Re: RDF Model Namespaces

[Andy Seaborne]

On 22/03/13 20:47, Pastrana, Rodrigo (RIS-BCT) wrote:
I'm new to Jena RDF API and I'm noticing some unexpected behavior regarding 
statement namespaces...
I've noticed that URI resources such as  
"http://www.govtrack.us/data/photos/412483.jpeg"; in the below excerpt of the 
congressional people graph(http://www.govtrack.us/data/rdf/people.rdf.gz)
Are reported to have namespace: " http://www.govtrack.us/data/photos/410069."; And local 
name "jpeg" using the com.hp.hpl.jena.rdf.model.Resource getLocalName(), and 
getNameSpace().
Is this correct behavior? It looks to me like the dot is being used as a 
delimiter between the NS and the local name. Is there a way to change that 
behavior ? thanks!

<foaf:Person 
rdf:about="http://www.rdfabout.com/rdf/usgov/congress/people/R000589";>
     <foaf:name>E. Rigell</foaf:name>
     <usgov:name>E. Rigell</usgov:name>
     <vcard:N>
       <rdf:Description>
         <vcard:Given>E.</vcard:Given>
         <vcard:Other>Scott</vcard:Other>
         <vcard:Family>Rigell</vcard:Family>
         <vcard:Prefix>Rep.</vcard:Prefix>
       </rdf:Description>
     </vcard:N>
     <foaf:gender>male</foaf:gender>
     <vcard:BDAY>1960-05-28</vcard:BDAY>
     <foaf:img rdf:resource="http://www.govtrack.us/data/photos/412483.jpeg"/>
     <usgov:congressBioGuideID>R000589</usgov:congressBioGuideID>
     <foaf:title>Rep.</foaf:title>
     <foaf:homepage>http://rigell.house.gov/</foaf:homepage>
   </foaf:Person>


Thanks, Rodrigo.

Jena is finding the maximal XML qname - the namespace mechanism can't be 
sure that it isn't going to be used a property.  Both properties (must) 
and types (can be) qnames in RDF/XML.  RDF does not distinguish 
classes/properties/individuals.

http://www.govtrack.us/data/photos/412483.jpeg

An XML qname local part can't start with a digit or a "." so  "jpeg" is 
the longest local part.

> Is this correct behavior?

Yes

> Is there a way to change that behavior ?

No - the RDF/XML serializer is relying on it.

But what are you using the namespace/localname for ?

If it's display, then you are not bound by the XML restrictions and can 
split it yourself.  The resource is the URI - it does not carry it's 
namespace with it.

In Turtle, the prefix names are not restricted, but then there is not a 
requirement to split a URI ever anyway.

        Andy