Self instance inside a closure

Question

I'm having a problem trying to animate and change some properties of ui elements inside a closure. When I tried to animate some views through a function, It execute the function but the animation fail to complete, nevertheless when I execute the function outside the closure, it works fine. This is my code, my problem is in the delegate extension at the bottom of AuthController , function called facebookAuth . I've been struggling almost for a day and I can not find the error.

I put some print statements inside the animation and function to track down purpose, these are the ones executing:

Login successful (this one is in the delegate function

slide (this one is in the slide function)

not complete (this one is in the animation closure)

AuthController

import UIKit
import AVFoundation
import FBSDKLoginKit
import FBSDKCoreKit
import Firebase

protocol AuthControllerDelegate {
    func login(withUser user: User)
    func facebookAuth()
    func signUp(withUser user: User)
    func facebookRegister(withEmail email: String, cellphone: String)
}

class AuthController: UIViewController {

    enum AuthView {
        case registerView
        case loginView
        case fbRegisterSecondStepCenter
    }

    private var player: AVPlayer!
    private var playerLayer: AVPlayerLayer!
    private var registerViewCenterConstraint: NSLayoutConstraint?
    private var loginViewCenterConstraint: NSLayoutConstraint?
    private var fbRegisterSecondStepCenterConstraint: NSLayoutConstraint?
    private var currentView: AuthView = .loginView
    private var facebookUserStore: User?

    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }

    override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
        return .portrait
    }

    private let purpleBackground: UIView = {
        let pb = UIView()
        pb.backgroundColor = .darkBackground
        pb.alpha = 0.5
        return pb
    }()

    //MARK: AuthViews

    private lazy var loginView: LoginView = {
        let view = LoginView()
        view.delegate = self
        return view
    }()

    private lazy var registerView: RegisterView = {
        let view = RegisterView()
//        view.delegate = self
        view.alpha = 0
        return view
    }()

    private lazy var fbRegisterSecondStep: FBRegisterSecondStep = {
        let view = FBRegisterSecondStep()
        view.alpha = 0
        view.delegate = self
        return view
    }()

    private lazy var bottomBtn: UIButton = {
        let btn = UIButton()
        let attributedString = NSMutableAttributedString(string: "Not registered? Sign up.", attributes: [.foregroundColor: UIColor.lightText, .font: UIFont.init(name: Fonts.lightFont.rawValue, size: 16)!])
        btn.setAttributedTitle(attributedString, for: .normal)
        btn.contentHorizontalAlignment = .center
        btn.addTarget(self, action: #selector(handleChangeView), for: .touchUpInside)
        return btn
    }()

    let alertController: AlertController = {
        let ac = AlertController()
        return ac
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        print(UserDefaults.Account.bool(forKey: .isUserLoggedIn))
        setVideoBackground()
        setupViews()
        alertController.transitioningDelegate = alertController
        alertController.modalPresentationStyle = .custom
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        navigationController?.isNavigationBarHidden = true
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillAppear(animated)
        navigationController?.isNavigationBarHidden = false
    }

    private func setupViews() {
        view.addSubview(purpleBackground)
        view.addSubview(loginView)
        view.addSubview(registerView)
        view.addSubview(fbRegisterSecondStep)
        view.addSubview(bottomBtn)

        _ = purpleBackground.anchor(top: view.topAnchor, bottom: view.bottomAnchor, right: view.rightAnchor, left: view.leftAnchor)

        loginViewCenterConstraint = loginView.centerInView().first
        _ = loginView.anchorWithMultiplier(top: nil, bottom: nil, right: nil, left: nil, height: view.heightAnchor, width: view.widthAnchor, topConstant: 0, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0.8, heightMultiplier: 0.6)

        registerViewCenterConstraint = registerView.centerInView().first
        registerViewCenterConstraint?.constant = 1000
        _ = registerView.anchorWithMultiplier(top: nil, bottom: nil, right: nil, left: nil, height: view.heightAnchor, width: view.widthAnchor, topConstant: 0, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0.8, heightMultiplier: 0.8)

        fbRegisterSecondStepCenterConstraint = fbRegisterSecondStep.centerInView().first
        fbRegisterSecondStepCenterConstraint?.constant = 1000
        _ = fbRegisterSecondStep.anchorWithMultiplier(top: nil, bottom: nil, right: nil, left: nil, height: view.heightAnchor, width: view.widthAnchor, topConstant: 0, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0.8, heightMultiplier: 0.5)

