Re: How to Version XML Applications

** Reply to message from Tim Bray <> on Wed, 11 Sep 2002
07:44:36 -0700

> I also am generally dubious about using namespaces to version, to the 
> extent that it might be worth considering an architectural principle 
> that this is a bad idea.

The problem is, how do you avoid using namespaces for versioning?  This is a
real problem that a great many people have, and need guidance on (ideally from
the W3C).  CMSMQ argues that HTML already has set the policy, by have 3 versions
in the one namespace.  So the namespace is not versioned, the schema is.
However, W3C XML Schemas only "hint" at schema locations, and so the only
positive piece of identifying information that you have is the namespace URI.
If that isn't versioned, how to you tell which version is being referred to?  I'm
yet to invent or read a solution that I find sufficiently robust and convincing.

Anthony B. Coates, Information & Software Architect
MDDL Editor (Market Data Definition Language)

Received on Wednesday, 11 September 2002 15:43:00 UTC