Re: [wsbpel] inputVariable optional on Invoke

[Ron Ten-Hove <Ronald.Ten-Hove@Sun.COM>]

R2202 does indeed allow for an empty soap body. The part I quoted 
presupposes that wsdl:messages with zero parts are, in fact, legal, 
lending weight to Yaron's supposition that the schema for WSDL 1.1 
trumps the prose.

-Ron

Prasad Yendluri wrote:

> Ron,
>
> This is only permits zero parts in the wsdl:message or the soap:body 
> (binding level) being empty. This does not say the wsdl:message or the 
> soap:envelope itself can be totally absent. Hence we can not interpret 
> that to imply the inputVariable can be absent. It can be empty or void 
> of  payload (body) content and with WSDL 1.1 headers can be present in 
> the soap:envelope coming from other wsdl:messages  etc.
>
> Regards, Prasad ||
>
> Ron Ten-Hove wrote:
>
>>     When faced with the oddities of WSDL 1.1, I usually consult my 
>> copy of the WS-I Basic Profile. Even though it is SOAP-centric, it 
>> does have a lot to say about service declarations. The BP 1.0 doesn't 
>> recognize (and clarify) the contradiction you found (concerning the 
>> cardinality of message parts), but I find this:
>>
>> From section 5.3.1 (Bindings and Parts):
>>
>>     Use of |wsdl:message| elements with zero parts is permitted in
>>     Document styles to permit operations that can send or receive
>>     messages with empty |soap:Body|s. Use of |wsdl:message| elements
>>     with zero parts is permitted in RPC styles to permit operations
>>     that have no (zero) parameters and/or a return value.
>>
>>     I'd say we have the WS-I's blessing on leaving the inputVariable 
>> as optional. Other implementations of SOAP may have different 
>> interpretations, but allowing the inputVariable to be optional is the 
>> most general choice, and will cover such implementations as well.
>>
>> -Ron
>>
>> Yaron Y. Goland wrote:
>>
>>> Executive Summary: Antony Miguel, in a private e-mail, pointed out 
>>> that the inputVariable attribute on invoke is currently optional. In 
>>> BPEL as it now is specified this doesn't make sense as all 
>>> operations MUST have a WSDL message associated with them. But if 
>>> issue 12 passes then the optional inputVariable makes sense in cases 
>>> where the message has no parts. Unfortunately the WSDL 1.1 spec 
>>> seems to contradict itself on the legality of partless messages.
>>>
>>> Long Winded Version:
>>>
>>> Antony Miguel, in a private e-mail with me, pointed out that the 
>>> inputVariable attribute is optional on invokes. Given that all 
>>> invoke MEPs MUST have an outgoing message does it make sense to have 
>>> the attribute be optional?
>>>
>>> The only scenario I can come up with where it makes sense to not 
>>> have an inputVariable attribute is if the outgoing message is 
>>> 'empty'. This is not a completely insane idea. Some protocols do 
>>> have 'empty' messages which have an address header but no body. This 
>>> could be used for things like pings.
>>>
>>> But all BPEL messages have to be sent using a WSDL message structure 
>>> and it isn't possible to define an operation that doesn't point at a 
>>> message. However it MAY be legal to define a WSDL message with no 
>>> parts. There is a contradiction between the text in WSDL 1.1 and the 
>>> schema. The text in section 2.3 says "Messages consist of one or 
>>> more logical parts.". But the psuedo-schema in 2.3 says:
>>>
>>> <definitions .... >
>>>     <message name="nmtoken"> *
>>>         <part name="nmtoken" element="qname"? type="qname"?/> *
>>>     </message>
>>> </definitions>
>>>
>>> Furthermore the XML Schema in the appendix says:
>>>
>>>    <complexType name="messageType">
>>>       <complexContent>
>>>          <extension base="wsdl:documented">
>>>             <sequence>
>>>                <element ref="wsdl:part" minOccurs="0"
>>>                         maxOccurs="unbounded"/>
>>>             </sequence>
>>>             <attribute name="name" type="NCName" use="required"/>
>>>          </extension>
>>>       </complexContent>
>>>    </complexType>
>>>
>>> Assuming the schema triumphs then this means that it is legal to 
>>> define a message with no parts. An empty message.
>>>
>>> But this still leaves the problem that BPEL requires that all 
>>> messages be contained in a WSDL container. This alone would require 
>>> that invoke MUST always have an inputVariable attribute.
>>>
>>> But, if issue 12 passes, then it would make sense to make 
>>> inputVariable optional to cover the case where the message for an 
>>> operation has no parts.
>>>
>>> To unsubscribe from this mailing list (and be removed from the 
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>>>
>>>
>>