performFetchAndUpdateTableView: that performs a fetch request on NSFetchedResultsController and updates table view

gistfile1.m

// ONLY WORKS WITH ONE SECTION!!
- (BOOL) performFetchAndUpdateTableView:(NSError **)error
{
    NSArray *objectsBefore = [self.fetchedResultsController.fetchedObjects retain];
    
    BOOL result = [self.fetchedResultsController performFetch:error];
    if (result) {
        
        NSArray *objectsAfter = self.fetchedResultsController.fetchedObjects;
        
        NSMutableArray *insertedObjects = [[objectsAfter mutableCopy] autorelease];
        [insertedObjects removeObjectsInArray:objectsBefore];
        
        NSMutableArray *removedObjects = [[objectsBefore mutableCopy] autorelease];
        [removedObjects removeObjectsInArray:objectsAfter];
        
        NSMutableArray *insertedIndexPaths = [NSMutableArray arrayWithCapacity:insertedObjects.count];
        [insertedObjects enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            [insertedIndexPaths addObject:[NSIndexPath indexPathForRow:[objectsAfter indexOfObject:obj] inSection:0]];
        }];
        
        NSMutableArray *removedIndexPaths = [NSMutableArray arrayWithCapacity:removedObjects.count];
        [removedObjects enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            [removedIndexPaths addObject:[NSIndexPath indexPathForRow:[objectsBefore indexOfObject:obj] inSection:0]];
        }];
        
        if (insertedIndexPaths.count > 0 || removedIndexPaths.count > 0) {
            [_tableView beginUpdates];
            
            [_tableView insertRowsAtIndexPaths:insertedIndexPaths 
                              withRowAnimation:UITableViewRowAnimationFade];
            [_tableView deleteRowsAtIndexPaths:removedIndexPaths 
                              withRowAnimation:UITableViewRowAnimationFade];
            
            [_tableView endUpdates];
        }
    }
    
    [objectsBefore release];
    return result;
}