NSFetchedResultsController refresh refetch?

Question

I want to refetch data from my NSFetchedResultsController using a different predicate which is set using a boolean value. How do I refresh NSFetchedResultsController to fetc

Answer 1

I had similar problem, I couldn't figure out why my collection view doesn't refresh its cells. Adding the method below fixed my problems.

-(void)didUpdateObjectAtIndexPath:(NSIndexPath *)indexPath{
    UICollectionView *strongCollectionView = self.collectionView;
    [strongCollectionView  reloadItemsAtIndexPaths:@[indexPath]];


}

Answer 2

Don't forget to set fetchedResultsController = nil before performFetch. Otherwise it will use the old one.

Answer 3

Here's how we do it in an application:

// Assuming these exist
NSPredicate * predicate;
NSString * cacheName;

[[fetchedResultsController fetchRequest] setPredicate:predicate];
[NSFetchedResultsController deleteCacheWithName:cacheName];

NSError * error = nil;
[fetchedResultsController performFetch:&error];
if (error) {
    // report error
}