Real-time Uninstall Tracking

Overview

Real-time uninstall tracking allows you to detect app uninstalls instantly using Firebase Analytics.

Prerequisites

Before you begin, ensure the following:

1. Firebase project with Blaze Plan (required for Cloud Functions)

2. Firebase Cloud Functions

   Cloud Functions for Firebase is a serverless framework that programmatically provides responses to events triggered by Firebase features and HTTPS requests.

   For more information, refer to Cloud Functions for Firebase.

3. Firebase Analytics enabled in your Android app

4. Node.js and npm installed

5. Firebase CLI installed and configured

6. WebEngage API Bearer Token: Refer this to generate your BEARER_TOKEN

7. Identify your WebEngage Dashboard region

   Dashboard Host URL	Region
   dashboard.webengage.com	Global Data Center (US)
   dashboard.in.webengage.com	India Data Center (in)
   dashboard.ksa.webengage.com	Saudi Arabia Data Center(ksa)

How It Works

1. Firebase logs the app_remove event when a user uninstalls the app (Android only)
2. A Firebase Cloud Function listens to this event
3. The event data is sent to WebEngage
4. WebEngage processes the uninstall in real time

How is real-time uninstall tracking different from the existing uninstall tracking?

The current uninstall tracking in WebEngage happens by sending Silent Push notifications once a day to all user devices or when a Push Campaign is triggered for the user device. Up to 24 hours is required to track uninstall. Using the real-time uninstall tracking, the uninstall is tracked immediately by the Firebase SDK so that you can respond quickly to user uninstalls

Implementation of real-time uninstall tracking

Step 1: Set Up Conversion Event Using Firebase

To enable real-time uninstall tracking, make sure the app_remove event is configured as conversion event in the Firebase dashboard.

To configure the conversion event, follow these steps:

1. Open the Firebase project linked to your Android app.
2. In the Firebase dashboard, go to Analytics > Events .
3. Locate app_remove and switch on the Mark as key event toggle.

Step 2: Creating Cloud function:

To create and publish a cloud function using Node JS, perform the following steps:

1. Open a terminal.
2. Set up Node.js and NPM
3. Run below command in CLI to install Firebase CLI.
   CLI Command

   npm install -g firebase-tools.

4. To initialize and authenticate the Firebase SDK for Cloud Functions, run below command
   CLI Command

   firebase login

5. From your Firebase project directory, run below command
   CLI Command

   firebase init functions

6. Select the option to Use an existing project and select your appropriate project
7. Select Javascript option for What language would you like to use to write Cloud Functions?
8. Select No option for Do you want to use ESLint to catch probable bugs and enforce style?
9. Identify your BASE_URL

10. Open index.js and add the following code:

'use strict';
const functions = require('firebase-functions/v1');
const admin = require('firebase-admin');
const request = require('requestretry');
admin.initializeApp();
exports.logAndroidUninstallToWebEngage = functions.analytics.event('app_remove').onLog((event) => {
    function myRetryStrategy(err, response, body, options) {
        const shouldRetry = !!err || [500, 502, 503].includes(response.statusCode);
        console.log(`Retry strategy invoked. Should retry: ${shouldRetry}`);
        if (err) console.log('Retrying due to error:', err);
        if (response) console.log('Retrying due to status code:', response.statusCode);
        return shouldRetry;
    }
    try {
        const weInstanceIdData = event.params.we_instance_id;
        var we_cuid = event.params.cuid;
        if(!we_cuid){
            we_cuid = "";
        }
        if (!weInstanceIdData) {
            console.error('Missing or undefined "we_instance_id" in event data.');
            return;
        }
        const applicationID = event.user.appInfo.appId
        const jsonBody = {we_instance_id:weInstanceIdData, cuid: we_cuid, appID: applicationID}
        
        const BASE_URL = "https://c.webengage.com"; //Choose your BASE_URL as per point 9.
      
        const API_URL = `${BASE_URL}/firebase/android/uninstall`;
       
        const options = {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': 'Bearer <BEARER_TOKEN>'
            },
            body: JSON.stringify({data:jsonBody}),
            url: API_URL,
            maxAttempts: 5,
            retryDelay: 2000,
            retryStrategy: myRetryStrategy
        };
        request(options, function (err, response, body) {
            if (err) {
                console.error('Request encountered an error:', err);
            }
            if (response) {
                console.log('Response status code:', response.statusCode);
                console.log('Response attempts:', response.attempts);
            }
            if (response && response.statusCode === 200) {
                console.log('Request successful.');
                return 0;
            } else {
                console.error('Request failed. Error:', err);
                return 1;
            }
        });
    } catch (error) {
        console.error('Unexpected error occurred:', error);
    }
});

11. Open package.json and add the following code:

{
  "name": "functions",
  "description": "Cloud Functions for Firebase",
  "scripts": {
    "serve": "firebase emulators:start --only functions",
    "shell": "firebase functions:shell",
    "start": "npm run shell",
    "deploy": "firebase deploy --only functions",
    "logs": "firebase functions:log"
  },
  "engines": {
    "node": "18"
  },
  "main": "index.js",
  "dependencies": {
    "firebase-admin": "^12.6.0",
    "firebase-functions": "^4.3.1",
    "request": "^2.88.2",
    "requestretry": "^4.1.2"
  },
  "devDependencies": {
    "firebase-functions-test": "^3.1.0"
  },
  "private": true
}

12. To deploy the function, run

1. firebase deploy --only functions

Step 3: Configure the Android App to send the unique WebEngage identifier

1. Ensure your app has integrated Firebase Analytics SDK. For more information, refer to Get started with Google Analytics.
2. Override the onNewSessionStarted method of the WebEngage Lifecycle callbacks to set the Firebase Analytics event parameters when new session is started.

   📘

   Refer WebEngage Lifecycle callbacks for detailed steps for implementing the callback

   Java

   @Override
       public void onNewSessionStarted() {
       setFirebaseAnalytics(MyApplication.getAppContext(), WebEngage.get().getCUID());
       }
   
       public static void setFirebaseAnalytics(Context context, String cuid) {
           try {
               FirebaseAnalytics mFirebaseAnalytics;
               mFirebaseAnalytics = FirebaseAnalytics.getInstance(context);
               Bundle bundle = new Bundle();
               String id = WebEngage.get().getWEInstanceId();
           
               if (!TextUtils.isEmpty(id)) {
                   bundle.putString("we_instance_id", WebEngage.get().getWEInstanceId());
                   bundle.putString("cuid", cuid);
                   mFirebaseAnalytics.setDefaultEventParameters(bundle);
               }
           } catch (Exception e) {
               Log.e("Google Messaging Service plugin not applied: " + e);
           }
       }