AlertController view is not in the window hierarchy - swift

Question

i am a beginner in swift, i was trying to use an UIAlertController but i have got an error and the UiAlertController do not show up and i can see an error in the console that says
2021-06-20 18:16:28.494162+0200 Bicycall[50670:543648] [Presentation] Attempt to present <UIAlertController: 0x7fbaca034e00> on <Bicycall.login: 0x7fbabb01d800> (from <Bicycall.login: 0x7fbabb01d800>) whose view is not in the window hierarchy.
2021-06-20 18:16:28.494339+0200 Bicycall[50670:543648] [Presentation] Attempt to present <UIAlertController: 0x7fbac9862800> on <Bicycall.login: 0x7fbabb01d800> (from <Bicycall.login: 0x7fbabb01d800>) whose view is not in the window hierarchy.
Here what i have tried:
import UIKit
import CoreData
import AVKit
import AVFoundation
import TKSubmitTransition
class login: UIViewController {
#IBOutlet weak var passwordView: UIView!
#IBOutlet weak var emailView: UIView!
var id: Int?
var name: String?
var lastname: String?
var email:String?
var password:String?
var phone:String?
var u = ConnectedUser()
var BR = BaseUrl.baseUrl
var player: AVPlayer?
let videoURL: NSURL = Bundle.main.url(forResource: "Bikers", withExtension: "mp4")! as NSURL
func getTopMostViewController() -> UIViewController? {
var topMostViewController = UIApplication.shared.keyWindow?.rootViewController
while let presentedViewController = topMostViewController?.presentedViewController {
topMostViewController = presentedViewController
}
return topMostViewController
}
func presentTestAlert(_ title: String, _ message: String){
let alert = UIAlertController(title: title , message: message, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: NSLocalizedString("OK", comment: "Default action"), style: .default, handler: { _ in
NSLog("The \"OK\" alert occured.")
}))
DispatchQueue.main.async {
self.getTopMostViewController()?.present(alert, animated: true, completion: nil)
}
}
override func viewDidLoad() {
super.viewDidLoad()
self.DeleteAllData()
player = AVPlayer(url: videoURL as URL)
player?.actionAtItemEnd = .none
player?.isMuted = true
let playerLayer = AVPlayerLayer(player: player)
playerLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
playerLayer.zPosition = -1
playerLayer.frame = view.frame
view.layer.addSublayer(playerLayer)
player?.play()
NotificationCenter.default.addObserver(forName: .AVPlayerItemDidPlayToEndTime, object: self.player?.currentItem, queue: .main) { [weak self] _ in
self?.player?.seek(to: CMTime.zero)
self?.player?.play()
// Do any additional setup after loading the view.
}
emailView.layer.cornerRadius = 30.0
emailView.layer.borderWidth = 0.5
emailView.layer.borderColor = UIColor.white.cgColor
passwordView.layer.cornerRadius = 30.0
passwordView.layer.borderWidth = 0.5
passwordView.layer.borderColor = UIColor.white.cgColor
}
//widgets
#IBOutlet weak var txtEmail: UITextField!
#IBOutlet weak var txtPassword: UITextField!
//Actions
#IBAction func btnLogin(_ sender: Any){
//get
/*
guard let url = URL(string: "http://localhost:3000/bikes") else {
return
}
let session = URLSession.shared
session.dataTask(with: url) { ( data , response ,error) in
if let response = response {
print(response)
}
if let data = data {
print(data)
do
{
let json = try JSONSerialization.jsonObject(with: data, options: [])
print(json)
}catch{
print(error)
}
}
}.resume()
*/
//post
guard let url = URL(string: BR+"/login") else {
return
}
let bodyparameters = ["email": txtEmail.text, "password": txtPassword.text]
if (txtEmail.text!.isEmpty || txtPassword.text!.isEmpty ){
self.presentTestAlert("Wrong credentials","Email and Password must not be empty")
}else{
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
guard let httpBody = try? JSONSerialization.data(withJSONObject: bodyparameters, options: []) else{
return
}
request.httpBody = httpBody
let session = URLSession.shared
session.dataTask(with: request) { (data,response,error) in
let status = (response as! HTTPURLResponse).statusCode
//print(response)
print(status)
if let response = response {
let status = (response as! HTTPURLResponse).statusCode
//print(response)
print(status)
}
if((status) == 200){
self.presentTestAlert("Connection Success", " internet connection")
