title: Can't get any navigation item in iOS
body: <p>I have a question regarding the navigation bar.</p>
  
  <p>As far as I understand from iOS: A view controller opened by a segue inherits the navigation bar of the parent view controller. Is this correct so far?</p>
  
  <p>Is there a view controller within a stack "owns" the navigation bar in a complex segue stack (e.g. TableViewController that opens a TabBarController that opens ...)? </p>
  
  <p>I very often run into the problem that I don't know where to get the actual navigation item in order to set the title or a bar button item.</p>
  
  <p>In this case, I have the following controllers:</p>
  
  <ul>
  <li><code>TabBarController</code></li>
  <li><code>EventPostsViewController</code> -> To display a list of posts, is a tabbed view within the TabBarController</li>
  <li><code>CreatePostViewController</code> -> To write a new post</li>
  </ul>
  
  <p>So within the <code>EventPostsViewController</code> I can do this (and it works):</p>
  
  <pre><code>class EventPostsViewController: UITableViewController {
      ...
      override func viewWillAppear(animated: Bool) {
          ...
          // This solution works, but only for EventPostsViewController
          self.tabBarController?.navigationItem.title = "text"
  </code></pre>
  
  <p>But within the <code>CreatePostViewController</code>, which is opened by a segue via <code>EventPostsViewController</code>, neither of this solutions work.</p>
  
  <pre><code>class CreatePostViewController: UIViewController {
      ...
      override func viewWillAppear(animated: Bool) {
          ...
          // Neither of these solutions works
          self.navigationItem.title = "Text"
          self.tabBarController?.navigationItem.title = "Text"
          self.navigationController?.navigationItem.title = "Text"
  </code></pre>
  
  <p>How do I get the actual navigation bar/navigationItem?</p>