Permission to break feature freeze for Nepomuk and Soprano

Mon Sep 3 21:23:01 BST 2007

On Monday 03 September 2007 19:39:32 Richard Dale wrote:
> On Monday 03 September 2007, Sebastian Trüg wrote:
> > BTW: The Jabber thing sounds very interesting and very close to what is
> > done in the Nepomuk project. Would you be interested in talking about the
> > ideas with some of the Nepomuk guys who do the same for the Nepomuk Java
> > prototype?
>
> Yes, do they have a mailing list? I read about the DBin project on the

Well, most mailing lists are private. I think it is best if I put you in 
contact with them directly. Hopefully we can then share ideas and you can 
benefit from research that has already been done in Nepomuk.
Let me get back to you on that tomorrow. :)

> nepomuk site, and I thought it would be better off if it used jabber/XMPP
> as a transport, rather than building their own. So I tried an experiment to
> send a SPARQL query over xmpp in ruby and it came out really well - there
> is a perfect match - you just use IQ message types. But when I wanted to
> try querying the nepomuk data store that's when I found you couldn't get
> the results in xml/sparql format which i needed to be able to send back to
> the other jabber client.
>
> This is what the code looks like:
>
> ---------------------------------------------------------------------------
>--------------- # SPARQL query from a jabber client:
>
>     # Create an 'IQ' message
>     def sparql_query(jid, text)
>       msg = Jabber::Iq.new(:get, jid)
>       @@iq_query_id += 1
>       msg.id = @@iq_query_id
>       query = IqQuery::new
>       query.add_namespace("http://www.w3.org/2005/09/xmpp-sparql-binding")
>       query.add_text(text)
>       msg.add(query)
>       puts msg.to_s
>       send!(msg)
>       return msg.id
>     end
> ...
> im = Jabber::Simple.new('admin at mardigras/sparqlclient','yyyy')
> msg_id = im.sparql_query('rdale at mardigras/sparqlserver',
>                          "PREFIX foaf: <http://xmlns.com/foaf/0.1/>
> SELECT DISTINCT ?o WHERE {?s foaf:name ?o.}")
> im.disconnect
>
> ---------------------------------------------------------------------------
>--------------- # Replying to the SPARQL query:
>
> SPARQL_RESULTS = <<-EOS
> <sparql xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>         xmlns:xs="http://www.w3.org/2001/XMLSchema#"
>         xmlns="http://www.w3.org/2005/sparql-results#">
>   <head>
>     <variable name="o"/>
>   </head>
>   <results>
>     <result>
>       <binding name="o">
>         <literal>Libby Miller</literal>
>       </binding>
>     </result>
>     <result>
>       <binding name="o">
>         <literal>Tim Berners-Lee</literal>
>       </binding>
>     </result>
> <!-- ... more bindings here -->
>   </results>
> </sparql>
> EOS
>
> im = Jabber::Simple.new('rdale at mardigras/sparqlserver','xxxx')
> messages = im.iq_messages
> msg = messages[0]
> doc = REXML::Document.new SPARQL_RESULTS
> im.sparql_results(msg.from.to_s, msg.id, doc)
> im.disconnect
>
> -- Richard