Protocol delegate not working within custom UIView button - ios

Question

I have been trying to create a protocol and delegate within my custom UIView subclass, but when I call it on View Controller class the button is not responding to the method. I have read almost all the answers on StackOverflow, none of them solve my issue. Here is the procedure I have followed:
UIView Subclass (View A)
Create the require delegate:
protocol LoginDelegates {
func loginButtonPressed(sender: AnyObject)
}
Within Subclass
class LoginViewController: UIViewController {
#IBOutlet weak var loginButton: UIButton!
var delegate: LoginDelegates? // Initite the delegate variable
//Login Button Action
#IBAction func loginButtonPressed(_ sender: UIButton) {
delegate?.loginButtonPressed(sender: loginButton)
}
}
View Controller Class (View B)
Call the delegate within the class:
class AccessViewController: UIViewController, LoginDelegates
In here I tried multiple approaches I have found on SO and around web. but none of them seems to work for me, the button still doesn't respond.
Approach 1:
override func viewDidLoad() {
super.viewDidLoad()
//Assign the delegate in current view
let LoginView = LoginViewController()
LoginView.delegate = self
}
Approach 2:
with this approach, I get the following error doesn't contain a view controller with identifier 'LoginViewController', which make sense cause the view is subclass and not within the storyboard.
override func viewDidLoad() {
super.viewDidLoad()
//Assign the delegate in current view
if let loginView = self.storyboard?.instantiateViewController(withIdentifier: "LoginViewController") as? LoginViewController {
loginView.delegate = self
}
}
and of course, call the method in the current view.
func loginButtonPressed(sender: AnyObject) {
performSegue(withIdentifier: "toDashboard", sender: self)
}
I also try to create a swift file and just put all the protocols separate from both views and just call them when needed. and At this point, I have no other option. Thank you for help in advance.

Answer 1

Update your LoginViewController like so:
class LoginViewController: UIViewController {
static weak var shared: LoginViewController?
#IBOutlet weak var loginButton: UIButton!
weak var delegate: LoginDelegates? // Initite the delegate variable
//Login Button Action
#IBAction func loginButtonPressed(_ sender: UIButton) {
delegate?.loginButtonPressed(sender: loginButton)
}
override func viewDidLoad() {
super.viewDidLoad()
// All your viewDidLoad stuff
LoginViewController.shared = self
}
}
Update your AccessViewController like so:
class AccessViewController: UIViewController, LoginDelegates {
override func viewDidLoad() {
super.viewDidLoad()
// All your viewDidLoad stuff
LoginViewController.shared?.delegate = self
}
func loginButtonPressed(sender: AnyObject) {
performSegue(withIdentifier: "toDashboard", sender: self)
}
}
The problem you have caused because you don't have access to your active instance of LoginViewController. In both your approaches you create a new instance of LoginViewController but you need to access existing instance. To make this you have to create static variable which will keeps for you a reference to the active instance of the LoginViewController.
Also please remember that in most cases you have to mark delegate variable as weak to avoid memory leaks.
Because of you load and present view of your LoginViewController directly in AccessViewController view your LoginViewController is not the firstResponder. Because of this the action of your button is not called while pressing.
You can make some trick in your AccessViewController class
class AccessViewController: UIViewController, LoginDelegates {
override func viewDidLoad() {
super.viewDidLoad()
// All your viewDidLoad stuff
let loginVC = LoginViewController()
loginVC.loginButton.addTarget(self, action: #selector(self.loginButtonPressed), for: .touchUpInside)
//add your LoginViewController view as subview to your AccessController view.
}
#objc func loginButtonPressed() {
performSegue(withIdentifier: "toDashboard", sender: self)
}
}