Fetched Results Controller Boilerplate

Fetched Results Controller

- (NSFetchedResultsController *)fetchedResultsController
{
    if (_fetchedResultsController != nil)
    {
        return _fetchedResultsController;
    }
    
    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Tag" inManagedObjectContext:[CoreDataHelper sharedInstance].managedObjectContext];
    [fetchRequest setEntity:entity];
    
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"tagName" ascending:YES];
    NSArray *sortDescriptors = [NSArray arrayWithObjects:sortDescriptor, nil];
    [fetchRequest setSortDescriptors:sortDescriptors];
    
    NSFetchedResultsController *frc = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
                                                                          managedObjectContext:[CoreDataHelper sharedInstance].managedObjectContext
                                                                            sectionNameKeyPath:nil
                                                                                     cacheName:@"Tag"];
    frc.delegate = self;
    self.fetchedResultsController = frc;
    
	NSError *error = nil;
	if (![self.fetchedResultsController performFetch:&error])
    {
	    NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
	}
    
    return _fetchedResultsController;
}

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
    [self.tableView reloadData];
}