Core Data in Objective-C, 3rd Edition

Consuming Changes from iCloud

Whether we’re using a standard Core Data stack or a UIManagedDocument, we need to know when changes come in from iCloud. Changes will always come in asynchronously, and our NSManagedObjectContext won’t know about them. It is our responsibility to notify our NSManagedObjectContext of any incoming changes. To do that, we first need to listen for the change notification via the NSNotificationCenter.

iCloud/PPRecipes/PPRAppDelegate.m

  NSString *name = nil;
  name = NSPersistentStoreDidImportUbiquitousContentChangesNotification;
  NSManagedObjectContext *moc = [[self dataController] managedObjectContext];
  [center addObserver:self
             selector:@selector(mergePSCChanges:)
                 name:name
 object:[moc persistentStoreCoordinator]]; ...