Binding NSPopUpButton to NSArray

Question

I'm a little lost with bindings on NSPopUpButton. I have a custom class that holds an array of items that I'd like to display in a pop up. These items are subclasses of NSManagedObjects and they are contained in an NSArray. I don't want to use an NSArrayController since I've had lots of trouble changing the selection programmatically and it feels like cluttering the implementation.

The problem is simply that I don't know how to bind the array properly to the pop up. All I have managed to do is list the array items on the pop up menu, but the titles are core data URIs. I believe I could use the description method to change the title, but this does not sound very advisable.

Any ideas how to bind NSArray to the NSPopUpButton properly?

Answer 1

I think I solved it. I simply created these bindings for NSPopUpButton:

1. "Content" to the items property (of type NSArray*)

2. "Selected Object" to selectedItem (of type Item*)

3. Finally "Content Values" to items.name

For the third binding I implemented valueForKeyPath:

- (id)valueForKeyPath:(NSString *)keyPath
{
    NSArray *components = [keyPath componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"."]];
    if ([components count] == 2 && [components objectAtIndex:0] == @"items")
    {
        return [self.items valueForKey:[components objectAtIndex:1]];
    }
    return [super valueForKeyPath:keyPath];
}

The third binding could've been also a separate array for titles, but I this is much more flexible.