topic Re: Does engine have a hook to install an event listener? in Alfresco Archive

Does engine have a hook to install an event listener?

chrisc — Fri, 08 Feb 2013 00:45:56 GMT

I was wondering if the Activiti engine has a hook to enable a listener to be configured whose callback method is invoked whenever a process instance progresses from one activity to the next.Our current 'in house' workflow has hooks that allow us to configure a listener that fires off certain actions

Re: Does engine have a hook to install an event listener?

trademak — Fri, 08 Feb 2013 07:49:17 GMT

Hi,

Yes this is supported via ExecutionListeners –> http://www.activiti.org/userguide/index.html#executionListeners
If you don't want to add the execution listener in every process definition, you can write a BpmnParseListener to add it to all process definitions.
Extend the AbstractBpmnParseListener class and hook it in to the process engine configuration like this:

<property name="customPostBPMNParseListeners">
        <list>
                <bean class="org.activiti.cdi.impl.event.CdiEventSupportBpmnParseListener" />
        </list>
</property>

Note that in Activiti 5.12 the BpmnParseListener changes quite a bit. But the idea and logic remains the same.

Best regards,

Re: Does engine have a hook to install an event listener?

chrisc — Fri, 08 Feb 2013 07:59:48 GMT

Thanks for the reply.

We don't use spring so I'm hoping that the 'bean' in

<bean class="org.activiti.cdi.impl.event.CdiEventSupportBpmnParseListener" />
does not imply Spring support must be present.

Does the BpmnParseListener activate when a process definition is added to the repository or each time a process instance is created for the process definition?

Re: Does engine have a hook to install an event listener?

frederikherema1 — Fri, 08 Feb 2013 08:47:58 GMT

No need to use spring, you can add the listener to the processEngineConfigurationImpl in code as well…

The listener is called when:

New process is deployed

Process is added to the deployment-cache (again) after engine reboot or when definition was evicted from cache.

So you can be 100% sure that EVERY process-definition that is going to be used, will pass through the listener. In that listener, you can add execution-listeners (class implementing ExecutionListener interface) to ALL flow-elements in the parsed process. This way, every process that runs, you'll be notified of every step completing…

Re: Does engine have a hook to install an event listener?

chrisc — Fri, 08 Feb 2013 08:55:15 GMT

So you can be 100% sure that EVERY process-definition that is going to be used, will pass through the listener. In that listener, you can add execution-listeners (class implementing ExecutionListener interface) to ALL flow-elements in the parsed process. This way, every process that runs, you'll be notified of every step completing…

That sounds like what I need.

Thanks,
Chris

Re: Does engine have a hook to install an event listener?

boberetezeke — Tue, 27 May 2014 17:12:00 GMT

I need to do the exact same thing (be notified of all state transitions). Would you be willing to share the code using the BpmnParseListener?

Thanks,

Steve

Re: Does engine have a hook to install an event listener?

jbarrez — Fri, 30 May 2014 09:03:17 GMT

It's called 'BpmnParseHandler' now. Implement that interface, and attach to each SequenceFlow your own ExecutionListener which is called on state transation, shouldn't be too hard.