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Lit Firebase Auth simplifies the process of adding Firebase Authentication to a Flutter application.

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Lit Firebase

Lit Firebase Auth

⚠️ Attention: This package is at an early stage. A lot of features are missing. Eventually this package will be "lit", but for now, use at your own risk.

Pre-lit Firebase authentication. It provides a set of convenient utilities and widgets to easily add Firebase authentication to a Flutter app.

Table of Contents

Features

Features

  • Multiple platform support
    • Works on mobile (Android/iOS) and web. No changes needed
    • Windows, macOS and Linux to be added in the future
  • Multiple authentication providers
  • Services and state managed for you
    • Easily interact with Firebase from anywhere in your app
    • Monitor the auth state and react to changes
  • Error handling and error messages
    • Built in error handling that will display friendly in-app error messages
    • Error/Success dialogs can be customized
  • Highly customizable
    • Either use the standard sign-in widgets, or create your own.

Getting started

Please note that before this package can be used, Firebase Core needs to be initialized in your application. See the official FlutterFire documentation for up to date information.

For a complete example (with Firebase initialization) see the example project.

Or take a look at a live demo.

Some videos on Lit Firebase: Introduction

Note that this video was recorded with the old version of FlutterFire and Lit Firebase Auth. As such, some configuration may be different. For example, this does not show how to initialize FlutterFire.

Customizing Lit Firebase UI

Platform Configuration

Android integration

Follow normal Firebase Initialization

Note: When you are debugging on android, use a device or AVD with Google Play services. Otherwise you will not be able to authenticate.

iOS integration

Follow normal Firebase Initialization

You will also need to define a global platform for your project. Modify the ios/Podfile and make sure the following is not commented out:

platform :ios, '8.0'

You can find this at the top of the Podfile.

Web integration

Follow normal Firebase Initialization

The above should be sufficient, and should provide up to date information. But for additional information, please see below:

You'll need to modify the web/index.html of your app following the Firebase setup instructions:

Read more in the firebase_auth_web README.

Below is an example of a Flutter Web index.html with Firebase Auth enabled:

...
<body>

  <!-- GOOGLE SignIn Client ID -->
  <meta name="google-signin-client_id" content="ADD-YOUR-CLIENT-ID.apps.googleusercontent.com">

  <!-- The core Firebase JS SDK is always required and must be listed first -->
  <script src="https://www.gstatic.com/firebasejs/7.15.5/firebase-app.js"></script>
  <script src="https://www.gstatic.com/firebasejs/7.15.5/firebase-auth.js"></script>

  <!-- TODO: Add SDKs for Firebase products that you want to use
     https://firebase.google.com/docs/web/setup#available-libraries -->

  <script>
    // Your web app's Firebase configuration
    var firebaseConfig = {
      ...// ADD CONFIG HERE
    };
    // Initialize Firebase
    firebase.initializeApp(firebaseConfig);
  </script>

  <!-- CONTINUE TO INITIALIZE FLUTTER WEB -->
  ...

Usage

The two most important widgets are

  • LitAuthInit - which initializes the package and exposes the services that will be used in your application.
  • LitAuth - which renders the UI (forms, buttons and dialogs).

Lit Firebase Initialization

First, you need to initialize the package with LitAuthInit. This should be at the root of your application. Above MaterialApp/CupertinoApp, and above any widgets that want to access authentication functionality.

For example:

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // Needs to be above [MaterialApp]/[CupertinoApp]
    return LitAuthInit(
      // specify which auth providers to enable
      authProviders: AuthProviders(
        emailAndPassword: true, // enabled by default
        google: true,
        apple: true,
        twitter: true,
        github: true,
        anonymous: true,
      ),
      child: MaterialApp(
        title: 'Material App',
        home: Home(),
      ),
    );
  }
}

Standard Sign-in widget

You can either create your own custom sign-in widget, or make use of the standard built in one. To use the standard sign-in form with no changes:

LitAuth();

This will use the default configuration and UI theming.

Lit Firebase

See the section on decoration and theming for customization.

NOTE: This widget needs to be a child of a Scaffold widget.

Handle auth state changes

To determine the current auth state, make use of LitAuthState:

class Home extends StatelessWidget {
  const Home({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: LitAuthState(
        authenticated: () => Text('Authenticated'), // Login widget, or sign in button
        unauthenticated: () => Text('Not Authenticated'), // Authenticated widget, or sign out button
      ),
    );
  }
}

Auth success and failure

You can provide optional callbacks in LitAuth to handle success and failure when performing sign-in.

return LitAuth(
  onAuthFailure: (failure) {
    print('Auth failed.'); // show error message
  },
  onAuthSuccess: () {
    print('Auth success.'); // navigate to new screen
  },
);

NOTE: these handlers will not be called if LitAuth is already disposed.

