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Re: Named Graph Homepage - second draft

From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Date: Thu, 08 Apr 2004 10:45:36 +0100
Message-ID: <40751F40.80001@hplb.hpl.hp.com>
To: Patrick Stickler <patrick.stickler@nokia.com>
Cc: ext Chris Bizer <chris@bizer.de>, www-archive@w3.org, Pat Hayes <phayes@ihmc.us>


I agree - this is the correct practical algorithm, I'll see if I can get 
some text in there.

i.e. the URI is the base URI in scope on the outermost RDF element of the 
document (typically the rdf:RDF of an RDF/XML or OWL document). This may be 
the xml:base or the retrieval URI of the document.

Jeremy





Patrick Stickler wrote:

> 
> On Apr 07, 2004, at 17:10, ext Chris Bizer wrote:
> 
>> Hi,
>>
>> I updated the draft for the Named Graph homepage and included the 
>> comments
>> from Patrick and Jeremy. I also added RDF/XML as a third possible 
>> syntax for
>> Named Graphs to section 3:
>>
>> 3.3 RDF/XML
>>
>> A collection of RDF documents can be seen as a set of Named Graphs. This
>> gives Named Graphs upward compatibility with RDF/XML, but has the
>> disadvantage that retrieval URL, document name and graph name are 
>> mixed up.
> 
> 
> I've been chewing on this a bit more recently, and I still think that it
> makes alot more sense to derive the name of an RDF/XML encoded graph based
> on the xml:base value *of the root <rdf:RDF> element*.
> 
> Yes, it is true that any element in the RDF/XML can have its own xml:base
> attribute defined, but there can be at most one such attribute defined
> for the <rdf:RDF> element, so there's no ambiguity there.
> 
> And since the xml:base value need have no correlation to the URI via which
> the RDF/XML instance was obtained, we avoid the URI denotation ambiguity
> otherwise introduced by taking the access URI as denoting the graph.
> 
> Otherwise, I'd prefer to simply state that there is no obviously correct
> and reliable means to associate a graph name URI with an RDF/XML instance
> in the instance itself, and avoid (being misunderstood) proposing that
> the access URI be used (which I think is a mistake/hack/etc.).
> 
> Thus,
> 
> <rdf:RDF xml:base="http://example.org/foo" ...>
>    ...
>    <rdf:Description xml:base="http://example.org/bar" ...>
>    ...
> </rdf:RDF>
> 
> equates to
> 
> <http://example.org/foo> {
>    ...
> }
> 
> Note that the second xml:base on the description element has
> no affect on the name of the graph.
> 
> Also, this works even when mulitiple RDF/XML fragments are
> embedded in the same e.g. XHTML document, since each root
> <rdf:RDF> element can have its own xml:base value and hence
> a distinct name.
> 
> We'd restrict the interpretation of xml:base to explicit
> attributes occurring on the root <rdf:RDF> element, not
> inherited from a higher XML scope.
> 
> Eh?
> 
> Patrick
> 
> 
> 
>>
>> Chris
>> <NamedGraphsPage.zip>
> 
> 
> -- 
> 
> Patrick Stickler
> Nokia, Finland
> patrick.stickler@nokia.com
> 
Received on Thursday, 8 April 2004 05:46:58 GMT

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