LocalNotification.m

- (void) notifyMessage: (NSString*) sender withMessage: (NSString*) message {
    // source: http://useyourloaf.com/blog/local-notifications-with-ios-10/
    NSLog(@"BackgroundServerice: Send a notification!");
    message = message?message:@"";
    UNUserNotificationCenter *center = [UNUserNotificationCenter currentNotificationCenter];
    
    // Create a content
    UNMutableNotificationContent *content = [UNMutableNotificationContent new];
    content.title = sender;
    content.body = [ NSString stringWithCString:[ message cStringUsingEncoding:NSUTF8StringEncoding ]
                                       encoding:NSNonLossyASCIIStringEncoding ];
    content.sound = [ UNNotificationSound defaultSound ];
    //content.badge = 1; // <-- shows badge number on app icon.
    
    // Schedule trigger time after 0 sec.
    UNTimeIntervalNotificationTrigger *trigger = [UNTimeIntervalNotificationTrigger triggerWithTimeInterval:0.1
                                                                                                    repeats:NO];
    
    NSString *identifier = @"MYLocalNotification";
    UNNotificationRequest *request = [UNNotificationRequest requestWithIdentifier:identifier
                                                                          content:content
                                                                          trigger:trigger];
    
    [center addNotificationRequest:request withCompletionHandler:^(NSError * _Nullable error) {
        if (error != nil) {
            NSLog(@"BackgroundServerice: Something went wrong with sending LOCAL Notification: %@",error);
        }
    }];
}