topic Re: How to interrupt and end processinstance? in Alfresco Archive

How to interrupt and end processinstance?

rusty — Tue, 20 Sep 2011 08:03:35 GMT

Hi,i'm new to Activiti and Bpmn.Is it possible to model the possibility to interrupt and end a processinstance at any time of the process? I know how to end it with Java but I want it to be modeled.Maybe I found a way with Bpmn2.0 but Activiti doesn't support the needed events.So I tried to model a

Re: How to interrupt and end processinstance?

mhw — Tue, 20 Sep 2011 08:09:57 GMT

Hi,

I would also be interested in that. At the moment I try to reach the following:

Show a Dialog to a user (userTask or javaService). User makes some input. If it ends "normally" the input is returned and its fine. But the user should be enabled to press "cancel" or "esc". Then process should stop returning to parent calling process. How would one model this with activiti?

Rusty, which constructs of BPMN do you mean? Which "needed events" you are talking about?

regards,
Michael

Re: How to interrupt and end processinstance?

rusty — Tue, 20 Sep 2011 08:37:09 GMT

Hi,

I'm talking about message events.
Maybe it could also work with signal events, but both aren't supported yet.

But I'm not even sure it would work with these events. I've never found an BPMN example, that allows to interrupt and end a process at any time.

Regards,
Rusty

Re: How to interrupt and end processinstance?

mhw — Tue, 20 Sep 2011 14:19:41 GMT

Hi,

I thought about this issue the whole afternoon. I see no possibility to model this kind of behavior with activity. For our use case it is enough to handle the failing of a sub process with the error event:

 <process processType="Private" isExecutable="true" id="EscapeRegionEvent"
  name="Escape region Event Process">

  <startEvent id="theStart" name="StartProcess" />

  <sequenceFlow sourceRef="theStart" targetRef="subprocessThatCouldBeCanceled" />

  <subProcess id="subprocessThatCouldBeCanceled">
   <startEvent id="startSubProcessEvent" />
   <sequenceFlow targetRef="userTaskThatCouldBeCanceled"
    sourceRef="startSubProcessEvent" />
   <userTask id="userTaskThatCouldBeCanceled" name="User task that could be canceled."
    activiti:assignee="kermit" />
   <sequenceFlow targetRef="endSubProcessError" sourceRef="userTaskThatCouldBeCanceled">
    <conditionExpression>
     ${cancelPressed}
    </conditionExpression>
   </sequenceFlow>
   <sequenceFlow targetRef="endSubProcessNormal" sourceRef="userTaskThatCouldBeCanceled">
    <conditionExpression>
     ${!cancelPressed}
    </conditionExpression>
   </sequenceFlow>
   <endEvent id="endSubProcessNormal" />
   <endEvent id="endSubProcessError">
    <errorEventDefinition errorRef="canceled" />
   </endEvent>

  </subProcess>

  <sequenceFlow sourceRef="subprocessThatCouldBeCanceled"
   targetRef="normalEnd" />

  <endEvent id="normalEnd" name="NormalEndProcess">
   <terminateEventDefinition />
  </endEvent>


  <boundaryEvent id="catchError" name="CatchErrorEvent"
   attachedToRef="subprocessThatCouldBeCanceled" cancelActivity="true">

   <errorEventDefinition errorRef="canceled" />

  </boundaryEvent>
  
  <sequenceFlow targetRef="handleEscalation" sourceRef="catchError"></sequenceFlow>

  <userTask id="handleEscalation" name="Handle escalated issue">
   <documentation>Escalation: user task was canceled.
   </documentation>
  </userTask>

  <sequenceFlow sourceRef="handleEscalation" targetRef="escalatedEnd" />

  <endEvent id="escalatedEnd" />

 </process>


…
  runtimeService
    .setVariable(task.getExecutionId(), "cancelPressed", true);

  taskService.complete(task.getId());

  task = taskService.createTaskQuery().processInstanceId(pi.getId())
    .singleResult();

  assertEquals("Handle escalated issue", task.getName());

…

Just similar to the process in the examples.

Would be nice to hear of some better solution (which could be viewed/edited in the model - without java).

Best regards,
Michael

Re: How to interrupt and end processinstance?

ronald_van_kuij — Tue, 20 Sep 2011 15:32:19 GMT

A better solution is to implement the missing events… Feel free to contribute those. The code of activiti is clearly written and fairly easy to understand. 🙂

Re: How to interrupt and end processinstance?

mhw — Wed, 21 Sep 2011 08:32:40 GMT

Hi Ronald,

yes, you are right. All code I viewed so far is clearly written. I am willing to contribute. I will take these steps here:
http://docs.codehaus.org/pages/viewpage.action?pageId=163872771

Then I will extend the class BpmnParse and add a method like
"parseBoundaryTimerEventDefinition" and "addTimerDeclaration"

Is there a tutorial how to setup a typical activiti developer workspace?

