Re: [wsbpel] Comments on Event Handlers

["Dieter Roller" <ROL@de.ibm.com>]

Ram,

no, it is not possible; we haven't thought about this. If this function is
desired, I think your proposal of adding a repeat attribute (which IMO only
works for the for attribute) is the right way to go. All your other
proposals look to complicated.


Cheers,

dieter



|---------+---------------------------->
|         |           Ram Jeyaraman    |
|         |           <Ram.Jeyaraman@Su|
|         |           n.COM>           |
|         |                            |
|         |           07/29/2003 02:50 |
|         |           AM               |
|         |                            |
|---------+---------------------------->
  >------------------------------------------------------------------------------------------------------------------------------|
  |                                                                                                                              |
  |       To:       Dieter Roller/Germany/IBM@IBMDE                                                                              |
  |       cc:       wsbpel@lists.oasis-open.org                                                                                  |
  |       Subject:  Re: [wsbpel] Comments on Event Handlers                                                                      |
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  >------------------------------------------------------------------------------------------------------------------------------|




> We have used three different examples for designing event handlers:
>
> (1) Provide the capability for requestors to obtain some information
> relative to the current execution of a process instance (query
capability).
>
> (2) Provide the capability for requestors to modify the current
processing
> of a process instance, such as terminating the process instance.
>
> (3) Provide the capability to perform a certain action at a certain time,
> such as informing somebody about the business process.

Dieter, is it be possible to setup periodic alarms? For example, setup a
periodic alarm / timer, which executes an onAlarm activity each time the
interrupt happens.

While the current spec allows specification of several alarm events per
scope,
there does not seem to be a provision for specifying periodicity for a
particular alarm event.

One can conceive of a periodic alarm associated with the top-level process
scope,  that does repetitive periodic activities, for example, process
state
monitoring, etc.

One possible way to setup periodic alarms is to extend the onAlarm
definition
to include an attribute "repeat", as follows:

<eventHandlers>?
    <onMessage ...>* ... </onMessage>
    <onAlarm for="duration-expr"? until="deadline-expr"? repeat
="bool-expr"?>*
        activity
    </onAlarm>
</eventHandlers>

Another possible way, perhaps, may be to use an empty dummy pick construct
with
an onAlarm activity, placed within a while loop. This may necessitate the
use
of a flow construct, in order to place the while loop as a concurrent
activity,
within the parent scope. Or even a wait construct within a while loop.
thanks.