Google Sign In All Platforms

A Flutter plugin for Google Sign-In across all platforms including Mobile, Web, and Desktop. This package leverages the google_sign_in package for Mobile and Web Platforms, and url_launcher for all platforms.

Table of Contents

• Installation
• Usage
• GoogleSignInParams
• GoogleSignIn
• Feedback

Installation

Add the following to your pubspec.yaml file:

dependencies:
  google_sign_in_all_platforms: ^1.0.0
  google_sign_in: ^5.0.7
  url_launcher: ^6.0.20

Then run:

flutter pub get

Usage

A simple usage example is as follows:

import 'package:flutter/material.dart';
import 'package:google_sign_in_all_platforms/google_sign_in_all_platforms.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: SignInDemo(),
    );
  }
}

class SignInDemo extends StatefulWidget {
  @override
  _SignInDemoState createState() => _SignInDemoState();
}

class _SignInDemoState extends State<SignInDemo> {
  late GoogleSignIn _googleSignIn;

  @override
  void initState() {
    super.initState();
    _googleSignIn = GoogleSignIn(
      params: GoogleSignInParams(
        clientId: 'YOUR_CLIENT_ID',
        clientSecret: 'YOUR_CLIENT_SECRET',
        redirectPort: 3000,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Google Sign-In Demo')),
      body: Center(
        child: Column(
          children: [
            const Spacer(),
            ElevatedButton(
              onPressed: () async {
                final credentials = await _googleSignIn.signIn();
                if (credentials != null) {
                  print('Signed in successfully: ${credentials.accessToken}');
                } else {
                  print('Sign in failed');
                }
              },
              child: const Text('Sign In'),
            ),
            const Spacer(),
          ],
        ),
      ),
    );
  }
}

GoogleSignInParams

This class contains all the parameters that might be needed for performing the Google sign-in operation.

Parameters

• timeout: The total time to wait for the user to log in on Desktop platforms. Default is 1 minute.
• saveAccessToken: A function to save the access token locally on Desktop platforms.
• retrieveAccessToken: A function to retrieve the stored access token on Desktop platforms.
• deleteAccessToken: A function to delete the stored access token on Desktop platforms.
• scopes: A list of OAuth2.0 scopes. Default includes userinfo.profile and userinfo.email.
• redirectPort: The localhost port for receiving the access code on Desktop platforms. Default is 8000.
• clientId: The Google Project Client ID, required for Desktop platforms.
• clientSecret: The Google Project Client Secret, required for Desktop platforms.

Certainly! Here's a clean and well-structured version of your instructions for the README, with a clear heading and chronological steps:

---

How to Get Google OAuth Credentials

To use Google OAuth in your application, you need to create OAuth 2.0 credentials (Client ID and Client Secret) from the Google Cloud Console. Follow these steps:

1. Go to the Google Cloud Console Open https://console.cloud.google.com/apis/credentials and sign in with your Google account.

2. Set up the OAuth Consent Screen Before creating credentials, you must configure the OAuth consent screen:

   • Select your project (or create a new one, if not already created for your app).
   • Navigate to "OAuth consent screen" in the sidebar.
   • Choose "External" for user type (recommended for most cases).
   • Fill in the required information (App name, user support email, etc.).
   • Save and continue through the steps until the setup is complete.

3. Create OAuth 2.0 Credentials

   • Go to "Credentials" in the sidebar.

   • Click "Create Credentials" → "OAuth client ID".

   • Choose "Web application" as the application type.

   • You can leave "Authorized JavaScript origins" empty.

   • Under "Authorized redirect URIs", add:

     http://localhost:<redirectPort>
     

     By default, <redirectPort> is 8000, so the URI would typically be:

     http://localhost:8000
     

4. Copy the Client ID and Client Secret After creation, you’ll receive your Client ID and Client Secret. Use these in your application’s configuration as required.

Example

GoogleSignInParams params = GoogleSignInParams(
  timeout: Duration(minutes: 2),
  saveAccessToken: (token) async {
    // Custom save logic
  },
  retrieveAccessToken: () async {
    // Custom retrieve logic
    return 'stored_token';
  },
  deleteAccessToken: () async {
    // Custom delete logic
  },
  scopes: [
    'https://www.googleapis.com/auth/userinfo.profile',
    'https://www.googleapis.com/auth/userinfo.email',
    'https://www.googleapis.com/auth/drive',
  ],
  redirectPort: 3000,
  clientId: 'YOUR_CLIENT_ID',
  clientSecret: 'YOUR_CLIENT_SECRET',
);

GoogleSignIn

This class is used to perform all types of Google OAuth operations.

Constructor

• GoogleSignIn({GoogleSignInParams params = const GoogleSignInParams()}): Initializes the GoogleSignIn instance with the provided parameters.

Methods

• Future<GoogleSignInCredentials?> signIn(): Executes signInOffline first, and if unsuccessful, executes signInOnline.
• Future<GoogleSignInCredentials?> signInOffline(): Performs sign-in using the token stored in internal storage. Falls back to online sign-in on mobile devices if offline sign-in fails.
• Future<GoogleSignInCredentials?> signInOnline(): Performs online sign-in for all platforms.
• Future<http.Client?> get authenticatedClient: Returns the authenticated HTTP client. Should be called after the user is signed in.
• Future<void> signOut(): Performs the sign-out operation and deletes the stored token.

Example

GoogleSignIn googleSignIn = GoogleSignIn(
  params: GoogleSignInParams(
    clientId: 'YOUR_CLIENT_ID',
    clientSecret: 'YOUR_CLIENT_SECRET',
    redirectPort: 3000,
  ),
);

Future<void> performSignIn() async {
  final credentials = await googleSignIn.signIn();
  if (credentials != null) {
    print('Signed in successfully: ${credentials.accessToken}');
  } else {
    print('Sign in failed');
  }
}

Future<void> performSignOut() async {
  await googleSignIn.signOut();
  print('Signed out successfully');
}

Feedback

We welcome feedback and contributions to this project. You can provide feedback in the following ways:

• GitHub Issues: Report issues or suggest features on our GitHub Issues page.
• Email: Send your feedback or queries to [email protected].

Thank you for using Google Sign In All Platforms!