Alternatives to skipExpression?

Camunda 7 Topics Discussion & Questions
1

Hi there,

I’m on my way to migrate Activiti to Camunda in our Information System and 99% of things are fine. But there is an Activiti feature we used a lot and, before changing all our BPMN, I want to be sure there is no other alternative in Camunda.

Activiti feature was : activiti:skipExpression. This expression is totally ignored by Camunda Process Engine.

This feature seems to be out of the scope right now : Operating Camunda 7 | Camunda Platform 8 Docs

In this post, a basic (and legit !) alternative is submitted by someone : How to skip a task in camunda?

But I’m just asking myself : is there another viable workaround who avoid me to change every BPMN in our system ?

Thanks a lot,
Matthieu

2

Hi Matthieu, you may want to think about using process instance modification APIs to skip tasks. With process modification you can move the process as needed. For more information see: https://docs.camunda.org/manual/latest/user-guide/process-engine/process-instance-modification/

I’m thinking it could be used in a listener at the start of a task. I’ll have a look at it to see if it’s feasible

Joe

3

Here’s an example though it seems to create two tasks which disappear when one is completed, still need to investigate. The code is as follows:
execution.getProcessEngineServices().getRuntimeService().createProcessInstanceModification(execution.getProcessInstanceId()).startAfterActivity(execution.getCurrentActivityId()).cancelActivityInstance(execution.getActivityInstanceId()).execute()

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4

Hi Joe,

Thanks a lot for this workaround. I’m a beginner with Camunda and I was not aware of all possibilities with process modification who could replace well the old “attribute”.

I’ll do my tests but it seems very clear to me.

Thanks again,
Matthieu

5

Hi Matthieu,
Trying to modify a process from within a process can lead to unpredictable behavior which is what I discovered earlier in the thread so it should not be your course of action. Using the APIs outside the context of the process will work. I’m imagining a service that could be called from an activity and that service could then modify the process instance via REST, say. Make sense?

Joe

6

Hi Joe,

Yes, I understand well what you explained and it make sense to me.

Thanks again,
Matthieu