topic Re: How to properly start a new process from inside a service task ? in Alfresco Archive

How to properly start a new process from inside a service task ?

guillaume1 — Thu, 22 May 2014 11:24:58 GMT

Hello, I have created a custom palette element following the user guide about this topic.This new activity is in fact a 'configuration mask' for a CallActivity with a complex input map.So the execute method of the JavaDelegate that is called by this custom palette element at runtime is like this:<

Re: How to properly start a new process from inside a service task ?

pmsevestre — Fri, 23 May 2014 00:21:52 GMT

If you want the started process to appear as a child I think you must use a "call activity" element in the parent process.

Since the process name can be an EL, you can dynamically determine which process to start based on your specific requirements.

Re: How to properly start a new process from inside a service task ?

guillaume1 — Fri, 23 May 2014 06:24:55 GMT

I don't know how to start a CallActivity when using custom palette element.
The documentation about this topic says that you have to use a JavaDelegate class and the XML generated by the custom element is a ServiceTask.

In fact, as said in my message, the custom palette element is a 'configuration mask' for a CallActivity with a complex input map.
We have some core processes that have a complex input map with mandatory/optionnal field. Having a custom palette element allow an easier integration of these processes: they have a specific Icon, and more important a custom form to set the input.

Re: How to properly start a new process from inside a service task ?

jbarrez — Tue, 27 May 2014 07:57:15 GMT

> I don't know how to start a CallActivity when using custom palette element.

You would need to extend the CallActivityBehavior, or at least inspire yourself by the code there.

Re: How to properly start a new process from inside a service task ?

guillaume1 — Tue, 27 May 2014 12:51:05 GMT

Ok, I'll try that. So we can re-use any activiti Behavior as a custom palette element delegate ?

Re: How to properly start a new process from inside a service task ?

guillaume1 — Tue, 27 May 2014 13:10:45 GMT

So it works, but now I have this error when the called sub-process terminates:
<java>
java.lang.ClassCastException: org.activiti.engine.impl.bpmn.helper.ClassDelegate cannot be cast to org.activiti.engine.impl.pvm.delegate.SubProcessActivityBehavior
at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessEnd.eventNotificationsCompleted(AtomicOperationProcessEnd.java:49)
</java>

In the AtomicOperationProcessEnd#eventNotificationsCompleted method the activity behavior is a ClassDelegate, and this last does not implements the SubProcessActivityBehavior.

in the eventNotificationCompleted(), around line 49
<java>
…
subProcessActivityBehavior = (SubProcessActivityBehavior) activity.getActivityBehavior();
…
</java>
debugger view:
<code>
activity = {org.activiti.engine.impl.pvm.process.ActivityImpl@6664}"Activity(test)"
activities = {java.util.ArrayList@6676} size = 0
activityBehavior = {org.activiti.engine.impl.bpmn.helper.ClassDelegate@6102}
activityBehaviorInstance = {my.palette.Test@6084}
bpmnActivityBehavior = {org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior@6706}
className = {java.lang.String@6703}"my.palette.Test"
executionListenerInstance = null
fieldDeclarations = {java.util.ArrayList@6704} size = 6
multiInstanceActivityBehavior = null
taskListenerInstance = null
</code>

Any idea about how to fix this? (I'm using activiti 5.14, so maybe it is a fixed bug)

Re: How to properly start a new process from inside a service task ?

jbarrez — Fri, 30 May 2014 09:42:24 GMT

Hmm seens like you've hit a bug here in the core engine

The fix is easy, I've done it already on master: https://github.com/Activiti/Activiti/commit/92262ae31fda26a153e16b1fe5e4eed5c1fa9903

There is a workaround, but it's pretty complex: you can replace the default Classdelegate with one that has the fix in the commit above. The ActivityBehavipourFactory is responsible for creating it, and you can plugin in your own version of it.

Re: How to properly start a new process from inside a service task ?

guillaume1 — Fri, 30 May 2014 10:43:27 GMT

Thank you very much for solving the bug so quickly and for your help about this topic.
I'll try to put the workaround in place in our current version in order to use the custom palette.

By the way I always got a nasty error message from eclipse that complains about the custom palette jar I have created:
"There was an error when processing an extension to Activiti Designer. The extension at location x/y/z.jar is not open. Please make sure it is not installed inside the Eclipse workspace."

Custom elements are not displayed, and processes containing those element are not loaded too !

However If I open a blank diagram (either a new or a saved one) in a new project, then the palette is loaded and I can use it with my other projects and open processes definition that contains those custom activity.
So I'm still not confident about the custom palette: I fear that for some reason the work around won't work anymore and that will prevent me to open any of the processes that will use the palette.

I found that some other people had the same issue, but I did not find any real fix. Do you have any idea about this ?

Re: How to properly start a new process from inside a service task ?

jbarrez — Mon, 02 Jun 2014 07:59:37 GMT

Hmmm could it be the old process was made with a palette that now "doesn't exist" anymore? Or do you also see it when the palette hasn't changed yet.

The workaround shouldn't have influence, cause it's on the engine (runtime - execution) level where the fix is.

Re: How to properly start a new process from inside a service task ?

guillaume1 — Mon, 02 Jun 2014 08:52:27 GMT

I always had the issue with my eclipse version (Eclipse SDK Version: 4.2.2 Build id: M20130204-1200) and the 5.14 designer.
I don't think it is related to the workaround, I think something is wrong with eclipse…

Re: How to properly start a new process from inside a service task ?

jbarrez — Mon, 02 Jun 2014 10:05:29 GMT

Seems to be an older version of Eclips, no. Maybe verify if it's still the same on the latest version?

Re: How to properly start a new process from inside a service task ?

guillaume1 — Mon, 02 Jun 2014 12:17:06 GMT

Same issue with latest eclipse: the palette is loaded when I start a new project, but trying to use the palette in my current project does not work until I open a blank process in a side empty project.

Something must be wrong with my current project settings.

Many thanks for all your help.

Re: How to properly start a new process from inside a service task ?

jbarrez — Wed, 04 Jun 2014 07:49:58 GMT

Strange - sorry we can't help you much further in this
Do post an update if you would find a solution. Maybe more people suffer from this!