Writing a URI Resolver for Collections
Saxon also allows you to write a CollectionURIResolver, which handles URIs
describing collections, particularly the argument to the collection() function. The
CollectionURIResolver is called either with the specfied URI or a null URI
in the zero-argument form, when resolving the result of this function and is is expected
to return a sequence of nodes.
A resolver may be registered using the setCollectionResolver() method on the
Configuration object,
or (in XSLT) using setAttribute() on the
TransformerFactory. The CollectionURIResolver may also be
nominated using the -cr option on the command line.