How to open a embedded segue controller from another controller? - ios

Question

I am making an app following the same design approach of this app https://github.com/Bailig/SurveyApp .
In the above GitHub project the controllers are designed in such a way like a common ViewController with ContainerView inside.And also this common ViewController is Embed Segue with the First Controller or very first page. The container view is getting replaced for all the next screens.
In the above project there is a thank you page in the last, in my app I placed a button on the thank you page. I want to open the very first page again on click of the button from thank you page. How can I do that from last page controller/FourthController?
ViewController
class ViewController: UIViewController {
var currentController: UIViewController?
var pageIndex = 1
var survey = Survey()
#IBOutlet weak var backButton: UIButton!
#IBOutlet weak var nextButton: UIButton!
#IBOutlet weak var containerView: UIView!
#IBOutlet weak var progressLabel: UILabel!
#IBAction func nextTapped(_ sender: Any) {
switch pageIndex {
case 1:
let nextController = storyboard?.instantiateViewController(withIdentifier: "SecondController")
if let fromController = currentController, let toController = nextController as? SecondController {
toController.survey = survey
moveAndSizeChildControllers(fromController: fromController, toController: toController)
pageIndex += 1
setButtonAndProgressLabel()
}
case 2:
let nextController = storyboard?.instantiateViewController(withIdentifier: "ThirdController")
if let fromController = currentController, let toController = nextController as? ThirdController {
toController.survey = survey
moveAndSizeChildControllers(fromController: fromController, toController: toController)
pageIndex += 1
setButtonAndProgressLabel()
}
case 3:
let nextController = storyboard?.instantiateViewController(withIdentifier: "FourthController")
if let fromController = currentController, let toController = nextController as? FourthController {
toController.survey = survey
moveAndSizeChildControllers(fromController: fromController, toController: toController)
pageIndex += 1
setButtonAndProgressLabel()
}
default:
break
}
}
#IBAction func backTapped(_ sender: Any) {
switch pageIndex {
case 2:
let nextController = storyboard?.instantiateViewController(withIdentifier: "FirstController")
if let fromController = currentController, let toController = nextController as? FirstController {
toController.survey = survey
moveAndSizeChildControllers(fromController: fromController, toController: toController)
pageIndex -= 1
setButtonAndProgressLabel()
}
case 3:
let nextController = storyboard?.instantiateViewController(withIdentifier: "SecondController")
if let fromController = currentController, let toController = nextController as? SecondController {
toController.survey = survey
moveAndSizeChildControllers(fromController: fromController, toController: toController)
pageIndex -= 1
setButtonAndProgressLabel()
}
default:
break
}
}
#IBOutlet weak var backTapped: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
currentController = segue.destination
if let firstController = currentController as? FirstController {
firstController.survey = survey
}
setButtonAndProgressLabel()
}
func moveAndSizeChildControllers(fromController: UIViewController, toController: UIViewController) {
fromController.willMove(toParentViewController: nil)
toController.view.frame = containerView.bounds
addChildViewController(toController)
containerView.addSubview(toController.view)
// animatin
toController.view.alpha = 0
UIView.animate(withDuration: 0.5, animations: {
toController.view.alpha = 1
fromController.view.alpha = 0
}) { (completed) in
fromController.view.removeFromSuperview()
fromController.removeFromParentViewController()
toController.didMove(toParentViewController: self)
self.currentController = toController
}
}
}

Answer 1

You can manage it by using Notification
Add in ViewController (main)
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(navigateToFirstPage), name:NSNotification.Name(rawValue:"NavigateToFirstPage") , object: nil)
}
#objc private func navigateToFirstPage() {
pageIndex = 2
self.backTapped(UIButton())
}
Add in you fourthViewController
// This is your button from where you need to perform action
#IBAction func thanksButtonAction(_ sender: Any) {
NotificationCenter.default.post(name: NSNotification.Name(rawValue:"NavigateToFirstPage"), object: nil)
}

Answer 2

I would better use delegation pattern. It's simple to manage and easily to understand.
On the top of FourthController after imports you need to add
protocol FourthControllerThankDelegate {
func didTapYourButton()
}
and then add the variable inside that class
class FourthController: UIViewController {
weak var delegate: FourthControllerThankDelegate?
...
}
then you need to call didTapYourButton() inside your button action handler
#IBAction func thanksButtonTapped(_ sender: Any) {
delegate?.didTapYourButton()
}
then inside your ViewController function nextTapped: you need to set this view controller as a delegate to FourthController
case 3:
... // I have skipped code above
toController.delegate = self
setButtonAndProgressLabel()
}
and finally you need to handle delegate action
extension ViewController: FourthControllerThankDelegate {
func didTapYoutButton {
pageIndex = 2
backTapped(self)
}
}
As you do that, backTapped handler will move you to first page. This is not the best way to move back. To improve that you can create a function "displayMeFirstPage" and move there part of the logic from backTapped() case: 2 and call it inside that case and inside delegate handler. There are a lot of ways to improve navigation. if you have any questions please let me know.