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>-----Message d'origine----- >De : Simon St.Laurent [mailto:simonstl@s...] >Envoyé : vendredi 18 janvier 2002 18:28 >À : Nicolas LEHUEN >Objet : RE: RDDL (was RE: Negotiate Out The Noise) > > >On Fri, 2002-01-18 at 11:09, Nicolas LEHUEN wrote: >> A document type cannot be guessed from the list of >namespaces it uses. > >I don't really believe in such things as document types - though I >suppose you're correct that a mere list of namespaces is inadequate if >you really want to nail down precisely what type of document it might >be, since the list doesn't define the possible interactions. Only the >document itself really does that... Well, DOCTYPE has always proven useful until now, but it only points to DTDs. So why drop the idea ? Pointing to a catalog of meta-data files (DTDs, schemas, human-readable documentation, etc.) would be very useful... >> There >> should be a way to bind a document to a series of meta-data >resources, and >> that's what I thought RDDL should be. > >I gave that a go once with XPDL: >http://www.simonstl.com/projects/xpdl/ Thanks for the pointer. I'll have a look at it right now. >There's also the XHTML meta tag and its cousins if you want to go that >route. I don't want to go the XHTML route, but the XML route. I'd like an equivalent of the DOCTYPE, but more opened. I don't want to answer the riddle 'what is at the end of a namespace URL', I just want a useful tool. >> But it is not, it is only a way to >> bind resources to a given namespace. If I followed your >logic, to validate a >> RDDL document using RDDL, I would load the RDDL for the >XHTML, RDDL and >> XLink namespaces. Now I don't have one, but three resources >directories in >> which I'm supposed to find a DTD. Great, I've got three : >the DTD for XHTML, >> the DTD for RDDL, and the DTD for XLink. How do I make my >computer select >> the good one, i.e. the RDDL DTD, instead of the two other >(and especially >> the XHTML one, since the root element html > >That's not a problem of RDDL - that's a general validation issue. >Schema mathematics (except for RELAX NG) are currently wretched. I'd >like to see RDDL files contain modules which only describe their >particular namespace, not the entire concoction. Using those is >currently difficult, however, so we're stuck with what we've got. > >Incremental progress, not the perfect solution you appear to >be seeking. > >> xmlns="xmlns="http://www.w3.org/1999/xhtml" is found in both >XHTML and RDDL >> ?). > >Yep. That's the current sad state of the schema art. It's just because a schema is in no way associated to a namespace. Just think of namespaces as the first half of a QName : a schema is just a set of constraints on where and when some QName can/have to appear in an XML document. Namespaces do not imply any particular schema, and vice-versa. If you see it this way, schemas aren't so wretched after all. We just have to lower the impression namespace can make on us. >> You bet it will ! As soon as someone will try to use RDDL for RDDL, >> XHTML+SVG, XHTML+MathML, people will begin to discover that >a namespace is >> not a document type, and that mixing different namespaces in the same >> document create new document types, different from each >original 'default >> document types' possibly associated to the namespace. From >there, they will >> throw out RDDL and try to think seriously about the problem. > >Nah. Maybe they'll get rid of their expectations about schemas and/or >the whole fuzzy notion of document types instead. > >It sounds like you want a complete solution. I don't think there are >any complete solutions in XML, just a box of parts. Change your >expectations, and you might be a lot happier. I think you're a bit pessimistic here. DOCTYPE does work. Why not keep the idea and point to a catalog of meta-data resources, each identified by a different role/purpose/language ? This does not seem unfeasable. Regards, Nicolas >-- >Simon St.Laurent >Ring around the content, a pocket full of brackets >Errors, errors, all fall down! >http://simonstl.com
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