rdf, xmp

[Andy Dingley]

Imbaud Pierre wrote:
> I have to add access to some XMP data to an existing python
> application.
> XMP is built on RDF, RDF is built on XML.

RDF is _NOT_  built on top of XML. Thinking that it is causes a lot of
trouble in the architecture of big RDF projects. RDF is a data model,
not a serialisation. The data model is also a graph (more than XML can
cope with) and can span multiple documents. It's only RDF/XML that's
the serialisation of RDF into XML and good architectures start from
thinking about the RDF data model, not this RDF/XML serialisation.

As to RDF handling, then the usual toolset is Jena (in Java) and
Redland has a Python binding although Redland is fairly aged now.

I'm unfamiliar with XMP and won't have a chance to look at it until
Monday. However if XMP is strongly "XML like" despite claiming to be
RDF, then you might find that handling a pure XMP problem is quite
easily done with XML tools.

Famously RDF/XML is unprocessable with XSLT if it's sophisticated, but
quite easy if it's restricted to only a simple XML-like RDF model. XMP
could well be similar.