title: Do I have to declare a callback method in .h file in objective c?
body: <p>I have two classes A and B. Class A gives class B a target/action pair which class B callbacks later. The target is self (= class A), action is a callback method. The callback is later done with:</p>
  
  <pre><code>[target performSelector:action withObject:anObject];
  </code></pre>
  
  <p>The method action is only called by this callback. It works fine if I don't declare the method in .h file of class A. But my question is, is that a bad design to not declare it in the .h file? Since the method is only called in callbacks, I think it is not nescessary to declare it, isn't it? I mean, the callback "performSelector" even can't check if the method exists at runtime. So what is your suggestion?</p>