Novelli 11/6/2005: Finalizing Changes for Recursion andOptionality...Update

[Monica J Martin <Monica.Martin@Sun.COM>]

As I indicated team, I've been corresponding with Cristiano on his 
process definition and use of condition expressions. He is interested in 
using OperationMapping and effectively implementing the condition 
expressions (including the Ends and Begins When).  I'd encourage any 
comments you have. Cristiano is considering how to use the expressions 
given his query to John Yunker, myself and Dale Moberg.  Comments 
encouraged. Thanks.

>> novelli: Ok, I like "beginWhen" and "endsWhen" solution.
>> How can I describe the condition expression:
>> "the BTA X is started"?
>> Is it BSI dependent?
>> Can you do some short XML fragment examples?
>
> mm1: Section 3.4.10.1 gives an example for endsWhen, as well as 
> references for semantic variables and condition expressions in 
> general. Dale/John/Kenji, can you help Cristiano with some examples of 
> condition expressions? We do have their use shown in Appendix A (for 
> UBL example). These latter examples could help you identify what 
> responses are needed, Cristiano, such as you identifying what 
> notification is required on an Order Status Report.  As well, for the 
> reuse of this BT in a BTA, you could have a Commission Order Change 
> used if the XPath (in condition expression) shows that the business 
> document includes such information.
>
> Guys, I'd encourage more suggestions for Cristiano so we ensure he has 
> a quality example to use and we understand what other changes we need 
> to include in the specification.
>
>>>            2. Any BT can be part of a recursive loop that continues
>>>                  until explicitly terminated (explicit recursions). Use
>>>                  endsWhen for example.
>>
>> novelli: If I don't specify endsWhen condition expression, is 
>> execution of a BT implicit recursive?
>> If false, how do I describe the loop? 
>
> mm1: As John indicated in his email (see below).  We've not encouraged 
> the implicit recursiveness.  John, can you give Cristiano more 
> details? Thanks.
>
> ====Yunker
>
> ....The "endsWhen" could be used to bound repeating BT, making the 
> modeling simpler in those cases.
>
>> I can't find our discussion, however the linking nature of the spec 
>> (decision / fork / join) allows for explicit modeling of the type 
>> raised by Cristiano.
>>
>> Any BT can be fronted by a decision that explicitly excludes 
>> execution of the BT (explicit optionality)
>>
>> Any BT can be part of a recursive loop that continues until 
>> explicitly terminated (explicit recursions)
>>
>> As I ponder this, it strikes me that any declaration of optionality 
>> or recursion needs to include the conditions that drive recursion and 
>> optionality.  If the conditions are "the partner feels like sending 
>> that document", then we handle that already through parallel 
>> execution paths and beginsWhen.
>>
>> I CAN see how an "optional" declaration may help with certain types 
>> of status messages, but when I think about it further I would like to 
>> see the execution paths explicitly modeled in either case, making the 
>> "optional" declaration "documentation" in essence.
>