For example, if you were to wrap this LitAuth in LitAuthState, such as:

return LitAuthState(
  authenticated: () =>
      Text('Authenticated'), // Login widget, or sign in button
  unauthenticated: () => LitAuth(
    onAuthFailure: (failure) {
      print('Auth failed.'); // show error message
    },
    onAuthSuccess: () {
      print('Auth success.'); // will not be called
    },
  ),
);

Then in this instance the onAuthSuccess handler may not be called. As the authenticated state will be triggered and the LitAuth widget disposed.

Sign out

To sign out the current user, make use of the signOut extension method on BuildContext. For example:

RaisedButton(
  onPressed: () {
    context.signOut();
  },
  child: Text('Sign out'),
);

Get current user

Depending on the status of the user you'll get a different state: empty, initializing, or success.

final litUser = context.getSignedInUser();
litUser.when(
  (user) => print(user.uid),
  empty: () {},
  initializing: () {},
);

The value.user is the Firebase User object.

Watch user for changes

Watches the Firebase User object for changes. Will be triggered every time the Firebase User changes (for example, on logout or new sign in).

final litUser = context.watchSignedInUser();
litUser.when(
  (user) => Text('Signed in ${user.uid}'),
  empty: () => Text('Not signed in'),
  initializing: () => Text('Loading'),
);

The above should only be used in the build method. If you need direct access to the current user, prefer context.getSignedInUser().

Determine if submitting is active

Whether Lit Firebase is currently attempting to authenticate. Can be used to show a loading indicator.

Should only be used in the build method. For example:

Widget build(BuildContext context) {
  final isSubmitting = context.isSubmitting();
  return Visibility(
    visible: isSubmitting,
    child: CircularProgressIndicator(),
  );
}

Authentication Providers

Lit Firebase Auth supports a number of third party authentication providers, such as Google, Apple, Github, etc.

Initialization

Enable the sign-in method you want to use in firebase console

Google Sign In for Android

Lit Firebase Auth uses the google_sign_in package for Google Sign in. Please see their documentation if you encounter difficulties.

Please ensure you have done the steps outline in Android integration

The majority of the configuration is on Firebase side. First, Google Sign In needs to be enabled in the Authentication section of your Firebase project. Next, if you have not done so yet, you will need to provide your application's SHA certificate within your Firebase settings and replace the google-services.json file with the updated one. This is needed for Google Sign in to be allowed.

A correctly setup Firebase project and the correct google-services.json file is all you'll need.

Google Sign In for iOS

Lit Firebase Auth uses the google_sign_in package for Google Sign in. Please see their documentation if you encounter difficulties.

Please ensure you have done the steps outline in iOS integration

Then add the CFBundleURLTypes attributes below into the [my_project]/ios/Runner/Info.plist file.

<!-- Put me in the [my_project]/ios/Runner/Info.plist file -->
<!-- Google Sign-in Section -->
<key>CFBundleURLTypes</key>
<array>
	<dict>
		<key>CFBundleTypeRole</key>
		<string>Editor</string>
		<key>CFBundleURLSchemes</key>
		<array>
			<!-- TODO Replace this value: -->
			<!-- Copied from GoogleService-Info.plist key REVERSED_CLIENT_ID -->
			<string>com.googleusercontent.apps.861823949799-vc35cprkp249096uujjn0vvnmcvjppkn</string>
		</array>
	</dict>
</array>
<!-- End of the Google Sign-in Section -->

iOS additional requirement

Note that according to https://developer.apple.com/sign-in-with-apple/get-started, starting June 30, 2020, apps that use login services must also offer a "Sign in with Apple" option when submitting to the Apple App Store.

Google Sign in for Web

You will need to add the Google Sign in Client ID to your index.html file. You can get this ID from the Firebase console, within the Google Sign-in Web Configuration (Authentication section).

An example is below:

web/index.html

...
<body>

  <!-- GOOGLE SignIn Client ID -->
  <meta name="google-signin-client_id" content="ADD-YOUR-CLIENT-ID.apps.googleusercontent.com">
...

Apple Sign In for Android

This should be working, but has not been tested. There should be configuration examples in the Firebase documentation.

Apple Sign In for iOS

  1. Configure your app in Xcode to add the "Sign In with Apple" capability

Twitter Sign In for iOS and Android

  1. Register your app as a developer application in Twitter Developer Portal
  2. Copy Paste your API Key and API Secret into the Twitter Sign In Method in Firebase
  3. Enable 3rd party authentication in Twitter Developer Portal and copy past callback URL from Firebase

Github Sign In for iOS and Android

Similar process to Twitter Sign in.

Using with Lit Firebase Auth

The supported third-party providers are:

  • Google
  • Apple
  • Github
  • Twitter

NOTE: Apple requires Apple sign in to be enabled if any other third-party sign-in option is used.

These need to be enabled in the LitAuthInit widget.

