We are running into a confusing issue when using Apple's Push Notifications via APN. We have the following scenario (quite standard i guess):
When our App, let's call it "MyApp" here, is installed and started for the first time we are asking the user for permissions to send him Push Notifications through "MyApp".
In this example the AppDelegate looks like this:
import UIKit
import UserNotifications
class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
// Register Remote Notifications
UNUserNotificationCenter.current().delegate = self
self.registerForPushNotifications()
return true
}
// MARK: - Remote Notifications
func registerForPushNotifications() {
UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { (granted, error) in
guard granted else {
return
}
self.getNotificationSettings()
}
}
func getNotificationSettings() {
UNUserNotificationCenter.current().getNotificationSettings { (settings) in
guard settings.authorizationStatus == .authorized else {
return
}
DispatchQueue.main.async {
UIApplication.shared.registerForRemoteNotifications()
}
}
}
func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
let tokenParts = deviceToken.map { (data) -> String in
return String(format: "%02.2hhx", data)
}
let token = tokenParts.joined()
print("ApnToken: \(token)")
}
func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
print("did Fail to Register for RemoteNotifications")
}
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
print("willPresentNotification!")
completionHandler([.badge, .sound, .alert])
}
func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
print("UserDidResponseToNotification!")
completionHandler()
}
func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
print("DidReceiveRemoteNotification!")
completionHandler(.newData)
}
}
So the user installs and the starts the app and is asked if "MyApp" is allowed to send the user Push Notifications. If the user accepts the Push Notifications application(_:didRegisterForRemoteNotificationsWithDeviceToken:) is called and we give the received deviceToken to our API.
Now the part that confuses me:
The user also has the option to turn Push Notifications off later via the iPhone-Settings like this: Settings > "MyApp" > Notifications > Allow Notifications > Turns the Switch off
Our API has now the deviceToken for APN but the user turned Push Notifications off via iPhone-Settings.
The "problem":
After the user turned off Push Notifications we are still able to send silent Push Notifications to the device and "MyApp" gets the data correct without any problems.
But in the other scenario: The User installs and starts "MyApp" and declines at the first start Push Notifications it is not possible to get a deviceToken from Apple. I tried to get a deviceToken from Apple even if the user declined the Push Notification Alert like this: (But this doesn't work - I guess Apple doesn't provide my any if the user declines)
func registerForPushNotifications() {
UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { (granted, error) in
self.getNotificationSettings()
}
}
func getNotificationSettings() {
UNUserNotificationCenter.current().getNotificationSettings { (settings) in
DispatchQueue.main.async {
UIApplication.shared.registerForRemoteNotifications()
}
}
}
func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
let tokenParts = deviceToken.map { (data) -> String in
return String(format: "%02.2hhx", data)
}
let token = tokenParts.joined()
print("ApnToken: \(token)")
}
It seems like it doesn't matter what the user does if he accepts Push Notifications at the first start. I mean ok, we cannot show the Information via Banner or anything to the user but we can transfer data to the device using APN's even if the user did turn off this setting at a later time. (But we cannot send anything if he declines at start of the app - we need a deviceToken once)
Am i misunderstanding a thing here? This seems inconsistent to me.
I tried to clarify my question so everyone can understand what i am asking for. Excuse my "bad" english it is not easy as a non-native-speaker to ask specific questions with a lot of context here. Anyway, if you need further informations or you didn't understand one or more points from what i am asking let me know i will provide detailed informations and will clarify my question.
I don't know if this matters but at the moment we are using an APN-Development-Certificate (not a distribution certificate yet)
Good question,
The thing is that if user allows you to send push notification (gives you his/her device token) you would be able to send pushes. The push data via notification could be send without notification for a user (silence notification) you could read more about it here: https://medium.com/@m.imadali10/ios-silent-push-notifications-84009d57794c
That's why you are able to send push even if user prevents notification from displaying. That settings controls only displaying appearance, but since he/she gives you the token you still could send data to them. There actually no way for a user to disable that token after it was granted.
来源：https://stackoverflow.com/questions/51055491/apple-push-notifications-apn-inconsistency