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Re: Relative URIs in xml:base - RDF/XML parser disagreement?

From: Dan Brickley <danbri@w3.org>
Date: Mon, 18 Jul 2005 15:21:08 +0100
Message-ID: <42DBBAD4.1060601@w3.org>
To: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Cc: semantic-web@w3.org, dave.beckett@bristol.ac.uk

Jeremy Carroll wrote:

>
>
> Thanks
>
> this is an ARP bug. I'll try and reproduce, and then fix it.
> (Hmmm, a surprise as well I thought I had coded for that case :( )
>
> I'll also dig down the specs. It may be a corner case, but I don't 
> recall any ambiguity in XML Base Rec for this case.
>
I'm cutting this across to semantic-web@w3.org since the bug seems 
confirmed.

http://swig.xmlhack.com/2005/07/18/2005-07-18.html#1121684177.102753 
links to www-archive
thread.

RDF/XML parser owners: see below for a little test case that might flush 
out a
potential (if minor; this idiom isn't widely used) interop problem.

Thanks to Tim Bray on atom-syntax list for reminding me of this xml:base 
subtlety.

cheers,

Dan

>
> Jeremy
>
>
> Dan Brickley wrote:
>
>>
>> Hi
>>
>> <?xml version="1.0"?>
>> <rdf:RDF xml:base="http://example.org/" 
>> xmlns:rdf="http://www.w3.org/1999/02/22-
>> rdf-syntax-ns#"
>>  xmlns:dc="http://purl.org/dc/elements/1.1/">
>>  <rdf:Description rdf:about="http://www.w3.org/" xml:base="test1/">
>>    <dc:title>World Wide Web Consortium</dc:title>
>>    <dc:source rdf:resource="test2/"/>
>>    <dc:relation rdf:resource=""/>
>>  </rdf:Description>
>> </rdf:RDF>
>>
>>
>> ...is a test of xml:base stacking with relative URIs.
>>
>> I tried the online Raptor service, and got:
>>
>> http://www.w3.org/     http://purl.org/dc/elements/1.1/relation     
>> http://example.org/test1/
>> http://www.w3.org/     http://purl.org/dc/elements/1.1/source     
>> http://example.org/test1/test2/
>> http://www.w3.org/     http://purl.org/dc/elements/1.1/title     
>> World Wide Web Consortium
>>
>> I tried latest ARP download on commandline, and got:
>>
>> Warning: 
>> file:///Users/danbri/Desktop/jena/Jena-2.2/../xmlbase1.rdf[4:69]: 
>> {W107} Bad URI <test1/>: No scheme found in URI 'test1/'
>> <http://www.w3.org/> <http://purl.org/dc/elements/1.1/title> "World 
>> Wide Web Consortium" .
>> <http://www.w3.org/> <http://purl.org/dc/elements/1.1/source> 
>> <file:///Users/danbri/Desktop/jena/test2/> .
>> <http://www.w3.org/> <http://purl.org/dc/elements/1.1/relation> 
>> <file:///Users/danbri/Desktop/jena/Jena-2.2/../xmlbase1.rdf> .
>>
>> The test case is basically an RDFization of the example in 
>> http://www.w3.org/TR/xmlbase/#syntax
>> (tried out of curiosity after a thread on the atom-syntax list).
>>
>> http://www.w3.org/TR/rdf-syntax-grammar/#section-Syntax-ID-xml-base 
>> doesn't seem to
>> require absolute URIs in RDF's treatment of xml:base, nor rule out 
>> the stacking behaviour.
>>
>> So from a quick look I'd guess that ARP is in error, rather than 
>> Raptor. This is a somewhat
>> obscure corner-case so I expect other parsers might also vary in 
>> behaviour...
>>
>> Thoughts?
>>
>> Dan
>>
>> ps. the dc:relation thing is in there because
>> http://lists.w3.org/Archives/Public/www-rdf-comments/2002JanMar/0234.html 
>> via
>> http://www.w3.org/2000/03/rdf-tracking/#rdfms-xml-base tells me that 
>> "" self-refs aren't
>> affected by xml:base. Not sure if that decision got reverted.
>> http://www.w3.org/TR/2004/REC-rdf-testcases-20040210/ has a good set 
>> of xmlbase tests
>> but it doesn't seem to exercise this possibility (of multiple 
>> xml:base, some relative).
>>
>>
>> ------------------------------------------------------------------------
>>
>> <?xml version="1.0"?>
>> <rdf:RDF xml:base="http://example.org/" 
>> xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>>   xmlns:dc="http://purl.org/dc/elements/1.1/">
>>   <rdf:Description rdf:about="http://www.w3.org/" xml:base="test1/">
>>     <dc:title>World Wide Web Consortium</dc:title>     <dc:source 
>> rdf:resource="test2/"/>
>>     <dc:relation rdf:resource=""/>
>>   </rdf:Description>
>> </rdf:RDF>
>>   
>
>
Received on Monday, 18 July 2005 14:22:00 GMT

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