Is it possible to pass data into the constructor to be used for the smart contract? Essentially I want to let a user on the front end enter data that will be used to generate a token.

contract TicketToken is ERC20 {

    string public symbol;
    string public name;
    uint256 public price;

    function TicketToken(string _name, string _symbol, uint256 _price) {
        owner = msg.sender;
        name = _name;
        symbol = _symbol;
        price = _price;

How would I be able to do this on web3/React?

1 Answer 1


Passing data to a smart contract via constructor is not different than deploying a contract without data passed in the constructor. from doc.

You just need to passe your data as your firsts parameters before setting configurations (from, gas, data ...)

// Deploy the contract asynchronous from Solidity file:
const fs = require("fs");
const solc = require('solc')

let source = fs.readFileSync('nameContract.sol', 'utf8');
let compiledContract = solc.compile(source, 1);
let abi = compiledContract.contracts['nameContract'].interface;
let bytecode = compiledContract.contracts['nameContract'].bytecode;
let gasEstimate = web3.eth.estimateGas({data: bytecode});
let MyContract = web3.eth.contract(JSON.parse(abi));

var myContractReturned = MyContract.new(param1, param2, {
   gas:gasEstimate}, function(err, myContract){
    if(!err) {
       // NOTE: The callback will fire twice!
       // Once the contract has the transactionHash property set and once its deployed on an address.

       // e.g. check tx hash on the first call (transaction send)
       if(!myContract.address) {
           console.log(myContract.transactionHash) // The hash of the transaction, which deploys the contract

       // check address on the second call (contract deployed)
       } else {
           console.log(myContract.address) // the contract address

       // Note that the returned "myContractReturned" === "myContract",
       // so the returned "myContractReturned" object will also get the address set.

Then with React you'll just have to create a form or something to get your client's values and pass then to a function which will deploy the contract like above, but this is kind of unrelated to web3

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