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Re: FW: Requirement: Define Equivalence of WSDL Definitions

From: <ryman@ca.ibm.com>
Date: Thu, 25 Jul 2002 12:27:58 -0400
To: "John Colgrave" <colgrave@hursley.ibm.com>
Cc: www-ws-desc@w3.org, www-ws-desc-request@w3.org
Message-ID: <OF4AFF4998.2C52DC36-ON85256C01.00597DEC@torolab.ibm.com>

Yes, it it true that UDDI does not store WSDL. However, the Best Practices
http://www.uddi.org/pubs/wsdlbestpractices-V1.07-Open-20020521.pdf
prescribe a way to reconstruct the WSDL <service> element from information
stored in UDDI.

The development scenario is:
1. WSDL is created in two documents: one for <service> and one for
<binding>. The <service> document <import>s the <binding> document.
2. The <service> document is converted to UDDI info and stored in the UDDI
registry.
3. When a client discovers the service in UDDI, the <service> document is
recreated as WSDL.

In this scenario the WSDL <service> document is transformed. The
transformation must preserve the semantics so the WSDL spec should say when
two documents are equivalent wrt semantics.

Arthur Ryman,

phone: 905-413-3077, TL 969-3077
assistant: 905-413-2323, TL 969-2323
fax: 905-413-4920, TL 969-4920
intranet: http://w3.torolab.ibm.com/~ryman/


                                                                                                                                                    
                      "John Colgrave"                                                                                                               
                      <colgrave@hursley        To:       <www-ws-desc@w3.org>                                                                       
                      .ibm.com>                cc:                                                                                                  
                      Sent by:                 Subject:  FW: Requirement: Define Equivalence of WSDL Definitions                                    
                      www-ws-desc-reque                                                                                                             
                      st@w3.org                                                                                                                     
                                                                                                                                                    
                                                                                                                                                    
                      07/25/2002 04:22                                                                                                              
                      AM                                                                                                                            
                                                                                                                                                    
                                                                                                                                                    




A UDDI registry should not store/transform a WSDL document, it should
refer to a WSDL document stored elsewhere.

If you want two documents to produce the same digital signature then I
believe you would have to ensure that they had the same canonical form.
The UDDI Working Group did some work on canonicalization [1] as part of
the development of the UDDI V3 Specification but if you want the same
digital signature for portTypes that have the same operations in a
different order then that would require a much more "intrusive"
canonicalization algorithm.

[1] http://www.uddi.org/pubs/SchemaCentricCanonicalization-20020710.htm

Regards,

John
--
John Colgrave    Telephone/FAX : +44 (0)1962 816887
IBM              e-mail        : colgrave@uk.ibm.com

-----Original Message-----
From: www-ws-desc-request@w3.org [mailto:www-ws-desc-request@w3.org]On
Behalf Of Jeffrey Schlimmer
Sent: 25 July 2002 00:00
To: Arthur Ryman; W3C WS-Description
Subject: RE: Requirement: Define Equivalence of WSDL Definitions



+1. See R115 [1].

Each extension to WSDL would have to define its own equivalence, right?

An additional, compatible objective would be to define a canonical form.

--Jeff

[1]
http://dev.w3.org/cvsweb/~checkout~/2002/ws/desc/requirements/ws-desc-re
qs.html

-----Original Message-----
From: Arthur Ryman [mailto:arthur-ryman@rogers.com]
Sent: Wednesday, April 10, 2002 5:20 PM
To: W3C WS-Description
Subject: Requirement: Define Equivalence of WSDL Definitions



The WSDL specification should define what it means for two definitions
of a
part
of a service description to be equivalent. The notion of equivalence
must be
defined
for each definable element, e.g. service, binding, port, etc. For
example,
if two
definitions of a portType only differ in the order that the operations
are
listed in the
document, then they are equivalent.

This requirement is important since in some usage scenarios a WSDL
document
may undergo transformations, e.g. storage and retrieval in a UDDI
registry.
These
transformations must result in a transformed document that is equivalent
to
the
original document.

The defined notion of equivalence should be used as the basis for
digital
signatures
in the sense that two equivalent documents must be assigned the same
digital
signature.

-- Arthur Ryman
Received on Thursday, 25 July 2002 12:28:03 GMT

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