loading childViewControllers first time logging in - swift

Question

I have been struggling with an issue for loading child ViewControllers. The first time I log in it shows the containerView but without the childViewControllers loaded. When I close the app and re-open the app with the logged in state saved the childViews in the containerView are displayed. I know it has something to do with my window hierarchy and rootviewController. I have researched this a bunch but still am having issues solving. Thanks in advance!
// app delegate
#UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
window = UIWindow(frame: UIScreen.main.bounds)
window?.makeKeyAndVisible()
window?.rootViewController = MainNavigationController()
return true
}
// mainNavigationController - RootViewController
class MainNavigationController: UINavigationController {
override func viewDidLoad() {
super.viewDidLoad()
let vc1 = TravelersFeedVC()
let vc2 = ProfileVC()
if isLoggedIn() {
// assume user is logged in
let homeController = HomeController()
homeController.firstViewController = vc1
homeController.secondViewController = vc2
viewControllers = [homeController]
} else {
perform(#selector(showLoginController), with: nil, afterDelay: 0.01)
}
}
fileprivate func isLoggedIn() -> Bool {
return UserDefaults.standard.isLoggedIn()
}
func showLoginController() {
let loginController = LoginController()
present(loginController, animated: true, completion: {
// perhaps do something here later
})
}
}
// log in function
func finishLoggingIn() {
let rootViewController = UIApplication.shared.keyWindow?.rootViewController
guard let mainNavigationController = rootViewController as? MainNavigationController else { return }
mainNavigationController.viewControllers = [HomeController()]
let vc1 = TravelersFeedVC()
let vc2 = ProfileVC()
let homeController = HomeController()
homeController.firstViewController = vc1
homeController.secondViewController = vc2
UserDefaults.standard.setIsLoggedIn(value: true)
dismiss(animated: true, completion: nil)
}
// HomeController
class HomeController: UIViewController, FBSDKLoginButtonDelegate {
// child view controllers to put inside content view
var firstViewController: TravelersFeedVC?
var secondViewController: ProfileVC?
private var activeViewController: UIViewController? {
didSet {
removeInactiveViewController(inactiveViewController: oldValue)
updateActiveViewController()
}
}
private func removeInactiveViewController(inactiveViewController: UIViewController?) {
if let inActiveVC = inactiveViewController {
// call before removing child view controller's view from hierarchy
inActiveVC.willMove(toParentViewController: nil)
inActiveVC.view.removeFromSuperview()
// call after removing child view controller's view from hierarchy
inActiveVC.removeFromParentViewController()
}
}
private func updateActiveViewController() {
if let activeVC = activeViewController {
// call before adding child view controller's view as subview
addChildViewController(activeVC)
activeVC.view.frame = contentView.bounds
contentView.addSubview(activeVC.view)
// call before adding child view controller's view as subview
activeVC.didMove(toParentViewController: self)
}
}
// UI elements
lazy var contentView: UIView = {
let tv = UIView()
tv.backgroundColor = UIColor.blue
tv.translatesAutoresizingMaskIntoConstraints = false
tv.layer.masksToBounds = true
return tv
}()
var segmentedController: UISegmentedControl!
override func viewDidLoad() {
super.viewDidLoad()
activeViewController = firstViewController
checkIfUserIsLoggedIn()
view.addSubview(contentView)
setupProfileScreen()
let items = ["Travelers", "Me"]
segmentedController = UISegmentedControl(items: items)
navigationItem.titleView = segmentedController
segmentedController.tintColor = UIColor.black
segmentedController.selectedSegmentIndex = 0
// Add function to handle Value Changed events
segmentedController.addTarget(self, action: #selector(HomeController.segmentedValueChanged(_:)), for: .valueChanged)
navigationItem.leftBarButtonItem = UIBarButtonItem(title: "Sign Out", style: .plain, target: self, action: #selector(handleSignOut))
navigationItem.leftBarButtonItem?.tintColor = UIColor.black
}
// reference to collectionViewController
var travelersFeedVC: TravelersFeedVC!
func segmentedValueChanged(_ sender:UISegmentedControl!)
{
switch segmentedController.selectedSegmentIndex {
case 0:
activeViewController = firstViewController
case 1:
activeViewController = secondViewController
default: // Do nothing
break
}
}

Answer 1

In your finishLoggingIn() it looks like you are using 2 separate HomeController instances.
Something like this should fix it.
func finishLoggingIn() {
let rootViewController = UIApplication.shared.keyWindow?.rootViewController
guard let mainNavigationController = rootViewController as? MainNavigationController else { return }
// create it
let homeController = HomeController()
// use it
mainNavigationController.viewControllers = [homeController]
let vc1 = TravelersFeedVC()
let vc2 = ProfileVC()
// use it again
homeController.firstViewController = vc1
homeController.secondViewController = vc2
UserDefaults.standard.setIsLoggedIn(value: true)
dismiss(animated: true, completion: nil)
}