Subtask inherited values not changing later if parent value changes

[Cody Reeves]

When a subtask is created, it inherits the value from a custom field 'Customer' on the parent task via a Post Function 'The value(s) of field Customer will be set from the issue's parent (replacing existing value). This works great!

Later, we found out the parent task was incorrect and we changed the parent value to a different customer but the customer field on the subtasks did not change. This is not good!

How do I get around this? 

[Andrea Carl]

A couple of options:

1. Make editing of the parent data only available in a transition in order to force a post function update.  (Remove the field from the edit screen and add it to a transition screen on a self-directed transition.)
2. Look at adding post functions in the sub-task workflow to grab data from the parent.

[Cody Reeves]

Thanks for the quick answer! Sorry to hear this is a limitation though.

[Nic Brough -Adaptavist-]

That's correct behaviour - subtasks are issues in their own right, and although grabbing a default from the parent is quite handy when they're created, the fields belong to the subtask, they're not tied to the parent.

You'll need a listener that can catch "parent updated" and run some code to iterate over the sub-tasks and  update the values.  I don't think there is one of these available for Cloud though.

(This is a weakness in JIRA in my opinion - there should be a way to flag subtask fields as directly inherited from the parent so that they appear, read only, on the sub-tasks, so you can search and sort on them, see them when looking only at the subtasks, and you don't have to think about maintaining them)