One Quickie
Invalidating a single row (UITableView->General)
Sometimes you want to update a single row of a tableview as new information comes in. Such as loading something in the background and you want to update a percentage being shown in the cell. You could -reloadData, but don't. That's an awfully big hammer. Instead just reload a row
NSIndexPath *indexPath = [NSIndexPath indexPathForRow: row
inSection: 0];
NSArray *array = [NSArray arrayWithObject: indexPath];
[_playlistTableView reloadRowsAtIndexPaths: array
withRowAnimation: UITableViewRowAnimationNone];