The describe servlet provides the DESCRIBE feature of a SPARQL Endpoint by returning a graph of triples about a named resource. It takes three parameters, the third being optional:
_resource is the URI of the resource you want described.
_format is the MIME type you are requesting for the returned triples, such as rdf%2Bxml or text%2Fturtle (in these examples, escaped for inclusion in a URL)
_base is the base URI of the model where the _resource URI is stored. If this is the same as the base URI of the _resource URI, then it is optional.
_withImports can be set to true if _base is also specified. It will expand the owl:imports of the query graph.
The following example URLs each retrieve a graph of triples about the Japan resource from the sample Geography model when running with the personal version of TopBraid EDG/Live included with TopBraid Composer. The first retrieves it as RDF/XML, and the second as Turtle.
http://localhost:8083/tbl/describe?_resource=http://topquadrant.com/ns/examples/geography%23Japan&_format=application%2Frdf%2Bxml&_base=urn:x-evn-master:geo http://localhost:8083/tbl/describe?_resource=http://topquadrant.com/ns/examples/geography%23Japan&_format=text%2Fturtle&_base=urn:x-evn-master:geo
Note that in TopBraid Live deployments, the TBL user permissions framework defines which named graphs can be accessed by the currently logged in user.