//appdelegate.m
- (void) resetApplicationModel
{
    __managedObjectContext = nil;
    __managedObjectModel = nil;
    __persistentStoreCoordinator = nil;
   // _allPageViewController.controller = nil;
    
    NSError *error;
    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"abc.sqlite"];
    
    
    if ([[self.managedObjectContext persistentStoreCoordinator] removePersistentStore:[[[self.managedObjectContext persistentStoreCoordinator] persistentStores] lastObject] error:&error])
    {
        // remove the file containing the data
        
        if([[NSFileManager defaultManager] removeItemAtURL:storeURL error:&error])
        {
            __persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
            if([__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error] == nil)
            {
                NSLog( @"could not create new persistent store at %@ - %@", [storeURL absoluteString], [error localizedDescription]);
            }
        }
        else
        {
            NSLog( @"could not remove the store URL at %@ - %@", [storeURL absoluteString], [error localizedDescription]);
        }
        
    }
    else
    {
        NSLog( @"could not remove persistent store - %@", [error localizedDescription]);
    }
    
     [[NSNotificationCenter defaultCenter] postNotificationName:@"kNotificationDestroyAllNSFetchedResultsControllers" object:self];
}

//RootViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
 
      
        [[NSNotificationCenter defaultCenter] addObserverForName:@"kNotificationDestroyAllNSFetchedResultsControllers" object:nil queue:nil usingBlock:^(NSNotification *note) {
            NSLog(@"[%@] must destroy my nsfetchedresultscontroller", [self class]);
            //m_controller = nil;
        
        
        
            NSError *error;
            if (![m_controller performFetch:&error]) {
                /*
                 Replace this implementation with code to handle the error appropriately.
        
                 abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
                 */
                NSLog(@"Unresolved error %@, %@", error, [error localizedDescription]);
                abort();
            }
                        
            }];
    }
    return self;
}