How to pass a ManagedObjectID to the main thread

Question

I am saving a ManagedObject on a background thread with its own context. I would then like to send a notification back to the main thread with the managed object context so that I can use its data.

According to the docs it looks like I instead should be passing the id to the main thread rather than the object.

Is this correct, what should I do with that Id then? Should I do a fetch on core data from the main thread with the ID to get a ManagedObject on the main thread?

Answer 1

You're correct in understanding the passing of the object ID back to the main thread. Once you've done that, use the objectWithID: method, passing the NSManagedObjectID sent from the other thread, to get the object out of the main thread's NSManagedObjectContext instance.

NSManagedObject *objectForThisThread = [managedObjectContextForThisThread objectWithID:managedObjectID];