Set Back title by the default for UINavigationController - ios

Question

This is how
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool
{
VAXApplicationSettings.configureApplicationAppearance()
window = UIWindow(frame: UIScreen.mainScreen().bounds)
window?.makeKeyAndVisible()
if let window = window {
guard let welcomeViewController = storyboard.instantiateViewControllerWithIdentifier("WelcomeViewController") as? VAXWelcomeViewController else {
return nil
}
let navigationController = UINavigationController(rootViewController: welcomeViewController)
window.rootViewController = navigationController
}
return true
}
On the Welcome View Controller I push New View Controller which looks like this:
And as you see here is a Cancel button.
This is a source code of class of pushed view controller:
import UIKit
class NewViewController: UIViewController
{
override func viewDidLoad()
{
super.viewDidLoad()
navigationItem.backBarButtonItem = UIBarButtonItem(title: "Back", style: .Plain, target: self, action: #selector(back))
}
func back()
{
navigationController?.popViewControllerAnimated(true)
}
}

Answer 1

This has nothing to do with your navigation controller or your navigation bar. The back button's title is, by default, the title of the view controller you would go back to if you tapped it. That view controller can also change the title of the back button that goes back to it. There is no overall "default"; it happens on a view controller by view controller basis.

Answer 2

i've set this for navigation item in my Welcome View controller which is root view controller of navigation controller.

Answer 3

For situations like this I like to create a sublass of UIViewController called BaseViewController Then all my view controllers inheirit from this instead of the standard iOS one. This allows me to add functionality that is applied throughout the app.
class BaseViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
self.navigationItem.backButtonItem = UIBarButtonItem(title: "Back", style: .Default, target: self, action: #selector(back))
}
func back() {
self.navigationController?.popViewController(animated: true)
}
}
Ideally your app should be built from the start using this but you can do an app-wide find/replace to update your existing view controllers.