        _ = bottomBtn.anchor(top: nil, bottom: view.bottomAnchor, right: view.rightAnchor, left: view.leftAnchor, topConstant: 0, bottomConstant: 20, rightConstant: 0, leftConstant: 0, widthConstant: 0, heightConstant: 0)
    }

    private func setVideoBackground() {
        let videoPath = Bundle.main.url(forResource: "trim720", withExtension: "mp4")
        player = AVPlayer(url: videoPath!)
        playerLayer = AVPlayerLayer(player: player)
        playerLayer.videoGravity = .resizeAspectFill
        playerLayer.frame = view.frame
        player.actionAtItemEnd = .none
        player.play()

        view.layer.insertSublayer(playerLayer, at: 0)

        NotificationCenter.default.addObserver(self, selector: #selector(handleStop), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: player.currentItem)
    }

    private func slide(toView view: AuthView, completion: @escaping (Bool) -> Void = { _ in }) {
        guard let registerCenterConstraint = registerViewCenterConstraint, let loginCenterConstraint = loginViewCenterConstraint, let fbRegisterSecondConstraint = fbRegisterSecondStepCenterConstraint else {
            fatalError("Error unwrapping auth views constraints.")
        }
        switch view {
        case .loginView:
            loginCenterConstraint.constant = 0
            registerCenterConstraint.constant = 1000
            fbRegisterSecondConstraint.constant = 1000
            currentView = .loginView
        case .registerView:
            loginCenterConstraint.constant = 1000
            registerCenterConstraint.constant = 0
            fbRegisterSecondConstraint.constant = 1000
            currentView = .registerView
        case .fbRegisterSecondStepCenter:
            loginCenterConstraint.constant = 1000
            registerCenterConstraint.constant = 1000
            fbRegisterSecondConstraint.constant = 0
            currentView = .fbRegisterSecondStepCenter
            print("slideeeeeeeeeeee")
        }
        let isRegisterVisible = registerCenterConstraint.constant == 0
        let isLoginVisible = loginCenterConstraint.constant == 0
        let isFbRegisterVisible = fbRegisterSecondConstraint.constant == 0

        UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.8, initialSpringVelocity: 1, options: .curveEaseOut, animations: {
            self.registerView.alpha = isRegisterVisible ? 1 : 0
            self.loginView.alpha = isLoginVisible ? 1 : 0
            self.fbRegisterSecondStep.alpha = isFbRegisterVisible ? 1 : 0
            self.view.layoutIfNeeded()
            print("slide")
        }) { (state) in
            if state {
                print("completed")
            } else {
                print("not completed")
            }
            completion(state)
        }
    }

    fileprivate func pushHome() {
        navigationController?.isNavigationBarHidden = false
        navigationController?.setViewControllers([HomeController()], animated: true)
    }

