- From: Graham Klyne <GK@ninebynine.org>
- Date: Tue, 01 Jul 2003 15:41:45 +0100
- To: www-archive <www-archive@w3.org>
[Copy of message sent to Martin Duerst] Martin, Sure, but this starts to look like "overloading" to me. I think these are exactly two cases that might be best handled separately. The trouble with recommending namespace declaration sis that they apply *only* for properties. rdf:ID, rdf:about and rdf:resource don't recognize qname syntax (much as we might wish they did ... RDFcore slightly considered this and decided it was out-of-charter). #g -- At 15:03 30/06/03 -0400, you wrote: >I think I didn't give my whole story. I think what I said >below applies one specific use of base, which is quite >usual for HTML, but not for other uses. > >Basically HTML <base> or xml:base can be used for two purposes: > >1) To indicate the actual base URI of the current document. > This is helpful in certain mirroring situations, in off-line > editing/processing, and so on. >2) To indicate any kind of base to shorten URIs, completely > independent of the original location of the current document. > >In HTML, because there is only one <base>, usage 1) is often >predominant. But there are exceptions. For example I have used ><base> on a page with test links to the RDF validator >(see http://www.w3.org/2002/08/rdf-i18n-tests/). In that case, ><base> came in very handy to shorten the URIs, and even more >handy because it easily allowed to switch between a test instance >of the validator and the production instance without having to >change dozens of links. > >For xml:base, the situation may be a bit different because >xml:base can be used repeatedly in an XML document. Also, we >have to take into account the (somewhat arbitrary) definition >of how xml:base interacts with external entities. > >Both HTML and RDF mainly look at 1) when defining how they >want to behave fragments that refer to the current document. >And the two things they want to do, namely a) knowing what the >current document's original address was (RDF) and b) making >sure that there is no unnecessary retrieval operations (HTML) >are not in conflict as long as we are dealing with 1). > >My guess is also that 2) is not really used with same-document >references. Definitely in my testing example, it wouldn't make >sense. Probably RDF could explicitly discourage the use of >xml:base for shortening URIs by recommending that suitable >namespace declarations can be used. > >Regards, Martin. ------------------- Graham Klyne <GK@NineByNine.org> PGP: 0FAA 69FF C083 000B A2E9 A131 01B9 1C7A DBCA CB5E
Received on Tuesday, 1 July 2003 12:02:18 UTC