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Re: [CSS21] Style sheet definition

From: Chris Lilley <chris@w3.org>
Date: Mon, 29 Aug 2005 21:32:12 +0200
Message-ID: <1802882986.20050829213212@w3.org>
To: Ian Hickson <ian@hixie.ch>
Cc: www-style@w3.org

On Sunday, August 28, 2005, 10:38:36 PM, Ian wrote:

IH> On Thu, 25 Aug 2005, Chris Lilley wrote:
>> 
>> This comment is sent from both the CDF WG and the SVG WG.
>> 
>>     A set of statements that specify presentation of a document.
>> 
>> Given the generality of the definition (is a Java program a style sheet, 
>> if it parses and then presents a document?), it seems that another term 
>> 'CSS style sheet' should *also* be defined. Then, statements which apply 
>> only to CSS style sheets can be distinguished from those which apply to 
>> all possible style sheet languages.

IH> So that we can ensure the new definition is adequate to resolve any 
IH> ambiguities that the CDF and SVG WGs believe exist, could the CDF and SVG
IH> WGs please let us know which statements were considered to ambiguously 
IH> refer to either style sheets in general or CSS style sheets in particular,
IH> and what the CDF and SVG WGs would consider appropriate language for the
IH> definition of the "CSS style sheet" term?

Existing text

Style sheet
    A set of statements that specify presentation of a document.

(OK, but very general. Covers CSS, DSSL, XSL, sXBL and indeed Java, Python
pretty much any 'set of statements' that produce presentation)

    Style sheets may have three different origins: author, user, and
    user agent. The interaction of these sources is described in the
    section on cascading and inheritance.

(Here its clearly talking about CSS (all versions) and not XSL etc
     
Valid style sheet

    The validity of a style sheet depends on the level of CSS used for
    the style sheet. All valid CSS1 style sheets are valid CSS 2.1 style
    sheets, but some changes from CSS1 mean that a few CSS1 style sheets
    will have slightly different semantics in CSS 2.1. Some features in
    CSS2 are not part of CSS 2.1, so not all CSS2 style sheets are valid
    CSS 2.1 style sheets.

So, all XSL style sheets are invalid because the level of CSS they
conform to is ???

    A valid CSS 2.1 style sheet must be written according to the grammar
    of CSS 2.1. Furthermore, it must contain only at-rules, property
    names, and property values defined in this specification. An illegal
    (invalid) at-rule, property name, or property value is one that is
    not valid.

Fine.

Suggested text:

Style sheet
    A set of statements that specify presentation of a document.

CSS style sheet
    A set of statements, expressed in CSS, that specify
    presentation of a document.

    CSS style sheets may have three different origins: author, user, and
    user agent. The interaction of these sources is described in the
    section on cascading and inheritance.

Valid CSS style sheet
    The validity of a style sheet depends on the level of CSS used for
    the style sheet. All valid CSS1 style sheets are valid CSS 2.1 style
    sheets, but some changes from CSS1 mean that a few CSS1 style sheets
    will have slightly different semantics in CSS 2.1. Some features in
    CSS2 are not part of CSS 2.1, so not all CSS2 style sheets are valid
    CSS 2.1 style sheets.

Valid CSS 2.1 style sheet
    A valid CSS 2.1 style sheet must be written according to the grammar
    of CSS 2.1. Furthermore, it must contain only at-rules, property
    names, and property values defined in this specification. An illegal
    (invalid) at-rule, property name, or property value is one that is
    not valid.


-- 
 Chris Lilley                    mailto:chris@w3.org
 Chair, W3C SVG Working Group
 W3C Graphics Activity Lead
Received on Monday, 29 August 2005 19:54:02 GMT

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