LitAuthInit(
  // specify which auth providers to enable
  authProviders: AuthProviders(
    emailAndPassword: true, // enabled by default
    google: true,
    apple: true,
    twitter: true,
    github: true,
    anonymous: true,
  ),
  child: MaterialApp(
    title: 'Material App',
    home: Home(),
  ),
);

To initiate authentication with one of these providers, call the relevant method. For example:

FlatButton(
  onPressed: () {
    context.signInWithGithub();
  },
  child: Text('Github Sign In'),
),

Other identity providers (for example, Facebook) will need to be implemented separately. After successful third party sign in you can sign in to Firebase by making use of the signInWithCredential method available on BuildContext.

For example:

 Widget build(BuildContext context) {
   AuthCredential credential = // get credential for identity provider (Facebook, etc.)
   context.signInWithCredential(credential);
 }

Decoration and theming

The UI can be as customizable as you need. But for simple usage it's fairly straight forward.

It's easy to provide custom decoration/configuration for the sign-in elements. You can either customize the elements of the standard sign-in widget, or create an entirely custom sign-in widget from scratch. Up to you.

Standard Sign-in widget customization

For example, to override the standard email TextFormField just provide a TextFieldConfig for the emailTextField parameter. In this example we are providing a new [style] and [inputDecoration]:

return LitAuth(
  config: AuthConfig(
    emailTextFormField: InputDecoration(labelText: 'My beautiful label'),
    emailTextField: TextFieldConfig(
      style: TextStyle(fontSize: 18),
      inputDecoration: InputDecoration(
        labelText: 'My beautiful label',
      ),
    ),
  )
);

To customize a button:

return LitAuth(
 config: AuthConfig(
   signInButton: ButtonConfig.raised(
     themedata: ButtonThemeData(buttonColor: Colors.red),
     child: Text('Sign in with Email'),
   ),
   googleButton: GoogleButtonConfig.light(),
   appleButton: AppleButtonConfig.dark(),
 ),
),

There are a number of different button customizations that you can do.

Notifications

Notifications are rendered using the flushbar package.

You can customize the error and success notifications:

LitAuth(
  errorNotification: NotificationConfig(backgroundColor: Colors.pink),
  successNotification: NotificationConfig(backgroundColor: Colors.pink),
);

There are many attributes that can be altered to create the desired notification. Please see the NotificationConfig class for additional information.

Additional Customization

For further customization you can directly make use of the Lit Firebase components to build a completely custom sign-in widget.

Instead of using the standard AuthConfig, set it to custom and provide your custom sign-in widget:

return LitAuth.custom(
  child: YourCustomSignInWidget(),
);

You can build any form you want, for example:

class YourCustomSignInWidget extends StatelessWidget {
  const CustomSignInWidget({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Text('Welcome', style: Theme.of(context).textTheme.headline4),
        // You need to wrap the custom sign-in widgets with a SignInForm.
        // This is used to validate the email and password
        SignInForm(
          formChild: Column(
            children: [
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: Text(
                  'A custom form',
                  style: Theme.of(context).textTheme.headline5,
                ),
              ),
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: EmailTextFormField(
                  style: TextStyle(fontSize: 18),
                  decoration: InputDecoration(labelText: 'My Email Label'),
                ),
              ),
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: PasswordTextFormField(
                  style: TextStyle(fontSize: 18),
                  decoration: InputDecoration(labelText: 'My Password Label'),
                ),
              ),
              RaisedButton(
                onPressed: () {
                  context.signInWithEmailAndPassword();
                },
                child: Text('Sign In'),
              ),
              FlatButton(
                onPressed: () {
                  context.signInAnonymously();
                },
                child: Text('Anony Sign In'),
              ),
            ],
          ),
        ),
      ],
    );
  }
}

NOTE: SignInForm needs to be provided above the EmailTextFormField and PasswordTextFormField.

The state of the password and email can be cleared manually by calling:

context.resetSignInForm()

This will reset the form to its initial state.

It's a good idea to do this when you have multiple EmailTextFormField and PasswordTextFormField widgets in separate locations, for example when you have a separate Sign-in form and a Registration form.

Icons

It's possible to use the OAuth icons provided by the package. For example:

class Icons extends StatelessWidget {
  const Icons({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        LitAuthIcon.google(),
        LitAuthIcon.appleBlack(),
        LitAuthIcon.appleWhite(),
        LitAuthIcon.github(),
        LitAuthIcon.twitter(),
      ],
    );
  }
}

This will display a column of icons (images).

Planned features

State
Platforms Support more platforms (Windows, macOS, Linux)
Auth providers Support more authentication providers (Facebook, Microsoft)
Cupertino Cupertino look and feel
Password reset Add services and UI to reset password/email
Email confirmation Add UI to notify users they need to confirm their email address
Support UI Assist users who cannot authenticate with support links
Custom dialogs ✔️ Add support to customize dialog messages
Adaptive layouts Adaptive layouts to support multiple screen sizes
Customization ✔️ Even more, or easier, customization
Testing Add testing

Dart Versions

  • Dart 2: >= 2.7.0

Maintainers

Starware

Lit Firebase is Starware This means you're free to use the project, as long as you star ⭐ its GitHub repository or give a thumbs up 👍 on Pub.