Untitled

How does one have a Singleton Observe Changes to Core Data Model?

@implementation Singleton

 

+ (Singleton *) sharedInstance

{

    static Singleton *sharedInstance = nil;

    static dispatch_once_t onceToken;

    dispatch_once(&onceToken, ^{

        sharedInstance = [[Singleton alloc] init];

 

        // Do any other initialisation stuff here

        AppDelegate *appDelegate = (AppDelegate *) [[UIApplication sharedApplication] delegate];

        NSManagedObjectContext *myManagedObjectContext = appDelegate.managedObjectContext;

 

        [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(handleDataModelChange:)

                                    name:NSManagedObjectContextObjectsDidChangeNotification

                                                   object:myManagedObjectContext];

 

    });

    return sharedInstance;

}

 

- (void)handleDataModelChange:(NSNotification *)note;

{

    NSSet *updatedObjects = [[note userInfo] objectForKey:NSUpdatedObjectsKey];

    NSSet *deletedObjects = [[note userInfo] objectForKey:NSDeletedObjectsKey];

    NSSet *insertedObjects = [[note userInfo] objectForKey:NSInsertedObjectsKey];

 

    // Do something in response to this

    NSLog(@"%@ Objects Updated, %@ Objects Deleted, %@ Objects Inserted",[updatedObjects count],[deletedObjects count],[insertedObjects count]);

}

 

@end

       

- (void)handleDataModelChange:(NSNotification *)note;

       

Deleted, %@ Objects Inserted",[updatedObjects count],[deletedObjects count],[insertedObjects count]);