allowance method
Gets how much allowance spender have from owner ownAdd_ : The address of the Token's owner. contractAddr_ : The address of the token. spenderAdd_ : The address of the Spender's address. An String representing the Allowance .
Implementation
Future<String> allowance(String ownerAdd_, contractAdd_, spenderAdd_) async {
final EthereumAddress ownAddress = EthereumAddress.fromHex(ownerAdd_);
final EthereumAddress contractAddr = EthereumAddress.fromHex(contractAdd_);
final contract = DeployedContract(
ContractAbi.fromJson(abiString, 'XRC20'), contractAddr);
final tokenAllowance = contract.function('allowance');
final EthereumAddress spender = EthereumAddress.fromHex(spenderAdd_);
final allowance = await client.call(
contract: contract,
function: tokenAllowance,
params: [ownAddress, spender]);
return '$allowance';
}