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RE: soap:header extensibility with mU primer example

From: <paul.downey@bt.com>
Date: Thu, 14 Jul 2005 08:37:48 +0100
Message-ID: <2B7789AAED12954AAD214AEAC13ACCEF2709E4D2@i2km02-ukbr.domain1.systemhost.net>
To: <dorchard@bea.com>, <www-ws-desc@w3.org>

Maybe another use-case for describing soap:mustUnderstand on header
would be so the publisher of a WSDL, possibly a consortium or virtual company,
can ensure all of the endpoints that purport to provide the service, 
are aware of the importance of the additional header, which otherwise could
be legitimately ignored under SOAP processing model.

I personally, see little harm or cost in continuing to enable WSDL to describe 
an application header as being mustUnderstand, even if the use-cases, such
as these ones, aren't totally compelling.



-----Original Message-----
From:	www-ws-desc-request@w3.org on behalf of David Orchard
Sent:	Tue 7/12/2005 11:48 PM
To:	www-ws-desc@w3.org
Cc:	
Subject:	soap:header extensibility with mU primer example

A proposed section for the Primer if people accept the example and
motivation.

 

Additional 5.2.5.4.  Additional mandatory elements in header.

 

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 the reservation interface is controlled by a 3rd
party such as a travel consortium.  The travel consortia decides to make
the NumberOfGuests 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.  The extension could be handled in a well
factored design at the service by a specialized piece of software.   A
3rd party specifying the header blocks is why Web Service specifications
will often require that the mustUnderstand flag is set to true. 

 

The binding using mustUnderstand is:

 

<operation ref="tns:opCheckAvailability">

       <input>

         <wsoap:header wsoap:mustUnderstand="true"
element="tns:NumberOfGuests"/>

       </input>

    </operation>

 

Any client that uses the new interface will set the soap:mustUnderstand
attribute in the message.  If the service receiving the messages does
not understand the extension, it will fault.

 

Cheers,

Dave

 

 
Received on Thursday, 14 July 2005 07:37:56 GMT

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