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Re: [css3-mediaqueries] Width/Height Clarifications

From: Andrew Fedoniouk <news@terrainformatica.com>
Date: Mon, 09 Jun 2008 09:20:26 -0700
Message-ID: <484D584A.50904@terrainformatica.com>
To: Anne van Kesteren <annevk@opera.com>
CC: www-style@w3.org

Anne van Kesteren wrote:
> On Fri, 06 Jun 2008 09:11:32 +0200, Andrew Fedoniouk 
> <news@terrainformatica.com> wrote:
>> @media non-existent
>> {
>>     something that may never be even parsed according
>>     to [1]: "So that user agents can avoid retrieving
>>     resources for unsupported media types"
>> }
>>
>> [1] http://www.w3.org/TR/CSS21/cascade.html#at-import
>>
>> So is the question: are MQ statements parse time of runtime
>> entities? If they are evaluating at runtime then this appears
>> as a change of the whole paradigm.
> 
> Media queries are identical to selectors in this aspect, no? Both may 
> match different "things" over time depending on changes to the "things" 
> they are matching against. (Both are also dropped at parse time if they 
> contain invalid or uknown aspects.)
> 
> 

MQs are intended to be used in @media and @import statements.
Currently these statements are parse time constructions as
clearly stated in CSS 2.1 spec.

We have two options:
- to change the way how @media,@import,<link>, etc.
   operate currently or
- to move MQs into the selector space (so to runtime)
   and to add say :media(...mq statements....) pseudo class.

If we will move MQs to runtime then we have to design some
unified and extendable syntax.
At least in current state of CSS3 we have calc() and MQ()
runtime evaluated constructions.
It is better in many senses if they will share common syntax.

Otherwise we shall clearly limit MQs by compile time only
environment. In any case execution model has to be clearly
defined somewhere in http://www.w3.org/TR/css3-mediaqueries.

-- 
Andrew Fedoniouk.

http://terrainformatica.com
Received on Monday, 9 June 2008 16:21:00 GMT

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