RE: [wsbpel] Do we need the createInstance attribute?

["Satish Thatte" <satisht@microsoft.com>]

We could certainly get rid of the createInstance attribute as you say
but in general we are tending to keep some redundant annotations as a
way of expressing intent, to be enforced and checked by static
analysers.

As for the offending potentially misleading sentence it was meant to
draw attention to the multiple start activities case.  But of course it
could be improved to be less misleading.

Satish

-----Original Message-----
From: Yaron Goland [mailto:ygoland@bea.com] 
Sent: Monday, October 20, 2003 4:49 PM
To: Wsbpel@Lists. Oasis-Open. Org (E-mail)
Subject: [wsbpel] Do we need the createInstance attribute?

Section 11.4 states "The only way to instantiate a business process in
BPEL4WS is to annotate a receive activity with the createInstance
attribute set to "yes" (see Pick for a variant). The default value of
this attribute is "no". A receive activity annotated in this way MUST be
an initial activity in the process, that is, the only other basic
activities may potentially be performed prior to or simultaneously with
such a receive activity MUST be similarly annotated receive activities."

If I understand this sentence correctly then the following is illegal in
BPEL:

<process>
   <flow>
      <receive portTypeA createInstance="yes".../>
      <receive portTypeB createInstance="no".../>
   </flow>
</process>

If that is the case then can't we just get rid of the createInstance
attribute since it is redundant? In other words, if an activity is an
initial activity then it must, by definition, be a createInstance
activity.

Also, if the previous example is illegal in BPEL then I think the
following sentence from section 11.4 could be misleading: "It is
permissible to have the createInstance attribute set to "yes" for a set
of concurrent initial activities."

This sentence implies that there are times when it is legal to have
concurrent initial activities where createInstance is equal to no.

	Thanks,
		Yaron