I am not a BPMN-specialist.
@Rusty: Have you a BPMN-example for me?

regards,

Michael

Re: How to interrupt and end processinstance?

ronald_van_kuij — Wed, 21 Sep 2011 12:56:25 GMT

Activiti is a typical maven project, nothing specific.

What events are missing btw? Please file jira issues for those after discussing them here

Re: How to interrupt and end processinstance?

mhw — Wed, 21 Sep 2011 13:17:26 GMT

Ok, I understand the setup. Will try it today evening at home.

We need the "signal boundary event" (not sure how this is formulated in BPMN) for cancellation of a sub process from "outside" (user press the cancel button).

I found the same thing discussed here:
http://forums.activiti.org/en/viewtopic.php?f=10&t=897

Will now try to

mimic a signal event using a wait state (receive task) + signal call from a service task

Re: How to interrupt and end processinstance?

rusty — Thu, 22 Sep 2011 06:47:49 GMT

Hi,

thanks for your support!
This is the way I would try to model a trigger to interrupt and end a process. But I'm not sure it would work. I'm really new to BPMN.

Regards,
Rusty

[attachment=0]BPMN_Bsp.PNG[/attachment]

Re: How to interrupt and end processinstance?

rusty — Thu, 22 Sep 2011 07:52:51 GMT

I think this one should work, but I guess it's not the best way.

Re: How to interrupt and end processinstance?

mhw — Thu, 22 Sep 2011 11:24:46 GMT

I am new to BPMN, too I think the needed cancel event would look like this:

…
</subProcess>
 <boundaryEvent id="_4" name="CancelEvent" attachedToRef="_2">
  <outgoing>_6</outgoing>
  <cancelEventDefinition/>
 </boundaryEvent>
 <sequenceFlow id="_6" name="Sequence Flow" sourceRef="_4" targetRef="_5"/>
 <scriptTask id="_5" name="Goodbye">
  <incoming>_6</incoming>
  <outgoing>_7</outgoing>
  <script>System.out.println(&quot;Cancel of subprocess handled&quot:smileywink:;</script>
 </scriptTask>
…

[attachment=0]cancelevent.jpg[/attachment]
Is this right? Should I implement behavior like this?

regards,
Michael

Re: How to interrupt and end processinstance?

rusty — Thu, 22 Sep 2011 11:37:18 GMT

Hi Micheal,

I also thought of this solution but my tutor (i'm a Student, doing an internship) means I shouldn't implement the whole process as a subprocess. I also think there should be another way. For Example to prevent subprocesses in a subprocess.

Regards,
Rusty

Re: How to interrupt and end processinstance?

mhw — Thu, 22 Sep 2011 11:48:08 GMT

Hi Rusty,

that is an interesting point. But as I understand according to BPMN 2.0 specification:

The catch Cancel Intermediate Event MUST only be attached to the boundary of a Transaction Sub-
Process and, thus, MAY NOT be used in normal flow.

With BPMN we only seem to have the ability to attach the cancel event to a sub process boundary. Perhaps there are other possibilities which I oversee…
With current version of activiti we cannot use the cancel event. So I will try it with a solution similar to your post and will post my results here.

If I should implement the cancel event in activiti, I would need a xml example how it should be.

Regards,
Michael

Re: How to interrupt and end processinstance?

rusty — Fri, 23 Sep 2011 13:46:36 GMT

After reflecting my examples again, I guess they will not work.
I think if I end one branch of the parallel gateway, the other will continue anyway.

I'm going to test this issue the next days.

Re: How to interrupt and end processinstance?

albertorugnone1 — Wed, 24 Oct 2012 22:42:28 GMT

I am sorry if I am here with a silly question. In my understanding from this discussion to interrupt a process you have to model it by BPMN with a process that seems very complex for newbe like me.
Why is not provided an interrupt function in activiti engine. It seems to me quite natural. Maybe I misunderstood the objective of activiti itself, but really I am a little bit confused.

Kind regards :ugeek: and Thank you very much for your patience

Re: How to interrupt and end processinstance?

jbarrez — Thu, 25 Oct 2012 08:18:13 GMT

@albertorugnone:

/** Delete an existing runtime process instance.
   * @param processInstanceId id of process instance to delete, cannot be null.
   * @param deleteReason reason for deleting, can be null.
   * @throws ActivitiException when no process instance is found with the given id.
   */
void deleteProcessInstance(String processInstanceId, String deleteReason);