Filter Predicate not called on NSArrayController

Question

I have an NSArrayController on which I apply a filter Predicate programatically:

- (void)setFilters {

    NSPredicate *pred = [NSPredicate predicateWithBlock:^BOOL(LMRootItem *rootItem, 
                    NSDictionary *bindings) {

        ...
        return YES;

    }];

    [_controller setFilterPredicate:pred];
}

When the NSArrayController's content bindings are set up using IB everything works correctly.

When I set up NSArrayController's content bindings programmatically then my filter predicate function is never called and the contents are never filtered:

[_controller bind:@"arrangedObjects" 
         toObject:_otherController    
      withKeyPath:@"arrangedObjects.@unionOfArrays.rootItems" 
          options:nil];

The binding is identical to the one that I do in IB.

Does anyone have any idea what's going wrong?

Answer 1

Found it. It seems that I should have done this:

[_controller bind:@"contentArray" 
         toObject:_otherController      
      withKeyPath:@"arrangedObjects.@unionOfArrays.rootItems" 
         options:nil]