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Re: How to add properties to the CSS syntax (Was: several messages)

From: Ian Hickson <ian@hixie.ch>
Date: Thu, 20 Oct 2005 16:12:56 +0000 (UTC)
To: Robin Berjon <robin.berjon@expway.fr>
Cc: www-style@w3.org
Message-ID: <Pine.LNX.4.62.0510201555121.23945@dhalsim.dreamhost.com>

On Thu, 20 Oct 2005, Robin Berjon wrote:
> 
> Good to hear. It needs some editing work and checking, but how about 
> something like the attached? Please keep in mind that this is just a 
> draft produced by yours truly and represent in no way the opinions of 
> any WG or in fact of any other person in a WG save myself. In some 
> cases, it may not even really represent my own opinion but rather an 
> attempt to JFDI and clear up this mess ;)

Looks great! This is exactly the kind of thing we need.

Specific notes:

| The actual definition of such graphics-oriented CSS properties is best 
| left to the SVG specification

Suggest s/best// (IMHO value judgements don't belong in specs).

| how the SVG properties are to be used in conjunction with those found in 
| other CSS modules,

Suggest replacing this with "how the SVG properties may be used in the CSS 
syntax, possibly in conjunction with those found in other CSS modules,

| CSS properties applicable to SVG

This section should be dropped, IMHO. Either the CSS specs for those 
properties should add the appropriate text to their Applies To: line, or, 
the SVG spec should say (as it presumably already does) that those 
properties apply to some SVG content.

In particular, the requirements "Properties defined in other CSS modules 
MUST also be accepted by SVG user-agents, though they MAY have no effect 
on an SVG document's styling." seems wrong -- it'd be up to those other 
modules to say they must be accepted (which would be true by definition), 
and up to those other modules or the SVG spec to say how those should 
affect an SVG document.


| This section lists properties defined in the SVG 1.1 specification 
| [SVG11] and not found in CSS 2.1 [CSS21]. These properties MUST be 
| accepted by CSS user-agents, though they MAY have to effect on rendering 
| if the document does not contain any SVG markup.

I'm not sure the last sentence is right. I'd suggest replacing it all 
with:

  This section lists properties specific to vector graphic styling. These 
  properties MUST be implemented by user agents conforming to this
  specification. The conformance requirements for how these properties 
  affect the rendering are defined in the SVG specification. The 
  descriptions below indicate the relevant sections as appropriate.


| Some of these properties, notably the 'filter' property, may be found to 
| collide with other properties that are proprietary extensions to the set 
| defined by CSS and do no use a prefix indicating their proprietary 
| nature.  It has been found however that the syntax of their values can 
| be disambiguated so that the proprietary properties will always be 
| ignored as invalid.

I'd recommend putting this just as a note for the 'filter' property. If 
you want to leave it before (or after) the table, make it class="note".


| [list of properties]

This list should IMHO be turned into fully-fledged property definitions, 
in terms of the CSS syntax (as opposed to the value syntax used by SVG, 
which is different). It should also define computed values for each 
property, whether it is inherited, etc, and should have clear Applies To: 
lines that exclude non-SVG content if appropriate.


| font-size-adjust
| font-stretch

These are defined in a CSS3 module so should be dropped from this list.


In addition to this module, SVG 1.2 Tiny should be changed so that it 
doesn't mention that CSS can't apply to SVG (assuming it says that). It 
should define the properties' syntaxes for when they are used in 
attributes, and maybe mention that the properties might also be applied in 
other ways such as using CSS style sheets. (I think I raised an issue to 
this effect, so this might already have been done.)

SVG 1.2 Full needn't add anything on top of this, except maybe in the 
conformance section require support for the relevant CSS modules (Syntax, 
Selectors, Cascade, Values, and SVG).


I this this is a significant step forward!

Cheers,
-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Thursday, 20 October 2005 16:13:08 GMT

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