title: Swift add viewController as a subview to other views
body: <p>I have multiple view controllers which should load a specific view like in this drawing. I defined that view in the storyboard as a separate view controller. The <code>reusable view controller</code> has some methods which make the view work.  What's the best way to do this?</p>
  
  <p>I tried using addSubview method but the IBOutlets won't initialize. Please help me.</p>
  
  <p><img src="https://i.stack.imgur.com/PbwwS.png" alt="enter image description here"></p>