Back button does not work in Navigation Controller - ios

Question

I try to implement a back button for my controllers.
My Navigation Controller implementation inside of the Container Controller:
func configureMainController(){
let mainController = MainController()
mainController.delegate = self
mainController.backDelegate = self
centerController = UINavigationController(rootViewController: mainController)
view.addSubview(centerController.view)
addChild(centerController)
centerController.didMove(toParent: self)
}
My Back Delegate:
extension ContainerController: BackDelegate {
func handleBack() {
print("ok")
centerController.navigationController?.popViewController(animated: true)
}
}
Back button inside of the Main Controller:
navigationItem.rightBarButtonItem = UIBarButtonItem(image: image2?.withRenderingMode(.alwaysOriginal), style: .plain, target: self, action: #selector(backAction))
#objc func backAction() -> Void {
backDelegate?.handleBack()
}
How I push the Controller that I need to pop:
DispatchQueue.main.async {
let vc = ScienceController(collectionViewLayout: UICollectionViewFlowLayout())
vc.modalPresentationStyle = .fullScreen
self.navigationController?.pushViewController(vc, animated: true)
}
Here is my Main Controller with relevant functions:
class MainController: UIViewController {
let tabBarCnt = UITabBarController()
var delegate: MainControllerDelegate?
var backDelegate: BackDelegate?
override func viewDidLoad() {
super.viewDidLoad()
createTabBarController()
}
#objc func backAction() -> Void {
//self.navigationController?.popViewController(animated: true)
backDelegate?.handleBack()
}
func checkIfUserIsLoggedIn(){
if Auth.auth().currentUser?.uid == nil{
performSelector(inBackground: #selector(handleLogout), with: nil)
}
}
#objc func handleLogout(){
do {
try Auth.auth().signOut()
} catch let logoutError {
print(logoutError)
}
DispatchQueue.main.async {
// UIView usage
let loginController = LoginController()
loginController.mainController = self
loginController.modalPresentationStyle = .fullScreen
self.present(loginController, animated: true, completion: nil)
}
}
func createTabBarController() {
let firstVc = Controller1()
firstVc.title = "vc1"
firstVc.view.backgroundColor = UIColor.white
firstVc.tabBarItem = UITabBarItem.init(title: "vc1", image: nil, tag: 0)
let secondVc = Controller2()
secondVc.title = "vc2"
secondVc.view.backgroundColor = UIColor.white
secondVc.tabBarItem = UITabBarItem.init(title: "vc2", image: nil, tag: 1)
let thirdVc = Controller3()
thirdVc.title = "vc3"
thirdVc.view.backgroundColor = UIColor.white
thirdVc.tabBarItem = UITabBarItem.init(title: "vc3", image: nil, tag: 2)
let controllerArray = [firstVc, secondVc, thirdVc]
tabBarCnt.viewControllers = controllerArray.map{
UINavigationController.init(rootViewController: $0)}
//tabBarCnt.selectedIndex = 1
self.view.addSubview(tabBarCnt.view)
}
}
Here is my Container Controller:
class ContainerController: UIViewController {
// MARK: - Properties
var menuController: MenuController!
var centerController: UINavigationController!
var isExpanded = false
// MARK: - Init
override func viewDidLoad() {
super.viewDidLoad()
configureMainController()
}
override var preferredStatusBarStyle: UIStatusBarStyle {
return .darkContent
}
override var preferredStatusBarUpdateAnimation: UIStatusBarAnimation{
return .slide
}
override var prefersStatusBarHidden: Bool{
return isExpanded
}
// MARK: - Handlers
func configureMainController(){
let mainController = MainController()
mainController.delegate = self
mainController.backDelegate = self
centerController = UINavigationController(rootViewController: mainController)
view.addSubview(centerController.view)
addChild(centerController)
centerController.didMove(toParent: self)
}
func configureMenuController(){
if menuController == nil{
menuController = MenuController()
menuController.delegate = self
view.insertSubview(menuController.view, at: 0)
addChild(menuController)
menuController.didMove(toParent: parent.self)
}
}
func animatePanel(shouldExpand: Bool, menuOption: MenuOption?){
if shouldExpand{
//show
UIView.animate(withDuration: 0.5, delay: 0.0, options: .curveEaseInOut, animations: {
self.centerController.view.frame.origin.x = self.centerController.view.frame.width - 80
}, completion: nil)
}
else{
//hide
UIView.animate(withDuration: 0.5, delay: 0, options: .curveEaseInOut, animations: {
self.centerController.view.frame.origin.x = 0
}) { (_) in
guard let menuOption = menuOption else {return}
self.didSelectMenuOption(menuOption: menuOption)
}
}
animateStatusBar()
}
func didSelectMenuOption(menuOption: MenuOption){
switch menuOption {
case .Profile:
let controller = ProfileController()
present(UINavigationController(rootViewController: controller), animated: true, completion: nil)
case .Settings:
let controller = SettingsController()
//controller.username = "pasha"
present(UINavigationController(rootViewController: controller), animated: true, completion: nil)
case .Logout:
handleLogout()
}
}
func animateStatusBar(){
UIView.animate(withDuration: 0.5, delay: 0.0, options: .curveEaseInOut, animations: {
self.setNeedsStatusBarAppearanceUpdate()
}, completion: nil)
}
#objc func handleLogout(){
do{
try Auth.auth().signOut()
DispatchQueue.main.async {
UIApplication.shared.keyWindow?.rootViewController = LoginController()
}
//UIApplication.shared.keyWindow?.rootViewController?.dismiss(animated: true, completion: nil)
} catch let logoutError {
print(logoutError)
}
}
}
extension ContainerController: MainControllerDelegate {
func handleMenuToggle(forMenuOption menuOption: MenuOption?) {
if !isExpanded {
configureMenuController()
}
isExpanded = !isExpanded
animatePanel(shouldExpand: isExpanded, menuOption: menuOption)
}
}
extension ContainerController: BackDelegate {
func handleBack() {
print("ok")
centerController.popViewController(animated: true)
}
}
The print("ok") statement works but not centerController.navigationController?.popViewController(animated: true). I also tried self.navigationController?.popViewController(animated: true) and It does not work too...

Answer 1

Since UINavigationController is subclass of UIViewController it has navigationController property on it. You should not be using navigationController property present on UINavigationController. So your code should be
centerController.popViewController(animated: true)
Edit:
As "Sylvan D Ash" mentioned you are pushing and popping from 2 different controllers.
self.navigationController?.pushViewController(vc, animated: true)
need to be replaced with
centerController.pushViewController(vc, animated: true)