Passing back data to first viewController - ios

Question

I have a basic understanding of how to handle swift protocols to pass data between two viewcontrollers. My situation is this: I wanted to pass data back to my first viewcontroller.
For example:
First ViewController
class ViewControllerA: UIViewController, ViewControllerCResult {
func set(data: String) {
}
}
Second ViewController
class ViewControllerB: UIViewController {
}
Third ViewController
protocol ViewControllerCResult {
set(data: String)
}
class ViewControllerC: UIViewController {
var delegate: ViewControllerCResult?
}
ViewControllerA -> ViewControllerB -> ViewControllerC
I would like to pass data from ViewControllerC to ViewControllerA.
Can anyone help me with this?

Answer 1

You can pass Delegates from Controller A -> B -> C , and when popViewcontroller will be called you can check the self.delegate in ViewController C, if it exist just call function like this self.delegate?.set("data from c"). Check
popControllerPressed Function in ViewController3
First View controller
class ViewController: UIViewController, ViewControllerCResult {
var delegate: ViewControllerCResult?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func pushControllerPressed(_ sender: Any) {
if let viewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "ViewController2") as? ViewController2 {
if let navigator = navigationController {
viewController.delegate = self
navigator.pushViewController(viewController, animated: true)
}
}
}
func set(data: String) {
}
}
Second ViewController
class ViewController2: UIViewController, ViewControllerCResult {
var delegate: ViewControllerCResult?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func pushControllerPressed(_ sender: Any) {
if let viewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "ViewController3") as? ViewController3 {
if let navigator = navigationController {
viewController.delegate = self.delegate
navigator.pushViewController(viewController, animated: true)
}
}
}
func set(data: String) {
print(data)
}
}
Third ViewController
protocol ViewControllerCResult {
func set(data: String)
}
class ViewController3: UIViewController, ViewControllerCResult {
var delegate: ViewControllerCResult?
func set(data: String) {
print(data)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func popControllerPressed(_ sender: Any) {
for controller in self.navigationController!.viewControllers as Array {
if controller.isKind(of: ViewController.self) {
delegate?.set(data: "data from C")
self.navigationController!.popToViewController(controller, animated: true)
break
}
}
}
}
Here is Code Link: Pass data forth and back