W3C home > Mailing lists > Public > www-ws-desc@w3.org > May 2005

RE: What is the purpose of #none?

From: Yalcinalp, Umit <umit.yalcinalp@sap.com>
Date: Thu, 12 May 2005 02:50:25 +0200
Message-ID: <2BA6015847F82645A9BB31C7F9D6416505EECD@uspale20.pal.sap.corp>
To: "Arthur Ryman" <ryman@ca.ibm.com>
Cc: <www-ws-desc@w3.org>, <www-ws-desc-request@w3.org>
Obviously, I know the meaning Arthur. ;-). 
I just want to show that how your example makes the use of
request-response like an outbound MEP. I am just asking the question
whether other folks in the wg anticipated the utility of the marker, or
empty messages, by passing the actual semantics for an MEP. 
For example, the example begs the question why can't we use an Outbound
MEP for the same purpose instead of #none? There is a SOAP response MEP
that we could use in the binding that we could refer to. Why this
formulation instead? Further,  if we want to illustrate the use of
#none, then probably burying the concept in this large example is not a
good idea. It appears part of the use case for Service References for
the first time. It should be tackled separately. 


From: Arthur Ryman [mailto:ryman@ca.ibm.com] 
Sent: Wednesday, May 11, 2005 2:37 PM
To: Yalcinalp, Umit
Cc: www-ws-desc@w3.org; www-ws-desc-request@w3.org
Subject: Re: What is the purpose of #none?


#none means the message is empty. 

Arthur Ryman,
Rational Desktop Tools Development

phone: +1-905-413-3077, TL 969-3077
assistant: +1-905-413-2411, TL 969-2411
fax: +1-905-413-4920, TL 969-4920
mobile: +1-416-939-5063, text: 4169395063@fido.ca
intranet: http://labweb.torolab.ibm.com/DRY6/ 

"Yalcinalp, Umit" <umit.yalcinalp@sap.com> 
Sent by: www-ws-desc-request@w3.org 

05/10/2005 09:45 PM 



What is the purpose of #none?


While I was reading the primer on service references, I came across an
interesting example in our primer. Apart from the fact that primer talks
about both Service and Endpoint references in Section 7.9 and the reader
is baffled about the differences here (endpoint references are not
introduced anywhere before) which is not the purpose of this email,
example 7.14 is particularly interesting: 

<interface name="reservationDetailsInterface"> 
   <operation name="retrieve" pattern="
        <input messageLabel="In" element="#none" /> 
        <output messageLabel="Out" element="wdetails:reservationDetails"
Check out the binding: 
<binding name="reservationDetailsSOAPBinding" 
             type=" <http://www.w3.org/2005/05/wsdl/soap>
http://www.w3.org/2005/05/wsdl/soap"  wsoap:protocol="

            <operation ref="tns:retrieve" wsoap:mep="
http://www.w3.org/2003/05/soap/mep/request-response" /> 
          <operation ref="tns:update" wsoap:mep="
http://www.w3.org/2003/05/soap/mep/request-response" /> 

The intent here appears to be that a "retrieve" action will cause
reservation details to be sent to the caller when an empty message is
received. According to our spec, this is perfectly legitimate, because
we allow empty messages, hence empty SOAP bodies to act as a trigger for
the response message. This pattern here seems like a poor man's SOAP
response MEP,  which is modeled on top of SOAP request-response MEP by
passing the request message using WSDL request-response MEP. Aren't we
confused yet ? ;-) 

I am wondering why we wanted to allow #none. It seems the whole purpose
is to paypass a designed MEP to masquarade as another. Can someone
refresh my memory why we wanted to allow element content to be empty
again? (As a side comment, can anyone truly believe that this kind of a
WSDL definition will be usable by a service provider without a mandatory
SOAP Action header  if many pseudo-output MEPs  similar to the one
quoted above were to be assigned to the same endpoint? ) 

Do we really want to promote this usecase in the Primer? 


Received on Thursday, 12 May 2005 00:52:42 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 23:06:50 UTC