[RDF] Queries, filters, context, trust, and more...

[Jonas Liljegren]

I will now try to write down what came up under the last discussion
about Wraf with Stefan Andersson.


Some of this builds on what has been said in a earlier message:

        http://www.uxn.nu/pipermail/rdf/2000/000118.html


Let's say we have a P3P-like tree structure for person information:

  A --type--> Person
  A --contact--> B
  B --home--> C
  C --phone--> "0012345"



You could (but not in the alpha version) get the phone number value by
saying:

 $phone_str = $person->contact->home->phone->value;



The person could have two home phone numbers.  You shouldn't have to
write:

 $phone_str = $person->contact->[0]->home->[0]->phone->[0]->value;

This would be the first contact information (maby out of many
sources), the first of the person home addresses, the first phone in
that home.



You shouldn't have to know exactly what the path to the information
is.  This will hopefully give the same answer:

 $phone_str = $person->phone->value;

... provided that the person only has one phone number.



And you should be able to specify the properties of what it is you are
requesting:

 $phone_str = $person->phone( destination => home )->value;

The specified properties acts as a search criterion.



Every resource object lives in the context of their retrieval.  The
original object is the service object, which is unique for each
session.  A session consist of the 'discussion' between the Service
and the Agent.

The metadata of the service object will contain information about what
is known about the agent.  This will include the starting time for the
session and IP address.  If the agent is authenticating itself to the
service, there will be a lot of metadata.




-- 
/ Jonas  -  http://jonas.liljegren.org/myself/en/index.html