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Re: XBL is (mostly) W3C redundant, and CSS is wrong W3C layer for semantic behavior *markup*

From: Tantek Çelik <tantek@cs.stanford.edu>
Date: Thu, 02 Jan 2003 02:54:35 -0800
To: Shelby Moore <shelby@coolpage.com>, Ian Hickson <ian@hixie.ch>
CC: <www-style@w3.org>
Message-ID: <BA3959F5.1DC69%tantek@cs.stanford.edu>

On 1/1/03 11:44 PM, "Shelby Moore" <shelby@coolpage.com> wrote:

> 
> Interesting to ponder how our discussion of semantics impacts CSS
> pseudo-elements (and pseudo-classes), e.g. ::visited or ::first-line:

More precisely (for CSS2):

 pseudo-elements (and pseudo-classes), e.g. :first-line (and :visited)

or for CSS3:

 pseudo-elements (and pseudo-classes), e.g. ::first-line (and :visited)


> http://www.w3.org/TR/REC-CSS2/selector.html#pseudo-elements
> 
> "Neither pseudo-elements nor pseudo-classes appear in the document source
> or document tree."

Note the immediately preceding sentence in the text:

"The exceptions are ':first-child', which can be deduced from the document
tree, and ':lang()', which can be deduced from the document tree in some
cases. "

In general, the sentence you quoted is not precisely correct, and should
probably be stricken from CSS2.1, since I believe the part of it that is
correct is already covered by the preceding prose description in the spec.

For more precise statements regarding pseudo-elements and pseudo-classes and
the document tree, I suggest viewing the Selectors spec

 http://www.w3.org/TR/css3-selectors/

and searching for the text "document tree".  Each pseudo-class (and
pseudo-element) has a more precise statement regarding this topic.


> In last few posts, we are discussing definitions related to semantic
> content _markup_.
> 
> The pseudo-elements also have semantics, but they are not explicitly marked
> up.

... not necessarily explicitly marked up.  Some pseudo-classes can be
inferred from the markup alone.


> They are inferred and/or created elements (or states) by the
> presentation layer.

Sometimes (perhaps most of the time).


> So in this case of pseudo-elements, I assert it is
> appropriate for the semantic binding to be at the CSS layer, since they do
> not exist above presentation layer.

I'm not touching that one since it is clear from the thread that the
meanings of some of the terms used in that sentence are
unclear/ambiguous/not-agreed-upon.

> I realize they are already semantically bound at CSS layer.  I just wanted
> to test our discussion to see if it generalizes.

Or that one.


Tantek


[I can't believe I have been drawn into responding to this thread.  Ah well,
good to get the first mistake of the year over with.]
Received on Thursday, 2 January 2003 05:38:57 GMT

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