[rdfweb-dev] XSLTs for FOAF, Spring v1.3.1 and plans for FOAF spec improvements

[James Carlyle]

Dan

<!--  FOAF is a mess circa 5/15/03. We did our best to smooth out the
differences.  -->
Sigh - people expect RDF to be standardised in the same way that XML
languages are.  Only the model and syntax are standardised.

> Re (iii), variation in the sense of their being different XML ways of
writing
> down the same RDF claims (triples) about the world. This is something
which
> RDF-based implementors barely encounter as a problem, but which can be
> frustrating for those using XSLT and XML-level tools. I would like to do
something
> to improve this situation.

>  - How about generic RDF-in-XSLT parsers? ie. tools that take any
RDF-in-XML
>   and output an XML representations of the triples that the document
encodes.
>
>   eg. http://www.w3.org/2001/12/rubyrdf/xsltrdf/ uses a 'two pass'
approach.
>   maybe that style would also help with normalising FOAF to a more
manageable
>   set of XML structures?
>
>   Also James Carlyle's RDF to NTriples XSLT parser,
>   http://www.semanticplanet.com/library/RdfToTriplesStylesheet
>   http://lists.w3.org/Archives/Public/www-rdf-interest/2003Apr/0010.html

I think that for publishers should not be constrained by the serialisation
format of their RDF in XML - if they are, then someone could start to argue
that FOAF might just as well be a plain XML language.  But at the same time
the flexibility and scope of the RDF XML serialisation syntax makes it very
hard to process RDF with XSLT, and every XSLT stylesheet author would need
to spend 10s of hours writing a stylesheet that can work with all forms of
RDF in XML.

I think Max Froumentin's two pass approach is a good one here.  If the
Spring people are looking for an XSLT processing solution for FOAF, then a
syntax-complete RDF XSLT stylesheet could be used to produce triples in XML
that Spring can consume.  Publishers would continue to use whatever valid
RDF XML statements they wish (within the bounds of correctness of the RDF
graph model) and Spring could work with a drop dead simple XML format for
the triples produced, to which they can apply simple stylesheets to pull out
the information they need.

>   ...these might help. But the Spring folks would still need to consume
the
>   RDF triples somehow. What lightweight tools are there for doing that?

Alternatively, I might be persuaded to modify the output of my RDF to
NTriples stylesheet to produce Spring format XML.

James Carlyle