W3C home > Mailing lists > Public > www-rdf-interest@w3.org > July 2000

Re: xmlns, uri+name pairs or just uris..? Clarification needed.

From: Pierre-Antoine CHAMPIN <champin@bat710.univ-lyon1.fr>
Date: Fri, 28 Jul 2000 15:05:41 +0200
Message-ID: <39818525.A82165F9@bat710.univ-lyon1.fr>
To: Dan Brickley <danbri@w3.org>
CC: "McBride, Brian" <bwm@hplb.hpl.hp.com>, "'caro@Adobe.COM'" <caro@Adobe.COM>, www-rdf-interest@w3.org
> On Fri, 28 Jul 2000, McBride, Brian wrote:
> > Unfortunately, this is a potential problem.  Given a URI reference for
> > a property, it is important to be able to determine the correct namespace
> > for that property because the namespace defines the schema that defines
> > its interpretation.

I believe there is a confusion here :

the notion of "namespace" seems innapropriate for RDF, sinces "names" in RDF are URIs, they all belong to a unique space of names.
The confusion comes from the fact that URIs are built in RDF by means of "XML namespaces" which is a syntactical mechanism.

On the other hand, a schema is an RDF document describing (and potentially defining) URIs to be used as RDF vocabulary.



It seems that the problem raised by anyone is about re-serializing an RDF model,
how to find the "correct" namespace for a given URI.
In my opinion, there is no "correct" namespace.

<ns:foobar xmlns:ns="http://somewhere.org/RDF/schema#">
<ns:bar xmlns:ns="http://somewhere.org/RDF/schema#foo">
<ns:ar xmlns:ns="http://somewhere.org/RDF/schema#foob">
<ns:r xmlns:ns="http://somewhere.org/RDF/schema#fooba">

are equally correct, though the forst one is much cleaner !
The implicit concern is to be able to retrieve the schema defining that URI,
but the specification does not require a property URI to give a clue about the schema defining it !
One could anyway attempt to retrieve
 http://somewhere.org/RDF/schema#foobar
in that case, which btw is equivalent to retrieving
 http://somewhere.org/RDF/schema
(fragment identifier are *not* really part of the URI)

The other solution as mentioned Dan Brickley,is to use the rdfs:isDefinedIn property, which is the only normative way to link a resource to its defining schema.

  Pierre-Antoine

--- Quid quid Latine dictum sit, altum viditur
    Whatever is said in Latin sounds important.
Received on Friday, 28 July 2000 08:54:16 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:51:43 GMT