    // MARK: Handlers

    @objc private func handleStop() {
        player.seek(to: kCMTimeZero)
    }

    @objc private func handleChangeView() {

        let isLoginVisible = currentView == .loginView
        let view: AuthView = isLoginVisible ? .registerView : .loginView
        slide(toView: view) { (completed) in
            let attributedString = self.bottomBtn.attributedTitle(for: .normal) as! NSMutableAttributedString
            let newTitle = isLoginVisible ? "Already an user? Sign In" : "Not registered? Sign up."
            attributedString.mutableString.setString(newTitle)
        }
    }
}

extension AuthController: Loginable, Registable, AuthControllerDelegate {

    func login(withUser user: User) {
        signIn(withUser: user) { (_) in
            self.pushHome()
        }
    }

    func facebookAuth(){
        let loginManager = FBSDKLoginManager()
        loginManager.logIn(withReadPermissions: ["email", "public_profile"], from: self) { (result, err) in
            if err == nil, !(result?.isCancelled)!, let token = result?.token.tokenString {
                print("Login successful")
                self.loginView.isHidden = true
                self.bottomBtn.isHidden = true
                self.slide(toView: .registerView)
            }
        }
    }

    func facebookRegister(withEmail email: String, cellphone: String) {
        guard let user = facebookUserStore else {
            fatalError("Error linking accounts")
        }
        register(withUser: user) { (completed) in
            if completed {
                self.linkAccount(withEmail: email, cellphone: cellphone, completion: { (completion) in
                    if completion {
                        self.pushHome()
                    }
                })
            }
        }
    }

    func signUp(withUser user: User) {
        register(withUser: user) { (_) in
            print("registrado")
            UserDefaults.Account.set(true, forKey: .isUserLoggedIn)
            self.pushHome()
        }
    }
}

The function execute through a delegate inside this view when the fbButton is clicked.

LoginView

//
//  LoginView.swift
//  TaxiApp
//
//  Created by Leonardo Dominguez on 10/2/17.
//  Copyright © 2017 Leonardo Dominguez. All rights reserved.
//

import UIKit

class LoginView: BaseView {

    var delegate: AuthControllerDelegate?

    private let emailField: TAField = {
        let pf = TAField(placeHolder: "E-mail", keyboardType: .emailAddress)
        return pf
    }()

    private let passwordField: TAField = {
        let pf = TAField(placeHolder: "Password")
        pf.isSecureTextEntry = true
        return pf
    }()

    private lazy var loginBtn: TAButton = {
        let btn = TAButton(title: "Login")
        btn.addTarget(self, action: #selector(handleLogin), for: .touchUpInside)
        return btn
    }()

    private let facebookBtn: TAButton = {
        let btn = TAButton()
        btn.backgroundColor = UIColor(hexString: "#3b5998")
        btn.setAttributedTitle(NSAttributedString(string: "Login with Facebook", attributes: [.foregroundColor: UIColor.lightText, .font: UIFont.init(name: Fonts.mediumFont.rawValue, size: 20)!]), for: .normal)
        return btn
    }()

    private let forgotPassword: UIButton = {
        let btn = UIButton()
        btn.setAttributedTitle(NSAttributedString(string: "Forgot password", attributes: [.foregroundColor: UIColor.placeholderText, .font: UIFont.init(name: Fonts.mediumFont.rawValue, size: 16)!]), for: .normal)
        btn.contentHorizontalAlignment = .right
        return btn
    }()

    private let orView: UIView = {
        let container = UIView()
        let lbl = UILabel()
        lbl.text = "or"
        lbl.textColor = .lightText
        lbl.font = UIFont(name: Fonts.mediumFont.rawValue, size: 20)
        let leftLine = UIView()
        let rightLine = UIView()
        leftLine.backgroundColor = .lightLine
        rightLine.backgroundColor = .lightLine
        container.addSubview(rightLine)
        container.addSubview(lbl)
        container.addSubview(leftLine)
        rightLine.centerYAnchor.constraint(equalTo: container.centerYAnchor).isActive = true
        _ = rightLine.anchor(top: nil, bottom: nil, right: container.rightAnchor, left: lbl.rightAnchor, topConstant: 0, bottomConstant: 0, rightConstant: 70, leftConstant: 3, widthConstant: 0, heightConstant: 1.0)
        _ = lbl.centerInView()
        leftLine.centerYAnchor.constraint(equalTo: container.centerYAnchor).isActive = true
        _ = leftLine.anchor(top: nil, bottom: nil, right: lbl.leftAnchor, left: container.leftAnchor, topConstant: 0, bottomConstant: 0, rightConstant: 3, leftConstant: 70, widthConstant: 0, heightConstant: 1.0)
        return container
    }()

    override func setupViews() {
        setupBtns()

        addSubview(emailField)
        addSubview(passwordField)
        addSubview(forgotPassword)
        addSubview(loginBtn)
        addSubview(orView)
        addSubview(facebookBtn)

