signInWithGoogle function

Future<UserInfo?> signInWithGoogle(Caller caller, { bool debug = false, String? clientId, String? serverClientId, List<String> additionalScopes = const [], required Uri redirectUri, })

Attempts to Sign in with Google. If successful, a UserInfo is returned. If the attempt is not a success, null is returned.

If clientId and serverClientId are not provided, the values are expected to be supplied via the json credentials file in your android and ios projects.

On the web, the serverClientId is mandatory and must be provided.

The ID's can be created at https://console.developers.google.com/apis/credentials

The redirect uri to web page that will handle the authentication. This page should send an event to the parent window with the server auth code. The event is expected to be a string with the server auth code. After the event is sent, the window can be closed safely.

Example web implementation:

 function returnToWebClient() {
   const serverAuthCode = findParam('code');
   window.opener.postMessage(serverAuthCode, '*');
   window.close();
 }

Consider using the GoogleSignInRedirectPageWidget inside serverpod_auth_server to handle the the logic for you.

// main.dart
pod.webServer.addRoute(auth.RouteGoogleSignIn(), '/googlesignin');

Assuming the above route is added, the redirect uri would be: https://example.com/googlesignin

Implementation

Future<UserInfo?> signInWithGoogle(
  Caller caller, {
  bool debug = false, //TODO: Remove this parameter on next breaking change.
  String? clientId,
  String? serverClientId,
  List<String> additionalScopes = const [],
  required Uri redirectUri,
}) async {
  var scopes = [
    'email',
    'https://www.googleapis.com/auth/userinfo.profile',
  ];
  scopes.addAll(additionalScopes);

  if (kDebugMode) print('serverpod_auth_google: GoogleSignIn');

  try {
    var tokens = await signInWithGooglePlatform(
      scopes: scopes,
      clientId: clientId,
      serverClientId: serverClientId,
      redirectUri: redirectUri,
    );

    // Authenticate with the Serverpod server.
    AuthenticationResponse serverResponse;
    if (tokens.serverAuthCode != null) {
      // Prefer to authenticate with serverAuthCode
      serverResponse = await caller.google.authenticateWithServerAuthCode(
        tokens.serverAuthCode!,
        redirectUri.toString(),
      );
    } else {
      // Fall back on idToken
      serverResponse =
          await caller.google.authenticateWithIdToken(tokens.idToken!);
    }

    if (!serverResponse.success) {
      if (kDebugMode) {
        print(
          'serverpod_auth_google: Failed to authenticate with Serverpod backend: '
          '${serverResponse.failReason ?? 'reason unknown'}. Aborting.',
        );
      }
      return null;
    }

    // Store the user info in the session manager.
    var sessionManager = await SessionManager.instance;

    await sessionManager.registerSignedInUser(
      serverResponse.userInfo!,
      serverResponse.keyId!,
      serverResponse.key!,
    );

    if (kDebugMode) {
      print(
        'serverpod_auth_google: Authentication was successful. Saved credentials to SessionManager',
      );
    }

    return serverResponse.userInfo;
  } catch (e, stackTrace) {
    if (kDebugMode) print('serverpod_auth_google: $e');
    if (kDebugMode) print('$stackTrace');
    return null;
  }
}