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Re: Specified values: what are they?

From: Etan Wexler <ewexler@stickdog.com>
Date: 12 Sep 2002 16:00-0700
To: www-style@w3.org
Message-ID: <CSS-specified-values@d20020912.etan.wexler>

Ian Hickson wrote to <www-style@w3.org> on 6 September 2002 in "Re:
Specified values: what are they?"
(<mid:Pine.LNX.4.21.0209060307380.26840-100000@dhalsim.dreamhost.com>):

>    http://www.w3.org/TR/REC-CSS2/cascade.html#specified-value
> 
> The specified value is the result of applying the cascade.

Sure enough.  I had unintentionally rewritten that part of the
specification in my mind.

> (There is no such thing as an "undeclared property", since all properties
> have initial values.)

I think our disagreement may be a mere difference in terminology.  If
you mean that all properties get assigned a value, then I agree.

However, a declaration is a particular syntactic construct.  It is
possible (indeed, probable and useful) that some property of some
element have no corresponding declaration anywhere in the applicable
cascade.  If it is the case that there is no corresponding declaration,
I call the property undeclared.

> Yes, I think maybe there is value in solidifying CSS3's terminology so
> that we have:
> 
>    Specified Value (the literal value of the winning declaration, if any)

I object to the redefinition of the term "specified value".  While CSS3
*drafts* may be ambiguous about the term, the CSS2 *Recommendation* is
quite clear.  We are trying to name the value in a winning declaration;
I suggest the term "declared value".

While we could retain the term "specified value" in its current meaning,
the meanings of "specified" and "declared" are close enough to cause
confusion.  I support the use of the term "cascaded value" to mean what
CSS2 calls "specified value".

>    Cascaded Value (the result of the cascade, after handling any
>    inheritance, initial values, and attr() forms -- defined for all
>    properties and all elements and pseudo-elements)

Does replacement of 'attr()' forms really take place during assignment
of cascaded values?  Why replace 'attr()' forms then instead of during
assignment of computed values?

>    Computed Value (the value used by the rendering engine and for
>    inheritance into children)

Some properties may inherit from cascaded values, rather than from
computed values.

-- 
Etan Wexler <mailto:ewexler@stickdog.com>
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Received on Thursday, 12 September 2002 17:08:27 GMT

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