How to return a variable form an embedded form on a multi-instance subprocess

Camunda 7 Topics Discussion & Questions
1

Hello all

I would like to collate the various “Approved” Boolean responses on a form served as multiple parallel instances of a sub-process.
I suspect I would have to initialize a JSON process variable, vJsonResponses, before the MI process is activated and then add a property to it for each instance of the MI. However I cannot get the variable to update.

Why is the Json variable not updating? Can this be done with EL / JS?

Test-MultiInstance-01.bpmn (9.1 KB)

Test-MultiInstance-01.png696×386 9.17 KB

2

@eugene take a look at:

In that thread, there is code example of running Multi-Instance on a Business Rule Task and for the output of each instance, the result is added to a array/collection. This should cover your use case to show the collated boolean responses in your Collate user task.

3

Thanks Stephen

I had a look at your link, but fail to see where I’m going wrong. Is my vJsonResponses.prop(loopCounter,vApprove); correct?

4

Can you confirm that doing setVariable('vJsonResponses', JSON("{}")) works?

5

Yip. In both Cockpit and on the final Collate form it appears as a JSON object, {}

6

I believe your problem is that in your End Listener on the Approve User Task, you are not updating the process variable. Look at my code examples from the DMN pattern.

7

Also take a look at how to work with JSON arrays with SPIN: https://docs.camunda.org/manual/7.6/reference/spin/json/01-reading-json/#work-with-json-arrays

8

Okay, I got it working, but no idea of how above-board this is, there might be a much better way of doing it:

Replace the vJsonResponses.prop(loopCounter,vApprove); with
execution.setVariable(‘vJsonResponses’,vJsonResponses.prop(loopCounter,vApprove));

Thanks for all your assistance @StephenOTT