- From: Frank Manola <fmanola@acm.org>
- Date: Thu, 02 Oct 2003 10:28:08 -0400
- To: dennis.hamilton@acm.org
- Cc: www-rdf-comments@w3.org
Hi Dennis-- The use of internal DTD subsets in these Primer examples was merely to illustrate the use of entities as an abbreviation mechanism. It *wasn't* intended to suggest that ordinary XML validation should be applied to RDF/XML. RDF/XML requires that the XML be well-formed, but it doesn't require that the XML be valid, and ordinary RDF/XML parsers and validators don't use DTDs or XML Schemas to do XML validation on the RDF/XML (the Primer examples are valid RDF/XML according to the W3C RDF validator). Moreover, it's perfectly OK to use internal DTD subsets to define entities in XML you don't intend to validate (there's a well-formedness constraint in the XML spec that covers this situation) and, technically, RDF/XML *without* a document type declaration isn't valid, so it isn't exactly the introduction of an internal DTD subset that causes the RDF/XML to be invalid. It's been known for some time that the current grammar of RDF/XML isn't amenable to description in a DTD (or an XML Schema). Producing such a grammar was considered by the RDF Core WG, but it was decided that the changes would be so extensive as to be outside the current WG's charter. This has been added to the RDF Core postponed issues list at: http://www.w3.org/2000/03/rdf-tracking/#rdfms-validating-embedded-rdf We also received related Last Call comments on this subject labeled as xmlsch-10 and xmlsch-12, which can be found at http://www.w3.org/2001/sw/RDFCore/20030123-issues/ Do you feel this issue needs additional discussion (in the Primer or some other RDF spec)? --Frank Dennis E. Hamilton wrote: > I have been reading over the current RDF Primer Working Document, > > <http://www.w3.org/TR/2003/WD-rdf-primer-20030905/> > > And I notice that the introduction of internal DTD subsets to provide entity definitions (e.g., for &xsd;) results in the XML document being [DTD] invalid. > > The problem is that there are no markup declarations so not even the <rdf:RDF> root element is valid. > > First, unless you also want to suppose a mythical external DTD, as in > > <!DOCTYPE rdf:RDF SYSTEM "http://example.com/example.dtd" > [ <!ENTITY xsd "http://www.w3.org/2001/XMLSchema#"> ] > > > the example just doesn't work. > > Second, making a valid DTD for an RDF/XML document is an interesting challenge, so maybe one shouldn't even go down this road. *I* like the idea, but I tend to be anal about creating DTDs, even if it means I must maintain the RDF/XML and a unique DTD for it side-by-side. > > -- Dennis > > Dennis E. Hamilton > ------------------ > AIIM DMware Technical Coordinator > mailto:Dennis.Hamilton@acm.org | gsm:+1-206.779.9430 > http://DMware.info > ODMA Support: http://ODMA.info > OpenPGP public key fingerprint BFE5 EFB8 CB51 8781 5274 C056 D80D 0C3F A393 27EC > > > >
Received on Thursday, 2 October 2003 10:06:42 UTC