Flutter Web3 cannot fetch data with address type

Question

I am using https://pub.dev/packages/flutter_web3 in order to connect my Flutter Web App with Solidity smart contract.

I could successfully connect with Metamask with my account

  Future<bool> connectProvider() async {
debugPrint("connectProvider");
if (Ethereum.isSupported) {
  final accs = await ethereum!.requestAccount();
  if (accs.isNotEmpty) {
    debugPrint("accounts not empty");
    currentAddress = accs.first;
    currentChain = await ethereum!.getChainId();
    debugPrint("current chain is $currentChain");
    debugPrint("current address $currentAddress");
  } else {
    debugPrint("accounts are empty");
  }
} else {
  debugPrint("not supported");
}
return false;
}

I could also get data about my balance:

 Future<bool> getBalance() async {
final rpcProvider = JsonRpcProvider('https://bsc-dataseed1.defibit.io/'); 
final lastBlock = await rpcProvider.getLastestBlock();
final balance = await rpcProvider.getBalance(address);
BigInt balanceFormatted = BigInt.from(10).pow(18);
double b = balance / balanceFormatted;
debugPrint("balance = $b");
return false;
}

The problem appears when I am trying to fetch information from smart contract:

final contract = Contract(smartContactAddress, jsonAbi, rpcProvider);
final something = await contract.call<String>('address');
debugPrint("something = $something");

Where method in abi file is:

   {
    "inputs": [],
    "name": "pick_address",
    "outputs": [
        {
            "internalType": "address",
            "name": "",
            "type": "address"
        }
    ],
    "stateMutability": "pure",
    "type": "function"
}

Here's the output:

  js_util_patch.dart:80 Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'apply')
at Object.callMethod$ [as callMethod] (js_util_patch.dart:80:66)
at ethers.Contract.__._call (contract.dart:193:43)
at _call.next (<anonymous>)
.....

Which is referring to this method:

@patch
 T callMethod<T>(Object o, String method, List<Object?> args) {
 assertInteropArgs(args);
 return JS<dynamic>('Object|Null', '#[#].apply(#, #)', o, method, o, args);
 }

Maybe anyone has a workaround for that or does know if I pass something in the wrong way.

EDIT

I have found some workaround to GET uint256 values from smart contract, but still cannot retrieve the value with type address. Post is edited. What is the equivalent type of address in flutter?

Flutter Web3 cannot fetch data with address type

0 Answers0