Display Model's Data in NSMenuItem

Question

I'd like to display some data of my model within a status bar menu. So, I bound my entity-object to the title of an NSMenuItem:

        [self.statusMenu setAutoenablesItems:NO];

        NSMenuItem * exportMenuItem = [[NSMenuItem alloc] init];
        [exportMenuItem bind:@"title" toObject:expo withKeyPath:@"menuItemTitle" options:nil];
        [exportMenuItem setEnabled:NO];

        [self.statusMenu insertItem:exportMenuItem atIndex:3];

It works fine so far from init. But when I update my Model it does not updates the title of the NSMenuItem.

Answer 1

For reference, the canonical solution to this issue is to implement a class method like this:

+ (NSSet *)keyPathsForValuesAffectingMenuItemTitle
{
    return [NSSet setWithObjects: @"propertyMenuItemTitleDependsOn1", 
                                  @"propertyMenuItemTitleDependsOn2",
                                  nil];
}

If you implement a method like this, then the framework will handle calling willChangeValueForKey: and didChangeValueForKey: for the key menuItemTitle any time any of the other properties are changed.