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Re: IDs, Classes : could CSS usefully use a third (abstract) concept ?

From: Ben Curtis <bcurtis@bivia.com>
Date: Fri, 11 Mar 2005 11:00:40 -0800
Message-Id: <deb76b321fc74fa7ada349c1e08388ce@bivia.com>
To: www-style@w3.org

On Mar 11, 2005, at 8:22 AM, Ryan Cannon wrote:

> Also a syntax like @define could allow great interaction with imported 
> stylesheets. If the format were strict such that the  CSS document  
> would have to be structured  as
>
>  - @definitions
>  - @imports
>  - css rules
>
>  then perhaps definitions in the originating files could be applied in 
> the imported files as well, allowing for a very slim way for sites to 
> achieve different color schemes for each section.


It is worth noting that this functionality, being client-side, offers 
abilities that are impossible or highly convoluted server-side. 
Therefore, @define or similar syntax serves a valuable and practical 
purpose.

Some example uses that would be exceedingly difficult server-side:

1. An XML-syndicated content provider supplies an accompanying embedded 
stylesheet that handles layout, sourced from their server and adjusted 
on occasion to take into account new content styles. The content is 
included in an XHTML web page on the client, and the author of this 
webpage would like the syndicated content to match his page's color and 
style schemes. She could compose her own stylesheet, but delivering it 
to override the embedded stylesheet so that her styles take effect 
through the cascade is difficult without making everything !important. 
She could have the server parse the embedded stylesheet and change it, 
but then as the publisher changes things so must she. Or, with @define, 
the publisher could use defined values and the page author supply those 
values once.

2. Author-supplied stylesheets could hook into user-supplied 
stylesheets allowing for easy customization of the styles that does not 
need to be re-worked if the author stylesheet undergoes changes.

Crossing the boundary between authors, and between authors and users is 
currently very difficult -- you can only override, but not adopt. Style 
declarations are either one or the other, which makes the cascade easy 
to calculate but reduces the ability of authors to interact and provide 
customizable services to users.

I think it is worth noting that user agents may already employ a 
strategy like #2 to allow for a default stylesheet to be configured via 
user preference dialogues. Also, this sort of ability is already in the 
CSS spec for quotes, which are defined in one location and the 
definition used on other locations.

-- 

	Ben Curtis : webwright
	bivia : a personal web studio
	http://www.bivia.com
	v: (818) 507-6613
Received on Friday, 11 March 2005 19:12:23 GMT

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