- From: Dan Brickley <danbri@danbri.org>
- Date: Mon, 18 Apr 2011 16:27:58 +0200
- To: nathan@webr3.org
- Cc: Pat Hayes <phayes@ihmc.us>, Pierre-Antoine Champin <pierre-antoine.champin@liris.cnrs.fr>, Ivan Herman <ivan@w3.org>, RDF Working Group WG <public-rdf-wg@w3.org>
[snip] Let me offer a practical use case: the evolving RDF graphs served from FOAF and Dublin Core namespace URIs. For the FOAF case xmlns="http://xmlns.com/foaf/0.1/", the RDF available (via conneg, link rel or sometimes embedded in HTML) can be found in our Subversion server at http://svn.foaf-project.org/foaf/trunk/xmlns.com/htdocs/foaf/0.1/index.rdf ... you can fetch any version going back to ~2002 via public SVN. For the Dublin Core case, xmlns="http://purl.org/dc/elements/1.1/" and others nearby are documented in http://dublincore.org/schemas/rdfs/ including links to each version of the schema file, and with social/process documentation of those changes at http://dublincore.org/usage/terms/history/ Consider a SPARQL service devoted to keeping record of what key namespaces have said about themselves over the years. They could take each of these snapshot RDF files and put the corresponding triples in a different named graph. (Maybe we should prepare N-Quads/Trig dumps of the data for testing?). We should be able to queries such as "when did foaf:givenName change from Unstable status" or "when did DCMI begin to mention dc:audience ?". If we use the URI we 'GET'd for the graph name, these sort of historically minded queries won't be possible as the graphs will get mixed up. All this talk of HTTP response codes is great and nice and practical, ... so long as we're crystal clear that the Web gives back different things over time, and often we'll want to be explicit about that. Eventually we'll also want to be a bit more clear about security properties, such as which copies of a schema check out as having been signed by such-and-so key. cheers, Dan ps. for the foaf case, revisions are available via: svn log http://svn.foaf-project.org/foaf/trunk/xmlns.com/htdocs/foaf/0.1/index.rdf ...then you can pull them (per directory) eg. with: svn co -r r186 http://svn.foaf-project.org/foaf/trunk/xmlns.com/htdocs/foaf/0.1/ ... so you can see that <http://xmlns.com/foaf/0.1/homepage> <http://www.w3.org/2000/01/rdf-schema#domain> <http://xmlns.com/foaf/0.1/Person> . ...used to be in there, before we broadened it. Question to my mind is, how do we elevate the tooling so you can find this out using SPARQL and RDF instead of SVN and grep?
Received on Monday, 18 April 2011 14:28:33 UTC