Question

I am getting a crash when changing a BOOL attribute of my NSManagedObject.

The code to save the object is:

self.detailItem.bookmark = [NSNumber numberWithBool:YES];
NSError *error = nil;
if (!    [self.detailItem.managedObjectContext save:&error]) 
{
    // Handle the error.
}
NSLog(@"%@", error);

And the error:

Serious application error.  Exception was caught during Core Data change processing.  This is usually a bug within an observer of NSManagedObjectContextObjectsDidChangeNotification.  The left hand side for an ALL or ANY operator must be either an NSArray or an NSSet. with userInfo (null)
2011-08-18 15:41:32.866 Codes[5260:707] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'The left hand side for an ALL or ANY operator must be either an NSArray or an NSSet.'

Answer 1

WARNING: This answer is based on a guess I’ve made based on the error message; it might be 100% wrong!

---

The error looks like it’s an incorrectly formed NSPredicate. You might have something like

NSString *name = @"Bob";
[NSPredicate predictaeWithFormat:@"ANY %K IN %@", @"name", name];

That looks like it might find anything where name = 'Bob' but it won’t, it will throw an exception 🙁

If you’re using ‘IN’ you need to pass an NSSet or NSArray i.e .

NSArray *names = [NSArray arrayWithObjects:@"Alice", @"Bob", nil];
[NSPredicate predictaeWithFormat:@"ANY %K IN %@", @"name", names];

This will find anything with the name ‘Bob’ or ‘Alice’.

If you just wanted to search for ‘Bob’, just do this :

NSString *name = @"Bob";
[NSPredicate predictaeWithFormat:@"%K == %@", @"name", name];