[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

RE: What is a namespace ... really?

• From: <david@m...>
• To: "XML Developers' List" <xml-dev@i...>
• Date: Fri, 15 Jan 1999 10:09:22 -0500 (EST)

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...)

• Follow-Ups:
  • RE: What is a namespace ... really?
    • From: "Borden, Jonathan" <jborden@m...>
  • RE: What is a namespace ... really?
    • From: "Borden, Jonathan" <jborden@m...>

• References:
  • re: What is a namespace ... really?
    • From: <david@m...>
  • RE: What is a namespace ... really?
    • From: "Borden, Jonathan" <jborden@m...>

• Prev by Date: Re: What is a namespace ... really?
• Next by Date: Re: XML media types revisited
• Previous by thread: RE: What is a namespace ... really?
• Next by thread: RE: What is a namespace ... really?
• Index(es):
  • Date
  • Thread