Delegate nil after setting it - ios

Question

I am using the delegate method but for some odd reason my delegate variable seems to be nil when I want to call the delegate method. I can't for the life of me figure out what I'm doing wrong
protocol ProfileProtocol {
func buttonTapped()
}
class ProfileView: UIView {
var delegate: ProfileProtocol?
#IBOutlet weak var button: UIButton!
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
override func awakeFromNib() {
configure()
}
func setup() {
...
}
#IBAction func buttonTapped(_ sender: UIButton) {
// delegate nil
delegate?.buttonTapped()
}
}
ProfileViewController (yes it conforms to ProfileProtocol):
override func viewDidLoad() {
swipeableView.nextView = {
createCardView()
}
}
func createCardView() -> UIView {
let cardView = ProfileView(frame: swipeableView.bounds)
cardView.delegate = self
let contentView = Bundle.main.loadNibNamed("ProfileCardView", owner: self, options: nil)?.first! as! UIView
contentView.translatesAutoresizingMaskIntoConstraints = false
contentView.backgroundColor = cardView.backgroundColor
cardView.addSubview(contentView)
activeCardView = cardView
return cardView
}
func buttonTapped() {
self.performSegue(withIdentifier: "profileToEmojiCollection", sender: self)
}
Whenever I tap the button in my ProfileView, my ProfileViewController should perform a segue, however the delegate method isn't even being called because delegate is nil when I tap the button

Answer 1

I like to keep my custom views modular, and do things programmatically, it avoids the use of a Xib.
You should keep your view's responsibilities and subviews to the view itself. Ultimately the View receiving the the action(s) should be responsible for calling the delegate's methods. Also nextView is a closure that returns a UIView: (() -> UIView?)? not a UIView, a call to a function in a closure is not an explicit return you should return the view: let view = createCardView() return view.
ProfileView.swift
import UIKit
protocol ProfileProtocol {
func buttonTapped()
}
class ProfileView: UIView {
var delegate: ProfileProtocol?
lazy var button: UIButton = {
let button = UIButton()
button.translatesAutoresizingMaskIntoConstraints = false
button.addTarget(self, action: #selector(buttonTapped(_:)), for: .touchUpInside)
button.setTitle("Profile Button", for: .normal)
button.backgroundColor = UIColor.black
return button
}()
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override func awakeFromNib() {
}
#objc func buttonTapped(_ sender: UIButton) {
// Check for a nil delegate, we dont want to crash if one is not set
if delegate != nil {
delegate!.buttonTapped()
} else {
print("Please set ProfileView's Delegate")
}
}
func setup() {
//setup subviews
self.addSubview(button)
button.widthAnchor.constraint(equalToConstant: 150).isActive = true
button.heightAnchor.constraint(equalToConstant: 50).isActive = true
button.centerXAnchor.constraint(equalTo: self.centerXAnchor).isActive = true
button.centerYAnchor.constraint(equalTo: self.centerYAnchor).isActive = true
}
}
You can create ProfileView's like any other UIView, but remember to set the Delegate of each of them after creation:
swipeableView.nextView = {
let view = createProfileView() //set properties during creation?
view.delegate = self
//set properties after creation?
//view.backgroundColor = UIColor.red
return view
}
ViewController.swift
import UIKit
class ViewController: UIViewController, ProfileProtocol {
lazy var profileView: ProfileView = {
let view = ProfileView()
view.backgroundColor = UIColor.lightGray
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
profileView.delegate = self
setup()
}
func buttonTapped() {
print("Do Something")
}
func setup() {
self.view.addSubview(profileView)
profileView.widthAnchor.constraint(equalTo: self.view.widthAnchor).isActive = true
profileView.heightAnchor.constraint(equalTo: self.view.heightAnchor, multiplier: 0.7).isActive = true
profileView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
profileView.centerYAnchor.constraint(equalTo: self.view.centerYAnchor).isActive = true
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}