[xml-dev] schema versioning and RDDL

forwarded on from XML-DEV mailing list: an interesting idea for 
describing versions of a namespace in an external RDDL document. 

Paul


-----Original Message-----
From: Nikita Ogievetsky [mailto:nogievet@cogx.com]
Sent: 02 May 2004 23:51
To: xml-dev@lists.xml.org
Subject: [xml-dev] schema versioning and RDDL


Dear All,

I started to look at the applications of using namespace URI for schema
versioning [1], [2] and RDDL [3]; and was wondering if anybody can give
any thoughts (or had already given) to the pros and cons of this approach.

The idea is to use "#" separator for namespace versioning
(not "/" as proposed in the referenced resources), i.g:

<myObj xmlns="http://www.cogx.com/myObject#v1.0">
  <myProp1 value="x">
</myObj>
<myObj xmlns="http://www.cogx.com/myObject#v1.2">
  <myProp1 value="x">
  <myProp2 href="http://www. cogx.com">
</myObj>

Than an RDDL document at the http://www.cogx.com/myObject location can
contain the following RDDL resource elements
with ids "v1.0" and "v1.2" correspondingly:

<xhtml xmlns="http://www.w3.org/1999/xhtml"
      xmlns:xlink="http://www.w3.org/1999/xlink"
      xmlns:rddl="http://www.rddl.org/">
 <head>
 <title>RDDL Resources for myObject </title>
 </head>
 <body>
  <h1>RDDL Resources for myObject</h1>
  <p>
  Here we are describing myObject,
  How it came about,
  Its relationships to other objects,
  its history, details,
  and other related information
  that can be useful for modelers and developers.
  </p>
  ...
  <rddl:resource
   id="v1.0"
   xlink:href="http://www.cogx.com/myobject/myobject20040401.xsd"
   xlink:title="Version 1.0 of myObject schema, approved on April 1, 2004"
   xlink:role="http://www.w3.org/2000/10/XMLSchema"
   xlink:arcrole="http://www.rddl.org/purposes#schema-validation"
  >
  <rddl:resource
   id="v1.2"
   xlink:href="http://www.cogx.com/myobject/myobject20040421.xsd"
   xlink:title="Version 1.2 of myObject schema, approved on April 21, 2004"
   xlink:role="http://www.w3.org/2000/10/XMLSchema"
   xlink:arcrole="http://www.rddl.org/purposes#schema-validation"
  >
  ...
 </body>
</xhtml>

This way information about all versions of myObject can be collocated in one
RDDL document.

Does it make sense?
--Nikita

[1] http://lists.xml.org/archives/xml-dev/200103/msg00995.html
[2] http://www-106.ibm.com/developerworks/xml/library/x-tipnamsp.html
[3] http://www.rddl.org

Received on Tuesday, 4 May 2004 05:25:03 UTC