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RE: Examples of substitution group extending WSDL.

From: Jonathan Marsh <jmarsh@microsoft.com>
Date: Tue, 1 Jul 2003 15:24:10 -0700
Message-ID: <DF1BAFBC28DF694A823C9A8400E71EA2441685@RED-MSG-30.redmond.corp.microsoft.com>
To: "Dale Moberg" <dmoberg@cyclonecommerce.com>, "Roberto Chinnici" <Roberto.Chinnici@Sun.COM>
Cc: <www-ws-desc@w3.org>

A wrapper, while largely aesthetic, represents specific knowledge of how
WSDL and the extension work together.  In general I prefer to allow
direct embedding to avoid a combinatorial explosion of special-case
interactions between vocabularies.  If I have a process that takes XML
and inserts a digital signature, why should that process have to treat
WSDL as a special case?

It is aesthetically offensive to add a wrapper if it's only an artifact
of the schema language we're considering.  It limits the power of the
language (in this case XML) to fit the failings of the description (in
this case schema) language.

> -----Original Message-----
> From: Dale Moberg [mailto:dmoberg@cyclonecommerce.com]
> Sent: Friday, June 27, 2003 6:20 AM
> To: Roberto Chinnici; Jonathan Marsh
> Cc: www-ws-desc@w3.org
> Subject: RE: Examples of substitution group extending WSDL.
>  Roberto Chinnici wrote
> >Jonathan Marsh wrote:
> >> Results of my tinkering
> >> Then I attempted the holy grail, a simple wrapper schema that would
> >> have the effect of the schema above, while importing the DSig
> >> without modification.  I failed in this because:
> >> - Element declarations in an imported schema cannot be overridden.
> >> - Redefine does not work on element declarations.
> >> - There is no other way to add elements to a substitution group.
> >This is bad news.
> >> I rejected modifications to the instance document that would enable
> >> wrapper schema:
> >> - Changing the namespace of the top level element.
> >> - Introducing a wrapper element.
> >
> >Given the issue with xsi:schemaLocation described earlier, I find the
> >wrapper solution more acceptable than the one above, no matter how
> >unaesthetical and inconvenient.
> I also don't sense that there is a lot of inconvenience in using a
> "wrapper" element;
> I would expect to find new tags for elements that are introduced with
> reference
> to a substitution group head element. {Maybe I have low expectations
> when it comes to
>  using schema tips and tricks, though.)
> And, my aesthetic sense favors having these new wrapper element in a
> distinct namespace
> (in terms of the example, neither in wsdl12 or DSIG namespace) that
> packages up the extension(s).
> Is there something other than aesthetics or a Ockhamistic fetish
> at work in disparaging the lowly wrapper element?
> Are we going to start littering the schema with "any*" constructs
> instead?
Received on Tuesday, 1 July 2003 18:24:21 UTC

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