Apparently, google sign in doesn't work on flutter except with Firebase/some cloud API backend service. I was using a local Laravel API for user auth so adding google sign in functionality requires setting up a firebase account/profile, downloading and adding the googleservices.json file to flutter project as explained in google_sign_in package installation manual. You also need to import firebase-auth package
Flutter Code (I use flutter modular pattern but same applies with Bloc/Provider if you get the idea as explained by Hamza Mogni above)
import 'package:google_sign_in/google_sign_in.dart';
import 'package:firebase_auth/firebase_auth.dart';
final GoogleSignIn _googleSignIn = GoogleSignIn();
final FirebaseAuth _auth = FirebaseAuth.instance;
Future<LoginResponseModel> googleLoginResponse() async {
String url = env['API_BASE_URL'] + '/api/auth/google';
//click on google sign in. Get accessToken from google through googlesignin
plugin.
//Send accessToken to socialite in backend to request/create user data
GoogleSignInAccount googleSignInAccount = await _googleSignIn.signIn();
if (googleSignInAccount == null) {
print('Google Signin ERROR! googleAccount: null!');
return null;
}
GoogleSignInAuthentication googleSignInAuthentication =
await googleSignInAccount.authentication;
//this is user access token from google that is retrieved with the plugin
print("User Access Token: ${googleSignInAuthentication.accessToken}");
String accessToken = googleSignInAuthentication.accessToken;
//make http request to the laravel backend
final response =
await http.post(
url,
body: json.encode({"token": accessToken}),
headers: {"Content-Type": "application/json"});
if (response.statusCode == 200 || response.statusCode == 422) {
return LoginResponseModel.fromJson(
json.decode(response.body), // {'message':'Google signin successful'}
);
} else {
throw Exception('Failed to load data!');
}
}
For Logout function, you need to signout of both firebase and google account instance or you will always be logged in by the first known/used google account in subsequent login attempts.
Future<LogoutResponseModel> logout() async {
try {
await _auth.signOut();
await _googleSignIn.disconnect();
} catch (e) {
print('Failed to sign out ' + e.toString());
}
//api route to destroy sanctum token. santum token is added as authorization header
var url = env['API_BASE_URL'] + "/api/logout";
final response =
await http.post(Uri.tryParse(url), headers: {'Bearer ' $sanctumtoken});
if (response.statusCode == 200 || response.statusCode == 422) {
return LogoutResponseModel.fromJson(
json.decode(response.body),
);
} else {
throw Exception('Failed to load data!');
}
}
Laravel Code (route to controller method is api/auth/google, method expects to receive google access token from flutter app)
public function requestTokenGoogle(Request $request) {
// Getting the user from socialite using token from google
$user = Socialite::driver('google')->stateless()->userFromToken($request->token);
// Getting or creating user from db
$userFromDb = User::firstOrCreate(
['email' => $user->getEmail()],
[
'email_verified_at' => now(),
'first_name' => $user->offsetGet('given_name'),
'last_name' => $user->offsetGet('family_name'),
'avatar' => $user->getAvatar(),
]
);
// Returning response
$token = $userFromDb->createToken('Laravel Sanctum Client')->plainTextToken;
$response = ['token' => $token, 'message' => 'Google Login/Signup Successful'];
return response($response, 200);
}
