Flutter SDK Setup

Instructions for adding the OneSignal Flutter SDK to your Flutter app for iOS and Android

Step 1. Requirements

iOS Requirements

Android Requirements

Amazon & Huawei Requirements

Follow these instructions if your app is distributed on the Amazon AppStore and/or the Huawei AppGallery.

Step 2. Add the OneSignal Flutter SDK

2.1 To add the OneSignal Flutter SDK to your project, edit your project's pubspec.yaml file:

dependencies:
	onesignal_flutter: ^3.5.0

2.2 Run flutter pub get to install the SDK. Or, if you are using Android Studio, Click Pub get in the action ribbon at the top of pubspec.yaml.

2.3 Now, in your Dart code, you can use:

import 'package:onesignal_flutter/onesignal_flutter.dart';

Step 3. Add an iOS Service Extension (iOS Apps Only)

The OneSignalNotificationServiceExtension allows your application (in iOS) to receive rich notifications with images and buttons, along with Badges and Confirmed Deliveries.

3.1 Within your project's ios folder, open the .xcworkspace file in Xcode.

3.2 Select File > New > Target

3.3 Select Notification Service Extension and press Next

3.4 Enter the Product Name as OneSignalNotificationServiceExtension and Language to Objective-C (if you need to use Swift that is ok).

Then click Finish. Do not select "Activate" on the dialog shown after selecting "Finish".

3.5 Press Cancel on the Activate Scheme prompt

250

By canceling, you are keeping Xcode set to debug your app instead of the extension. If you selected Activate by accident, you can simply switch back to debug your app in Xcode (next to the Play button).

3.6 In the Project Navigator, select the top-level project directory and select the OneSignalNotificationServiceExtension target.

Ensure the Deployment Target is set to the same value as your Main Application Target. Unless you have a specific reason not to, you should set the Deployment Target to be iOS 10 which is the version of iOS that Apple released Rich Media for push. iOS versions under 10 will not be able to get Rich Media.

3024

This should be the same value as your Main Application Target.

3.7 Close the Xcode project. In the /ios directory of your project, open the Podfile and add the following outside of the main target (should be at the same level as your main target):

target 'OneSignalNotificationServiceExtension' do
  use_frameworks!
  pod 'OneSignalXCFramework', '>= 3.4.3', '< 4.0'
end
# Uncomment this line to define a global platform for your project
platform :ios, '9.0'

# CocoaPods analytics sends network stats synchronously affecting flutter build latency.
ENV['COCOAPODS_DISABLE_STATS'] = 'true'

project 'Runner', {
  'Debug' => :debug,
  'Profile' => :release,
  'Release' => :release,
}

def flutter_root
  generated_xcode_build_settings_path = File.expand_path(File.join('..', 'Flutter', 'Generated.xcconfig'), __FILE__)
  unless File.exist?(generated_xcode_build_settings_path)
    raise "#{generated_xcode_build_settings_path} must exist. If you're running pod install manually, make sure flutter pub get is executed first"
  end

  File.foreach(generated_xcode_build_settings_path) do |line|
    matches = line.match(/FLUTTER_ROOT\=(.*)/)
    return matches[1].strip if matches
  end
  raise "FLUTTER_ROOT not found in #{generated_xcode_build_settings_path}. Try deleting Generated.xcconfig, then run flutter pub get"
end

require File.expand_path(File.join('packages', 'flutter_tools', 'bin', 'podhelper'), flutter_root)

flutter_ios_podfile_setup

target 'Runner' do
  use_frameworks!
  use_modular_headers!

  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
end

post_install do |installer|
  installer.pods_project.targets.each do |target|
    flutter_additional_ios_build_settings(target)
  end
end

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

3.8 At the top of your Podfile make sure you have platform :ios, '9.0'.
- Or a newer iOS version if your app requires it.

# Uncomment this line to define a global platform for your project
platform :ios, '9.0'

3.9 Open terminal, cd to the ios directory, and run pod install.

If you see the error below, remove # from the above in front of use_frameworks! and try again.

- Runner (true) and OneSignalNotificationServiceExtension (false) do not both set use_frameworks!.

