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RE: Proposed revision to URI fragment text in RDF Concepts (20030411)

From: <Patrick.Stickler@nokia.com>
Date: Tue, 15 Apr 2003 10:00:01 +0300
Message-ID: <A03E60B17132A84F9B4BB5EEDE57957B5FBB88@trebe006.europe.nokia.com>
To: <GK@NineByNine.org>, <w3c-rdfcore-wg@w3.org>


Is it possible to say less yet still sufficiently address this issue?

I.e.

> [[
> 7. Fragment identifiers
> 
> RDF uses an RDF URI Reference, which may include a fragment 
> identifier, as 
> a context free identifier for a resource. RFC 2396 [URI] 
> states that the 
> meaning of a fragment identifier depends on the MIME 
> content-type of a 
> document, i.e. is context dependent.
> 
> These apparently conflicting views are reconciled by 
> considering that a URI 
> reference in an RDF graph is treated with respect to the MIME type 
> application/rdf+xml [RDF-MIME-TYPE]. Given an RDF URI 
> reference consisting 
> of an absolute URI and a fragment identifier, the fragment identifer 
> identifies the same thing that it does in an application/rdf+xml 
> representation of the resource identified by the absolute URI 
> component. Thus:
> 
>      * we assume that the URI part (i.e. excluding fragment 
> identifier) 
> identifies a resource, which is presumed to have an RDF 
> representation. So 
> when eg:someurl#frag is used in an RDF document, eg:someurl 
> is taken to 
> designate some RDF document (even when no such document can 
> be retrieved).
>      * eg:someurl#frag means the thing that is indicated, 
> according to the 
> rules of the application/rdf+xml MIME content-type 

by the URIref as it might occur in the RDF document identified 
by the URI part.

>      * the RDF treatment of a fragment identifier allows it 
> to indicate a 
> thing that is entirely external to the document, or even to 
> the "shared 
> information space" known as the Web. That is, it can be a 
> more general 
> idea, like some particular car or a mythical Unicorn.
>      * in this way, an application/rdf+xml document acts as 
> an intermediary 
> between some Web retrievable documents (itself, at least, 
> also any other 
> Web retrievable URIs that it may use, possibly including 
> schema URIs and 
> references to other RDF documents), and some set of possibly 
> abstract or 
> non-Web entities that the RDF may describe.
> 
> This provides a handling of URI references and their 
> denotation that is 
> consistent with the RDF model theory and usage, and also with 
> conventional 
> Web behavior. Note that nothing here requires that an RDF 
> application be 
> able to retrieve any representation of resources identified 
> by the URIs in 
> an RDF graph.
> ]]

I think that the minor edit of removing the statement that a URIref
denotes a "view" or "fragment" of an RDF document (which is IMO
in most cases not true) and simply saying that the interpretation of
the URIref is the same as it would be if the base URI were an RDF
document and the URIref occurs in that RDF document (which is what
I think is all we really should say) addresses the issue of how
the MIME type affects the interpretation of the fragment identifier
without having to posit some kind of "view" or "fragment" nature
to the resource denoted by the URIref.

Patrick


--
Patrick Stickler, Nokia/Finland, (+358 40) 801 9690, patrick.stickler@nokia.com
 
Received on Tuesday, 15 April 2003 03:00:08 EDT

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