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Re: URIs for "xml" and "xmlns" prefixes?

From: James Clark <jjc@jclark.com>
Date: Wed, 26 Aug 1998 10:08:05 +0700
Message-ID: <35E37C15.43E4ABD2@jclark.com>
To: David Brownell <db@Eng.Sun.COM>
CC: xml-names-issues@w3.org
David Brownell wrote:
> 
> James Clark wrote:
> >
> > David Brownell wrote:
> > >
> > > The namespace spec states that there are two "implicitly declared"
> > > namespace prefixes, "xml" and "xmlns".  But it doesn't give their
> > > associated URIs, as needed for uniformity within implementations.
> >
> > I don't see a need for a URI for "xmlns".  Names with the "xmlns"
> > prefix  are never seen by applications.
> 
> That's not in the current spec.  How will applications know where the
> namespaces are declared, if not through this (IMHO) natural model?
> Or you assuming that preserving the declaration structure of source
> data is not a goal?

You were thinking that you would expose the declaration structure by
passing through the expanded xmlns attributes? I hadn't thought of doing
it like that.  There are other ways to do it (see XT for one example).

> I note that the XSL draft includes a requirement that applications be
> able to see the list of namespace prefixes that are "in scope".  (2.4.2)
> Looks like some API-like requirements are bubbling up; I don't think they
> would naturally belong in this document.

I think some kinds of application will need this (though they'll
probably be in a minority).

> > We know we need a URI for "xml".
> 
> Good ...
> 
> > The intention on "xmlns" is that's it's a keyword.
> 
> That might simplify some things.  Like supporting default namespace
> declarations.
> 
> But -- just "xmlns", and not "xml"?  So it'd be allowable to say
> "xmlns:xml='http://www.example.com'" and thus change the meaning
> of an "xml:space" or "xml:lang" attribute?

I don't think I would want to allow that. It's not obvious exactly what
to do here, so I think it's best to keep it simple (restrictive) for
now, and maybe generalize later if the simple approach turns out to be
problematic.

James
Received on Wednesday, 26 August 1998 00:12:13 UTC

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