Deploy new contract through another contract function in Truffle

Question

I have a function in my contract minter.sol that creates another contract etnX.sol:

function createNewContract(string memory name, string memory symbol, uint256 _maxSupply) 
public onlyOwner {
    etnX c = new etnX(name, symbol, _maxSupply, address(store));
}

I want to call this function in truffle and get new contract address. I'm trying to do so:

const minter = artifacts.require('../contracts/minter.sol')
const etnX = artifacts.require('etnX')
const etnXs = [100,200,500,1000,10000,100000,1000000,10000000]
module.exports = async function(deployer) {
    deployer.deploy(minter).then(async() => {
       var minterInstance = await minter.deployed();
       for (var i=0; i<etnXs.length;i++)
           await minterInstance.createNewContract("x","x", etnXs[i]);
           var x = await etnX.deployed();
           console.log(x.address);
    })
};

However, it doesn't deploy. Can someone explain me how to do this?

Answer 1

1.) You can make the function emit an event that broadcasts the new address and then check the logs of the transaction receipt. Receipt

// Solidity
function createNewContract(string memory name, string memory symbol, uint256 _maxSupply) 
public onlyOwner {
    etnX c = new etnX(name, symbol, _maxSupply, address(store));
    emit NewContract(address(c));
}

// Javascript
let tx = await minterInstance.createNewContract("x", "x", 300); 
// Look through tx.logs for event results

2.) You can return the contract address in the solidity function and then instead of initiating a transaction make a call() to get the address. (Then make the transaction....it will be deployed at the same address as returned by the call())

// Solidity
function createNewContract(string memory name, string memory symbol, uint256 _maxSupply) 
public onlyOwner 
returns (address) {
    etnX c = new etnX(name, symbol, _maxSupply, address(store));
    return address(c)
}

// Javascript
let addr = await minterInstance.createNewContract.call("x", "x", 300); 

3.) Manually calculate it