Xcode - How can i programmatically embed/change view controller within a container view?

I might have found a solution for this. I'm answering here, in case it can help anyone else in my situation.

What I did was add a new View Controller and then embed it to the View Container - This will work as a "master view" - I then use this blank view controller to decide which other view controller should be changed within the self of the blank.

Here's some code I have in the blank view controller, but I suppose the blank view controller can also be used as a master view controller (in my case for "Account"), and then it can add the login/register view as a child.

override func viewDidLoad() {    super.viewDidLoad()    updateView()}private lazy var loginViewController: loginViewController = {    // Load Storyboard    let storyboard = UIStoryboard(name: "Main", bundle: Bundle.main)    // Instantiate View Controller    var viewController = storyboard.instantiateViewController(withIdentifier: "loginViewController") as! loginViewController    // Add View Controller as Child View Controller    self.add(asChildViewController: viewController)    return viewController}()private lazy var registerViewController: registerViewController = {    // Load Storyboard    let storyboard = UIStoryboard(name: "Main", bundle: Bundle.main)    // Instantiate View Controller    var viewController = storyboard.instantiateViewController(withIdentifier: "registerViewController") as! registerViewController    // Add View Controller as Child View Controller    self.add(asChildViewController: viewController)    return viewController}()private func add(asChildViewController viewController: UIViewController) {    // Add Child View Controller    addChildViewController(viewController)    // Add Child View as Subview    view.addSubview(viewController.view)    // Configure Child View    viewController.view.frame = view.bounds    viewController.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]    // Notify Child View Controller    viewController.didMove(toParentViewController: self)}private func remove(asChildViewController viewController: UIViewController) {    // Notify Child View Controller    viewController.willMove(toParentViewController: nil)    // Remove Child View From Superview    viewController.view.removeFromSuperview()    // Notify Child View Controller    viewController.removeFromParentViewController()}private func updateView() {    add(asChildViewController: registerViewController)    /*     if segmentedControl.selectedSegmentIndex == 0 {     remove(asChildViewController: sessionsViewController)     add(asChildViewController: summaryViewController)     } else {     remove(asChildViewController: summaryViewController)     add(asChildViewController: sessionsViewController)     }     */}

Credit to this guy: https://cocoacasts.com/managing-view-controllers-with-container-view-controllers/

The easiest way to do that is to have 3 container views in Storyboard above each other, each one of them is connected to a different view controller, then in your code, make 2 of these 3 container views hidden and leave one visible based on your business needs.

This is described in detail in this blog post. Hope this helps!