Problem with a conditonal start event

I have written a subprocess with a conditional event non-Interrupt start event to start a subprocess. This willl be called in case a variable called “testcollection” (it’s an arraylist with strings) has been created or updated in the main process. If i add the expression ${!empty testcollection} in the start event this seems to be always false (the subprocess will not be started).
In case the expression has to be set ${true} and I check the expression ${!empty testcollection} in the first task of the subprocess it works always as expected.
What mistake do I make?

Hi @Samsun17,

you need to trigger the evaluation of the conditional start event. To do so, you can use the following REST API endpoint: POST /condition. For more information, please see the documentation about Conditional Start Events.

Edit: short clarification as you are using conditional start events in context of an Event Sub Process. In this case it behaves differently. Please see the documentation about Triggering via Variable API

Cheers,
Tassilo

Hi Tassilo,

thanks for your fast feedback. But I didn’t undestand. I thought that the conditional event will be triggered by creating the variable testCollection (Triggering via Variable API). This will be generated automatically during the main process (by executing a decision matrix).
So, why do I need an external call?

Best regards,
Steffen