topic Re: How to trigger a Sub flow using "Signal Event" which is getting generated in Parent Flow ? in Alfresco Forum

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

sushant — Fri, 20 Jan 2017 13:43:53 GMT

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 :

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

gdharley — Fri, 20 Jan 2017 19:41:57 GMT

Before I "check your code", is there a specific reason you are trying to target a specific execution in your signalEventReceived call?

I ask because a simple inline signal throw event should trigger a deployed process that has a registered signal start event.

If you must use the signalEventReceived() method of runtimService, try using the global version (i.e. dont include an execution id).

Greg

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

sushant — Sat, 21 Jan 2017 15:47:33 GMT

Hey Greg, Thanks for your reply.

No particular reason, I can make use of global version.

If I model my flow as per your suggestion and pic above, will the signal thrown be caught by subflow(refer my step 3 depiction) which is having signal start event ? assuming i do not explicitly need to call the subflow(like the un-preferred option shown in my original thread)

Please comment.

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

gdharley — Sat, 21 Jan 2017 16:20:24 GMT

Hey Sushant, if you use global signals, all process instances (including called sub processes) will pick up the signal.

Obviously there are always details that are specific to your scenario, but in terms of signals, global means global.

Hope this helps,

Greg

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

sushant — Mon, 23 Jan 2017 03:15:31 GMT

Hi Greg,

I tried the option above, but my subflow is not getting invoked(may be because USer Task is blocking operation). Please do comment, here is the subflow configuration again

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

gdharley — Mon, 23 Jan 2017 18:22:30 GMT

Hi Sushant, I tried what I had proposed and found it didnt work, so I checked the Activiti defect list.

Seems this is a known (unresolved) issue:

Issue Navigator - ACTIVITI-286 - Activiti: Event sub process not triggered with start signal thrown

I suggest you vote up this issue so we can get it resolved.

Sorry,

Greg

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

thuynh — Tue, 24 Jan 2017 05:36:21 GMT

Hi Sushant,

While the signal start event is not working with 'event subprocess'. it is working if you have your signal-started process as standalone process. Is this acceptable workaround for you?

I have tested a few signal catching scenarios and they all worked except for the 'event subprocess' one.

Also make sure that you DEPLOY all process definitions to have it work. For example,

public class SignalUnitTest {
Logger logger = Logger.getLogger(SignalUnitTest.class);
@Rule
public ActivitiRule activitiRule = new ActivitiRule();
@Test
@Deployment(resources = {"org/activiti/test/signal/signal-test-process.bpmn",
"org/activiti/test/signal/signal-catch-process.bpmn",
"org/activiti/test/signal/signal-start-process.bpmn"})
public void test() throws InterruptedException {
RuntimeService runtimeService = activitiRule.getRuntimeService();
.
.
.
}}

Here are my test scenarios,

Firstly, I have a process to throw a signal event

Then I have another process to catch that signal event as a start event (remember to configure the signal name correctly. Have a look at my attached process def xml)

And another catching process in which the signal event is an intermediate event

Here is my unit test run log. See the highlighted lines. They show that the error service task in the catching processes were executed.

-------------------------------------------------------
T E S T S
-------------------------------------------------------
Running org.activiti.signal.SignalUnitTest
12:16:26,342 [main] INFO org.springframework.beans.factory.xml.XmlBeanDefinitionReader - Loading XML bean definitions from class path resource [activiti.cfg.xml]
12:16:28,542 [main] INFO org.activiti.engine.impl.db.DbSqlSession - performing create on engine with resource org/activiti/db/create/activiti.h2.create.engine.sql
12:16:28,765 [main] INFO org.activiti.engine.impl.db.DbSqlSession - performing create on history with resource org/activiti/db/create/activiti.h2.create.history.sql
12:16:28,765 [main] INFO org.activiti.engine.impl.db.DbSqlSession - performing create on identity with resource org/activiti/db/create/activiti.h2.create.identity.sql
12:16:28,781 [main] INFO org.activiti.engine.impl.ProcessEngineImpl - ProcessEngine default created
12:16:28,828 [main] INFO org.activiti.engine.impl.bpmn.deployer.BpmnDeployer - Processing resource org/activiti/test/signal/signal-test-process.bpmn
12:16:29,452 [main] INFO org.activiti.engine.impl.bpmn.deployer.BpmnDeployer - Processing resource org/activiti/test/signal/signal-catch-process.bpmn
12:16:29,608 [main] INFO org.activiti.engine.impl.bpmn.deployer.BpmnDeployer - Processing resource org/activiti/test/signal/signal-start-process.bpmn
12:16:29,812 [main] INFO org.activiti.signal.SignalUnitTest - ------------------------- START SIGNAL CATCH PROCESS -------------------------
12:16:29,874 [main] INFO org.activiti.signal.SignalUnitTest - Execution counts: 2
12:16:29,890 [main] INFO org.activiti.signal.SignalUnitTest - Execution: null - 12
12:16:29,890 [main] INFO org.activiti.signal.SignalUnitTest - Execution: null - 14
12:16:34,897 [main] INFO org.activiti.signal.SignalUnitTest - ------------------------- START SIGNAL TEST PROCESS -------------------------
12:16:34,897 [main] INFO org.activiti.signal.SignalServiceTask - SingalServiceTask execution : 17
12:16:34,929 [main] INFO org.activiti.signal.SendErrorService - SendErrorService executed. Process: signalCatchProcess:1:9
12:16:34,945 [main] INFO org.activiti.signal.SendErrorService - SendErrorService executed. Process: signalStartProcess:1:10
12:16:34,976 [main] INFO org.activiti.signal.SignalUnitTest - Process instance id: 17
12:16:39,984 [main] INFO org.activiti.signal.SignalUnitTest - ------------------------- CHECK SIGNAL CATCH PROCESS -------------------------

I have attached my unit test zip.

