attribute in
>>> XHTML2.0 _only_ takes a CSS2 media type (aural, braille, etc.).
>>> That wasn't enough for the people who designed DIAL, and that's why
>>> the expr attribute from DISelect allows complex XPath epxressions.
>> Well, instead of inventing new things you could give comments (or ask)
>> to the HTML WG regarding this.
> Discussions with the HTML WG, date back from 2003. See
> <http://lists.w3.org/Archives/Member/w3c-html-cg/2003AprJun/0061.html>
> for instance, (HCG, member only).

So what's the problem?

>> In the end I think, if XHTML 2.0 ever ends up being implemented, you
>> would like to support media queries there. Just like media queries
>> currently extends HTML4 in some way.
> I agree that this is an important topic, which has already been the  
> subject of
> discussions between the CSS and DI groups (see
> <http://lists.w3.org/Archives/Member/w3c-css-wg/2006JanMar/0250.html>).
>> The DI WG could also introduce an attribute similar to media="" which
>> does accept a media query.
> Yes, or they could just import media in DIAL. I don't how sel:expr and
> media would interact when used together but it may make sense to allow
> both (in different places).

Yeah, make it even more complicated :-) media="" and sel:expr do quite  
different things as I understand it though. It seems that media="" only  
changes that what's rendered and sel:expr actually changes the resulting  
document (as it's supposedly preprocessed or something like that).

> The problem is the simplicity of media queries versus the power of
> XPath, of course.  And also the speed of deployment: at the moment,
> XHTML2 doesn't have the power that device independent content authors
> require. And they want something quickly.

I don't see how XPath is more powerful here, actually. Especially when  
used as the DI WG uses it within sel:expr. Could you give some specific  

Also, with regard to what device independent content authors want, I'm not  
really sure if more functionality is one of their requirements... Being  
able to deploy some HTML page and have it just work (perhaps with a  
special handheld style sheet if the author thought of that and had the  
time to do QA on it) seems far better to me than having to learn  
namespaces, XPath and a whole let of other things DIAL and DISelect seem  
to import.

Anne van Kesteren
Received on Friday, 26 May 2006 18:05:57 UTC

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