DisplayOrder

//This function adds a new Entity

- (void)insertNewObject
{
    Test *test = [NSEntityDescription insertNewObjectForEntityForName:@"Test" inManagedObjectContext:self.managedObjectContext];

 NSManagedObject *lastObject = [self.controller.fetchedObjects lastObject];

float lastObjectDisplayOrder = [[lastObject valueForKey:@"displayOrder"] floatValue];

[test setValue:[NSNumber numberWithDouble:lastObjectDisplayOrder + 1.0] forKey:@"displayOrder"];

}

- (NSFetchedResultsController *)controller
{
    if (m_controller != nil)
    {
        return m_controller;
    }

    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

   NSEntityDescription *entity = [NSEntityDescription entityForName:@"TEST" inManagedObjectContext:self.managedObjectContext];
    [fetchRequest setEntity:entity];

     [fetchRequest setFetchBatchSize:20];

    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"displayOrder" ascending:YES];

    NSArray *sortDescriptors = [NSArray arrayWithObjects:sortDescriptor, nil];

    [fetchRequest setSortDescriptors:sortDescriptors];

   NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
    aFetchedResultsController.delegate = self;
    self.controller = aFetchedResultsController;

    NSError *error = nil;
    if (![self.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 userInfo]);
        abort();
    }

    return  m_controller;
}