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Re: RDF/XML Syntax Working Draft 2002-11-08 Published

From: Dave Beckett <dave.beckett@bristol.ac.uk>
Date: Wed, 13 Nov 2002 14:51:01 +0000
To: www-rdf-interest@w3.org
Message-ID: <10525.1037199061@hoth.ilrt.bris.ac.uk>


I thought I'd say a little more behind the changes.

>>>Dave Beckett said:
>   RDF/XML Syntax Specification (Revised)
>   W3C Working Draft 8 November 2002
>   http://www.w3.org/TR/2002/WD-rdf-syntax-grammar-20021108/
> 
> The main changes from the previous 25 March 2002 draft are as
> follows:
> 
>   Section 2 "An XML syntax for RDF" expanded with many more examples.

We got feedback that people didn't understand RDF/XML, and the way it
works.  This is an attempt to explain the many forms of abbreviation
with examples.  We don't suggest you use all of them.  One suggestion
was that we describe a simple profile that you can stick to if you
don't care.

This is similar to the approach Adobe did with their use of RDF/XML
in XMP, which has been described as RDF/XML-7 - they don't use 7
forms of the abbreviation

>   -- in particular we ask for feedback on this section since it has a
>      lot of new words and examples.

This is important.  We need to know if this section helps.

>   RDF typed literals added using a new rdf:datatype attribute.
>   -- so you can mark literals as being of type  XSD integer, for example.

This is explained more in the RDF Concepts and Abstract Syntax
working draft at http://www.w3.org/TR/rdf-concepts/#dfn-typed-literal

>   rdf:nodeID attribute added to allow referencing of blank nodes.
>   -- this makes going from RDF graphs to RDF/XML a lot easier

I should have said, and going the other way too.  This makes
serializing an RDF graph much more straighforward.  The main
caveat is property URI-references that can't be written as XML Qnames.
More at http://www.w3.org/TR/rdf-syntax-grammar/#section-Serialising

>   rdf:parseType="Collection" added for collections of nodes.
>   -- modelled after daml:Collection, generating a lisp-like triple
>      structure of rdf:first, rdf:rest, rdf:nil.

The Web Ontology Working Group and others asked for this.  It
hopefully will makes things easier for OWL and in general,
inferencing over or describing such structures in triples.

>   Some non-namespaced attributes were returned to the grammar:
>      ID, bagID, about, resource, parseType or type
>   -- this makes a lot of existing RDF/XML work without warnings.

Apart from other existing forms, In particular we wanted to ensure
that the Adobe XMP profile of RDF/XML and that used in Mozilla
remained valid.

These syntax changes are already being implemented in parsers for
several languages, and I'm expecting these to be getting pretty
completely done shortly.

Dave
Received on Wednesday, 13 November 2002 09:55:25 GMT

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