Skip to main content

Usage of PnP Flutter SDK

Logging in a User​

login(LoginParams)​

Trigger login flow will navigate the user to a browser model allowing the user to login into the service. You can pass in the supported providers to the login method for specific social logins such as GOOGLE, APPLE, FACEBOOK, etc., and do whitelabel login. The login function takes in LoginParams as a required input.

Arguments​

LoginParams

ParameterDescription
loginProviderIt sets the oAuth login method to be used. You can use any of the supported values are GOOGLE, FACEBOOK, REDDIT, DISCORD, TWITCH, APPLE, LINE, GITHUB, KAKAO, LINKEDIN, TWITTER, WEIBO, WECHAT, EMAIL_PASSWORDLESS.
extraLoginOptions?It can be used to set the OAuth login options for corresponding loginProvider. For instance, you'll need to pass user's email address as. Default value for the field is null, and it accepts ExtraLoginOptions as a value.
redirectUrl?Url where user will be redirected after successfull login. By default user will be redirected to same page where login will be initiated. Default value for the field is null
appState?It can be used to keep track of the app state when user will be redirected to app after login. Default is null, and accepts String as a value.
mfaLevel?Customize the MFA screen shown to the user during OAuth authentication. Default value for field is MFALevel.DEFAULT, which shows MFA screen every 3rd login. It accepts MFALevel as a value.
dappShare?Custom verifier logins can get a dapp share returned to them post successful login. This is useful if the dapps want to use this share to allow users to login seamlessly. It accepts String as a value.
curve?It will be used to determine the public key encoded in the jwt token which returned in getUserInfo function after user login. This parameter won't change format of private key returned by We3Auth. Private key returned by getPrivKey is always secp256k1. To get the ed25519 key you can use getEd25519PrivKey method. The default value is Curve.secp256k1.

getPrivkey()​

Use getPrivkey() to get the private key of the user. The method returns an EVM compatible private key which can be used to sign transactions on EVM compatible chains.

getEd25519PrivKey()​

Use getEd25519PrivKey() to get the Ed25519 private key of the user. This private key can be used to sign transactions on Solana.

getUserInfo()​

Use getUserInfo() to get the user info of the user.

UserInfo Response​

{
  "userInfo": {
    "email": "w3a-heroes@web3auth.com",
    "name": "Web3Auth Heroes",
    "profileImage": "https://lh3.googleusercontent.com/a/Ajjjsdsmdjmnm...",
    "verifier": "torus",
    "verifierId": "w3a-heroes@web3auth.com",
    "typeOfLogin": "google",
    "aggregateVerifier": "w3a-google-sapphire",
    "dappShare": "", // 24 words of seed phrase will be sent only incase of custom verifiers
    "idToken": "<jwtToken issued by Web3Auth>",
    "oAuthIdToken": "<jwtToken issued by OAuth Provider>", // will be sent only incase of custom verifiers
    "oAuthAccessToken": "<accessToken issued by OAuth Provider>", // will be sent only incase of custom verifiers
    "isMfaEnabled": false // Returns whether the user has enabled MFA or not
  }
}
Usage
Future<void> initWeb3Auth() async {
  Uri redirectUrl;

  if (Platform.isAndroid) {
    redirectUrl = Uri.parse('{SCHEME}://{HOST}/auth');
    // w3a://com.example.w3aflutter/auth
  } else if (Platform.isIOS) {
    redirectUrl = Uri.parse('{bundleId}://auth');
    // com.example.w3aflutter://openlogin
  } else {
    throw UnKnownException('Unknown platform');
  }

  await Web3AuthFlutter.init(Web3AuthOptions(
    clientId: "WEB3AUTH_CLIENT_ID",
    network: Network.sapphire_mainnet,
    redirectUrl: redirectUrl,
  ));

  await Web3AuthFlutter.initialize();
}

// Login
final Web3AuthResponse response = await Web3AuthFlutter.login(
  LoginParams(loginProvider: Provider.google)
);

Selecting Curve​

The LoginParams class has a curve parameter. This parameter can be used to select the elliptic curve to use for the signature.

final Web3AuthResponse response = await Web3AuthFlutter.login(LoginParams(
  loginProvider: Provider.google,
  curve: Curve.secp256k1 // Can be ed25519, secp256k1
));
Usage
Future<void> initWeb3Auth() async {

  Uri redirectUrl;
  if (Platform.isAndroid) {
    redirectUrl = Uri.parse('{SCHEME}://{HOST}/auth');
    // w3a://com.example.w3aflutter/auth
  } else if (Platform.isIOS) {
    redirectUrl = Uri.parse('{bundleId}://auth');
    // com.example.w3aflutter://openlogin
  } else {
    throw UnKnownException('Unknown platform');
  }

  await Web3AuthFlutter.init(Web3AuthOptions(
    clientId: "WEB3AUTH_CLIENT_ID",
    network: Network.sapphire_mainnet,
    redirectUrl: redirectUrl,
  ));

  await Web3AuthFlutter.initialize();
}

final Web3AuthResponse response = await Web3AuthFlutter.login(LoginParams(
  loginProvider: Provider.google,
  curve: Curve.secp256k1 // Can be ed25519, secp256k1
));

Logging out a user​

logout()​

This method will logout the user and remove the session id from the device. The user will need to login again to use the dApp next time the dApp is opened.

await Web3AuthFlutter.logout();
sample-app

Get started with a sample app found here.

Triggering Login exceptions​

setResultUrl()​

This method will trigger login exceptions for Android. For iOS, you don't need this method to trigger the login exceptions. The Android SDK uses the custom tabs and from current implementation of chrome custom tab, it's not possible to add a listener directly to chrome custom tab close button and trigger login exceptions.

Hence, it's necessary to user setResultUrl method in your login screen to trigger exceptions.

class LoginScreen extends State<T> with WidgetsBindingObserver {

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void dispose() {
    super.dispose();
    WidgetsBinding.instance.removeObserver(this);
  }

  @override
  void didChangeAppLifecycleState(final AppLifecycleState state) {
    // This is important to trigger the user cancellation on Android.
    if (state == AppLifecycleState.resumed) {
      Web3AuthFlutter.setResultUrl();
    }
  }

   @override
  Widget build(BuildContext context) {
    // Your UI code
  }

  Future<void> _login() async {
    try {
      await Web3AuthFlutter.login(LoginParams(loginProvider: Provider.google));
    } on UserCancelledException {
        log("User cancelled.");
    } on UnKnownException {
        log("Unknown exception occurred");
    } catch (e) {
        log(e.toString());
    }
  }