How to add biometric authentication in FlutterFlow?

Implementing Biometric Authentication in FlutterFlow

Adding biometric authentication to a FlutterFlow project involves multiple steps and the integration of some external packages alongside custom functions. Here is a highly detailed guide for implementing biometric authentication within your FlutterFlow app:

Prerequisites

• Ensure you have a FlutterFlow account with an existing project where you want to add biometric authentication.
• Basic knowledge of FlutterFlow's UI and custom functions.
• Familiarity with native code platforms like Android (Java/Kotlin) and iOS (Swift/Objective-C) for potential configurations.

Setting Up Your FlutterFlow Project

• Log into FlutterFlow and open the project where you intend to implement biometric authentication.
• Review your widget tree to determine where the login logic will integrate with biometric checks.

Installing Necessary Packages

• FlutterFlow does not directly provide biometric authentication UI components, so you need external Flutter packages.
• Go to your project’s pubspec.yaml and add the local\_auth package for handling biometric authentication.
• Update your dependencies to ensure the package is correctly installed:

• 
  dependencies:
  
    flutter:
  
      sdk: flutter
  
    local\_auth: ^2.1.5
  
    

Configuring Android and iOS Platforms

• For Android, edit the AndroidManifest.xml to include the required permissions:
• For iOS, you must modify the Info.plist file to include a description of why you need Face ID/Touch ID usage:

• 
  NSFaceIDUsageDescription
  
  We require Face ID to secure your account.
  
    

• Ensure both platforms are set up for biometric authentication. This may require additional settings based on your target device or iOS/Android version.

Creating Custom Functions in FlutterFlow

• FlutterFlow allows custom functions where you can integrate the local\_auth plugin functionality.
• Create a new custom function and name it to reflect its purpose, such as authenticateWithBiometrics.
• Within this function, write the Dart code that utilizes the local\_auth package to verify the user's identity:

• 
  import 'package:local_auth/local_auth.dart';
  
  final LocalAuthentication auth = LocalAuthentication();
  
  Future authenticateWithBiometrics() async {
  
    bool authenticated = false;
  
    try {
  
      authenticated = await auth.authenticate(
  
        localizedReason: 'Scan your fingerprint to authenticate',
  
        options: const AuthenticationOptions(
  
          useErrorDialogs: true,
  
          stickyAuth: true,
  
        ),
  
      );
  
    } catch (e) {
  
      print(e);
  
    }
  
    return authenticated;
  
  }
  
    

Integrating the Biometric Functionality

• Attach the custom function to a button or a specific page event where biometric verification is necessary.
• For example, trigger authenticateWithBiometrics when a user attempts to access sensitive sections of your app.
• Ensure your UI provides feedback based on authentication success or failure.

Testing Biometric Authentication

• Use both Android and iOS emulators, ensuring each has biometric capabilities enabled, to validate your implementation.
• If possible, run your app on real devices to confirm accuracy, latency, and performance under real-world conditions.

Deploying and Final Considerations

• After thorough testing, prepare your app for deployment, checking documentation for any additional biometric capabilities or behavior customization.
• Monitor user feedback and be prepared to handle any issues with specific devices or operating system versions concerning biometric authentication.

By following these detailed steps, you can effectively implement biometric authentication within your FlutterFlow project, adding an additional layer of security and enhancing user experience. Ensure to stay updated with the ongoing changes in FlutterFlow and biometric standards to maintain optimal app functionality.