AQGridView backed by a NSFetchedResultsController - objective-c

Question

I'm trying to implement a AQGridView that uses a fetched results controller as its datasource.
I'm not particular sure how to handle the NSFetchedResultsController delegate methods using the grid view; namely the content changing ones. I understand how to use the FRC for the other grid view datasource delegates.
Could somebody point me in the right direction?

Answer 1

The result should look a little something like this:
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[gridView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type)
{
case NSFetchedResultsChangeInsert:
break;
case NSFetchedResultsChangeDelete:
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
ChannelPageViewController *currentPageController, *destinationPageController;
NSIndexSet * indices = [[NSIndexSet alloc] initWithIndex: indexPath.row];
NSIndexSet *newIndices = [[NSIndexSet alloc] initWithIndex:newIndexPath.row];
switch(type) {
case NSFetchedResultsChangeInsert:
[gridView insertItemsAtIndices:newIndices withAnimation:AQGridViewItemAnimationNone];
break;
case NSFetchedResultsChangeDelete:
[gridView deleteItemsAtIndices:indices withAnimation:AQGridViewItemAnimationNone];
break;
case NSFetchedResultsChangeUpdate:
[gridView reloadItemsAtIndices:indices withAnimation:AQGridViewItemAnimationNone];
break;
case NSFetchedResultsChangeMove:
[gridView deleteItemsAtIndices:indices withAnimation:AQGridViewItemAnimationNone];
[gridView insertItemsAtIndices:newIndices withAnimation:AQGridViewItemAnimationNone];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[gridView endUpdates];
if ([[frc fetchedObjects] count] == 1) {
[gridView reloadData];
}
}

Answer 2

Since AQGridView doesn't have sections, the best way to handle it would be to implement the NSFethcedresultscontroller delegate methods, and ignore any code for the cases related to updated sections. Also make sure you initialize the fetchrequest with no sectionNameKeyPath.
Then just follow the normal pattern for updating rows, but using NSIndexSet instead of NSIndexPath and InsertItemAtIndicies/DeleteItemAtIndicies instead of insertRowAtIndexPath/deleteRowAtIndexPath
I'm moving my AQGridView to CoreData now, so I'll post any updates to my answer as soon as I'm done...

Answer 3

When the content changes I do a
[self.gridView reloadData];
or something like that in your case. It is exactly the same as with a tableview.