Implementing reCAPTCHA Verification in Flutter App

Introduction

• Tutorial on implementing reCAPTCHA verification in a Flutter application.
• Simple demo app created for demonstration.
• Main feature: reCAPTCHA checkbox for verification.
• Successful verification redirects to a welcome page.

Step 1: Create reCAPTCHA API Key

• Visit Google reCAPTCHA to create an API key.
• Steps to create the key:
  • Create a new project, name it (e.g., "try").
  • Select reCAPTCHA version 2 and checkbox option ("I am not a robot").
  • Specify your own domain name (this is important).
  • Accept terms and conditions.
  • API keys will be provided after setup.

Step 2: Set Up Flutter Project

• Open Android Studio and create a Flutter project.
• Remove default counter code to start with a blank state.
• Scaffold widget used with an empty container.

Step 3: Load HTML Page

• Create an HTML page for reCAPTCHA verification.
• Reference to previous tutorial on loading HTML in Flutter.
• Add Library:
  • Update pubspec.yaml to include necessary libraries for web view.
  • Run pub get to install the library.

HTML Page Implementation

• In main.dart, import the library and set up the web view:
  • Enable JavaScript in web view.
  • Load specified URL (e.g., protocodespoint.com).

Permissions

• Add internet permissions in AndroidManifest.xml:
  • Include ACCESS_NETWORK_STATE permission.
  • Set android:usesCleartextTraffic="true" in the application tag.

Step 4: Loading Local HTML Page

• Create an assets folder containing web pages.
• Create index.html with simple content (e.g., <h1>Example</h1>).
• Update pubspec.yaml to give access to assets folder.
• Load local HTML page by adjusting the path in main.dart:
  • Example path: assets/webpages/index.html.

Step 5: Implement reCAPTCHA Widget

• Replace dummy HTML with reCAPTCHA widget in index.html.
• Load reCAPTCHA API script using the generated key.

Step 6: Handling Verification Response

• Listen for successful verification in main.dart:
  • Use JavaScript channel to receive messages from the web view.
  • On successful verification (
    • Redirect to welcome page (home_page.dart).
• Create home_page.dart for the welcome page layout.

Final Steps

• Restart the app after all modifications.
• Verify reCAPTCHA and check redirection to the welcome page.

Conclusion

• Tutorial covered reCAPTCHA implementation in a Flutter app.
• Source code available in the description.
• Encouragement to practice side by side with the video.
• Reminder to subscribe to Protocols Point.