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撰寫（費用委託）

當您要執行智能合約時，您可以向 feepayer 發送**"交易 "，其中包括支付請求**。

導入 web3 和 @kaiachain/web3js-ext 軟件包，在 web3 上添加 kaia 功能

定義發送方、付費方地址和私人密鑰

使用指定的 kairos 測試網 URL 設置提供程序。 web3 中的提供者是訪問區塊鏈數據的只讀抽象。

此外，您還可以將提供商 URL 從 kairos 更改為 quicknode

使用web3.eth.accounts.privateKeyToAccount從定義的私鑰創建發送方和繳費方賬戶

定義合同阿比和合約地址

使用定義了 contractAbi 和 address 的 Web3.eth.Contract創建合約實例。您可以通過該實例讀寫合約

更新前獲取數字的值

使用contract.methods.increment().encodeABI()對合約方法數據進行編碼

創建事務以更新編號的值，其類型為 "FeeDelegatedSmartContractExecution"：收費委託智能合約執行

使用 signTransaction 在發送方賬戶上籤署交易

使用 "signTransactionAsFeePayer "以付費方賬戶簽署交易

將交易發送到區塊鏈。它將返回交易收據

獲取數字的更新值

smartContractWriteFeeDelegated.js


const { Web3, TxType } = require("@kaiachain/web3js-ext");
const senderAddr = "0x24e8efd18d65bcb6b3ba15a4698c0b0d69d13ff7";
const senderPriv = "0x4a72b3d09c3d5e28e8652e0111f9c4ce252e8299aad95bb219a38eb0a3f4da49";
const feePayerAddr = "0xcb0eb737dfda52756495a5e08a9b37aab3b271da";
const feePayerPriv = "0x9435261ed483b6efa3886d6ad9f64c12078a0e28d8d80715c773e16fc000cff4";
const provider = new Web3.providers.HttpProvider("https://public-en-kairos.node.kaia.io");
const web3 = new Web3(provider);
const senderAccount = web3.eth.accounts.privateKeyToAccount(senderPriv);
const feePayerAccount = web3.eth.accounts.privateKeyToAccount(feePayerPriv);
/* compiled in remix.ethereum.org (compiler: 0.8.18, optimizer: false)
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.13;
contract Counter {
    uint256 public number;
    event SetNumber(uint256 number);
    constructor(uint256 initNumber) {
        number = initNumber;
    }
    function setNumber(uint256 newNumber) public {
        number = newNumber;
        emit SetNumber(number);
    }
    function increment() public {
        number++;
        emit SetNumber(number);
    }
}
*/
const contractAbi = JSON.parse('[{"inputs":[{"internalType":"uint256","name":"initNumber","type":"uint256"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"internalType":"uint256","name":"number","type":"uint256"}],"name":"SetNumber","type":"event"},{"inputs":[],"name":"increment","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"number","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"newNumber","type":"uint256"}],"name":"setNumber","outputs":[],"stateMutability":"nonpayable","type":"function"}]');
const contractAddr = "0x95Be48607498109030592C08aDC9577c7C2dD505";
async function main() {
  const contract = new web3.eth.Contract(contractAbi, contractAddr);
  console.log("number before", (await contract.methods.number().call()).toString());
  const data = contract.methods.increment().encodeABI();
  const tx = {
    type: TxType.FeeDelegatedSmartContractExecution,
    from: senderAddr,
    to: contractAddr,
    data: data,
  };
  // Sign transaction by sender
  const signResult1 = await senderAccount.signTransaction(tx);
  console.log("senderTxHashRLP", signResult1.rawTransaction);
  // Sign and send transaction by fee payer
  const signResult2 = await feePayerAccount.signTransactionAsFeePayer(signResult1.rawTransaction);
  console.log("signedTx", signResult2.transactionHash);
  const receipt = await web3.eth.sendSignedTransaction(signResult2.rawTransaction);
  console.log("receipt", receipt);
  console.log("number after", (await contract.methods.number().call()).toString());
}
main();

output


❯ node smartContractWriteFeeDelegated.js
number before 296
senderTxHashRLP 0x31f8844c850ba43b7400830111939495be48607498109030592c08adc9577c7c2dd505809424e8efd18d65bcb6b3ba15a4698c0b0d69d13ff784d09de08af847f8458207f6a03a9ade9fb5c2e4e513c56341ab64ad0a70613d826479f2117b53d3b57cee5021a07612c8538ee5b895f44b50858164dd67da473e264c29d331437273e581652eea
signedTx 0x66f7d99d2236145baa4bb84f66d283c508639bd6150c68b300323f7aa016676f
receipt {
  blockHash: '0x6b2201b6bcc999395e247fc8b85062b1a9313cc0db53a50a746203c9995af8b9',
  blockNumber: 148743711n,
  cumulativeGasUsed: 38014n,
  effectiveGasPrice: 25000000000n,
  from: '0x24e8efd18d65bcb6b3ba15a4698c0b0d69d13ff7',
  gasUsed: 38014n,
  logs: [
    {
      address: '0x95be48607498109030592c08adc9577c7c2dd505',
      topics: [Array],
      data: '0x0000000000000000000000000000000000000000000000000000000000000129',
      blockNumber: 148743711n,
      transactionHash: '0x66f7d99d2236145baa4bb84f66d283c508639bd6150c68b300323f7aa016676f',
      transactionIndex: 0n,
      blockHash: '0x6b2201b6bcc999395e247fc8b85062b1a9313cc0db53a50a746203c9995af8b9',
      logIndex: 0n,
      removed: false
    }
  ],
  logsBloom: '0x00000000000040000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000000000000001200000002',
  status: 1n,
  to: '0x95be48607498109030592c08adc9577c7c2dd505',
  transactionHash: '0x66f7d99d2236145baa4bb84f66d283c508639bd6150c68b300323f7aa016676f',
  transactionIndex: 0n,
  type: 0n
}
number after 297