Question

Does anyone has sample code for ordering in UITableView using NSOrderedSet?

Had read many articles about reordering, but still don’t understand how to do this in iOS5.

Answer 1

Hi i implemented it like this. The “currentObject” is root object of the relationship and “subItems” the name of the ordered relationship in the model which is managed by the UITableViewController.

 - (void)moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
 {

   NSMutableOrderedSet* orderedSet = [self.currentObject mutableOrderedSetValueForKey:@"subItems"];

   NSInteger fromIndex = fromIndexPath.row;
   NSInteger toIndex = toIndexPath.row;

   // see  http://www.wannabegeek.com/?p=74
   NSIndexSet *indexes = [NSIndexSet indexSetWithIndex:fromIndex];

   if (fromIndex > toIndex) {
    // we're moving up
    [orderedSet moveObjectsAtIndexes:indexes toIndex:toIndex];
   } else {
    // we're moving down
    [orderedSet moveObjectsAtIndexes:indexes toIndex:toIndex-[indexes count]];
   }

   [self.dataStore saveObjectContext];
 }