How to send signed raw transaction with some data?

[tzuhanli]

Hello, I have a simple smart contract about read and write some value.

I can read my “owner” value successfully, but can not write value to the “owner”. When I send transaction to contract, it will return “Error(code: -32000, message: “insufficient funds for gas * price + value”)”, but I’m sure my account have enough gas. (2996400390000000001)

I created a EthereumTransaction, signed it with my privateKey, and use “sendRawTransaction” to send it. Please help me realize my problem, thank you very much!

My Contract:

pragma solidity ^0.4.4;

contract Car {
  bytes public vehicleName = "Tesla";
  uint public owner;

  function setOwner(uint newOwner) public
  {
    owner = newOwner;
  }
}

My Code:

////////////////////////////
/// owner
do {
    let contract = try web3.eth.Contract(json: data!, abiKey: "abi", address: contractAddress)
            firstly {
                contract["owner"]!().call()
                }.done { outputs in
                    print(outputs)
                }.catch { error in
                    print(error)
            }
} catch {
    print(error)
}

////////////////////////////
/// setOwner
do {
    let myPrivateKey = try EthereumPrivateKey(hexPrivateKey: "**********")
    
    web3.eth.getBalance(address: myPrivateKey.address, block: try .string("latest") ) { response in
        print("myAccount - result?.quantity(wei): ", response.result?.quantity)
    }
    
    let contract: DynamicContract = try web3.eth.Contract(json: data!, abiKey: "abi", address: contractAddress)
    
    let c = contract["setOwner"]?(contractAddress!,BigUInt(789))
    let transaction: EthereumTransaction = c!
        .createTransaction(nonce: 0,
                            from: myPrivateKey.address,
                           value: 0,
                             gas: 210000,
            gasPrice: EthereumQuantity(quantity: 1.gwei))!
    
    let signedTx: EthereumSignedTransaction = try transaction.sign(with: myPrivateKey)

    firstly {
        web3.eth.sendRawTransaction(transaction: signedTx)
    }.done { txHash in
        print(txHash)
    }.catch { error in
        print(error)
    }

} catch {
    print(error)
}

[koraykoska]

Please change the following line:

let signedTx: EthereumSignedTransaction = try transaction.sign(with: myPrivateKey)

to something like that:

let signedTx: EthereumSignedTransaction = try transaction.sign(with: myPrivateKey, chainId: 1)

and change the chainId accordingly if you are in a different network than mainnet. See this link for testnet chainIds.

#62 Will "solve" this issue by removing the default value of 0. Actually you should never omit the chainId to have the simple replay protection from EIP155.