Re: XML Schema implications of

Dear Mary, 
as I wrote you before in [1], we logged your earlier comments as issues
1 and 2 in the SAWSDL issues list [2]. Both were resolved by the group:

1) you requested that we add XML Schema component wording about adding
our properties {lifting schema mapping}, {lowering schema mapping} and
{model reference} to schema components. Such wording is now present in
section 4 of the editor's draft [3], for instance (from 4.1.1):

        In the XML Schema component model, a non-empty modelReference on
        a top-level simple type is represented as {model reference}
        property of the XML Schema Simple Type Definition Schema
        component; the case of an empty modelReference or no
        modelReference at all is represented with an XML Schema Simple
        Type Definition component that does not have a {model reference}
        property. {model reference} properties are propagated from a
        simple type definition schema component to all attribute and
        element declaration schema components that are defined with that
        simple type.

2) you ask why only global elements and types can be annotated with
lifting and lowering schema mappings. While the distinction between
global and local element declarations and type definitions is, indeed,
largely a matter of policy, it is only the global type definitions and
element declarations that can stand alone and be used to describe the
whole contents of a message, especially in WSDL. Our lifting and
lowering schema mappings must apply to the complete message, because
otherwise we would have to specify how the results of multiple mappings
are put together - this would be easy in RDF, but hard in XML. 

Of course the mappings themselves (for instance XSLT stylesheets) can
include other mappings for any internal structures as necessary,
therefore we do not feel that our restriction on the placement of
lifting and lower schema mapping annotations is practically limiting.

Hope these are satisfactory resolutions, please reply on whether you
agree, so we can record your consent or work to resolve whatever is
left. 8-)

Thank you for your comments,
Jacek Kopecky


On Mon, 2006-12-18 at 09:09 -0800, Mary Holstege wrote:
> The XML Schema WG was asked to review the above document.
> For various reasons the individuals tasked to this
> responsibility have been very remiss and for this
> we humbly beg your pardon.
> What follows has not been reviewed by the Schema WG as
> a whole, but in the interests of time, we thought it
> better to get it to you, even if it has a somewhat
> informal standing. So you should take this as a personal
> response, unless you hear otherwise:
> As you indicated in our call of a couple weeks ago,
> you do not use the XML Schema formal component model
> in the relevant sections.  Reference to the component
> model would be preferable, and may make the story
> cleaner in some respects. One aspect that would be
> cleared up is a crisp statement of which types and elements
> may be annotated in which ways. However, in the case of
> non-schema namespace attributes, the exposition with the
> transfer syntax is probably easier to grasp, so there
> is no particular objection to using it. We would like,
> however, for some kind of reference to the schema component
> model (perhaps something as simple as "or the corresponing
> schema component).
> It was unclear to me why only global elements (and types)
> could be annotated with lifting and lowering schema mappings.
> The distinction of global versus local elements is
> largely a matter of internal schema construction
> policy so it seems unwise to force particular policies of
> schema writing.
> Cheers
> //Mary Holstege

Received on Tuesday, 29 May 2007 13:10:36 UTC