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Re: Why is xml:base a URI *reference*?

• To: Eric van der Vlist <vdv@d...>
• Subject: Re: Why is xml:base a URI *reference*?
• From: Bob Foster <bob@o...>
• Date: Thu, 08 Jan 2004 04:46:29 -0600
• Cc: xml-dev@l...
• In-reply-to: <1073557553.6359.122.camel@delleric>
• References: <4C4EB02E-4177-11D8-A4BC-000A95BA5A2C@o...> <p06010201bc22855ac223@[192.168.254.4]> <f5br7yaeoug.fsf@e...> <1073557553.6359.122.camel@delleric>
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Eric van der Vlist wrote:
> On Thu, 2004-01-08 at 11:06, Henry S. Thompson wrote:
> 
>>Elliotte Rusty Harold <elharo@m...> writes:
>>
>>
>>>At 8:09 PM -0500 1/7/04, Jonathan Borden wrote:
>>>
>>>>Does anyone here know the reasoning behind this? In specific, why
>>>>does xml:base allow URI references (i.e. with fragment identifiers)
>>>>rather than simply using URIs (URIrefs sans fragment identifiers)?
>>>
>>>I seem to recall that the thinking was that relative URIs are only URI
>>>references, not true URIs; and URI references were used to enable
>>>this, not to enable fragment identifiers.
>>
>>That's my belief also.  IIRC, the RFC defines URI to be what you and I
>>would call an absolute URI.
> 
> 
> That makes sense, but how does that relate to the namespaces' URI
> references, then?
> 
> Is that an indication that the WG did really want to allow relative URIs
> or does "URI reference" have a different meaning in the namespaces
> specification?

It is equally likely they wanted to allow fragment identifiers. The 
guidance in the namespace spec is that URI references used as namespace 
identifiers should be globally unique, which is hard to do with a 
relative URI.

> I hope I am not restarting the most terrible XML-DEV permathread, but I
> hadn't understood clearly this difference between URI and URI references
> when this has been discussed.

The RFC 2396 definition:

URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]

> Also, this doesn't seem to be coherent either with WXS' definition of
> anyURI
> http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#anyURI that says:
> 
> "anyURI represents a Uniform Resource Identifier Reference (URI). An
> anyURI value can be absolute or relative..."
> 
> If the W3C has another definition of what are URIs and URI references
> than the IETF which seems to be the case, shouldn't that definition be
> used coherently in all the W3C specifications (instead of having some of
> them use the W3C definitions and some other use the IETF one)? 

The complete paragraph in WXS is: "anyURI represents a Uniform Resource 
Identifier Reference (URI). An anyURI value can be absolute or relative, 
and may have an optional fragment identifier (i.e., it may be a URI 
Reference)."

This is consistent with the IETF definition.

Bob Foster
http://xmlbuddy.com/

> Eric
> 
>>ht

• Follow-Ups:
  • Re: Why is xml:base a URI *reference*?
    • From: Eric van der Vlist <vdv@d...>

• References:
  • Why is xml:base a URI *reference*?
    • From: Jonathan Borden <jonathan@o...>
  • Re: Why is xml:base a URI *reference*?
    • From: Elliotte Rusty Harold <elharo@m...>
  • Re: Why is xml:base a URI *reference*?
    • From: ht@c... (Henry S. Thompson)
  • Re: Why is xml:base a URI *reference*?
    • From: Eric van der Vlist <vdv@d...>

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