WSDL 2.0 LC Comments, specifically LC issue 76d

Jonathan, 

 

In [1], you expressed concern with the wsoap:mustUnderstand attribute by
saying

"However, we
don't see the utility of the mustUnderstand attribute.  Why would you
put the header in the WSDL if the service didn't understand it?  Please
explain or remove this attribute."

 

The working group decided to keep the wsoap:mustUnderstand attribute but
not create a primer example.

 

A primary motivation for soap:mustUnderstand is to enable a client to
ensure that a service understands a soap header block that the client
sends.  Imagine that an interface is controlled by a 3rd party such as a
travel consortium.  The travel consortia decides to make an element a
soap header block rather than part of the body, perhaps on the initial
version or a subsequent version.  There are a variety of reasons for
this, such as they do not control the schema for the body or even the
interface itself.   The WSDL 2.0 author thus wants to fully specify the
contract between the client and server, which includes mandating
soap:mustUnderstand.   A 3rd party specifying the header block, such as
most Web services specficaitons, is another example of an interface
description language that specifies that the mustUnderstand flag is set
to true.  Whereas a WS-* specification can specify via a Policy
statement attached in WSDL how soap headers are used and any mU
attributes, WSDL 2.0 provides the wsoap:header functionality for WSDL
2.0 authors and for completeness reasons this includes
wsoap:mustUnderstand.  

 

We hope that you find this rationale sufficient.  Please let as know as
soon as possible if you continue to disagree.  

 

Cheers,

Dave Orchard for the WSDL 2.0 WG.

 

[1]
http://lists.w3.org/Archives/Public/public-ws-desc-comments/2005May/0091
.html