title: Function Not Being Called Through Segue in Swift 4.0
body: <p>I've started to learn Swift 4 and iOS app development.  </p>
  
  <p>I've set up a basic app that allows users to sign up and add themselves to a user table or log in and display the users that are already registered.  I've created a bar button item (logout) in my main storyboard and have connected that button to the main user screen with a segue. I've also created a user table view controller with the function to logout the user.  Here are the images of if the code, main storyboards, and segue and button definitions.  </p>
  
  <p>The issue is that when I press the logout button in the app, the actual logout function is never called.  I believe it works because it flashes the main user signup screen for a second (as per the segue), but that code is never executed. It just goes back to the main user table view. I added print statements (for the console) and breakpoints in the code but it never gets that far.  Here's the code below. It's in the UserTableViewController.swift file.</p>
  
  <p>import UIKit
  import Parse</p>
  
  <p>class UserTableViewController: UITableViewController {</p>
  
  <pre><code>//function to control what happens when the user presses the logout button
  
  
  @IBAction func logoutUser(_ sender: Any) {
  
      // log the user out; make sure you import Parse into the view controller so you can access the PFUser functions
      print ("getting ready to logout user")
  
      PFUser.logOut()
  
      print ("logged out user from parse")
  
      // perform the segue to the main login screen; don't need self. before the performSegue because we want the action to happen in the main view controller
  
      performSegue(withIdentifier: "logoutSegue", sender: self)
  
      print("You should see the main screen now")
  
  }
  </code></pre>
  
  <p>Thanks in advance for your help. Sorry for adding in the pictures earlier.  </p>
  
  <p>Mike</p>