Hope this helps.

Thanks,

Thong Huynh

bp3‌

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

sushant — Tue, 24 Jan 2017 13:00:48 GMT

Hey Thong,

This is a problem with User Task(you box seems Java Service Task), if you have " Throw Signal" event after a user task, that wont be called unless you do an action.(which is not the use case for me).

This is why, i had to configure a listener to generate an event without getting blocked. Now,this generated event is not caught by Subflow's start signal event. This is what is bug, as Greg mentioned.

Thanks and Regards,

Sushant

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

sushant — Tue, 24 Jan 2017 13:05:15 GMT

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

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

thuynh — Tue, 24 Jan 2017 15:06:16 GMT

Hi Sushant,

I tried user task and it also works for me. Do you have a unit test for us to inspect why it's not working for you?

Unit Test Log

-----------------------------------------------------------------------------------------------------------------------------------------

10:00:55,585 [main] INFO org.activiti.engine.impl.bpmn.deployer.BpmnDeployer - Processing resource org/activiti/test/signal/signal-test-process.bpmn
10:00:56,178 [main] INFO org.activiti.engine.impl.bpmn.deployer.BpmnDeployer - Processing resource org/activiti/test/signal/signal-usertask-process.bpmn
10:00:56,365 [main] INFO org.activiti.engine.impl.bpmn.deployer.BpmnDeployer - Processing resource org/activiti/test/signal/signal-catch-process.bpmn
10:00:56,523 [main] INFO org.activiti.engine.impl.bpmn.deployer.BpmnDeployer - Processing resource org/activiti/test/signal/signal-start-process.bpmn
10:00:56,726 [main] INFO org.activiti.signal.SignalUnitTest - ------------------------- START SIGNAL CATCH PROCESS -------------------------
10:00:56,788 [main] INFO org.activiti.signal.SignalUnitTest - Execution counts: 2
10:00:56,788 [main] INFO org.activiti.signal.SignalUnitTest - Execution: null - 15
10:00:56,788 [main] INFO org.activiti.signal.SignalUnitTest - Execution: null - 17
10:01:01,796 [main] INFO org.activiti.signal.SignalUnitTest - ------------------------- START SIGNAL TEST PROCESS -------------------------
10:01:01,828 [main] INFO org.activiti.signal.SignalUnitTest - Process instance id: 20
10:01:01,844 [main] INFO org.activiti.signal.SignalUnitTest - Open task : 24 - Review Create Subscription Failure / assigned to: kermit
10:01:01,890 [main] INFO org.activiti.signal.SendErrorService - SendErrorService executed. Process: signalStartProcess:1:13
10:01:01,906 [main] INFO org.activiti.signal.SendErrorService - SendErrorService executed. Process: signalCatchProcess:1:12
10:01:06,945 [main] INFO org.activiti.signal.SignalUnitTest - ------------------------- CHECK SIGNAL CATCH PROCESS -------------------------
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 19.371 sec

Thank you,

Thong Huynh

‌

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

sushant — Wed, 25 Jan 2017 05:35:48 GMT

I can do a screenshare and show you. BTW, on the User Task , did the event generated after you actioned the user task ? if yes, then I fear that is not the use case. I see above in logs, the task getting assigned.

Here are the steps:

1. Create a flow which generated the user task.

2. Do not action the User task i.e keep it open.

3. Configure Java User Task Listener(on Create event of task) on this which generates the event.

4. Now, configure the same event on a subflow as start signal event.

Now, if you run, the subflow at #4 does not get invoked.

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

thuynh — Wed, 25 Jan 2017 08:52:54 GMT

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

‌

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

gdharley — Wed, 25 Jan 2017 12:46:57 GMT

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.

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

sushant — Wed, 25 Jan 2017 12:54:59 GMT

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.

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

thuynh — Thu, 26 Jan 2017 07:09:10 GMT

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

thuynh — Thu, 26 Jan 2017 07:15:26 GMT

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

‌

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

sushant — Fri, 27 Jan 2017 14:03:24 GMT

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());

}
}

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

gdharley — Fri, 27 Jan 2017 15:41:21 GMT

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

‌

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

sushant — Fri, 27 Jan 2017 15:44:25 GMT

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());

}
}

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

gdharley — Fri, 27 Jan 2017 17:38:51 GMT

Hey Sushant,

I am still trying to work out why the Signal is not being picked up.

But since you are calling the signal task from a Listener, I found a work around.

Rather than using a signal start event. Just use a regular start event.

Then, instead of sending the signal, simply start the sub process from the runtimeService using startProcessInstanceByKeyAndTenantId().

I have attached an updated project with the work around implemented.
Agreed, I dont like it and we need to work out why signals are not working in this scenario, but it shoudl get you moving.

Greg

bp3‌