How to trigger a Sub flow using "Signal Event" which is getting generated in Parent Flow ?

[sushant]

Issue - At step 3, Subflow is not getting called in spite of configuration. Please provide any pointers. I do not want to call this child flow from  parent flow like below :

[thuynh]

Hi Sushant,

Hmm ok. I'm not sure. I just tried firing even from a TaskListener and it worked for me as well. Here's my task listener class.

public class MyTaskCreateListener implements TaskListener {

Logger logger = Logger.getLogger(MyTaskCreateListener.class);

public void notify(DelegateTask delegateTask) {
// Custom logic goes here
logger.info("User task is created.");
logger.info("Listener executed.");

DelegateExecution execution = delegateTask.getExecution();
RuntimeService runtimeService = execution.getEngineServices().getRuntimeService();
runtimeService.signalEventReceived("EMAIL_SUPPORT_SIGNAL");
}
}

And here is the unit test log

03:43:19,694 [main] INFO org.activiti.signal.SignalUnitTest - ------------------------- START SIGNAL CATCH PROCESS -------------------------
03:43:19,761 [main] INFO org.activiti.signal.SignalUnitTest - Execution counts: 2
03:43:19,771 [main] INFO org.activiti.signal.SignalUnitTest - Execution: null - 18
03:43:19,772 [main] INFO org.activiti.signal.SignalUnitTest - Execution: null - 20
03:43:24,773 [main] INFO org.activiti.signal.SignalUnitTest - ------------------------- START SIGNAL TEST PROCESS -------------------------
03:43:24,789 [main] INFO org.activiti.signal.MyTaskCreateListener - User task is created.
03:43:24,789 [main] INFO org.activiti.signal.MyTaskCreateListener - Listener executed.
03:43:24,806 [main] INFO org.activiti.signal.SendErrorService - SendErrorService executed. Process: signalStartProcess:1:16
03:43:24,823 [main] INFO org.activiti.signal.SendErrorService - SendErrorService executed. Process: signalCatchProcess:1:15
03:43:24,855 [main] INFO org.activiti.signal.SignalUnitTest - Process instance id: 23
03:43:24,870 [main] INFO org.activiti.signal.SignalUnitTest - Open task : 27 - Review Create Subscription Failure / assigned to: null
03:43:29,870 [main] INFO org.activiti.signal.SignalUnitTest - ------------------------- CHECK SIGNAL CATCH PROCESS -------------------------
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 19.549 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 22.353s
[INFO] Finished at: Wed Jan 25 15:43:35 ICT 2017
[INFO] Final Memory: 8M/153M
[INFO] ------------------------------------------------------------------------

Let me know if this still not matching your use case.

Thanks

Thong Huynh

‌

[sushant]

Hi Thong,

Reason why your works is because:

1. In your subflow, usual "Start Event" is used followed by "Intermediate Catch Event".

2. Subflow is explicitly getting called in the unit test class.

      ProcessInstance processInstance2 = activitiRule.getRuntimeService().startProcessInstanceByKey("signalCatchProcess");

So, in gist this is like calling a subflow like below(my un-preferred option of original thread)

What I want is :

My subflow should have "Start Signal Event" instead of #2 above. Which would be starting the subflow automatically when it sees an event getting fired from Task listener, as illustrated below

Hope, I am clear.

[thuynh]

Hi 

[thuynh]

Hi Sushant Kumar ,

1. In your subflow, usual "Start Event" is used followed by "Intermediate Catch Event".

This is just one scenario. Please look at the other one as well, signal-start-process.bpmn. This one has a signal start event. In my unit test, you can see both scenarios work.

2. Subflow is explicitly getting called in the unit test class.

      ProcessInstance processInstance2 = activitiRule.getRuntimeService().startProcessInstanceByKey("signalCatchProcess");

Again, this is for the 1st scenario where I want to test the intermediate signal catch event. Have a look at signal-start-process.bpmn

I have attached the unit test project.

Please look at signal-start-process.bpmn, you can disable the other one 'signal-catch-process' to be less confused about it.

If you still see problem, please upload a unit test. 

Thank you,

Thong Huynh

‌

[sushant]

Hi Thong Huynh,

It works with Junits - where I am starting the main flow using start process instance - i.e signalTaskListenerProcess. So, may be :

1. It does not work, if i start using REST call

2. I am using version activiti-engine-5.19.0.3 version.

Attaching my test case, Please use REST call to start as below

POST /activiti-app/api/runtime/process-instances HTTP/1.1
Host: localhost:8080
Content-Type: application/json
Authorization: Basic gskkanaoa10177161==
Cache-Control: no-cache
Postman-Token: 969177c4-b779-386a-29f4-708e9e93bd0f

{
"processDefinitionId":"Sushant-Signal-Throw-Process:4:2425624",
"businessKey":"Sushant-Signal-Throw-Process"

}

Link to testcase - Test-Signal-App.zip 

Listener class

package com.pb.saase2e.cs.workflow.task.listener;

import org.activiti.engine.RuntimeService;
import org.activiti.engine.delegate.DelegateTask;
import org.activiti.engine.delegate.TaskListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class UserTaskListener implements TaskListener {

private static final long serialVersionUID = 1L;
private static Logger logger = LoggerFactory.getLogger(UserTaskListener.class);

@Override
public void notify(DelegateTask delegateTask) {

RuntimeService runtimeService = delegateTask.getExecution().getEngineServices().getRuntimeService();

delegateTask.getExecution().setVariable("TaskId", delegateTask.getId());
delegateTask.getExecution().setVariable("TaskName", delegateTask.getName());

runtimeService.signalEventReceived("EMAIL_SUPPORT_SIGNAL");
logger.info("Sent signal event:{} for taskId:{} and taskName:{}", "EMAIL_SUPPORT_SIGNAL", delegateTask.getId(),
delegateTask.getName());

}
}

[Destryon]

Hi Thuynh,

I was trying to create a trigger in my main flow that will be triggering sub flows. Now i am confused whether we can use timer event or sub process to achieve it?  

[sushant]

Any idea, if this is fixed in 5.x version ?

[gdharley]

This remains a defect and doesnt appear to be fixed in the latest 5.x engine release.

In addition, it appears to be an issue in the version 6 Beta release as well.

[gdharley]

Sushant,
I opened up your package and I think we will need you to attach the TaskListener since this is what throws the signal.

com.pb.saase2e.cs.workflow.task.listener.UserTaskListener

It appears the key piece was missing from the application package.

Thanks,
Greg

‌

[sushant]

Edited my post to include the listener java class. Here it is again

package com.pb.saase2e.cs.workflow.task.listener;

import org.activiti.engine.RuntimeService;
import org.activiti.engine.delegate.DelegateTask;
import org.activiti.engine.delegate.TaskListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class UserTaskListener implements TaskListener {

private static final long serialVersionUID = 1L;
private static Logger logger = LoggerFactory.getLogger(UserTaskListener.class);

@Override
public void notify(DelegateTask delegateTask) {

RuntimeService runtimeService = delegateTask.getExecution().getEngineServices().getRuntimeService();

delegateTask.getExecution().setVariable("TaskId", delegateTask.getId());
delegateTask.getExecution().setVariable("TaskName", delegateTask.getName());

runtimeService.signalEventReceived("EMAIL_SUPPORT_SIGNAL");
logger.info("Sent signal event:{} for taskId:{} and taskName:{}", "EMAIL_SUPPORT_SIGNAL", delegateTask.getId(),
delegateTask.getName());

}
}