How to implement passwordless login in FlutterFlow?

Implementing Passwordless Login in a FlutterFlow App

Passwordless login provides a seamless user experience by allowing users to log in without needing to remember a password. Here's a detailed guide on how to implement passwordless login in your FlutterFlow app.

Prerequisites

• Create a FlutterFlow account and set up a project where you want the passwordless login functionality.
• Have a basic understanding of Firebase, as it will be used for authentication.
• Ensure that you have FlutterFlow configured with Firebase.

Configuring Firebase for Passwordless Login

• Go to the Firebase Console and select your project.
• Navigate to the Authentication section, then click on the Sign-in method tab.
• Enable the Anonymous sign-in method for temporary access without creating an account.
• Optionally, enable Email/Password or other providers for multi-mode authentication flexibility.

Setting Up FlutterFlow for Firebase Integration

• Open your project in FlutterFlow.
• Navigate to the Settings > Firebase > Firestore tab and make sure Firebase is linked to your project.
• Add your GoogleService-Info.plist (for iOS) and google-services.json (for Android) files if needed.

Designing the Login Interface

• In FlutterFlow, create a new page dedicated to login or modify an existing one.
• Add necessary input fields for users to enter an email or phone number, depending on the intended login method.
• Include a Button widget labeled appropriately, like “Send Login Link.”

Creating the Passwordless Login Logic

• Use a Custom Action to include custom authentication logic.
• If using email, integrate Firebase's sendSignInLinkToEmail method within your custom action to draft and dispatch the login link:

  FirebaseAuth.instance.sendSignInLinkToEmail(
    email: userEmail,
    actionCodeSettings: ActionCodeSettings(
      url: 'https://.firebaseapp.com',
      handleCodeInApp: true,
      iOSBundleId: 'com.example.ios',
      androidPackageName: 'com.example.android',
      androidInstallApp: true,
    ),
  );
  

• Ensure the URL in ActionCodeSettings matches your app's domain and handle code both in app and web.

Integrating the Login Link Reception

• After sending the login link, make sure your app captures and verifies the incoming link.
• Use a Dynamic Link Handler in your custom function to intercept the link and authenticate the user:

  FirebaseAuth.instance.signInWithEmailLink(
    email: userEmail,
    emailLink: receivedLink,
  );
  

• Set up your app to navigate users to the appropriate page after a successful login.

Testing and Debugging

• Utilize FlutterFlow's preview mode to test the login interface and flow.
• Check the Firebase console to ensure users are being authenticated correctly without creating traditional account credentials.
• Use logs to debug any issues with link reception or authentication callbacks.

Deploying Your App with Passwordless Login

• Once the functionality is thoroughly tested, package your app for deployment ensuring all dynamic link handling works on production URLs.
• Check the deployment on various devices and platforms to ensure universal compatibility.

By following these steps, you can effectively incorporate passwordless authentication into your FlutterFlow app, providing a modern login experience while ensuring user security and convenience.