Display Firebase Notification Popup in swift 4 - ios

Question

Notice: Solution at the bottom.
Original issue.
I followed the directions on firebase to set up push notifications in iOS. I do successfully get notification to the phone and will display at the top of the phone if the app is closed, but if I'm in the app the notification never displays. I see the print out in the terminal though so I know its receiving the notification.
Ideal functionality would be:
1) if app is closed or in background when the user clicks the notification it opens the app then a in app popup alert will display with the notification with a Okay button to click
2) if the app is in the foreground the notification displays as a popup alert with a Okay button to click.
Below is the AppDelegate.swift code which when I run it and send a notification, I get the notification but I also get the following error when trying to display the alert. Warning: Attempt to present UIAlertController on Company.AuthorizationCheckViewController whose view is not in the window hierarchy!
Thank you for any help you can provide.
import UIKit
import GoogleMaps
import Sentry
import UserNotifications
import Firebase
#UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
let userDefaults = UserDefaults.standard
FirebaseApp.configure()
Messaging.messaging().delegate = self
if #available(iOS 10.0, *) {
UNUserNotificationCenter.current().delegate = self
let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
UNUserNotificationCenter.current().requestAuthorization(
options: authOptions,
completionHandler: {_, _ in })
} else {
let settings: UIUserNotificationSettings =
UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
application.registerUserNotificationSettings(settings)
}
application.registerForRemoteNotifications()
return true
}
func applicationWillResignActive(_ application: UIApplication) {
}
func applicationDidEnterBackground(_ application: UIApplication) {
}
func applicationWillEnterForeground(_ application: UIApplication) {
VersionCheck.shared.IsUpdateRequired()
}
func applicationDidBecomeActive(_ application: UIApplication) {
}
func applicationWillTerminate(_ application: UIApplication) {
}
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
if let messageID = userInfo["gcm.message_id"] {
print("Message ID: \(messageID)")
}
let message : [String : Any] = userInfo["aps"] as! [String : Any]
let messageAlert : [String : Any] = message["alert"] as! [String : Any]
let lBody : String = messageAlert["body"] as! String
let lTitle : String = messageAlert["title"] as! String
print("body 1 = \(lBody)") //this works!
print("title = \(lTitle)") //this works!
let alert = UIAlertController(title: lTitle, message: lBody, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil);
self.window?.rootViewController?.present(alert, animated: true, completion: nil)
}
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any],
fetchCompletionHandler completionHandler: #escaping (UIBackgroundFetchResult) -> Void) {
let message : [String : Any] = userInfo["aps"] as! [String : Any]
let messageAlert : [String : Any] = message["alert"] as! [String : Any]
let lBody : String = messageAlert["body"] as! String
let lTitle : String = messageAlert["title"] as! String
print("body 2 = \(lBody)")
print("title = \(lTitle)")
let alert = UIAlertController(title: lTitle, message: lBody, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil);
self.window?.rootViewController?.present(alert, animated: true, completion: nil)
completionHandler(UIBackgroundFetchResult.newData)
}
func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
print("Unable to register for remote notifications: \(error.localizedDescription)")
}
func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
print("APNs token retrieved: \(deviceToken)")
}
}
#available(iOS 10, *)
extension AppDelegate : UNUserNotificationCenterDelegate {
func userNotificationCenter(_ center: UNUserNotificationCenter,
willPresent notification: UNNotification,
withCompletionHandler completionHandler: #escaping (UNNotificationPresentationOptions) -> Void) {
let userInfo = notification.request.content.userInfo
let message : [String : Any] = userInfo["aps"] as! [String : Any]
let messageAlert : [String : Any] = message["alert"] as! [String : Any]
let lBody : String = messageAlert["body"] as! String
let lTitle : String = messageAlert["title"] as! String
print("body 3 = \(lBody)")
print("title = \(lTitle)")
let alert = UIAlertController(title: lTitle, message: lBody, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
self.window?.rootViewController?.present(alert, animated: true, completion: nil)
completionHandler([UNNotificationPresentationOptions.alert])
}
func userNotificationCenter(_ center: UNUserNotificationCenter,
didReceive response: UNNotificationResponse,
withCompletionHandler completionHandler: #escaping () -> Void) {
let userInfo = response.notification.request.content.userInfo
if let messageID = userInfo["gcm.message_id"] {
print("Message ID: \(messageID)") //can use the id later to privent multiple popups of the same message
}
let message : [String : Any] = userInfo["aps"] as! [String : Any]
let messageAlert : [String : Any] = message["alert"] as! [String : Any]
let lBody : String = messageAlert["body"] as! String
let lTitle : String = messageAlert["title"] as! String
print("body 4 = \(lBody)")
print("title = \(lTitle)")
let alert = UIAlertController(title: lTitle, message: lBody, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil)
self.window?.rootViewController?.present(alert, animated: true, completion: nil)
completionHandler()
}
}
extension AppDelegate : MessagingDelegate {
func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String) {
print("Firebase registration token: \(fcmToken)")
let dataDict:[String: String] = ["token": fcmToken]
NotificationCenter.default.post(name: Notification.Name("FCMToken"), object: nil, userInfo: dataDict)whenever a new token is generated.
}
func messaging(_ messaging: Messaging, didReceive remoteMessage: MessagingRemoteMessage) {
print("Received data message: \(remoteMessage.appData)")
}
}
Solution:
I added PresentedViewController? to the code and it allowed the alert popup to display.
Also by adding UIBackgroundFetchResults.newData to the completionHandler I was able to have the notification displayed in the app
new code looks like this
let alert = UIAlertController(title: lTitle, message: lBody, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
self.window?.rootViewController?.presentedViewController?.present(alert, animated: true, completion: nil)
completionHandler(UIBackgroundFetchResult.newData)