RE: New Issue: Support of evolution of messages described in Schema 1.0

Tracked as LC124 [1], the WG decided to close this issue with no action.
If you would like us to raise this issue during the CR call with the
Director, please let us know within two weeks.


> -----Original Message-----
> From: []
> On Behalf Of
> Sent: Thursday, April 14, 2005 4:07 PM
> To:
> Subject: New Issue: Support of evolution of messages described in
> Schema 1.0
> Following our decision to retire Jonathan's issue to get a joint task
> force with the XML Schema WG, I took an action item to propose a new
> issue for extensibility/versioning for wsdl using schema 1.0 [1]:
> Issue: Support for evolution of messages described in Schema 1.0
> Description:
> The XML Schema Working Group is currently collecting use cases for
> versioning [2] and are likely to provide support for more 'open
> content'
> in Schema 1.1. This direction is supported by members of the WSD WG
> who would like WSDLs using Schema 1.0 to be able to describe message
> contents which may compatibly evolve within a given namespace.
> Describing messages with more open content in Schema 1.0, whilst
> possible, is an unnatural and difficult enough activity to be the
> subject
> of numerous articles and conference papers, some written by members
> of this WG, offering techniques for publishers to provide
> extensibility
> points in schemas. An author has to know in advance where content
> will be added in the future; it's not possible to evolve schemas
> published by a third party, unless they have provided such
> extensibility
> points.
> Abstract Proposal:
> WSDL could define how a type description relates to a message, either
> specifically for schema 1.0 or through a "schemaProcessingStyle"
> property.
> That is a WSDL could describe how a schema processor should be
> employed
> when building or parsing messages. An example of such a processing
> style is a technique demonstrated by Henry Thompson [3] whereby the
> PSVI from a first pass validation of a message is processed to remove
> unexpected content from a message before validating the message again,
> thereby enabling more open message content.
> Paul
> [1]
> 20050331-ws-desc-minutes.html#action01
> [2]
> [3] Henry Thompson, XML2004 "Versioning made easy with W3C Schema":
> slides:

Received on Monday, 25 July 2005 14:44:52 UTC