print(" Connection Successssssssssssssss")
if let data = data {
do {
//let json = try JSONSerialization.jsonObject(with: data, options: [])
// print(json);
print(data)
let user = try JSONDecoder().decode(User.self, from: data)
DispatchQueue.main.async {
self.id = user.user_id
self.name = user.name
self.lastname = user.lastname
self.email = user.email
self.password = user.password
self.phone = user.phone
print(self.id!)
print(self.email!)
if(user.user_id != 0){
self.saveUser()
self.DisplayConnectedUser()
self.performSegue(withIdentifier: "HomeSegue", sender: "nil")
}else{
self.presentTestAlert("Login Failed","Wrong credentials")
}
}
}catch{
print(error)
}
}
}else {
self.presentTestAlert("No Connection", "No internet connection")
print(" Connection Nooooooooooooooooooooooooo")
}
}.resume()
}
}
func DeleteAllData(){
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let managedContext = appDelegate.persistentContainer.viewContext
let DelAllReqVar = NSBatchDeleteRequest(fetchRequest: NSFetchRequest<NSFetchRequestResult>(entityName: "Users"))
do {
try managedContext.execute(DelAllReqVar)
}
catch {
print(error)
}
}
func saveUser() {
let appDelegate = UIApplication.shared.delegate as! AppDelegate
//represente l'ORM
let persistentContainer = appDelegate.persistentContainer
let managedContext = persistentContainer.viewContext
let entityDescription = NSEntityDescription.entity(forEntityName: "Users" , in: managedContext)
let object = NSManagedObject(entity: entityDescription! , insertInto: managedContext )
object.setValue(id! , forKey: "user_id" )
object.setValue(email! , forKey: "email" )
object.setValue(password! , forKey: "password" )
object.setValue(name! , forKey: "name" )
object.setValue(lastname! , forKey: "lastname" )
object.setValue(phone! , forKey: "phone" )
do {
try managedContext.save()
print("INSERT SUCCESSFULLY")
print(id!)
}
catch {
print("INSERT ERROR")
}
}
#IBAction func btnSignup(_ sender: Any) {
performSegue(withIdentifier: "signupSegue", sender: "nil")
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
}
func DisplayConnectedUser() {
let appDelegate = UIApplication.shared.delegate as! AppDelegate
//represente l'ORM
let persistentContainer = appDelegate.persistentContainer
let managedContext = persistentContainer.viewContext //retourne NSManagedObject toujours
//la requete retourne un NSManagedObject
let request = NSFetchRequest<NSManagedObject>(entityName : "Users")
//execution de la requete
do {
let result = try managedContext.fetch(request)
for item in result {
print(item.value(forKey: "user_id") as! Int )
print(item.value(forKey: "email") as! String)
self.u.user_id = (item.value(forKey: "user_id") as! Int)
self.u.email = (item.value(forKey: "email") as! String)
self.u.password = (item.value(forKey: "password") as! String)
self.u.name = (item.value(forKey: "name") as! String)
self.u.lastname = (item.value(forKey: "lastname") as! String)
self.u.phone = (item.value(forKey: "phone") as! String)
print(self.u.user_id!)
print(self.u.email!)
print(self.u.password!)
print(self.u.name!)
print(self.u.lastname!)
print(self.u.phone!)
}
}
catch {
print("NO DATA FOUND , Error")
}
}
}
What is annoying me is that none of my alerts worked! i read some other answer in stackoverflow but the solutions did not work for me
What i am trying is to make my alerts working good
Any help will be so appreciated

Answer 1

It seems you want to present the alert over the video player (playerLayer) but you are calling your alert over the layer behind the playerLayer, it will give you the error that you're getting.
With reference to Swift 4 Attempt to present ViewController whose view is not in the window hierarchy
Add this function in your code
func getTopMostViewController() -> UIViewController? {
var topMostViewController = UIApplication.shared.keyWindow?.rootViewController
while let presentedViewController = topMostViewController?.presentedViewController {
topMostViewController = presentedViewController
}
return topMostViewController
}
And replace (Line 33)
self.present(alert, animated: true, completion: nil)
with
DispatchQueue.main.async {
getTopMostViewController()?.present(alert, animated: true, completion: nil)
}