Custom FirebaseUI AuthViewController - swift

Question

Using the FirebaseUI Auth 1.0 version and swift 3.
Followed the sample and read the explains how to subclass the FUIAuthPickerViewController but everything I tried it's giving me a
fatal error: unexpectedly found nil while unwrapping an Optional valueonlet controller = self.authUI!.authViewController()
I exactly copied the example and there is it working, so can someone explain what I did wrong or why this is happening?
Code in my ViewController where I want the user to login
ViewController.swift
import Firebase
import FirebaseAuthUI
import FirebaseGoogleAuthUI
import FirebaseFacebookAuthUI
var ref: FIRDatabaseReference!
var remoteConfig: FIRRemoteConfig!
fileprivate var _refHandle: FIRDatabaseHandle!
fileprivate var _authHandle: FIRAuthStateDidChangeListenerHandle!
fileprivate(set) var auth: FIRAuth? = FIRAuth.auth()
fileprivate(set) var authUI: FUIAuth? = FUIAuth.defaultAuthUI()
fileprivate(set) var customAuthUIDelegate: FUIAuthDelegate = FUICustomAuthDelegate()
func configAuth() {
//listen for changes in auth state
_authHandle = FIRAuth.auth()?.addStateDidChangeListener({ (auth: FIRAuth, currentuser: FIRUser?) in
self.users.removeAll(keepingCapacity: false)
self.tableView.reloadData()
if currentuser != nil {
// User is signed in.
self.fetchUser()
} else {
// No user is signed in.
//self.login()
self.loginSession()
}
})
}
func loginSession() {
self.authUI?.delegate = self.customAuthUIDelegate
let googleAuth = FUIGoogleAuth(scopes: [kGoogleUserInfoEmailScope,
kGooglePlusMeScope,
kGoogleUserInfoProfileScope])
let facebookAuth = FUIFacebookAuth(permissions: ["public_profile",
"email",
"user_friends"])
self.authUI?.providers = [googleAuth, facebookAuth]
let controller = self.authUI!.authViewController()
self.present(controller, animated: true, completion: nil)
}
Here the
FUICustomAuthDelegate.swift
import UIKit
import FirebaseAuthUI
import FirebaseAuth
class FUICustomAuthDelegate: NSObject, FUIAuthDelegate {
func authUI(_ authUI: FUIAuth, didSignInWith user: FIRUser?, error: Error?) {
guard let authError = error else { return }
let errorCode = UInt((authError as NSError).code)
switch errorCode {
case FUIAuthErrorCode.userCancelledSignIn.rawValue:
print("User cancelled sign-in");
break
default:
let detailedError = (authError as NSError).userInfo[NSUnderlyingErrorKey] ?? authError
print("Login error: \((detailedError as! NSError).localizedDescription)");
}
}
func authPickerViewController(forAuthUI authUI: FUIAuth) -> FUIAuthPickerViewController {
return FUICustomAuthPickerViewController(authUI: authUI)
}
and the
FUICustomAuthPickerViewController.swift
import FirebaseAuthUI
#objc(FUICustomAuthPickerViewController)
class FUICustomAuthPickerViewController: FUIAuthPickerViewController {
#IBAction func onClose(_ sender: AnyObject) {
self.cancelAuthorization()
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
}