3.10 Reopen the .xcworkspace file in Xcode.
Make sure to always open the workspace file.
In your project, in the OneSignalNotificationServiceExtension/ folder, open NotificationService.m and replace the whole file contents with:

#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)
        }
    }
    
}

📘

Ignore Any Build Errors

The build errors will disappear once you run the app.

3.11 Finally, you will need to enable an App Group to use Confirmed Deliveries and increment/decrement Badges through push notifications.

Please follow the iOS SDK App Groups setup guide to add the OneSignal App Group in your app.

Step 4. Enable iOS Push Capability in Xcode (iOS Apps Only)

4.1 In the main app target, select Signing & Capabilities > All > + Capability, enable Push Notifications.

4.2 Next, enable Background Modes and check Remote Notifications.

Step 5. Set up OneSignal for Android

Verify the Android compileSdkVersion is at least 33 for your project. Open your android/app/build.gradle file and inspect the compileSdkVersion property.

  • If compileSdkVersion in your android/app/build.gradle file is set to flutter.compileSdkVersion, open your android/local.properties file and ensure a property of flutter.compileSdkVersion is either non-existent or is set to a value of 33 or higher.

  • If compileSdkVersion in your android/app/build.gradle file is set to a number less than 33, update it to a value of 33 or higher:

// ...
android {
    compileSdkVersion 33
    // ...
}
// ...

For more information about the Gradle build configuration in relation to Flutter, view the Flutter documentation

Step 6. Initialize the OneSignal SDK (All Platforms)

6.1 You can now initialize OneSignal using the following code in your main.dart file:

//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 or Android 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");
});

6.2 You can also add observers for various events, such as a new notification being received or opened, or observe changes to the subscription status:

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
});

Step 7. Run Your App and Send Yourself a Notification

Run your app on a physical device to make sure it builds correctly. Note that the iOS Simulator does not support receiving remote push notifications.

  • Android devices should be subscribed to push notifications immediately upon opening the app.
  • iOS devices should be prompted to subscribe to push notifications if you used the example setup code provided.

Check your OneSignal Dashboard Audience > All Users to see your Device Record.

Then head over to Messages > New Push to Send your first Push Notification from OneSignal.

📘

Troubleshooting

If you run into any issues please see our Flutter troubleshooting guide.

Try the example project on our Github repository.

If stuck, contact support directly or email [email protected] for help.

For faster assistance, please provide:

  • Your OneSignal App Id
  • Details, logs, and/or screenshots of the issue.
  • Steps to reproduce

Step 8. Set Custom User Properties

Recommended
After initialization, OneSignal will automatically collect common user data by default. Use the following methods to set your own custom userIds, emails, phone numbers, and other user-level properties.

Set External User Id

Required if using integrations.
Recommended for messaging across multiple channels (push, email, sms).

OneSignal creates channel-level device records under a unique Id called the player_id. A single user can have multiple player_id records based on how many devices, email addresses, and phone numbers they use to interact with your app.

If your app has its own login system to track users, call setExternalUserId at any time to link all channels to a single user. For more details, see External User Ids.

let externalUserId = '123456789'; // You will supply the external user id to the OneSignal SDK
OneSignal.shared.setExternalUserId(externalUserId);

Set Email and Phone Number

Recommended if using Email and SMS messaging.
Use the provided SDK methods to capture email and phone number when provided. Follow the channel quickstart guides for setup:

// Pass in email provided by customer
OneSignal.shared.setEmail("[email protected]");

// Pass in phone number provided by customer
OneSignal.shared.setSMSNumber(smsNumber: "+11234567890")

Data Tags

Optional
All other event and user properties can be set using Data Tags. Setting this data is required for more complex segmentation and message personalization.

await OneSignal.shared.sendTag("test", "value");

Step 9. Implement a Soft-Prompt In-App Message

Optional

It is recommended that apps create an alert, modal view, or other interface that describes the types of information they want to send and gives people a clear way to opt in or out.

OneSignal provides an easy option for a "soft-prompt" using In-App Messages to meet this recommendation and have a better user experience. This also permits you to ask for permission again in the future, since the native permission prompt can no longer be shown in your app if the user clicks deny.

See our How to Prompt for Push Permissions with an In-App Message Guide for details on implementing this.

👍

Setup Complete!

Visit Mobile Push Tutorials for next steps.