Re: CSS2.1 :lang

2003-10-16T18:11:09Z Chris Lilley <chris@w3.org> wrote:

> On Thursday, October 16, 2003, 3:09:41 PM, Bert wrote:


BB>> Tex Texin writes:

>>> Does ':lang()' match elements that have language set to the empty tag?
>>> 
>>> It might be thought to match all languages, since in the absence of simple
>>> selectors, * is presumed, so it is conceivable that absence of a tag might be
>>> equivalent to all. It might also be deemed to be an error to have no tag inside
>>> the parens.
>>> So the spec should address the issue.

> It would match those that have no language set.

BB>> But making it match elements with no language seems the most useful,
BB>> especially since it parallels RFC 3066.

> I agree, and that is also the definition of xml:lang="".

>>> For the purposes of matching, I wonder if it makes sense to
>>> reference the RFCs at all.

> Yes, it does, because matching is to a hyphen separated token list..

>>> Isn't it really string matching based on strings formatted with hyphen
>>> separators? Does any software verify that the language tag contains
>>> appropriately registered codes or uses ISO codes? Should it be an error, or
>>> perhaps the rule ignored, if a CSS document specifies  :lang(k9) since k9 is
>>> not an offical language code or a properly formatted private code.

> No, it just means that it probably does not match anything since
> nothing has that lang code.

BB>> I like that suggestion: it removes a dependency.

> I don't see the value of removing that dependency.

BB>> The definition of the "|=" operator is already generic.

> Yes.

BB>> It only
BB>> requires a UA to split a string value at every "-" and doesn't require
BB>> the string to be a valid language. The ':lang()' refers to that
BB>> definition and could be made generic as well,

> It could. But how would that help?

BB>> e.g.:

BB>> Current text in 5.11.4:

BB>>     The pseudo-class ':lang(C)' matches if the element is in language
BB>>     C. Here C is a language code as specified in HTML 4.0 [HTML40] and
BB>>     RFC 1766 [RFC1766]. It is matched the same way as for the '|='
BB>>     operator.

BB>> Proposed:

BB>>     The pseudo-class ':lang(C)' matches if the element is in language
BB>>     C. CSS doesn't define what are valid language names and the string
BB>>     C doesn't have to be a valid language name in the source document.
BB>>     It is matched the same way as for the '|=' operator.

BB>> And in 5.8.1, in the informative reference to RFC 1766, "1766" is
BB>> replaced by "3066."


> I agree that CSS should not be required to know whether language tags
> have been registered or not.

It would however be nice if the CSS Validator throwed warnings in case
of encountering the unregistered tags.

Alex.
-- 
  Alexander "Croll" Savenkov                  http://www.thecroll.com/
  w3@hotbox.ru                                     http://croll.da.ru/

Received on Thursday, 16 October 2003 23:59:42 UTC