How to transfer eth to a solidity function from a Dapp

Question

I am trying to build a Dapp which includes functionality to deposit funds to a contract and withdraw them. The functions look like this

function fundContract() public payable {
        require (msg.sender == users[msg.sender].addr);
        users[msg.sender].balance += msg.value;
        contractBalance+=msg.value;

    }


function withdraw (uint amount) public onlyUser() payable{

        require (msg.sender == users[msg.sender].addr);
        require (amount > 0);
        require (amount <= users[msg.sender].balance);

        msg.sender.transfer(amount);

        users[msg.sender].balance -= amount;
        contractBalance-= amount;
    }

I understand that there will be a function call to withdraw() specifying the amount parameter from the front end using web3.js send() command, but how do I provide the msg.value for the fundContract method from the viewpoint of a Dapp. Remix allows specifying the value in the message , but I can't find a way to do so for a Dapp.

Answer 1

You should use the value field, then call the contract send method.

https://web3js.readthedocs.io/en/1.0/web3-eth-contract.html#methods-mymethod-send

myContract.methods.fundContract().send({value: 'AMOUNT IN WEI'})