UICollection View & performBatchUpdate - nsfetchedresultscontroller

Question

I a trying to build an application where i can use UICollectionviewcontroller & NSFetchresultcontroller , i found the following link "https://github.com/AshFurrow/UICollectionView-NSFetchedResultsController/blob/master/AFMasterViewController.m
Here you can find the Code
#pragma mark - UICollectionVIew
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
return [[self.fetchedResultsController sections] count];
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> sectionInfo = [self.fetchedResultsController sections][section];
return [sectionInfo numberOfObjects];
}
// The cell that is returned must be retrieved from a call to -dequeueReusableCellWithReuseIdentifier:forIndexPath:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
AFCollectionViewCell *cell = (AFCollectionViewCell *)[collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];
NSManagedObject *object = [self.fetchedResultsController objectAtIndexPath:indexPath];
#warning Unimplement Cell Configuration
return cell;
}
#pragma mark - Fetched results controller
- (NSFetchedResultsController *)fetchedResultsController
{
if (_fetchedResultsController != nil) {
return _fetchedResultsController;
}
#warning Unimplemented fetched results controller
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:<#entity#>inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:<#batch size#>];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:<#descriptor#> ascending:NO];
NSArray *sortDescriptors = #[sortDescriptor];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:self.managedObjectContext sectionNameKeyPath:nil cacheName:#"Master"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return _fetchedResultsController;
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
NSMutableDictionary *change = [NSMutableDictionary new];
switch(type) {
case NSFetchedResultsChangeInsert:
change[#(type)] = #[#(sectionIndex)];
break;
case NSFetchedResultsChangeDelete:
change[#(type)] = #[#(sectionIndex)];
break;
}
[_sectionChanges addObject:change];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
NSMutableDictionary *change = [NSMutableDictionary new];
switch(type)
{
case NSFetchedResultsChangeInsert:
change[#(type)] = newIndexPath;
break;
case NSFetchedResultsChangeDelete:
change[#(type)] = indexPath;
break;
case NSFetchedResultsChangeUpdate:
change[#(type)] = indexPath;
break;
case NSFetchedResultsChangeMove:
change[#(type)] = #[indexPath, newIndexPath];
break;
}
[_objectChanges addObject:change];
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
if ([_sectionChanges count] > 0)
{
[self.collectionView performBatchUpdates:^{
for (NSDictionary *change in _sectionChanges)
{
[change enumerateKeysAndObjectsUsingBlock:^(NSNumber *key, id obj, BOOL *stop) {
NSFetchedResultsChangeType type = [key unsignedIntegerValue];
switch (type)
{
case NSFetchedResultsChangeInsert:
[self.collectionView insertSections:[NSIndexSet indexSetWithIndex:[obj unsignedIntegerValue]]];
break;
case NSFetchedResultsChangeDelete:
[self.collectionView deleteSections:[NSIndexSet indexSetWithIndex:[obj unsignedIntegerValue]]];
break;
case NSFetchedResultsChangeUpdate:
[self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:[obj unsignedIntegerValue]]];
break;
}
}];
}
} completion:nil];
}
if ([_objectChanges count] > 0 && [_sectionChanges count] == 0)
{
[self.collectionView performBatchUpdates:^{
for (NSDictionary *change in _objectChanges)
{
[change enumerateKeysAndObjectsUsingBlock:^(NSNumber *key, id obj, BOOL *stop) {
NSFetchedResultsChangeType type = [key unsignedIntegerValue];
switch (type)
{
case NSFetchedResultsChangeInsert:
[self.collectionView insertItemsAtIndexPaths:#[obj]];
break;
case NSFetchedResultsChangeDelete:
[self.collectionView deleteItemsAtIndexPaths:#[obj]];
break;
case NSFetchedResultsChangeUpdate:
[self.collectionView reloadItemsAtIndexPaths:#[obj]];
break;
case NSFetchedResultsChangeMove:
[self.collectionView moveItemAtIndexPath:obj[0] toIndexPath:obj[1]];
break;
}
}];
}
} completion:nil];
}
[_sectionChanges removeAllObjects];
[_objectChanges removeAllObjects];
}
#end
I have the Following error
NSFetchedResultsController during a call to -controllerDidChangeContent:. -[__NSArrayI unsignedIntegerValue]
The NS Log for the _sectionsChange give me the following output
1 = (
6
);
I am trying to know how to solve this problem , so any help would be appreciated
Thank you

Answer 1

NO , the Error was fixed after i updated the following code:
{
case NSFetchedResultsChangeInsert:
[self.collectionView insertItemsAtIndexPaths:#[obj]];
[self.collectionView.window endEditing:YES];
break;
}
Instead of case NSFetchedResultsChangeInsert:
[self.collectionView insertItemsAtIndexPaths:#[obj]];
break;
Then delete all objects , create everything from scratch , problem solved !