NSFetchedResultsController with predicate gets NSFetchedResultsChangeDelete after update - ios

Question

There is some serious issue with NSFetchedResultsController which has a predicate. the issue occurs after a value is updated for a property of a contact. so that's how its configured:
NSEntityDescription *entityDescription = [NSEntityDescription entityForName:#"Contacts" inManagedObjectContext:_addressbookMainObjectContext
NSSortDescriptor *sortNameDescriptor = [[NSSortDescriptor alloc] initWithKey:#"lastnameFirstLetter" ascending:YES selector:#selector(localizedCaseInsensitiveCompare:)];
NSSortDescriptor *sortNameDescriptor1 = [[NSSortDescriptor alloc] initWithKey:#"firstName" ascending:YES selector:#selector(localizedCaseInsensitiveCompare:)];
NSArray *sortDescriptors = [NSArray arrayWithObjects:sortNameDescriptor, sortNameDescriptor1, nil];
NSFetchRequest *fetchRequest = [NSFetchRequest new];
[fetchRequest setEntity:entityDescription];
[fetchRequest setSortDescriptors:sortDescriptors];
fetchRequest.predicate = [NSPredicate predicateWithFormat:#"contactType == 3"];;
NSFetchedResultsController *fetchedResultsController =
[[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:_addressbookMainObjectContext
sectionNameKeyPath:#"sectiononIdentifier"
cacheName:nil];
_fetchResultController = fetchedResultsController;
_fetchResultController.delegate = self;
the predicate is set to fetch filtered rows.
and this is how the parent child context is configured:
_addressbookMainObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
_addressbookMainObjectContext setMergePolicy:NSMergeByPropertyObjectTrumpMergePolicy];
_addressbookMainObjectContext setParentContext:_writerContext];
_writerContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
[_writerContext setMergePolicy:NSMergeByPropertyObjectTrumpMergePolicy];
[_writerContext setPersistentStoreCoordinator:_persistentStoreCoordinator];
for updating a row another private context is used to do the job:
NSManagedObjectContext *ctx = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
[ctx setMergePolicy:NSMergeByPropertyObjectTrumpMergePolicy];
[ctx setParentContext:[PalDataCache sharedInstance].addressbookMainObjectContext];
[ctx performBlockAndWait:^{
NSError *errorAllCons = nil;
NSArray *allCons = [context executeFetchRequest:allContacts error:&errorAllCons];
Contacts * contact = [allCons objectAtIndex:0];
contact.pictureUpdatedForRedownload = [NSNumber numberWithBool:YES];
}];
so after saving the changes in this temporary context. the NSFetchedResultsControllerDelegate is getting triggered:
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tableView = self.tableView;
switch(type)
{
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:#[newIndexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
break;
case NSFetchedResultsChangeDelete:
{
[tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
break;
}
case NSFetchedResultsChangeUpdate:
[self configureCell:(contactCell*)[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[tableView insertRowsAtIndexPaths:#[newIndexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
break;
}
}
and this triggers NSFetchedResultsChangeDelete that causes the row to get delete from the table but its not deleted from database. after refetching everything is back there. and that's a very bad user experience. the predicate is set according to the user defined filter. the issue doesn't happen if there is no predicate in fetch request. what am I doing wrong? is there a work around for this behaviour?
edit:
this issue still occur when i try to update a record on the main context for contacts. so it's then main context and write context combination.

Answer 1

I faced the same problem. This is how I fixed:
My predicate was using something like ("index == %#")
I was filtering an integer value, but I was passing #"1".
Changing it to %i and passing integer, worked.