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Re: Fixed base

From: Dan Connolly <connolly@w3.org>
Date: Tue, 20 Jun 2000 12:47:54 -0500
Message-ID: <394FAE4A.8CA53358@w3.org>
To: James Clark <jjc@jclark.com>
CC: xml-uri@w3.org
James Clark wrote:
> [...]  Absolutizing namespace names
> relative to a fixed based such as "contextdependent:/" satisfies both
> these requirements. 
>  This makes the behaviour of xmlns="" not be an
> ugly special exception, but just a consequence on the normal rules on
> resolving relative URIs.

Not an exception? Please consider the following document,
with a base URI of http://purl.org/dc/notes :

	<title>some notes on Dublin Core stuff</title>
	<p>In development of
	<a href="elements/1.1/">the dublin core vocabulary</a>,
	we discovered ...

Clearly, the link points to

This "fixed base" suggestion proposed that the dc prefix
be associated with

That certainly looks like an ugly special exception to me.
If namespace declarations use URI references, then
I think it's pretty intuitive to folks that have been
using the Web for a while that the dc
prefix is associated with the same thing that
the link points to, namely:

To do otherwise is clearly an exception to the way URI references
have worked for the last 10 years. 

HTML's <base> and xml:base create exceptions too...
the URI spec allows for such exceptions
on a per-mime-type basis (5.1.1. Base URI within Document Content),
so we could specify that this is how text/xml, applicaiton/xml
etc. work, if we wanted to.

Ugly is a matter of taste... I think making a special case
for namespace declarations is ugly. I don't see any motivation
for it (other than the fact that there are
implementations that don't grok relative URI references
at all, which I don't find compelling.)

I think HTML <base> is ugly, but at least
it affects all URI references in the document the same
way. xml:base is motivated by the case of
canonicalizing a multi-entity document, so that
you can express an element's base URI when
you copy it out of context.

Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Tuesday, 20 June 2000 13:49:35 UTC

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