NSManagedObjectContextObjectsDidChangeNotification not always called instantly

I have an Mac Application using a NSPersistentDocument. I want to get notified when Objects are deleted to save this information using Core Data. So I'm listening for NSManagedObjectContextObjectsDidChangeNotification. Often it is called instantly when objec开发者_Go百科ts are deleted, but sometimes it is only called after the persistent document is saved with all deleted objects not being notified before. Because I want to let the user directly export all existing objects (and not the deleted anymore) what to I have to do to become notified instantly to save the delete information or do I have to use it in another way?

NSManagedObjectContextObjectsDidChangeNotification is no longer issued as frequently or quickly on 10.7 as on 10.6. You can force Core Data to issue the notification (assuming there are changes) by calling -[NSManagedObjectContext processPendingChanges].