web3-eth-contract

Deploying a Contract

This feature allows you to deploy a new smart contract to the Ethereum blockchain. The code sample demonstrates how to use the web3-eth-contract package to deploy a contract using its ABI and bytecode.

const Web3 = require('web3');
const web3 = new Web3('http://localhost:8545');
const contractABI = [ /* ABI array */ ];
const contractBytecode = '0x...';
const deployContract = async () => {
  const accounts = await web3.eth.getAccounts();
  const contract = new web3.eth.Contract(contractABI);
  const deployedContract = await contract.deploy({ data: contractBytecode }).send({ from: accounts[0], gas: 1500000, gasPrice: '30000000000000' });
  console.log('Contract deployed at address:', deployedContract.options.address);
};
deployContract();

Calling a Contract Method

This feature allows you to call a method on an already deployed smart contract. The code sample demonstrates how to call a method named 'myMethod' on a contract using its ABI and address.

const Web3 = require('web3');
const web3 = new Web3('http://localhost:8545');
const contractABI = [ /* ABI array */ ];
const contractAddress = '0x...';
const contract = new web3.eth.Contract(contractABI, contractAddress);
const callMethod = async () => {
  const result = await contract.methods.myMethod().call();
  console.log('Method call result:', result);
};
callMethod();

Listening to Contract Events

This feature allows you to listen for events emitted by a smart contract. The code sample demonstrates how to listen for an event named 'MyEvent' from a contract using its ABI and address.

const Web3 = require('web3');
const web3 = new Web3('http://localhost:8545');
const contractABI = [ /* ABI array */ ];
const contractAddress = '0x...';
const contract = new web3.eth.Contract(contractABI, contractAddress);
contract.events.MyEvent({
  fromBlock: 0
}, (error, event) => {
  if (error) {
    console.error('Error:', error);
  } else {
    console.log('Event:', event);
  }
});