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Referring to Contexts by URI

From: Alex Barnell <aeb99@doc.ic.ac.uk>
Date: Mon, 17 Sep 2001 18:34:31 +0100
To: www-rdf-interest@w3.org
Message-ID: <20010917183431.A453@alex.parkhillroad.co.uk>
Currently I believe it is possible to refer to a context by reifing all
the statements in that context and putting them in a bag. This is quite
clumsy if there are many statements in the context, and I want to refer
to it from many other contexts. Also this makes it impossible to refer
to contexts where the statements in that context are changing from time
to time, without also updating the referrant context, implying massive
overhead and possible synchronisation problems.

Instead of refering to a context by statement enumeration, I'd like to
be able to refer to a context by just using it's URI. Applications then
acting on my referral could then resolve the referred to context
by various means, depending on the form of the context referral. 

If the context was a page of RDF statements, then referring to it and
the subsequent resolving of it would be quite simple:

<rdf:Description about="http://www.data.com/somestatements.rdf">
 <rdf:type resource="http://something.com/Context/>
</rdf:Description>

A more complicated case would be if a wanted to refer to a context that
is the resultant context after applying an RDF query to another context.
If the query itself has a URI, this might be done like this:

<rdf:Description about=urn:context:somecontextname>
 <rdf:type resource="http://something.com/Context/>
 <rdfs:isDefinedBy>
  <rdf:Description about="http://coolqueries.com/query1">
   <rdf:type resource="http://something.com/Query/>
  </rdf:Description>
 </rdfs:isDefinedBy>
</rdf:Description>

Alternatively, we might want to define the query directly in RDF:

<rdf:Description about=urn:context:somecontextname>
 <rdf:type resource="http://something.com/Context/>
 <rdfs:isDefinedBy>
  <rdf:Description>
   <rdf:type resource="http://something.com/Query/>
   <query:sourcecontext>
    <rdf:Description about="http://www.data.com/somestatements.rdf">
     <rdf:type resource="http://something.com/Context/>
    </rdf:Description>
   </query:sourcecontext>
   <query:query>
     <query:predicate resource="urn:dc:author">
   </query:query>
  </rdf:Description>
 </rdfs:isDefinedBy>
</rdf:Description>


The problem is that there are currently no standards for this kind of
stuff. In particular, there is no schema for contexts.

Are there any plans to develop such standards? Or should I define my
own context schemas and application behaviour and hope my application data
works with everyone elses? 

-- 
Regards,
Alex
Received on Monday, 17 September 2001 13:33:06 GMT

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