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Namespaces are dead.

From: Rick Jelliffe <ricko@allette.com.au>
Date: Sat, 5 Jun 1999 13:08:48 +1000
Message-ID: <005a01beaf00$c079c860$40f96d8c@NT.JELLIFFE.COM.AU>
To: <xml-dev@ic.ac.uk>
Cc: <www-xml-schema-comments@w3.org>
 Both BizTalk and the recent XML Schema draft use the namespace identifier as the schema identifier.

However, BizTalk says that people *must* use XML Data for their schemas. So BizTalk documents cannot use XML Schema documents, and vice versa, unless both XML Schema and BizTalk/XML-Data are considered selective transformations of some other document type which has the namespaces in some schema neutral format. 

In the absense of a schema invocation mechanism (e.g., a version of the style sheet PI for schemas) that seperates Namespace identifiers from particular schemas (and therefore allows multiple schemas), both XML Schemas and BizTalk/XML-Data capture your data to particular paradigms. For BizTalk this is marginally more understandable: BizTalk frames itself as a wrapper, but then doesn't allow any flexibility in the schema language for the body: in other words, if you use BizTalk, you have to use XML-Data.

This means that developers who require a degree of portability should maintain their documents using some schema-independent namespace, and only attach the namespace for a particular schema when the document is generated for a particular purposes. BizTalk could have allowed multiple schemas with XML-Data as the default; this would have allowed a lot of competition inside the wrapper/routing framework. But they didn't: is it a framework or a straightjacet?

In other words, namespaces are dead (for database documents) as ways of uniquely naming elements independent of any other considerations. They are now "name-in-a-particular-schema-in-a-particular-schema-language--spaces".

Congratulations to all concerned.

The practical question is now what to do? Should we just lay down and die; should we go back to architectural forms; should we invent a parallel namespace PI that is concerned with uniquely identifying names and not with tieing elements to a schema?  

The first thing that is required is for W3C to create a Schema PI, in a similar fashion to the Stylesheet PI. In the absense of that mechanism, the Devourers can excuse themselves that there is nothing else to use for invoking schemas apart from namespaces.

This is a matter of urgency and should take priority over all XML Schema activities, IMHO.


Rick Jelliffe
Received on Saturday, 5 June 1999 00:05:51 GMT

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