Core Data: deleteObject crashes application, NSPredicate the cause? - ios

Question

I'm using a UICollectionView along with Core Data.
I can't seem to figure out why I can't remove an object from Core Data. It crashes at [self.managedObjectContext deleteObject:animation]; with an index 0 beyond bounds for empty array error. The following method is a delegate method that gets invoked from another viewcontroller. It gets a timestamp NSInteger and should create an NSPredicate with that timestamp.
The strange thing is that when I take the animationTimestamp NSInteger and hardcode it like:
[NSPredicate predicateWithFormat:#"timestamp == %i", #"1370169109"] it works and the object gets deleted without the error. However, when I want to pass the parameter as the argument it crashes. I've tried making it a string, NSNumber etc. Nothing works when I take the parameter, it only does when I hardcode it. I've logged animationTimestamp and it shows the correct value, so I'm stuck.
Thanks!
- (void)deleteAnimationWithTimestamp:(NSInteger)animationTimestamp {
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:#"Animations" inManagedObjectContext:self.managedObjectContext];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"timestamp == %i", animationTimestamp];
[fetchRequest setPredicate:predicate];
[fetchRequest setEntity:entity];
NSError *error;
NSArray *animations = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];
for (NSManagedObject *animation in animations) {
[self.managedObjectContext deleteObject:animation];
}
// Save core data
if (![self.managedObjectContext save:&error]) {
NSLog(#"Couldn't save: %#", [error localizedDescription]);
}
[self.animationsCollectionView reloadData];
}
EDIT:
More info that might matter. The timestamp attribute in the model is a 64 bit integer (should it be by the way?). When I create the object I use:
NSNumber *timestampNumber = [NSNumber numberWithInt:timestamp];
[newAnimation setValue:timestampNumber forKey:#"timestamp"];

Answer 1

Get the NSInteger value from NSNumber
Like
NSInteger timestampNumber = [[NSNumber numberWithInt:timestamp] integerValue];
// then use this integer
[newAnimation setValue:timestampNumber forKey:#"timestamp"];
// or in
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"timestamp == %d", timestampNumber];