[SOLVED] Calling functions on BSC deployed contract

hey everyone, I have a super newb question

I have a bep20 already deployed on BSC and there’s a claim function for rewards, I wanna build a simple dapp to pull some information from the events and create a couple buttons to call the functions. Can I do that with Moralis?

Hi,
You can get the events synced with Moralis in a database table. You can also call contract functions if you know the ABI and the contract address.
https://docs.moralis.io/moralis-server/automatic-transaction-sync/smart-contract-events#sync-and-watch-contract-events

That’s awesome! Can you tell me which tutorials to watch for this? The ones I’ve seen so far seems to be for testnet and what not. I’m sorry lol I’m super new to this and I appreciate any help I can get.

You could try this one: https://www.youtube.com/watch?v=rd0TTLjQLy4&ab_channel=MoralisWeb3

Thanks! I am watching it and following along right now. But I ran into an issue and I’ve been trying to figure out what went wrong for the last hour.

I copied the codes from Github and I am following along in the video. I was able to log in and authenticate with metamask before it got to the step for logging in before the game shows. Now when I click on the button, nothing happens. Can you help me?

Here is the index.html code:

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

    <title>Title</title>
    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/web3.min.js"></script>
    <script src="https://code.jquery.com/jquery-3.6.0.min.js" integrity="sha256-/xUj+3OJU5yExlq6GSYGSHk7tPXikynS7ogEvDej/m4=" crossorigin="anonymous"></script>
    <script src="https://unpkg.com/moralis/dist/moralis.js"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
    <link rel="stylesheet" href="./style.css">
</head>
<body>
<div class="jumbotron jumbotron-fluid">
    <div class="container">
        <h1 class="display-4">Welcome</h1>
    </div>
</div>
<div class="container">
        <button id="login_button">Sign in with MetaMask</button>


    <div id="game" style="display: none;">
        <input type="number" id="amount">
        <button id="heads_button">Play Heads</button>
        <button id="tails_button">Play Tails</button>
    </div>

</div>

<script type="text/javascript" src="./main.js"></script>
</body>
</html>


And here is the main.js code:

Moralis.initialize("u5Xh0IBymdEsuqDiUJSYz6GvVMngBfhLc0sL2hJo"); // Application id from moralis.io
Moralis.serverURL = "https://mk09emev5xpe.grandmoralis.com:2053/server"; //Server url from moralis.io

async function login() {
    try {
        currentUser = await Moralis.User.current();
        if(!currentUser) {
            currentUser = await Moralis.Web3.authenticate();
        }
            console.log(user);
            alert ("User logged in")
            document.getElementById("login_button").style.display = "none";
            document.getElementById("game").style.display = "block";
    } catch (error) {
        console.log(error);
    }
}

async function flip(side){
    alert(side);
}

document.getElementById("login_button").onclick = login;
document.getElementById("heads_button").onclick = function(){flip("heads")};
document.getElementById("tails_button").onclick = function(){flip("tails")};

Thank you for any help I can get!

On what button you click and nothing happens?

on “Sign in with Metamask”. I think it’s because I’m already signed in. But for signed in users, they’re supposed to see the game.

If it helps at all, the Youtube video you showed me, at the timestamp 11:59 is where I’m stuck.

In case you need the video link again:

You can open the console to see if it says anything there.

Thanks. It turns out that the console.log(user) was supposed to be console.log(currentUser). I didn’t make any changes to it because I thought whatever I copied from the Github should be the right code to use. Next time I know! Thank you again.

yep, now I also found that this was the problem :slight_smile:

Okay so I followed through all the videos, now I am back to building the frontend dapp to call a function of my contract. I saw in the Moralis docs and also another post in this forum that @Yoomoo recommended to use the Moralis.execute code.

Here’s the code I found in the docs:

const ABI = [
  {
    constant: true,
    inputs: [
      {
        internalType: "address",
        name: "owner",
        type: "address"
      },
      {
        internalType: "address",
        name: "spender",
        type: "address"
      }
    ],
    name: "allowance",
    outputs: [
      {
        internalType: "uint256",
        name: "",
        type: "uint256"
      }
    ],
    payable: false,
    stateMutability: "view",
    type: "function"
  }
];

const options = {
  contractAddress: "0xe...56",
  functionName: "allowance",
  abi: ABI,
  params: {
    owner: "0x2...45",
    spender: "0x3...49"
  },
};

const allowance = await Moralis.executeFunction(options);

Since I have the abi of the contract code in another js file from when I followed the Serverless dapp videos, I modified the codes a little. Please take a look:

const claimRewards = {
    contractAddress: "0xb48D1488266F636dB97597875dE305Bb981EC5a5",
    functionName: "claimRewards",
    abi: window.abi,
    params: {
      // I don't know what to set for params because the function is claimRewards.
     // It simply calls the contract to send the rewards to the connected wallet.


    }
  };
  
  const allowance = await Moralis.executeFunction(claimRewards);

I’d appreciate any help I can get with this!

You could try to use it without params.
An example without params.

Thanks for the super fast response!
I got this error in the console:

Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'find')
    at module.exports (moralis.js:26832)
    at Function.<anonymous> (moralis.js:5871)
    at tryCatch (moralis.js:25921)
    at Generator.invoke [as _invoke] (moralis.js:26151)
    at Generator.next (moralis.js:25976)
    at asyncGeneratorStep (moralis.js:25368)
    at _next (moralis.js:25390)
    at moralis.js:25397
    at new Promise (<anonymous>)
    at new Wrapper (moralis.js:28450)

I am using a Moralis server on Ganache, deployed smart contract to Ganache. I changed my code to this:

async function claimBudsRewards(){
    const web3 = await Moralis.enable();
    const contract = new web3.eth.Contract(window.abi, "0xac5FB3Ac3De96470C612CeDBcE80EB42b1f5C0e7");
    
    const Rewards = {
    contractAddress: "0xac5FB3Ac3De96470C612CeDBcE80EB42b1f5C0e7",
        functionName: "claimRewards",
        abi: window.abi,
    };
    const BudsRewards = await Moralis.executeFunction(claimBudsRewards);

}

Thank you again!

You may want to use:

async function claimBudsRewards(){

      const Rewards = {
    contractAddress: "0xac5FB3Ac3De96470C612CeDBcE80EB42b1f5C0e7",
        functionName: "claimRewards",
        abi: window.abi,
    };
    const BudsRewards = await Moralis.executeFunction(Rewards);

}

I got a ‘missing web3 instance’

so I added the line back in:

async function claimBudsRewards(){

    const web3 = await Moralis.enable(); // added this line back in

    const Rewards = {
  contractAddress: "0xac5FB3Ac3De96470C612CeDBcE80EB42b1f5C0e7",
      functionName: "claimRewards",
      abi: window.abi,
  };
  const BudsRewards = await Moralis.executeFunction(Rewards);

}

It worked! Thank you for guiding me through this. I’m new to all this and coding scared the crap out of me. But thanks to you guys, I’m actually enjoying this quite a bit now. Can’t wait to come back and show y’all the results!

1 Like