Changes

The way that a view controller object interacts with a Model is through the methods and properties exposed by that model object. This, in fact, is no different from the way one object interacts with another in any object-oriented programming environment.

In terms of the view controller’s interactions with the view, however, things get a little more complicated. In practice, this is achieved using the Target-Action pattern, together with Outlets and Actions.

== The Target-Action pattern, IBOutlets and IBActions ==

When you create an iOS iPad app you will typically design the user interface (the view) using the Interface Builder tool and write the view controller and model code in Objective-C using the Xcode code editor. The previous section looked briefly at how the view controller interacts with the model. In this section we will look at how the view created in Interface Builder and our view controller code interact with each other.

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