How to control when to prompt user for push notification permissions in iOS

Question

I\'ve built an application for iPhone using Swift and Xcode 6, and the Parse framework to handle services.

While following the Parse tutorials on how to set up push noti

Answer 1

This is for Swift 2. I have placed promptUserToRegisterPushNotifications() in MainViewController.swift, but I have left didRegisterForRemoteNotificationsWithDeviceToken in AppDelegate because it didn't work when I place it on the same MainViewController.swift.

// In 'MainViewController.swift' file
func promptUserToRegisterPushNotifications() {
    // Register for Push Notifications

    let application: UIApplication = UIApplication.sharedApplication()

    if application.respondsToSelector(#selector(UIApplication.registerUserNotificationSettings(_:))) {
        print("registerUserNotificationSettings.RegisterForRemoteNotificatios")

        let notificationSettings = UIUserNotificationSettings(
            forTypes: [.Badge, .Sound, .Alert], categories: nil)
        application.registerUserNotificationSettings(notificationSettings) // Register for Remote Push Notifications
        application.registerForRemoteNotifications()
    }
}


// In AppDelegate
func application(application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: NSData) {
    let tokenChars = UnsafePointer<CChar>(deviceToken.bytes)
    var tokenString = ""

    for i in 0..<deviceToken.length {
        tokenString += String(format: "%02.2hhx", arguments: [tokenChars[i]])
    }

    NSUserDefaults.standardUserDefaults().setObject(tokenString, forKey: "deviceToken")

    print("Device Token:", tokenString)

}

Answer 2

This is method I have written in the code and works fine once it called on launch (didFinishLaunch)

class func registerNotification() {
    if #available(iOS 10.0, *) {
        // push notifications
        UNUserNotificationCenter.current().requestAuthorization(options: [.sound, .alert, .badge]) {
            (granted, error) in
            if (granted) {
                UIApplication.shared.registerForRemoteNotifications()
            }
        }

        let center  = UNUserNotificationCenter.current()
        center.delegate = AppManager.appDel()
        center.requestAuthorization(options: [.sound, .alert, .badge]) { (granted, error) in
            if error == nil {
                UIApplication.shared.registerForRemoteNotifications()
            }
        }
    } else {
        UIApplication.shared.registerUserNotificationSettings(UIUserNotificationSettings(types: [.badge, .sound, .alert], categories: nil))
        UIApplication.shared.registerForRemoteNotifications()
    }
}

Answer 3

The answer is simple. If you want the user to be prompted some other time, for instance on a button press then simply move the code regarding the request into that function (or call promptUserToRegisterPushNotifications() from somewhere else).

To get a hold of the application variable outside the AppDelegate, simply do this:

let application = UIApplication.shared

Hope that helps :)