Switch Between Child View Controllers - ios

Question

I have a view controller that contains multiple container views, we will call it HomeViewController. I declare these container views (childViewControllers) as so (each one is a Container View with its own embeded viewController:
private lazy var startContactViewController: StartContactViewController = {
//Load Storyboard
let storybaord = UIStoryboard(name: "Main", bundle: Bundle.main)
//Instantiate View Controller
var viewController = storyboard?.instantiateViewController(withIdentifier: "StartContact") as! StartContactViewController
//Add View Controller as Child View Controller
self.add(asChildViewController: viewController)
return viewController
}()
private lazy var stopContactViewController: StopContactViewController = {
//Load Storyboard
let storybaord = UIStoryboard(name: "Main", bundle: Bundle.main)
//Instantiate View Controller
var viewController = storyboard?.instantiateViewController(withIdentifier: "StopContact") as! StopContactViewController
//Add View Controller as Child View Controller
self.add(asChildViewController: viewController)
return viewController
}()
private lazy var startDayViewController: StartDayViewController = {
//Load Storyboard
let storybaord = UIStoryboard(name: "Main", bundle: Bundle.main)
//Instantiate View Controller
var viewController = storyboard?.instantiateViewController(withIdentifier: "StartDay") as! StartDayViewController
//Add View Controller as Child View Controller
self.add(asChildViewController: viewController)
return viewController
}()
private lazy var loadingViewController: LoadingViewController = {
//Load Storyboard
let storybaord = UIStoryboard(name: "Main", bundle: Bundle.main)
//Instantiate View Controller
var viewController = storyboard?.instantiateViewController(withIdentifier: "loading") as! LoadingViewController
//Add View Controller as Child View Controller
self.add(asChildViewController: viewController)
return viewController
}()
I then have these 2 functions to add and remove the childViewControllers:
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)
}
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()
}
When my app first loads the StartDayViewController is presented. Within this view controller their is a button. When the users presses that button I would like the StartDayViewController to be removed and the StartContactViewController to be presented. How can I achieve this from the StartDayViewController?
I have also included a picture of the storyboard.
Storyboard image

Answer 1

You can do it using protocol
protocol StartVcProtocol {
func startButtonPressed()
}
Let HomeViewController implement it
extension HomeViewController: StartVcProtocol {
func startButtonPressed() {
// start button pressed -- do your remove and add stuff here
}
}
Now in StartVc
class StartVc: UIViewController {
var delegate: StartVcProtocol?
//inside you start button iBaction
delegate?.startButtonPressed()
}
Then when lazy initializing the StartVc
viewController.delegate = self
Hope you get all the pieces .