        _ = emailField.anchor(top: topAnchor, bottom: nil, right: rightAnchor, left: leftAnchor, topConstant: 20, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthConstant: 0, heightConstant: Theme.fieldHeight)

        _ = passwordField.anchorWithMultiplier(top: emailField.bottomAnchor, bottom: nil, right: emailField.rightAnchor, left: emailField.leftAnchor, height: emailField.heightAnchor, width: nil, topConstant: Theme.topPadding, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0, heightMultiplier: 1)

        _ = forgotPassword.anchor(top: passwordField.bottomAnchor, bottom: nil, right: emailField.rightAnchor, left: emailField.leftAnchor, topConstant: 5, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthConstant: 0, heightConstant: 0)

        _ = loginBtn.anchorWithMultiplier(top: passwordField.bottomAnchor, bottom: nil, right: emailField.rightAnchor, left: emailField.leftAnchor, height: emailField.heightAnchor, width: nil, topConstant: Theme.topPadding, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0, heightMultiplier: 1)

        _ = orView.anchor(top: loginBtn.bottomAnchor, bottom: nil, right: rightAnchor, left: leftAnchor, topConstant: Theme.topPadding / 2, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthConstant: 0, heightConstant: 10)

        _ = facebookBtn.anchorWithMultiplier(top: orView.bottomAnchor, bottom: nil, right: emailField.rightAnchor, left: emailField.leftAnchor, height: emailField.heightAnchor, width: nil, topConstant: Theme.topPadding / 2, bottomConstant: 0, rightConstant: 0, leftConstant: 0, widthMultiplier: 0, heightMultiplier: 1)

    }

    func setupBtns() {
        facebookBtn.addTarget(self, action: #selector(handleFacebookLogin), for: .touchUpInside)
    }

    @objc func handleFacebookLogin() {
        delegate?.facebookAuth()
    }

    @objc func handleLogin() {
        if let email = emailField.text, let password = passwordField.text {
            let user = User(email: email, password: password)
            delegate?.login(withUser: user)
        }
    }

}

UPDATE

So after a lot of patinete trying the whole app, I just notice that the error belong to a RouterController that is a UINavigationController subclass where AuthController is embed. When I change the windows rootviewcontroller to avoid RouterController and go directly to AuthController , everything Start to work.. Now my doubt is, why this is happening? I was trying to figure out, so I can fixed or in future cases but I don't know why, here is my code:

RouterController

import UIKit

class RouterController: UINavigationController {

    override func viewDidLoad() {
        super.viewDidLoad()
//        perform(#selector(redirect), with: nil, afterDelay: 0)
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        redirect()
    }

    @objc func redirect() {
        if UserDefaults.Account.bool(forKey: .isUserLoggedIn) {
            viewControllers = [HomeController()]
        } else {
            setViewControllers([AuthController()], animated: false)
        }
    }
}

Answer 1

Try executing everything in the closure on the main thread like so:

func facebookAuth(){
    let loginManager = FBSDKLoginManager()
    loginManager.logIn(withReadPermissions: ["email", "public_profile"], from: self) {[weak self] (result, err) in
        if err == nil, !(result?.isCancelled)!, let token = result?.token.tokenString {
            print("Login successful")
            DispatchQueue.main.async {
                self?.loginView.isHidden = true
                self?.bottomBtn.isHidden = true
                self?.slide(toView: .registerView)
            }
        }
    }
}