title: Correct location of navigation controller code for iOS?
body: <p>For customizing the navigation bar in the navigator view, I used <code>self.navigationController!.navigationBar</code>
  to access it. I did this from the .swift file of the first view controller I had. It works fine but I was wondering if there is a better place to put the code that I am missing? Does anyone ever use separate .swift files for the navigation view?</p>