Setting an execution's local variable according to the flow led to the sub-process

Question

I have a BPMN process with a sub-process within it. There are different flows leading to the sub-process. And I want to know, once inside the sub-process' execution, which flow has led to the current execution.

To this end I think variables could be handy. So I conducted a test in which I wrote a couple of scripts for flow's listener leading to the sup-process.

execution.setVariableLocal("V", "Expecting it to be local to the sub-process' execution");

But it turned out that execution points to the outer/parent process and thus the variable was set in parent scope.

So is there anyway to set an execution local variable from outside?

Answer 1

The simplest approach (basically use getVariable instead of getVariableLocal):

1. Add an execution listener to the take event of the sequence flows of interest

2. In the execution listener, perform

   execution.setVariableLocal("flowTaken", execution.getCurrentTransitionId());
   

3. Access it in the sub process via

   execution.getVariable("flowTaken");
   

If it has to be a local variable in the sub process:

1. Add an execution listener to the take event of the sequence flows of interest

2. In the execution listener, perform

   execution.setVariableLocal("flowTaken", execution.getCurrentTransitionId());
   

3. In the BPMN 2.0 XML, define a variable input mapping for the subprocess:

   <subProcess ...>
     <extensionElements>
       <camunda:inputOutput>
         <camunda:inputParameter name="flowTakenAsSubprocessLocalVariable">${flowTaken}</camunda:inputParameter>
       </camunda:inputOutput>
     </extensionElements>
     ...
   </subProcess>