title: UIViewController viewDidLoad vs. viewWillAppear: What is the proper division of labor?
body: <p>I have always been a bit unclear on the type of tasks that should be assigned to <code>viewDidLoad</code> vs. <code>viewWillAppear</code>: in a <code>UIViewController</code> subclass. </p>
  
  <p>e.g. I am doing an app where I have a <code>UIViewController</code> subclass hitting a server, getting data, feeding it to a view and then displaying that view. What are the pros and cons of doing this in <code>viewDidLoad</code> vs. <code>viewWillAppear</code>?</p>