RE: WSD WG requests to XML Schema WG

Funny you should mention this.  My paper from XML 2003 talks about
exactly to do this.

I also had a propsal along these lines recently [1].

Matthew

[1]
http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2003Oct/0086.html

> -----Original Message-----
> From: w3c-xml-schema-ig-request@w3.org [mailto:w3c-xml-schema-ig-
> request@w3.org] On Behalf Of Glen Daniels
> Sent: Sunday, February 22, 2004 11:49 AM
> To: David Orchard; Matthew Fuchs; w3c-xml-schema-ig@w3.org
> Cc: www-ws-desc@w3.org
> Subject: Re: WSD WG requests to XML Schema WG
> 
> 
> Hi folks!
> 
> David Orchard wrote:
> > If an older receiver gets the <name xsi:type="nameType2">, how does
it
> > know that nameType2 is an extension of nameType?  Is there some way
of
> > saying "because  the receiver knows about nameType1 and it gets an
> > element called name, it can ignore anything that is different
between
> > nameType1 and nameType2?
> 
> We had this same issue in a lot of the early SOAP encoding
conversations,
> and I remember talking through this in detail with Eric Prud'Hommeaux
back
> in 2000 in the context of object types and inheritance.  We came up
with a
> parentTypes="" (not sure what we called it tho) attribute which would
> allow
> self-describing inheritance hierarchies for compatible extension
types,
> though it never went beyond that into any of the WG's.
> 
> If you know the schema for <name>, I think it's OK to simply ignore
the
> xsi:type - assuming what you're receiving is still schema-valid with
> respect
> to the base type, it shouldn't matter if you don't understand the new
> type.
> 
> I believe .NET used to (or maybe still does) *always* ignore the
xsi:type
> attribute....
> 
> --Glen