I have two views with respective controllers. An object is created in the first controller. The second view has some UI controls for settings. When a control value is changed in the second view, how do I set a new value for a property of an object instantiated in the first controller? If I wanted to set a new value from within the first controller, I could use [self.object setProperty:newValue]. Can I set the new value from another controller? If not, what's the best approach?