signTypedData

Future<String> signTypedData({
  required String chainId,
  required String typedData,
})

import 'dart:convert';
import 'package:portal_flutter/portal_flutter.dart';

final portal = Portal();

final typedData = jsonEncode({
  'types': {
    'EIP712Domain': [
      {'name': 'name', 'type': 'string'},
      {'name': 'version', 'type': 'string'},
      {'name': 'chainId', 'type': 'uint256'},
    ],
    'Message': [
      {'name': 'content', 'type': 'string'},
    ],
  },
  'primaryType': 'Message',
  'domain': {
    'name': 'Example App',
    'version': '1',
    'chainId': 1,
  },
  'message': {
    'content': 'Hello, Portal!',
  },
});

final signature = await portal.signTypedData(
  chainId: 'eip155:1',
  typedData: typedData,
);

print('EIP-712 Signature: $signature');

import 'dart:convert';
import 'package:portal_flutter/portal_flutter.dart';

Future<String> signPermit({
  required Portal portal,
  required String owner,
  required String spender,
  required String tokenAddress,
  required int value,
  required int nonce,
  required int deadline,
}) async {
  final typedData = jsonEncode({
    'primaryType': 'Permit',
    'types': {
      'EIP712Domain': [
        {'name': 'name', 'type': 'string'},
        {'name': 'version', 'type': 'string'},
        {'name': 'chainId', 'type': 'uint256'},
        {'name': 'verifyingContract', 'type': 'address'},
      ],
      'Permit': [
        {'name': 'owner', 'type': 'address'},
        {'name': 'spender', 'type': 'address'},
        {'name': 'value', 'type': 'uint256'},
        {'name': 'nonce', 'type': 'uint256'},
        {'name': 'deadline', 'type': 'uint256'},
      ],
    },
    'domain': {
      'name': 'MyToken',
      'version': '1',
      'chainId': 1,
      'verifyingContract': tokenAddress,
    },
    'message': {
      'owner': owner,
      'spender': spender,
      'value': value,
      'nonce': nonce,
      'deadline': deadline,
    },
  });

  return portal.signTypedData(
    chainId: 'eip155:1',
    typedData: typedData,
  );
}

try {
  final signature = await portal.signTypedData(
    chainId: 'eip155:1',
    typedData: typedData,
  );
} on PortalException catch (e) {
  print('Failed to sign typed data: ${e.code} - ${e.message}');
}