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Re: rdfms-uri-substructure: some clarifying advice [was: A collection of issue resolutions]

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Wed, 13 Feb 2002 16:28:59 +0000
Message-Id: <5.1.0.14.0.20020213162249.0253ecc0@0-mail-1.hpl.hp.com>
To: Dan Connolly <connolly@w3.org>
Cc: RDF Core <w3c-rdfcore-wg@w3.org>
Dan,

Your proposal looks like a good idea.  Can we combine the two.  The strict 
answer to the issue is that no, we are not going to change from URI's to 
pairs.  And then add the guidance.

A small nit type question:  Jena does store URI's internally as pairs and 
allows a client app to specify the namespace and the local name:

    Property p = m.createProperty(namespace, localname);

When it comes to serializing such a property the serializer has been told 
where to split by the application.  Are you suggesting that this should 
still throw an exception when the namespace does not end in an appropriate 
character?

Brian



At 15:35 12/02/2002 -0600, Dan Connolly wrote:
>On Tue, 2002-02-12 at 13:05, Brian McBride wrote:
> > Propose the WG resolve that the proposed change would be a major change to
> > the RDF specification and is out of scope for this WG.
> >
> > rdfms-uri-substructure: xmlns, uri+name pairs or just uris..? 
> Clarification
> > needed (Sergey Melnik)
> >
> >
> > Propose the WG resolves that changing how resources are named on the 
> web is
> > a web architecture issue and beyond the scope of our charter.
>
>I can live with that, but I have a proposal that I prefer:
>
>It's just clarifying advice to users/implementors, not a change to the
>language:
>
>
>Whereas:
>
>(a) the RDF 1.0 spec says that property and class names
>are computed from element and attribute names
>by concatenating their namespace names with their local names
>
>(b) it's useuful to be able to process RDF with
>XPath and XSLT, where even though
>         concat(namespace-name(qname1), local-name(qname1))
>is the same as
>         concat(namespace-name(qname2), local-name(qname2))
>the qnames themselves may not compare equal in XPath expressions.
>
>(c) lots of implementors have looked for advice on
>how to serialize RDF, and, in particular, how to
>compute a namespace name and localname from
>the name of a property or a class.
>
>we advise RDF schema/namespace/vocabulary designers
>
>(d) choose namespace names that end in non-xml-name-characters
>such as / # ?
>
>and we advise implementors of RDF serializers:
>
>(e) in order to break a URI into a namespacename and a local
>name, split it at the last XML name character. If the URI
>ends in a non-name-character, throw a "this graph
>cannot be serialized in RDF 1.0" exception.
>
>Provided this is agreed, the syntax editor should salt to taste
>and add it to the syntax spec, and the test cases editor
>should add something close to what follows:
>
>Test cases:
>
>implementors are advised to throw a "cannot serialize in RDF 1.0"
>exception if asked to serialize:
>
>   <mid:something@example> <http://example/ill-advised-name/> "abc".
>
>and implementors are advised to serialize
>
>   <mid:something@example> <http://example/ok-name/> "abc".
>
>as, for example:
>
><rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
>
>     <rdf:Description rdf:about="mid:something@example">
>         <ok-name xmlns="http://example/">abc</ok-name>
>     </rdf:Description>
></rdf:RDF>
>
>--
>Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Wednesday, 13 February 2002 11:30:20 EST

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