Ask for notification in ViewController. - ios

Question

Currently, my app asks users for notification permission right on initial opening, how do I ask them when they click a specific button and how do I run the registerForRemoteNotifications in that ViewController when they click yes. The following is my AppDelegate where its currently promoting users.
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
FirebaseApp.configure()
UIApplication.shared.applicationIconBadgeNumber = 0
if #available(iOS 10.0, *) {
// For iOS 10 display notification (sent via APNS)
UNUserNotificationCenter.current().delegate = self as? UNUserNotificationCenterDelegate
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
}

Answer 1

Put this inside a ViewController and run the function inside an action or the ViewDidLoad.
func registerForRemoteNotification() {
if #available(iOS 10.0, *) {
let center = UNUserNotificationCenter.current()
center.requestAuthorization(options: [.sound, .alert, .badge]) { (granted, error) in
if error == nil{
UIApplication.shared.registerForRemoteNotifications()
}
}
}
else {
UIApplication.shared.registerUserNotificationSettings(UIUserNotificationSettings(types: [.sound, .alert, .badge], categories: nil))
UIApplication.shared.registerForRemoteNotifications()
}
}

Answer 2

You need to set it in your completionHandler.
This line: UNUserNotificationCenter.current().requestAuthorization(
options: authOptions,
completionHandler: {_, _ in })
Should be:
UNUserNotificationCenter.current().requestAuthorization(
options: authOptions,
completionHandler: { granted, error in
if granted {
application.registerForRemoteNotifications()
// Do other things after user has been granted authorization
}
})