Pass value from child view page to Pageview controller in swift - ios

Question

I am android developer and pretty new to iOS.
I have a pageView Controller say A. It is connected to three child View Controller. I want to get back a value from child View Controller back to Root Page View Controller.
In android it can be easily done through interface passing and having trouble in doing in iOS with protocols.
I am doing like this
protocol Z {
func runZ()
}
Class A: UIViewController, Z {
func runZ( withValue value: String)
{
//Perform some function
}
var orderedViewControllers: [UIViewController] = {
var myViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "myViewController") as! MyViewController
myViewController.z = self
return [ myViewController,
UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "C")]
}()
}
Class B : UIViewController{
var z = A.self
func sendBackToA(){
(z as! Z).runZ(withValue : "CustomString")
}
I get the error at myViewController.z = self as
Cannot assign value of type '(A) -> () -> A' to type 'A.Type'.
I made it work somehow by initializing like this
myViewController.z = A.self
but my app is crashing
Could not cast value of type 'A.Type' (0x1e0d854d8) to 'Z'

Answer 1

protocol Z:class {
func runZ(withValue value: String?)
}
class A: UIViewController, Z, UINavigationControllerDelegate {
func runZ(withValue value: String?)
{
//Perform some function
}
var orderedViewControllers: [UIViewController] = {
var myViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "B") as! B
myViewController.z = self
return [ myViewController,
UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "C")]
}()
}
class B : UIViewController{
weak var z:Z?
func sendBackToA(){
z?.runZ(withValue : "CustomString")
}
}

Answer 2

A few things....
protocol Z {
func runZ(withValue value: String)
}
class A: UIViewController, Z { // "class" rather than "Class"
func runZ( withValue value: String)
{
//Perform some function
}
func orderedViewControllers() -> [UIViewController] { // func because variable declarations don't have a "self"
// Should get rid of the forced unwrap in the next line
let myViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "myViewController") as! B
myViewController.z = self
return [ myViewController, UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "C")]
}
}
class B : UIViewController { // "class" rather than "Class"
var z: Z? // The other controller will do the initialization.
func sendBackToA(){
// Verify that the delegate is registered
if let z = z {
z.runZ(withValue : "CustomString")
} else {
print("Missing delegate assignment")
}
}
}