RE: [wsbpel-spec-edit] Optional and required nature of @variable issue

makes sense to me

 

 

 

From: Prasad Yendluri 
[mailto:] 
Sent: Wednesday, October 27, 2004 
5:07 PM
To: 
Subject: 
[wsbpel-spec-edit] Optional and required nature of @variable 
issue

Folks,

Per the action I took on the BPEL call this morning, I 
am proposing the following issue text. Want to run it by you for a sanity check. 
Can you pls let me know if this matches your understanding or if needs any 
amendments..

Thanks.

The optional or required nature of Variable 
attribute is inconsistent in the specification. On <receive> activity, 
onMessage clause of the <Pick> activity the @variable is optional.  
Where as on <onEvent> handler the @variable is required.  
Additionally per section 15.1 it is 
permissible in abstract processes to omit the variable reference attributes from 
the <invoke/>, <receive/>, and <reply/> activities. However 
for executable processes there is no specification on the optional or required 
nature of @variable. In the case of OnEvent handler which can have several 
simultaneous active instances, the @variable is defined to be of 
@messageType declared within an implicit scope associated with the event 
handler; upon 
receipt of the input message the event handler is required to assign the input 
message to the variable before proceeding to perform the event handler activity, 
which makes the @variable required.  This inconsistency of  optional 
and required nature of the @variable on different activities seems to be a 
source of confusion, that needs to be clarified in the 
specification.
Proposed Resolution: Consistently require the @variable 
on all these activities for executable processes making it optional for abstract 
processes only.