How to write data or change varibles in smart contract on Rinkeby from web3.js

Question

I have a smart contract which have a function to allow/disallow user to send ether to my contract. By default all ETH address are allow to send ether to smart contract.

But, if I want to disallow some ETH address not to send ether, I have to write data on to the blockchain.

The same I want to do it from my WEB APP using web3.js

Can anyone provide me with example for the same.

Thanks In Advanced .......

Answer 1

Create a mapping of the user's address and their ability to pay, make the default value True to allow them to deposit Ether, do a simple comparison of if (arrayOfUsers[UsersAddress] == True){allow deposit} else{don't allow deposit}

Answer 2

Not sure if the question is still open, if so, maybe you can make a list ^ and monitor smart contract events with Web3. Hope it helps ;)

Answer 3

Using a mapping for authorised addresses you can implement a user controlled contract to deposit ethers. Below contract code can be used for this.

//SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

contract TestContract {
    address private _owner ;
    mapping (address=>bool) allowedAddresses;

    constructor() {
        _owner = msg.sender;
    }
    receive() external payable {
        require(allowedAddresses[msg.sender], "Not aurthorised to deposit ether");
    }

    modifier onlyOwner() {
        require(msg.sender == _owner, "This transaction MUST be called from owner's account.");
        _;
    }

    function modifyFundDepositStatus(address accountAddress, bool status) external onlyOwner {
        require(accountAddress != address(0x0), "Not a valid address");
        allowedAddresses[accountAddress] = status;
    }
}

For Web3.js you can call modifyFundDepositStatus() method to allow/disallow an address to deposit funds in the contract.