I have a form with a project list on it, from here a sub-form can be opened for editing some of the details.

If details are changed and saved in the sub form, how do I notify the original form of changes?

Currently both the parent and child forms have their own copy of the business object registered. I pass in the ID required to the child form.

Is it perhaps better (in this case) to pass in the currently referenced entity from the parent form instead, or is there a better way?