WalletConnectV2 Connector

Interface

Each project may have a different way to connect to a wallet. We provide a unified interface as the entry point for connecting and signing wallets. When the SDK needs wallet information or signatures, it will call the corresponding methods in WalletConnector. Because wallet communication supports the unified CAIP standard, whether through WalletConnectV2 or other wallet communication SDKs, it can be easily adapted to the WalletConnectorinterface.

• connectWallet is used to get wallet accounts’ ids
• personalSign is used to get a wallet signature

abstract class WalletConnector {
  /// Gets the signature of `personal_sign`.
  Future<String> personalSign(String message, String address,
      {String? password});

  /// Connects wallet, and gets the user wallet info.
  Future<Wallet> connectWallet();
}

class Wallet {
  /// account_id should supports CAIP-10
  List<String> accounts = [];

  /// Gets the list of DIDs.
  List<DID> get dids =>
      accounts.map((e) => getDidFromAccount(Account.from(e))).toList();

  Wallet(this.accounts);

  /// Gets the DID of the given account.
  static DID getDidFromAccount(Account account) {
    // convert account.address to lower case
    return DID(_walletType(account), account.address.toLowerCase());
  }

  /// Gets the wallet type of the given account.
  static String _walletType(Account account) {
    switch (account.namespace) {
      case 'eip155':
        return 'eth';
      default:
        return account.namespace;
    }
  }
}

The WalletConnectV2Connector Sample Code

1. Add this to your package’s pubspec.yaml file

dependencies:
  walletconnect_flutter_v2: ^2.1.4
 url_launcher: ^6.1.11

then run flutter packages get

2. Create a class with above code:

// ignore_for_file: avoid_print

import 'package:url_launcher/url_launcher.dart';
import 'package:walletconnect_flutter_v2/walletconnect_flutter_v2.dart';
import 'package:web3mq/web3mq.dart';

/// You need to modify the code to match your Dapp metadata information and
/// the namespace required for the session request, as well as the parameters
/// required for the personal_sign function.
/// For more details on WalletConnectV2
/// plz see: https://github.com/WalletConnect/WalletConnectFlutterV2#commands-run-in-ci
class WalletConnectV2Connector implements WalletConnector {
  late Web3App wcClient;

  SessionData? session;

  @override
  Future<Wallet> connectWallet() async {
    // the projectId
    wcClient = await Web3App.createInstance(
      relayUrl: 'wss://relay.walletconnect.com',
      // The relay websocket URL, leave blank to use the default
      projectId: 'a0c738558362613d6a95c7b4bd9e8d6c',
      metadata: const PairingMetadata(
        name: 'web3mq-test dApp',
        description: 'A dapp that can request that transactions be signed',
        url: 'https://web3mq.com',
        icons: ['https://avatars.githubusercontent.com/u/40848675?s=200&v=4'],
      ),
    );

    ConnectResponse resp = await wcClient.connect(requiredNamespaces: {
      'eip155': const RequiredNamespace(
        chains: ["eip155:1"], // Ethereum chain
        methods: ['personal_sign'], events: [], // Requestable Methods
      )
    });

    final uri = resp.uri;
    if (null != uri) {
      await launchUrl(uri);
      session = await resp.session.future;
      final accounts = session!.namespaces['eip155']?.accounts;
      return Wallet(accounts ?? []);
    } else {
      return Wallet([]);
    }
  }

  @override
  Future<String> personalSign(String message, String address,
      {String? password}) async {
    final currentSession = session;
    if (currentSession == null) {
      throw Exception('Session is null');
    }

    // just send request won't lanuch wallet automatically,
    // so we need to launch it manually
    await launchUrl(Uri.parse('wc:'));

    final dynamic signResponse = await wcClient.request(
      topic: currentSession.topic,
      chainId: 'eip155:1',
      request: SessionRequestParams(
        method: 'personal_sign',
        params: [message, address],
      ),
    );

    return signResponse as String;
  }
}

note

You need to modify the code to match your Dapp metadata information and the namespace required for the session request, as well as the parameters required for the personal_sign function. For more details on WalletConnectV2 plz see: https://github.com/WalletConnect/WalletConnectFlutterV2#commands-run-in-ci