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Re: using namespaces to version
- From: Jonathan Borden <firstname.lastname@example.org>
- To: Paul Spencer <email@example.com>,Tony Coates <Tony.Coates@reuters.com>, Xml-Dev <firstname.lastname@example.org>
- Date: Thu, 03 May 2001 10:21:26 -0400
Paul Spencer wrote:
> But now RDDL comes along and gives us something for the namespace to point
> to. This could result in a need to version namespaces so that we can point
> to different RDDL documents. But if we do this, what happens (as David
> Carlisle mentioned) to processing code that uses fully-qualified names
> as code that uses XPath expressions)? I'm just starting to think about
> for UK Govt.
I think the reasons whether or not to change a namespace URI (i.e. create a
new namespace) when new versions of something come out have been well
addressed. Generally I agree that changes in a namespace vocabulary which
_are not_ backward compatible should be accompanied by a new namespace,
whereas version changes that _are_ backward compatible should use the same
namespace (in order to allow software to continue to recognize the
documents). These are all important design decisions.
RDDL does provide a mechanism to tie versioning of namespace related
schemata to the namespace. One can embed multiple rddl:resources with
natures and purposes that indicate prior versions of the same type of
resource (e.g. XML Schema).
Similarly a RDDL resource might indicate a related namespace URI, perhaps
purpose="http://www.rddl.org/purposes#prior-version" would indicate a prior
version of a RDDL document/namespace URI , whereas the purpose
http://www.rddl.org/purposes#prior-version with a nature
http://www.w3.org/2001/XMLSchema would indicate a prior version of an XML
Schema in the same namespace.
Does this make sense?