- From: Sean B. Palmer <sean@miscoranda.com>
- Date: Thu, 2 Nov 2006 19:52:36 +0000
- To: "Danny Ayers" <danny.ayers@gmail.com>
- Cc: "Dan Connolly" <connolly@w3.org>, public-grddl-wg <public-grddl-wg@w3.org>, www-archive@w3.org
> This may be ok, but as it stands steps outside the grddl-wg's remit > into TAG and (unchartered) RDF group's territory. Actually it doesn't. From a corollary of the definition of application/xml in RFC 3023, it can be demonstrated that someone publishing an RDF/XML document as application/xml is asserting the triples therein. The argument is that the following: [[[ An XML document labeled as text/xml or application/xml might contain namespace declarations, stylesheet-linking processing instructions (PIs), schema information, or other declarations that might be used to suggest how the document is to be processed. For example, a document might have the XHTML namespace and a reference to a CSS stylesheet. Such a document might be handled by applications that would use this information to dispatch the document for appropriate processing. ]]] - Section 3, http://www.ietf.org/rfc/rfc3023.txt Means that it is appropriate for a user agent to interpret an RDF/XML document served as application/xml as RDF based on the namespace of the root element. Since such a behaviour is allowed, it follows that an author/publisher of such a document must expect the triples therein to be taken as asserted; therefore they are asserted. See http://lists.w3.org/Archives/Public/public-grddl-comments/2006OctDec/0019 > Content-Type: application/xml > > <html xmlns="http://www.w3.org/1999/xhtml " > [...] > XHTML, RDF/XML or both? XHTML. > Keying off the root element narrows things down considerably, but > then RDF/XML doesn't mandate a specific root element. No, but this is an application/xml document. You must interpret it per the application/xml specification, which says that one may dispatch by following the namespace mechanism, whereby it is an XHTML document by root namespace dispatch. It doesn't say that you may use random heuristics; therefore it cannot be an RDF/XML document. You can think of this as being an analogy to rdfms-qnames-cant-represent-all-uris. The RDF syntax can't model all possible RDF graphs. Likewise, neither can application/xml be the carrier type for all possible syntactically valid application/xml documents. Unlike with the former problem, however, there is a workaround: just use application/rdf+xml! It could be argued that root namespace dispatch isn't documented as being the primary mechanism for namespace dispatch, but it seems common sense given that the root element encapsulates the entire rest of the document; moreover I would consider there to be overwhelming tool support for it, and consensus amongst specificationeers seems to be converging upon it. Cheers, -- Sean B. Palmer, http://inamidst.com/sbp/
Received on Thursday, 2 November 2006 19:53:07 UTC