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Another way to go about it would be to have a special transformation to "namespace-normalize" the instance document. This version would be used for DTD Validation. The ns-normalized version could then be discarded, and the actual instance document presented to the user or application for further processing. Nobody has done this though, because it would require: 1. changes to existing validating parsers 2. consensus on how to write DTDs that would work with this process (compare DTDs for XML-Schema and XHTML for two different approaches). This kind of change would be much easier if XML Processing were a nice layered architecture. But it's not. -Wayne Steele >From: "Rick Jelliffe" <ricko@a...> >To: "The Deviants" <xml-dev@l...> >Subject: Re: life support for DTDs? was RE: >misprocessing namespaces) >Date: Fri, 1 Feb 2002 21:52:14 +1100 > > From: "Alan Kent" <ajk@m...> > > > At the risk of looking like a fool (having started reading the thread > > half way through), I don't quite understand the above. I would have > > thought you would have done something like (syntax is indicative only) > > > > <!XMLNS y "http://foo.bar/baz/"> > > <!XMLNS q "http://rumplestiltskin.com/"> > > <!ELEMENT y:x (y:a, q:a)> > > <!ELEMENT y:a (#PCDATA)> > > <!ELEMENT q:a (#PCDATA)> > > <!ATTLIST q:a age CDATA #IMPLIED > > q:type CDATA #FIXED "123"> > > > > The name spaces would be in scope for the DTD only (not instances). > > It would allow you to mix different namespaces in one DTD. There would > > be some scoping ssues to be resolved because you would want to import > > other DTDs and not accidentally collide on namespace prefixes > > (eg: DTD namespace declarations are local to the current external entity > > or something like that). > >Oh, the thread was asking "could we extend DTDs to include namespaces?" >and I was pointing out that we didn't need to change DTDs, just to >widen their interpretation. That way we don't have to change any parsers >or existing DTDs (except to add xmlns declarations for all elements) >or existing documents, just the validators used. Of course, >if you write a document that didn't use the literal names given in the DTD, >that document would not validate if the DTD was used with XML 1.0, but >that is no different from now. > >The approach of revising the DTD syntax for a special kind of schema >has been tried before, but failed to thrive. > >Cheers >Rick Jelliffe > > >----------------------------------------------------------------- >The xml-dev list is sponsored by XML.org <http://www.xml.org>, an >initiative of OASIS <http://www.oasis-open.org> > >The list archives are at http://lists.xml.org/archives/xml-dev/ > >To subscribe or unsubscribe from this list use the subscription >manager: <http://lists.xml.org/ob/adm.pl> > _________________________________________________________________ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx
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