- From: Graham Klyne <Graham.Klyne@Baltimore.com>
- Date: Fri, 15 Jun 2001 14:50:44 +0100
- To: Dan Brickley <danbri@w3.org>
- Cc: rdf core <w3c-rdfcore-wg@w3.org>
I note that one of the options for 5.1.2 is "None". The transfer protocol *might* supply a value, but then again it might not. Maybe we might say that a relative URI is meaningful only if there *is* a URI (per 5.1.1-5.1.4) relative to which it can be evaluated? #g At 07:45 AM 6/15/01 -0400, Dan Brickley wrote: >On Fri, 15 Jun 2001, Graham Klyne wrote: > > > At 02:29 AM 6/15/01 -0500, Dan Connolly wrote: > > > > RDF absolutely has to make sense even outside the context of > > > > an enclosing document which can be given a uri. so ... > > > > > >So... what? That doesn't make any sense to me. > > > > > >An RDF document is an XML document. Each XML document > > >has a base URI (cf the infoset spec). > > > > If this is true, then it is not possible to transfer RDF data in transient > > protocol elements. > > > > Which means that (say) the CC/PP spec, formulated *by design* as a *format* > > only for client capability data, cannot be regarded as a valid RDF > application. > >Can't we just say that it picks up the base URI from (broadly conceived) >surrounding context? It remains true that each XML document has a base >URI. How we determine that base is the only issue here. > > >RFC2396 is pretty clear on this. See: >http://www.faqs.org/rfcs/rfc2396.html section 5.1: establishing a base URI > >Both XML Protocol and CC/PP use seems to fall under 5.1.2, 'base URI of >the encapsulating entity'. XML:base, by contrast, looks to fall under >'base URI embedded in document's content'. > >[[ >5.1. Establishing a Base URI > The term "relative URI" implies that there exists some absolute "base > URI" against which the relative reference is applied. Indeed, the > base URI is necessary to define the semantics of any relative URI > reference; without it, a relative reference is meaningless. In order > for relative URI to be usable within a document, the base URI of that > document must be known to the parser. > The base URI of a document can be established in one of four ways, > listed below in order of precedence. The order of precedence can be > thought of in terms of layers, where the innermost defined base URI > has the highest precedence. This can be visualized graphically as: > .----------------------------------------------------------. > | .----------------------------------------------------. | > | | .----------------------------------------------. | | > | | | .----------------------------------------. | | | > | | | | .----------------------------------. | | | | > | | | | | <relative_reference> | | | | | > | | | | `----------------------------------' | | | | > | | | | (5.1.1) Base URI embedded in the | | | | > | | | | document's content | | | | > | | | `----------------------------------------' | | | > | | | (5.1.2) Base URI of the encapsulating entity | | | > | | | (message, document, or none). | | | > | | `----------------------------------------------' | | > | | (5.1.3) URI used to retrieve the entity | | > | `----------------------------------------------------' | > | (5.1.4) Default Base URI is application-dependent | > `----------------------------------------------------------' >[...] > >]] > >Dan ------------------------------------------------------------ Graham Klyne Baltimore Technologies Strategic Research Content Security Group <Graham.Klyne@Baltimore.com> <http://www.mimesweeper.com> <http://www.baltimore.com> ------------------------------------------------------------
Received on Friday, 15 June 2001 09:58:31 UTC