Just a quick status update...
I've just been working on an XSLT issue. I already had an xml:base
resolver for Atom/RDF implemented in XSLT 1.0, but it didn't quite
work with GRDDL because it expected you to pass in a baseURI parameter
of the source document, which GRDDL won't do. I've just made some
changes to the XSLT function so that the resolveRef function can
operate in two modes:
If you pass returnRef=false to the function, it behaves as before and
expects an absolute baseURI, and outputs a resolved URI;
However, if you pass returnRef=true, it allows a relative base to be
used, and outputs a relative URI reference. If run this way it
actually outputs fairly scrappy-looking URI-refs with unmerged dot and
dotdot segments, but that shouldn't matter as the RDF/XML parser that
processes the GRDDL, will automatically resolve those against the
base-URI of the source document to get back to URIs.
I'll post it on the web soon, and update Atom/RDF to call the function
with the apropriate parameters.