- From: Arnold deVos <adv@langdale.com.au>
- Date: Tue, 13 Feb 2001 12:44:03 +1100
- To: "David Megginson" <david@megginson.com>, <www-rdf-interest@w3.org>, <xmlschema-dev@w3.org>
I forgot to say: this hack does not actually make the extname<->URI-ref mapping reversible. The hack is to treat namespaces http://mydomain/mynamespace and http://mydomain/mynamespace# as identical. Thus its not possible to reconstruct the precise, original namespace from the URI-ref. Further to the hack: when declaring a namespace in RDF document we add the trailing '#', for other XML documents we leave it off. This is mostly interoperable, but unless everyone else followed the same convention, its not reliable. I said it was a hack didn't I? To do better would require the RDF spec to be changed, I think. - Arnold ----- Original Message ----- From: Arnold deVos <adv@langdale.com.au> To: David Megginson <david@megginson.com>; <www-rdf-interest@w3.org>; <xmlschema-dev@w3.org> Sent: Tuesday, February 13, 2001 8:39 AM Subject: Simple extname<->URI-ref hack > > From: "David Megginson" <david@megginson.com> > > [...] under the current state of the RDF-Syntax > > spec, it is not possible to write robust, interoperable software > > because of the concatenation of the Namespace URI with the local name > > -- this is a pragmatic engineering problem, not an abstract one. > > Yes - surely this is the key point. As David wrote earlier, the RDF way of > creating a URI-reference from an XML extended name is not reversible. > > As a workaround we use this simple hack: before concatenating the > namespace and local name we add a trailing '#' to the namespace iff the > namespace does not alreasy have a trailing '#' . This ensures that the > generated URI-reference always has a fragment part and the local name can be > recovered. > > OK its not perfect and its not per the RDF spec. But it works the same way > as RDF for typical RDF namespaces (with trailing '#') and it makes other > namespaces work also. > > Regards, > Arnold
Received on Monday, 12 February 2001 20:45:37 UTC