dependencies:
    onesignal_flutter: ^3.0.0

import 'package:onesignal_flutter/onesignal_flutter.dart';

target 'OneSignalNotificationServiceExtension' do
  pod 'OneSignalXCFramework', '>= 3.4.3', '< 4.0'
end

#import <OneSignal/OneSignal.h>

#import "NotificationService.h"

@interface NotificationService ()

@property (nonatomic, strong) void (^contentHandler)(UNNotificationContent *contentToDeliver);
@property (nonatomic, strong) UNNotificationRequest *receivedRequest;
@property (nonatomic, strong) UNMutableNotificationContent *bestAttemptContent;

@end

@implementation NotificationService

- (void)didReceiveNotificationRequest:(UNNotificationRequest *)request withContentHandler:(void (^)(UNNotificationContent * _Nonnull))contentHandler {
    self.receivedRequest = request;
    self.contentHandler = contentHandler;
    self.bestAttemptContent = [request.content mutableCopy];
    
    //If your SDK version is < 3.5.0 uncomment and use this code:
    /*
    [OneSignal didReceiveNotificationExtensionRequest:self.receivedRequest
                       withMutableNotificationContent:self.bestAttemptContent];
    self.contentHandler(self.bestAttemptContent);
    */
    
    /* DEBUGGING: Uncomment the 2 lines below and comment out the one above to ensure this extension is excuting
                  Note, this extension only runs when mutable-content is set
                  Setting an attachment or action buttons automatically adds this */
    // NSLog(@"Running NotificationServiceExtension");
    // self.bestAttemptContent.body = [@"[Modified] " stringByAppendingString:self.bestAttemptContent.body];
    
    // Uncomment this line to set the default log level of NSE to VERBOSE so we get all logs from NSE logic
    //[OneSignal setLogLevel:ONE_S_LL_VERBOSE visualLevel:ONE_S_LL_NONE];
    [OneSignal didReceiveNotificationExtensionRequest:self.receivedRequest
                       withMutableNotificationContent:self.bestAttemptContent
                                   withContentHandler:self.contentHandler];
}

- (void)serviceExtensionTimeWillExpire {
    // Called just before the extension will be terminated by the system.
    // Use this as an opportunity to deliver your "best attempt" at modified content, otherwise the original push payload will be used.
    
    [OneSignal serviceExtensionTimeWillExpireRequest:self.receivedRequest withMutableNotificationContent:self.bestAttemptContent];
    
    self.contentHandler(self.bestAttemptContent);
}

@end

import UserNotifications

import OneSignal

class NotificationService: UNNotificationServiceExtension {
    
    var contentHandler: ((UNNotificationContent) -> Void)?
    var receivedRequest: UNNotificationRequest!
    var bestAttemptContent: UNMutableNotificationContent?
    
    override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {
        self.receivedRequest = request
        self.contentHandler = contentHandler
        self.bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)
        
        if let bestAttemptContent = bestAttemptContent {
            //If your SDK version is < 3.5.0 uncomment and use this code:
            /*
            OneSignal.didReceiveNotificationExtensionRequest(self.receivedRequest, with: self.bestAttemptContent)
            contentHandler(bestAttemptContent)
            */
            
            /* DEBUGGING: Uncomment the 2 lines below to check this extension is excuting
                          Note, this extension only runs when mutable-content is set
                          Setting an attachment or action buttons automatically adds this */
            //OneSignal.setLogLevel(.LL_VERBOSE, visualLevel: .LL_NONE)
            //bestAttemptContent.body = "[Modified] " + bestAttemptContent.body
            
            OneSignal.didReceiveNotificationExtensionRequest(self.receivedRequest, with: bestAttemptContent, withContentHandler: self.contentHandler)
        }
    }
    
    override func serviceExtensionTimeWillExpire() {
        // Called just before the extension will be terminated by the system.
        // Use this as an opportunity to deliver your "best attempt" at modified content, otherwise the original push payload will be used.
        if let contentHandler = contentHandler, let bestAttemptContent =  bestAttemptContent {
            OneSignal.serviceExtensionTimeWillExpireRequest(self.receivedRequest, with: self.bestAttemptContent)
            contentHandler(bestAttemptContent)
        }
    }
    
}

buildscript {
    repositories {
        // ...
        maven { url 'https://plugins.gradle.org/m2/' } // Gradle Plugin Portal
    }
    dependencies {
        // ...
        // OneSignal-Gradle-Plugin
        classpath 'gradle.plugin.com.onesignal:onesignal-gradle-plugin:[0.12.10, 0.99.99]'
    }
}

apply plugin: 'com.onesignal.androidsdk.onesignal-gradle-plugin'

//Remove this method to stop OneSignal Debugging 
OneSignal.shared.setLogLevel(OSLogLevel.verbose, OSLogLevel.none);

OneSignal.shared.setAppId("YOUR_ONESIGNAL_APP_ID");

// The promptForPushNotificationsWithUserResponse function will show the iOS push notification prompt. We recommend removing the following code and instead using an In-App Message to prompt for notification permission
OneSignal.shared.promptUserForPushNotificationPermission().then((accepted) {
    print("Accepted permission: $accepted");
});

OneSignal.shared.setNotificationWillShowInForegroundHandler((OSNotificationReceivedEvent event) {
  // Will be called whenever a notification is received in foreground
  // Display Notification, pass null param for not displaying the notification
        event.complete(event.notification);                                 
});

OneSignal.shared.setNotificationOpenedHandler((OSNotificationOpenedResult result) {
  // Will be called whenever a notification is opened/button pressed.
});

OneSignal.shared.setPermissionObserver((OSPermissionStateChanges changes) {
    // Will be called whenever the permission changes
    // (ie. user taps Allow on the permission prompt in iOS)
});

OneSignal.shared.setSubscriptionObserver((OSSubscriptionStateChanges changes) {
    // Will be called whenever the subscription changes 
    // (ie. user gets registered with OneSignal and gets a user ID)
});

OneSignal.shared.setEmailSubscriptionObserver((OSEmailSubscriptionStateChanges emailChanges) {
    // Will be called whenever then user's email subscription changes
    // (ie. OneSignal.setEmail(email) is called and the user gets registered
});

OneSignal.shared.promptUserForPushNotificationPermission();

// If you want to know if the user allowed/denied permission,
// the function returns a Future<bool>:
bool allowed = await OneSignal.shared.promptUserForPushNotificationPermission();