controllerWillChangeContent not being called when deleting all entries of an entity - objective-c

Question

Below is the method I have implemented for a tableView "reset" button. I've verified that the entries in the Entity are being deleted, however my controllerWillChangeContent is not being called after the deletion. Is there a way to call this method manually?
CoreDataStack *coreDataStack = [[CoreDataStack alloc]init];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:#"FoodEntry"];
[fetchRequest setIncludesPropertyValues:NO];
NSError *error;
NSArray *fetchedObjects = [coreDataStack.managedObjectContext executeFetchRequest:fetchRequest error:&error];
for (NSManagedObject *object in fetchedObjects)
{
[coreDataStack.managedObjectContext deleteObject:object];
}
error = nil;
[coreDataStack.managedObjectContext save:&error];
EDIT : FRC CODE
- (NSFetchedResultsController *)fetchedResultsController {
if (_fetchedResultsController != nil) {
return _fetchedResultsController;
}
CoreDataStack *coreDataStack = [CoreDataStack defaultStack];
NSFetchRequest *fetchRequest = [self entryListFetchRequest];
_fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:coreDataStack.managedObjectContext sectionNameKeyPath:nil cacheName:nil];
_fetchedResultsController.delegate = self;
return _fetchedResultsController;
}

Answer 1

Can't be certain, without knowing the internals of CoreDataStack, but it looks like you are using two different stacks: notice that your code uses:
CoreDataStack *coreDataStack = [[CoreDataStack alloc] init];
whereas the FRC uses:
CoreDataStack *coreDataStack = [CoreDataStack defaultStack];
You could change your code to use the same as the FRC (defaultStack is probably a singleton and will return the same stack whenever it is called). But if the FRC is in the same class as the delete code, it will be easier (and clearer) to just use the FRC's managedObjectContext:
NSManagedObjectContext *context = self.fetchedResultsController.managedObjectContext
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] initWithEntityName:#"FoodEntry"];
[fetchRequest setIncludesPropertyValues:NO];
NSError *error;
NSArray *fetchedObjects = [context executeFetchRequest:fetchRequest error:&error];
for (NSManagedObject *object in fetchedObjects)
{
[context deleteObject:object];
}
error = nil;
[context save:&error];
Incidentally, it's always worth checking if the executeFetchRequest: and save: return an error.