UNUserNotificationCenterDelegate methods not being called Xcode 8 iOS 10

Question

I have followed all the steps exactly as mentioned here: Push notification issue with iOS 10. But unfortunately, these two methods are not being called:

-(void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler

-(void)userNotificationCenter:(UNUserNotificationCenter *)center didReceiveNotificationResponse:(UNNotificationResponse *)response withCompletionHandler:(void(^)())completionHandler

The only method called is:

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))handler

However, didReceiveRemoteNotification is not called when app is closed.

I am using Xcode version 8 and iOS 10.0.2

AppDelegate.h

#import <UserNotifications/UserNotifications.h>

@interface AppDelegate : UIResponder   <UIApplicationDelegate,UNUserNotificationCenterDelegate>

AppDelegate.m

#import "AppDelegate.h"

#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedAscending)


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
     if( SYSTEM_VERSION_LESS_THAN( @"10.0" ) )
{

    [[UIApplication sharedApplication] registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:(UIUserNotificationTypeSound |    UIUserNotificationTypeAlert | UIUserNotificationTypeBadge) categories:nil]];
    [[UIApplication sharedApplication] registerForRemoteNotifications];
}
else
{
    UNUserNotificationCenter *center = [UNUserNotificationCenter currentNotificationCenter];
    center.delegate = self;
    [center requestAuthorizationWithOptions:(UNAuthorizationOptionSound | UNAuthorizationOptionAlert | UNAuthorizationOptionBadge) completionHandler:^(BOOL granted, NSError * _Nullable error)
     {
         if( !error )
         {
             [[UIApplication sharedApplication] registerForRemoteNotifications];  // required to get the app to do anything at all about push notifications
             NSLog( @"Push registration success." );
         }
         else
         {
             NSLog( @"Push registration FAILED" );
             NSLog( @"ERROR: %@ - %@", error.localizedFailureReason, error.localizedDescription );
             NSLog( @"SUGGESTIONS: %@ - %@", error.localizedRecoveryOptions, error.localizedRecoverySuggestion );  
         }  
     }];  
}
return YES;
}

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))handler
{


if( SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO( @"10.0" ) )
{
    NSLog( @"iOS version >= 10. Let NotificationCenter handle this one." );
    // set a member variable to tell the new delegate that this is background
    return;
}
}

-(void)userNotificationCenter:(UNUserNotificationCenter *)center willPresentNotification:(UNNotification *)notification withCompletionHandler:(void (^)(UNNotificationPresentationOptions options))completionHandler{

//Called when a notification is delivered to a foreground app.

NSLog(@"Userinfo %@",notification.request.content.userInfo);

completionHandler(UNNotificationPresentationOptionAlert);
}

-(void)userNotificationCenter:(UNUserNotificationCenter *)center didReceiveNotificationResponse:(UNNotificationResponse *)response withCompletionHandler:(void(^)())completionHandler{

//Called to let your app know which action was selected by the user for a given notification.

NSLog(@"Userinfo %@",response.notification.request.content.userInfo);

}

Besides, I get an error if I call return in didReceiveRemoteNotification:

Warning: Application delegate received call to -application:didReceiveRemoteNotification:fetchCompletionHandler: but the completion handler was never called.

When I see iOS console (a tool to get more logs of push notification), I can see this error:

20/10/16 15:06:48 SpringBoard(UserNotificationsServer)[55]: Not saving push notification to store 3995-06A9, error=Error Domain=UNErrorDomain Code=1401 "Notification has no user-facing content" UserInfo={NSLocalizedDescription=Notification has no user-facing content}

Answer 1

(Posted solution on behalf of the OP).

The push notification was missing alert key in aps, so User Notifications Server was not saving notification in the store and hence these two methods were not being called.