Question

I have been looking at the NSFetchedResultsControllerDelegate Protocol Reference and some sample code online and have noticed two different implementations for updating a UITableViewCell when calling:

- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
    atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
    newIndexPath:(NSIndexPath *)newIndexPath {

Can anyone explain the two different approaches?

They are:

// ONE
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath]atIndexPath:indexPath];
break;

OR

// TWO
case NSFetchedResultsChangeUpdate:
[self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;

Answer 1

As a selectors’ names imply, in case ONE a cell is configured in a custom method (not Apple’s API) and most probably will be updated when a reload of the table view occurs.

In a TWO case reloadRowsAtIndexPaths: is UITableView method where you have an animation effect “for free”. How and where a cell is updated? Can’t tell without a code.