topic Re: How to send specific signal to receive tasks? in Alfresco Archive

How to send specific signal to receive tasks?

jhahn — Fri, 27 Mar 2015 01:06:25 GMT

Hello,I have two receive tasks, called task1 and task2.I arrive at task1 and I have multiple services that could potentially send a signal to the executionId of task1. How do I limit the receiveTask so that it proceeds only when it receives a certain eventName?I couldn't find any example in the REST

Re: How to send specific signal to receive tasks?

martin_grofcik — Fri, 27 Mar 2015 08:06:07 GMT

Hi,

Signals are broadcasts. I would use messages - I would use them instead.
examplerg.activiti.engine.test.bpmn.event.message.MessageIntermediateEventTest

Regards
Martin

Re: How to send specific signal to receive tasks?

jhahn — Fri, 27 Mar 2015 18:00:18 GMT

Is this not supported in the REST API?

Re: How to send specific signal to receive tasks?

trademak — Sun, 29 Mar 2015 18:01:11 GMT

Yes, the REST API also provides support for signal and message events. Receive tasks can't be coupled to a message or signal event however. You need to use an intermediate catch event for that purpose.

Best regards,

Re: How to send specific signal to receive tasks?

jhahn — Tue, 31 Mar 2015 21:06:22 GMT

But I need to have a timer on the task to escalate.

I need to do something like this.
http://blog.goodelearning.com/wp-content/uploads/2014/05/diagram-3.jpg

So for the "Waiting for response", I want it to wait until a message called "responseReturned" gets sent to the process instance.

So you're saying receive task doesn't support the ability to complete the task for a specific messageName only?
I see "Message Ref" property on intermediate message event, which is what I think I need.

If impossible, I guess I could use User Task for this purpose and just assign the owner to the "system"…

I'm relatively new to bpmn/activiti so I apologize if this is all trivial knowledge…

Re: How to send specific signal to receive tasks?

trademak — Wed, 01 Apr 2015 11:41:59 GMT

Ah ok, that wasn't clear to me. Yes you can attach a boundary message event to a receive task.
In the user guide this points to the correct REST API service to call to invoke the boundary message event:

15.6.2. Execute an action on an execution

PUT runtime/executions/{executionId}

Best regards,

Re: How to send specific signal to receive tasks?

jhahn — Wed, 01 Apr 2015 17:44:05 GMT

Ok, so now I attached the boundary message event to a receive task. However, this pattern FEELS wrong…
http://i.imgur.com/DYbooAl.png

Anyway, it still won't recognize the message and throw the error

Execution with id '10684728' does not have a subscription to a message event with name 'thingFinished'

Do I need to subscribe this receive task to a message event? If that functionality exists, I probably don't need the message boundary event?

Maybe I'm not understanding the purpose of receive task correctly…

Re: How to send specific signal to receive tasks?

jbarrez — Tue, 07 Apr 2015 12:42:33 GMT

The receive task waits, does nothing until you call runtimeService.signal(executionID).

Now, this is pretty confusing, cause it has NOTHING to do with a BPMN signal event (that's signalEventReceived, rather).

So either you call the API directly, on receiving the message (eg on a JMS queue or whatever), or you have a message event, in that case you will need to call the void messageEventReceived(String messageName, String executionId); method.