Help with web3.js

Web3
1

Hello everyone!

I have deployed a contract to ethereum with web3.js that just simple changes a number on the frontend when the contract call finishes.

Im trying to create a simple tool to benchmark harmony txs vs eth txs for users to experience the speed of the harmony chain.

You can try it on Ethereum at https://s-server.nl however fees and time is at the order on this side im working on implementing this page on both chains but im having no luck on harmony i managed to deploy the contract trough remix.

This is what it looks like! (on both sides)

pragma solidity ^0.6.6;

contract CoolNumberContract {
    uint public coolNumber = 10;
    
    function setCoolNumber(uint _coolNumber) public {
        coolNumber = _coolNumber;
    }
}

And here it is in the explorer:

i couldnt find it in the documentation how this snippet would work on the harmony side.

async function loadWeb3() {
            if (window.ethereum) {
                window.web3 = new Web3(window.ethereum);
                window.ethereum.enable();
            }
        }

        async function loadContract() {
            return await new window.web3.eth.Contract([
	{
		"inputs": [],
		"name": "coolNumber",
		"outputs": [
			{
				"internalType": "uint256",
				"name": "",
				"type": "uint256"
			}
		],
		"stateMutability": "view",
		"type": "function"
	},
	{
		"inputs": [
			{
				"internalType": "uint256",
				"name": "_coolNumber",
				"type": "uint256"
			}
		],
		"name": "setCoolNumber",
		"outputs": [],
		"stateMutability": "nonpayable",
		"type": "function"
	}
], '0x5feC37dBd31212B6d8E9B40b7533d5d617f9B3C9');
        }

Anyone can help me out?

Im using metamask

2

should work exactly the same. tried loading harmony network in metamask, however giving error:

web3.min.js:1 Uncaught (in promise) Error: Couldn't decode uint256 from ABI: 0x
    at o.formatOutputUInt [as _outputFormatter] (web3.min.js:1)
    at o.decode (web3.min.js:1)
    at web3.min.js:1
    at Array.forEach (<anonymous>)
    at b.decodeParameters (web3.min.js:1)
    at M.d._decodeMethodReturn (web3.min.js:1)
    at f.outputFormatter (web3.min.js:1)
    at f.formatOutput (web3.min.js:1)
    at o (web3.min.js:1)
    at web3.min.js:1
3

Then there seems to be something wrong with the ABI?
i took it directly from the harmony one remix.

Im using vanilla JS with web3 from a CDN.

This the the whole JS part

</div>
    <script type="text/javascript">

        async function loadWeb3() {
            if (window.ethereum) {
                window.web3 = new Web3(window.ethereum);
                window.ethereum.enable();
            }
        }

        async function loadContract() {
            return await new window.web3.eth.Contract([
	{
		"inputs": [],
		"name": "coolNumber",
		"outputs": [
			{
				"internalType": "uint256",
				"name": "",
				"type": "uint256"
			}
		],
		"stateMutability": "view",
		"type": "function"
	},
	{
		"inputs": [
			{
				"internalType": "uint256",
				"name": "_coolNumber",
				"type": "uint256"
			}
		],
		"name": "setCoolNumber",
		"outputs": [],
		"stateMutability": "nonpayable",
		"type": "function"
	}
], '0xd736657F66cb117eCDea54070D861Bd6Ed246f1b');
        }

        async function printCoolNumber() {
            updateStatus('fetching current number');
            const coolNumber = await window.contract.methods.coolNumber().call();
            updateStatus(`<span> The current number is: <b>${coolNumber}</b><span>`);
            updateHeader(`<span><h1><b>${coolNumber}</b></h1><span>`);
        }

        async function getCurrentAccount() {
            const accounts = await window.web3.eth.getAccounts();
            return accounts[0];r
        }

        async function changeCoolNumber() {
            const value = Math.floor(Math.random() * 10);
            updateStatus(`Updating the Number with: <b>${value}</b>`);
            const account = await getCurrentAccount();
            const coolNumber = await window.contract.methods.setCoolNumber(value).send({ from: account });
            updateStatus('Updated.');
        }

        async function load() {
            await loadWeb3();
            window.contract = await loadContract();
            const coolNumber = await window.contract.methods.coolNumber().call();
            updateHeader(`<span><h1><b>${coolNumber}</b></h1><span>`);
            updateStatus('Ready');
        }


        function updateHeader(status) {
            const statusEl = document.getElementById('nmbr');
            statusEl.innerHTML = status;
        }

        function updateStatus(status) {
            const statusEl = document.getElementById('status');
            statusEl.innerHTML = status;
            console.log(status);
        }

        load();
    </script>
4

can you try remix.ethereum.org instead of harmony remix and see if you get a different ABI? ethereum remix works without any additional steps, just needs adding harmony network to metamask.

5

Okay I will try that Ganesha, just saw the dev call updating the docs for a web3 newbie like me would be awesome thanks!

1 Like
6

Hey ganesha after using the ethereum remix the ABI seems correct!
My little first project Dapp now is successfully deployed on harmony mainnet!

Thanks for the help

Debug info:

Harmony remix ABI:

[
	{
		"inputs": [],
		"name": "coolNumber",
		"outputs": [
			{
				"internalType": "uint256",
				"name": "",
				"type": "uint256"
			}
		],
		"stateMutability": "view",
		"type": "function"
	},
	{
		"inputs": [
			{
				"internalType": "uint256",
				"name": "_coolNumber",
				"type": "uint256"
			}
		],
		"name": "setCoolNumber",
		"outputs": [],
		"stateMutability": "nonpayable",
		"type": "function"
	}
]

Eth remix on harmony trough metamask:

[
	{
		"inputs": [
			{
				"internalType": "uint256",
				"name": "_coolNumber",
				"type": "uint256"
			}
		],
		"name": "setCoolNumber",
		"outputs": [],
		"stateMutability": "nonpayable",
		"type": "function"
	},
	{
		"inputs": [],
		"name": "coolNumber",
		"outputs": [
			{
				"internalType": "uint256",
				"name": "",
				"type": "uint256"
			}
		],
		"stateMutability": "view",
		"type": "function"
	}
]

There seems a bit off difference on how the JSON is formatted and some values appear to be missing? Mabey this helps to fix later on harmony remix for the fellow developers!

7

awesome. thanks for updating the status. would you mind creating an issue here: Issues · harmony-one/remixide · GitHub with details of this problem so that it is tracked and fixed? thanks.