W3C home > Mailing lists > Public > www-ws-desc@w3.org > September 2002

RE: Rationale for Dropping the <soap:body use=...> Attribute

From: Anne Thomas Manes <anne@manes.net>
Date: Thu, 19 Sep 2002 09:30:40 -0400
To: "Jacek Kopecky" <jacek@systinet.com>, <ryman@ca.ibm.com>
Cc: "WS Description WG" <www-ws-desc@w3.org>
Message-ID: <ECEDLFLFGIEENIPIEJJPCEAPCHAA.anne@manes.net>

One more point:

WS-I has chosen to not include Encoded in the Basic profile. That isn't
quite the same thing as saying that they have made the recommendation to use
only Literal. This was a hefty topic of debate, and one of the primary
reasons why they decided not to include Encoded was to reduce the scope of
the Basic profile.

Anne

> -----Original Message-----
> From: www-ws-desc-request@w3.org [mailto:www-ws-desc-request@w3.org]On
> Behalf Of Jacek Kopecky
> Sent: Thursday, September 19, 2002 8:07 AM
> To: ryman@ca.ibm.com
> Cc: WS Description WG
> Subject: Re: Rationale for Dropping the <soap:body use=...> Attribute
>
>
>
>  Arthur,
>  just two points:
>
>  1. By constraining oneself to XML Schema as the abstract type system,
> one constrains oneself to the tree data model inherent in XML Schema,
> other data models being out of reach (describing other data models in
> XML Schema is at best a kludge). For example - what if I want to
> transfer some specific RDF data in a service? How do I describe the
> service using only XML Schema?
>  It is true that the real representation need not be XML, but this is an
> orthogonal topic.
>
>  2. WS-I doesn't seem to support SOAP Encoding in their activities, and
> if I understand you correctly, they are in fact creating their own graph
> encoding. It is understandable for them, but I don't think it is
> possible for WSDL 1.2 not to support SOAP Encoding properly, since SOAP
> Encoding is part of SOAP 1.2 - the product of a peer W3C Working Group -
> and the WS-Desc WG has sent no comments against SOAP Encoding in the
> Last Call phase.
>
>                    Jacek Kopecky
>
>                    Senior Architect, Systinet Corporation
>                    http://www.systinet.com/
>
>
>
> On Wed, 2002-09-18 at 19:35, ryman@ca.ibm.com wrote:
> >
> > Jacek,
> >
> > I think it's useful to seperate the discussion into two parts:
> >
> > 1) abstract (binding neutral) definition of messages in WSDL
> > 2) format of messages in the SOAP binding
> >
> > Concerning 1) I am in favour of just using XML schema. In fact, there is
> > also discussion that the <message> element be removed and that
> messages be
> > directly defined using schema, i.e. without <part>s. Allowing different
> > schema languages is a step in the opposite direction.
> >
> > Concerning 2) the WS-I.org recommendation is to just use literal. Also,
> > WS-I.org is working on an algorithm to encode graphs in a way
> that can be
> > described using a literal schema. So if the concrete message
> format is XML,
> > then I see little benefit in allowing the concrete schema to be
> different
> > than the abstract schema. However, there are important cases where the
> > concrete message format is not XML. For example, in HTTP GET the input
> > parameters are url encoded. (e.g. the input gets encoded as
> symbol=IBM and
> > not as <symbol>IBM</symbol>). Also, if the message includes binary
> > resources, then we can describe them abstractly as some restriction of
> > xsd:hexBinary, but the concrete message format could be a MIME
> type such as
> > image/jpeg using SOAP with attachments.
> >
> > To summarize:
> > - First, we should view the message definition as abstract and use XML
> > Schema as the abstract data type language. This establishes a proper
> > layering in WSDL by isolating the message definition from the bindings.
> > -Second, we should define the concrete message format in the binding.
> > -Third, evidence from WS-I.org tells us that for the SOAP
> binding, we can
> > live with literal only for concrete XML messages.
> > -Fourth, using literal only doesn't mean that the abstract message
> > definition is always concrete since there are other important non-XML
> > formats such as url encoding and MIME.
> >
> > Arthur Ryman
> >
> >
> >
>
>
> >                       Jacek Kopecky
>
>
> >                       <jacek@systinet.c        To:       Arthur
> Ryman/Toronto/IBM@IBMCA
>
> >                       om>                      cc:       WS
> Description WG <www-ws-desc@w3.org>
>
> >                                                Subject:  Re:
> Rationale for Dropping the <soap:body use=...> Attribute
>
> >                       09/18/2002 12:11
>
>
> >                       PM
>
>
> >
>
>
> >
>
>
> >
> >
> >
> >  Arhur,
> >  if you want an abstract schema at the wsdl:message level, that's OK
> > with me and it's understandable. On the other hand, if you want to
> > remove the use attribute by saying that "literal XML Schema" is the only
> > possible way in SOAP, I disagree because that either results in ugly
> > *and* ambiguous data structure schemata or in disallowing other data
> > models altogether (with SOAP Data Model among them).
> >  I think that especially because the parts of wsdl:message should be
> > described abstractly, we may need different data models right here,
> > otherwise we'll say that, abstractly, WSDL only describes services that
> > can transfer trees with very raw untyped references.
> >  So, either let's keep use="encoded" or let's allow different schema
> > languages (other than XML Schema), and I prefer the latter because it
> > agrees with the requirement "abstract description of wsdl:message
> > parts".
> >  Best regards,
> >
> >                    Jacek Kopecky
> >
> >                    Senior Architect, Systinet Corporation
> >                    http://www.systinet.com/
> >
> >
> >
> >
>
>
Received on Thursday, 19 September 2002 09:30:10 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:58:21 GMT