[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: What is a namespace ... really?
David, My mind is still out on this topic. I've had a look at Microsoft's XML Schema stuff in IE5 b2 however, and currently when the namespace uri starts with "urn:" the namespace behaves as you desire. When the namespace uri begins with another prefix, the implication is that this points to a schema definition. I don't see a problem with this one-to-one relationship, after all, a namespace *is* defined by a uri, so... and I don't immediately see why this precludes inclusion of elemements from different namespaces. I think the idea is that if a namespace is defined by a uri, it may inherit a meaning associated with that uri, for example, suppose the uri was a .DTD, would this cause a problem or work any less well than a DTD which defines a default namespace and is specified in a <!DOCTYPE definition? Jonathan Borden > > > Borden, Jonathan writes: > > > This is the *current* state of affairs. There are people who also > > believe that in the future the namespace concept is to be extended > > to incorporate Schema definition. That is, when a namespace URN > > points to a Schema definition, the Schema may, can or will be > > enforced in the same way that a DTD is enforced by a validating > > parser and a <!DOCTYPE definition. > > Ack! No! Please don't hardcode a one-to-one relationship between > schemas and namespaces. > > A single schema could define structures using elements and attributes > from more than one namespace, and elements and attributes from a > single namespace can be used and structured in many different ways. > > SGML people handle this problem in a fairly clumsy way by using public > identifiers for indirection and then swapping entity catalogues at > different stages of production. We can do better if do what a > database designer does for many-to-many relationships: add separate > associations between the namespace and the schema. > > The alternative would be to rely on HTTP content negotiation to get > the kind of schema you want, and that is a pretty grim prospect > (especially for people with web sites hosted by large ISPs who really > aren't going to let them fiddle with the web server). > > > All the best, > > > David > > -- > David Megginson david@m... > http://www.megginson.com/ > > xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... > Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ > To (un)subscribe, mailto:majordomo@i... the following message; > (un)subscribe xml-dev > To subscribe to the digests, mailto:majordomo@i... the > following message; > subscribe xml-dev-digest > List coordinator, Henry Rzepa (mailto:rzepa@i...) > > xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
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