web3_webview 1.0.11

web3_webview is a powerful bridge between a DApp running inside a WebView and your Flutter application, enabling secure and seamless two-way communication between them

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:web3_webview/web3_webview.dart';

/// Example app for `web3_webview` – 3 modes: read-only, privateKey, external signer.
///
/// Loads `privateKey` from secure storage in production – here placeholders.
/// Do NOT hardcode keys in real apps.
void main() => runApp(const ExampleApp());

/// Root widget with tab demo for 3 modes.
class ExampleApp extends StatelessWidget {
  /// Creates example app.
  const ExampleApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'web3_webview example',
      theme: ThemeData(useMaterial3: true),
      home: const ExampleHome(),
    );
  }
}

class ExampleHome extends StatefulWidget {
  const ExampleHome({super.key});
  @override
  State<ExampleHome> createState() => _ExampleHomeState();
}

class _ExampleHomeState extends State<ExampleHome> {
  int _index = 0;

  static final NetworkConfig _eth = NetworkConfig(
    chainId: '0x1',
    chainName: 'Ethereum Mainnet',
    nativeCurrency: NativeCurrency(name: 'Ether', symbol: 'ETH', decimals: 18),
    rpcUrls: ['https://mainnet.infura.io/v3/YOUR_KEY'],
    blockExplorerUrls: ['https://etherscan.io'],
  );

  // Demo private key – NEVER hardcode in production, load from secure storage
  static const _demoPk =
      '0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('web3_webview example (1.0.11)')),
      body: IndexedStack(
        index: _index,
        children: [
          // 1. Read-only – no privateKey/signer, DApp still loads
          Web3WebView(
            web3WalletConfig: Web3WalletConfig(
              currentNetwork: _eth,
              supportNetworks: [_eth],
              name: 'Read-only Demo',
              id: 'com.example.readonly',
              onError: (m, p, msg) => debugPrint('read-only onError $m: $msg'),
            ),
            initialUrlRequest:
                URLRequest(url: WebUri('https://metamask.github.io/test-dapp/')),
            onPermissionRequest: (c, r) async => PermissionResponse(
              resources: r.resources,
              action: PermissionResponseAction.DENY,
            ),
          ),
          // 2. Local private key
          Web3WebView(
            web3WalletConfig: Web3WalletConfig(
              privateKey: _demoPk,
              currentNetwork: _eth,
              supportNetworks: [_eth],
              name: 'PrivateKey Demo',
              id: 'com.example.privatekey',
              onError: (m, p, msg) => debugPrint('pk onError $m: $msg'),
            ),
            initialUrlRequest:
                URLRequest(url: WebUri('https://metamask.github.io/test-dapp/')),
            onPermissionRequest: (c, r) async => PermissionResponse(
              resources: r.resources,
              action: PermissionResponseAction.DENY,
            ),
          ),
          // 3. External signer (WalletConnect etc.)
          Web3WebView(
            web3WalletConfig: Web3WalletConfig(
              signer: DemoSigner('0x1111111111111111111111111111111111111111'),
              currentNetwork: _eth,
              supportNetworks: [_eth],
              name: 'External Signer Demo',
              id: 'com.example.signer',
            ),
            initialUrlRequest:
                URLRequest(url: WebUri('https://metamask.github.io/test-dapp/')),
            onPermissionRequest: (c, r) async => PermissionResponse(
              resources: r.resources,
              action: PermissionResponseAction.DENY,
            ),
          ),
        ],
      ),
      bottomNavigationBar: NavigationBar(
        selectedIndex: _index,
        onDestinationSelected: (i) => setState(() => _index = i),
        destinations: const [
          NavigationDestination(icon: Icon(Icons.visibility), label: 'Read-only'),
          NavigationDestination(icon: Icon(Icons.key), label: 'PrivateKey'),
          NavigationDestination(icon: Icon(Icons.wallet), label: 'Signer'),
        ],
      ),
    );
  }
}

/// Minimal external signer demo – replace with WalletConnect / enclave logic.
class DemoSigner extends Web3Signer {
  @override
  final String address;
  DemoSigner(this.address);

  @override
  Future<String> signMessage(String method, String from, dynamic message, String password) async {
    // TODO: delegate to WalletConnect, show your own UI, then return 0x signature
    throw WalletException('DemoSigner: implement signMessage', code: 4200);
  }

  @override
  Future<String> sendTransaction(Map<String, dynamic> txParams) async {
    // TODO: delegate to WalletConnect
    throw WalletException('DemoSigner: implement sendTransaction', code: 4200);
  }
}