- From: Yalcinalp, Umit <umit.yalcinalp@sap.com>
- Date: Thu, 12 May 2005 19:20:56 +0200
- To: "Arthur Ryman" <ryman@ca.ibm.com>, "Sanjiva Weerawarana" <sanjiva@opensource.lk>
- Cc: <www-ws-desc@w3.org>, <www-ws-desc-request@w3.org>
- Message-ID: <2BA6015847F82645A9BB31C7F9D6416505EF94@uspale20.pal.sap.corp>
I just would like to get a feeling of the working groups understanding of interaction of #none and the semantics of MEPs. The questions are very basic: Considering JUST the abstract level of WSDL: -- What is the difference between the following two cases? -- Why should a description choose one over the other? (or What is the use case that needs to be differentiated for the specification and for the primer? The definition of #none is very terse in the spec and does not help someone using WSDL) (A) <interface name="fooInterface"> <operation name="bogusinout" pattern="http://www.w3.org/2005/05/wsdl/in-out"> <input messageLabel="In" element="#none" /> <output messageLabel="Out" element="tns:myoutput" /> </operation> </interface> (B) <interface name="foo2Interface"> <operation name="realout" pattern="http://www.w3.org/2005/05/wsdl/out-only"> <output messageLabel="Out" element="tns:myoutput" /> </operation> </interface> Further, can I have the following? (or variations of these you can just imagine...). It is perfectly legal of course. <interface name="MayBeNoOpInterface"> <operation name="whatever" pattern="http://www.w3.org/2005/05/wsdl/in-only"> <output messageLabel="Out" element="#none" /> </operation> </interface> Why would someone use this? I have answers to them, however I just want to hear from folks who wanted to put #none in the spec in the first place to refresh my memory about the motivation. --umit _____ From: Arthur Ryman [mailto:ryman@ca.ibm.com] Sent: Thursday, May 12, 2005 9:39 AM To: Sanjiva Weerawarana Cc: Yalcinalp, Umit; www-ws-desc@w3.org; www-ws-desc-request@w3.org Subject: Re: What is the purpose of #none? Sanjiva, I thought #none was introduced to support the case where there was a SOAP body, but the body was empty, i.e. had no child elements. This is a different situation than an RPC style no-argument SOAP body which does contain a single empty child element. In both of these cases, the MEP is still input-output, NOT output-only. Is that correct? 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/ Sanjiva Weerawarana <sanjiva@opensource.lk> Sent by: www-ws-desc-request@w3.org 05/12/2005 11:13 AM To Arthur Ryman/Toronto/IBM@IBMCA cc "Yalcinalp, Umit" <umit.yalcinalp@sap.com>, www-ws-desc@w3.org, www-ws-desc-request@w3.org Subject Re: What is the purpose of #none? Hi Arthur, #none means there's *no input*, period. Its not that there are no arguments .. there will be no body at all. The usecase is some operation where just by connecting to the EPR its clear what must be sent back. Sanjiva. On Thu, 2005-05-12 at 08:20 -0400, Arthur Ryman wrote: > > Umit, > > I guess I didn't provide the motivation. > > Suppose you have an operation that takes no input arguments. It is > still a request-response, but the request is empty, e.g. get the > current time of day. > > 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/ > > > Arthur Ryman/Toronto/IBM@IBMCA > Sent by: > www-ws-desc-request@w3.org > > 05/11/2005 05:36 PM > > > To > "Yalcinalp, Umit" > <umit.yalcinalp@sap.com> > cc > www-ws-desc@w3.org, www-ws-desc-request@w3.org > Subject > Re: What is the > purpose of #none? > > > > > > > > > > Umit, > > #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 > > > > To > <www-ws-desc@w3.org> > cc > > Subject > 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="http://www.w3.org/2005/05/wsdl/in-out"> > <input messageLabel="In" element="#none" /> > <output messageLabel="Out" > element="wdetails:reservationDetails" /> > </operation> > ... > Check out the binding: > <binding name="reservationDetailsSOAPBinding" > interface="tns:reservationDetailsInterface" > type="http://www.w3.org/2005/05/wsdl/soap" > wsoap:protocol="http://www.w3.org/2003/05/soap/bindings/HTTP"> > > <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" /> > </binding> > > 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? > > End-Of-Rant, > > --umit >
Received on Thursday, 12 May 2005 17:23:41 UTC