Conditional execution - subtask created only if custom field is empty

[erica_dahl]

I'm trying to modify an existing subtask so that it is only created if a specific field in the task is empty.  

Basically, I would like to generate a subtask to assign a project number only if the custom field "project number" is empty

It seems that the conditional execution for the "create issue" post function should work, and I found  out how to specify the custom field, but can't figure out how to say "if field is empty"

[Niranjan]

Hi @erica_dahl ,

Try with issue.get("customfield_12345") is null  in Conditional Execution

where customfield_12345 is the field id of project number