Implementing In-App Updates in Flutter

Keeping your Flutter application up-to-date is crucial for providing users with the latest features, bug fixes, and security patches. Google Play’s in-app updates feature allows you to prompt users to update your app while they’re still using it. This article will guide you through implementing in-app updates in Flutter, including setup, code implementation, and best practices.

What are In-App Updates?

In-app updates are a feature provided by the Google Play Store that allows you to request users to update your app without leaving the app itself. This avoids the traditional route of having users navigate to the Play Store to update. There are two types of in-app updates:

• Flexible Updates: Allow users to continue using the app while the update downloads in the background. These updates are suitable for optional feature enhancements.
• Immediate Updates: Block the user from using the app until the update is installed. These updates are suitable for critical bug fixes or security patches.

Why Implement In-App Updates?

• Improved User Experience: Users can update without leaving the app.
• Faster Adoption of Updates: Encourage users to install updates promptly.
• Security: Patch vulnerabilities quickly and ensure users have the latest security features.
• Access to New Features: Roll out new features and improvements seamlessly.

Prerequisites

Before implementing in-app updates, make sure you have the following:

• A Flutter project set up and running.
• An Android device or emulator connected.
• The Google Play Billing Library dependency.
• Uploaded your app to the Google Play Console (internal testing track is sufficient).

Step-by-Step Implementation

Step 1: Add Dependencies

First, you need to add the in_app_update plugin to your pubspec.yaml file:

dependencies:
  flutter:
    sdk: flutter
  in_app_update: ^3.1.1  # Use the latest version

Run flutter pub get to install the dependency.

Step 2: Configure AndroidManifest.xml

No specific configuration is required in the AndroidManifest.xml file for in-app updates, as the in_app_update package handles most of the setup.

Step 3: Implement In-App Update Logic

Now, let’s implement the in-app update logic in your Flutter app. Here’s a complete example that includes checking for updates and initiating both flexible and immediate updates.

import 'package:flutter/material.dart';
import 'package:in_app_update/in_app_update.dart';
import 'package:flutter/foundation.dart';
void main() {
  runApp(MyApp());
}
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'In-App Update Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}
class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
  AppUpdateInfo? _updateInfo;
  GlobalKey<ScaffoldMessengerState> scaffoldKey = GlobalKey();
  InAppUpdate _inAppUpdate = InAppUpdate.instance;
  @override
  void initState() {
    super.initState();
    checkForUpdate();
  }
  Future<void> checkForUpdate() async {
    try {
      final result = await _inAppUpdate.checkForUpdate();
      setState(() {
        _updateInfo = result;
      });
      if (_updateInfo?.updateAvailability == UpdateAvailability.available) {
        if (_updateInfo?.isImmediateUpdateAllowed == true) {
          _inAppUpdate.performImmediateUpdate().catchError((e) {
            showSnack(e.toString());
            return AppUpdateResult.inAppUpdateFailed;
          });
        } else if (_updateInfo?.isFlexibleUpdateAllowed == true) {
          await _inAppUpdate.startFlexibleUpdate().then((_) {
            setState(() {});
            showSnack('Flexible update started!');
          }).catchError((e) {
            showSnack(e.toString());
          });
        }
      }
    } catch (e) {
      print(e);
    }
  }
  void showSnack(String text) {
    if (mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(text),
        ),
      );
    }
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      key: scaffoldKey,
      appBar: AppBar(
        title: Text('In-App Update Demo'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'Check for In-App Updates:',
              style: TextStyle(fontSize: 20),
            ),
            SizedBox(height: 20),
            ElevatedButton(
              onPressed: checkForUpdate,
              child: Text('Check for Update'),
            ),
            SizedBox(height: 20),
            if (_updateInfo != null)
              Column(
                children: <Widget>[
                  Text('Update Availability: ${_updateInfo!.updateAvailability}'),
                  Text('Install Status: ${_updateInfo!.installStatus}'),
                  Text('Is Immediate Update Allowed: ${_updateInfo!.isImmediateUpdateAllowed}'),
                  Text('Is Flexible Update Allowed: ${_updateInfo!.isFlexibleUpdateAllowed}'),
                ],
              ),
          ],
        ),
      ),
    );
  }
}

In this example:

• The checkForUpdate() function checks for available updates using _inAppUpdate.checkForUpdate().
• If an update is available, it checks whether an immediate or flexible update is allowed.
• For immediate updates, it calls _inAppUpdate.performImmediateUpdate().
• For flexible updates, it calls _inAppUpdate.startFlexibleUpdate().
• The UI displays the update information and a button to trigger the update check.

Step 4: Handling Flexible Updates Completion

To complete a flexible update, you should prompt the user to restart the app once the download is complete. Use the completeFlexibleUpdate() method:

ElevatedButton(
    onPressed: () {
        _inAppUpdate.completeFlexibleUpdate();
    },
    child: Text('Complete Flexible Update'),
),

Step 5: Testing In-App Updates

To test in-app updates, you need to:

• Upload your app to the Google Play Console on an internal testing track or using internal app sharing.
• Install the app on a test device from the Play Store.
• Increase the version code in your pubspec.yaml file.
• Upload the updated APK to the Play Console.
• Run the app and check for updates.

Best Practices

• Graceful Handling: Always handle potential errors and edge cases.
• User Communication: Inform users about the update process.
• Update Types: Use immediate updates only for critical fixes; prefer flexible updates for non-critical features.
• Testing: Thoroughly test in-app updates on different devices and network conditions.
• Fallback Mechanism: In case of failure, direct users to the Play Store to update manually.

Common Issues and Solutions

• No Update Found: Ensure the version code in your Play Console is higher than the installed app version.
• Update Fails: Check network connectivity and Play Store availability.
• Play Store Not Recognizing Update: Wait a few hours after uploading the new version to the Play Console for the update to propagate.

Conclusion

Implementing in-app updates in your Flutter application enhances user experience, ensures quicker adoption of new features and security patches, and keeps your user base on the latest version. By following this guide and implementing best practices, you can seamlessly integrate in-app updates into your app and keep it up-to-date with minimal disruption to your users.