Save project B from project A

Question

I have a requirement to update a certain project (project B) whenever a certain other project is changed (project A).
For that, I am planning to create a subsystem that is called whenever project A is changed (works fine).
I am also able to load project B (cl_dpr_appl_object_manager=>LOAD_PROJECTS ).
However, how can I save project B?
Using cl_dpr_appl_object_manager=>SAVE_CHANGES will not work, since it will also save project A and therefore cause an endless loop.

Answer 1

Hi Daniel,
  A subsystem is a good idea. However, I am not sure you would run into an infinite loop. When you call a save on Project B, yes a save will be called on Project A as well. However, since A has already committed, there will be no changes on it (the method has_changes() will fail) and hence save will do no further processing.
  However, you might run into issue with DPR_TRANSACTION_MANAGER if not anything else.
  While you will have to play around the transaction manager, it would be a good bet to call the save in the method INITIALIZE_AFTER_SAVE() of the subsystem, since that will be called after the first project has been persisted.
  Do use the BAPI as mentioned in the other reply and not he save_changes() method of the object manager.
  If project B will be updated once 'save' is pressed, then another idea would be to write an exit that will be called immediately when the 'save' button is pressed and does all the required updates to B before handing control back to project A. Only one save will then be performed and both the projects will be committed (since both are in the same session). In this case, be sure that the subsystem doesn't do a save since the save of the first project will be sufficient.
Hope this helps,
Best Regards,
Prashanth