Hello,
I am creating a test app that reward users that complete a survey with an ERC20 token. I already have the ERC20 smart contract with a token supply of 5000000 token and the survey app in react and javascript. I want to link the two together so when a user click on submit, they receive 10 token from the initial wallet address.
Thank you very much.
Congrats for your project. Great idea. pls send me the Link of your App. Wishing . .
Hello,
I just need help to create the reward function in solidity. This is what i did, but it is not working.
mapping(uint => Reward) public rewards;
</>
struct Reward{
uint id;
uint tokenReward;
address payable author;
}
event UserRewarded(
uint id,
string content,
uint tokenReward,
address payable author
);
constructor() ERC20("MyTestToken", "MTT") {
_mint(msg.sender, 7000000000000000000000000);
}
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
function rewardUser(uint _id) public payable {
//Make sure Id is valid
require(_id > 0);
// Fetch reward
Reward memory _reward = rewards[_id];
// Fetch the user
address payable _user = _reward.id;
//Pay user by sending them MTT
address(Reward.author).transfer(msg.value);
// Increment the reward amount
_reward.tokenReward = _reward.tokenReward + msg.value;
// Trigger event
emit UserRewarded(_id, _reward.content, _reward.tokenReward, Reward._author);
// transfer(recipient, 10 * 10^18);
// address(recipient).transfer(msg.value);
}
}
</>
thank you
Hey, welcome! 
It seems like your target is to reward some token, but for your code just like above, it means you want to reward ETH. I think it should be token.transfer(to, amount)
Hi Skyge,
Yes i want to reward with the token that i created. So it is just a simple transfer function right? I don't need all of this?
Thank you.
Up to you, I just mean, you should use token.transfer(to, amount) to transfer token, the code you wrote above address(Reward.author).transfer(msg.value); is transferring ETH.
Thank you very much, so my code should look like this.
contract MyTestToken is ERC20, Ownable {
using SafeMath for uint256;
mapping(address => uint256) private _balances;
constructor() ERC20("MYTestToken", "MTT") {
_mint(msg.sender, 7000000000000000000000000);
}
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
token.transfer(to,amount);
}
}
Okay, maybe I misled you. It should be YOUR_TOKEN.transfer(RECIPIENT_ADDRESS, TRANSFER_AMOUNT), for example, Alice should get 10 DAI, so it should be DAI_CONTRACT.transfer(ALICE_ADDRESS, 10e18)
Thank you,I think that's the easiest way. I fixed it. But now how do i implement it in web3 please?
await MyTestToken.methods
.transfer(this.state.account, 707e18)
.send({ from: contractAddress }, function (error, transactionHash) {
console.log(transactionHash);
});
No, contract can not send transactions automatically, there must be someone(A user or another contract) triggers it.
Maybe your function should be:
function rewardUser(uint _id) public {
//Make sure Id is valid
require(_id > 0);
// Fetch reward
Reward memory _reward = rewards[_id];
// Fetch the user
address payable _user = _reward.id;
//Pay user by sending them MTT
MTT.transfer(msg.sender, EXPECTED_AMOUNT); // <<<<<<-------------------here
// Increment the reward amount
_reward.tokenReward = _reward.tokenReward + msg.value;
// Trigger event
emit UserRewarded(_id, _reward.content, _reward.tokenReward, Reward._author);
// transfer(recipient, 10 * 10^18);
// address(recipient).transfer(msg.value);
}
Hello, I tried what you did but didn't manage to do it. I think the easir thing to achieve what i want is to implement an airdrop function or contract.
function getAirdrop() public {
token.transfer(msg.sender, 100000000000000000000); //18 decimals token
}
Do i need it to put in a different file or can i put it in the same contract as the token creation?
Thank you very much
Up to you.
And I think at least you should have a flag to define whether the caller account has claimed, so do you expect the user can claim all the time?
Yes since it is just a test app
This is what my code look like. But i get an error when i call the function in my JavaScript.
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.1;
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
contract MyTestToken is ERC20, Ownable {
mapping(address => uint256) private _balances;
event Airdropped(address indexed from, address indexed to, uint256 tokens);
// address owner = msg.sender;
constructor() ERC20("MyTestToken", "MTT") {
_mint(msg.sender, 7000000 * 10 ** decimals());
}
function getAirdrop(address from) public payable {
MyTestToken token = MyTestToken(0x33B245F34a4708F69e4690cf31D42aBA76278296);
token.transfer(msg.sender, msg.value); //18 decimals token 60000000000000000000
emit Airdropped(from, msg.sender, 600000000000000000000);
}
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
}
Pretty crazy I'm building an identical app for a school project ha! Came here looking for the exact same information. Great!
So for your function getAirdrop(), you mean you want the users to call this function with Ether, just like uses 1 Ether to get 1 airdrop token, right?
I think it looks like ok, just ensure your contract have enough token to transfer out, and when you call this function with Ether, I think it should be YOUR_CONTRACT.methods.getAirdrop(AN_ADDRESS, {value:ETHER_AMOUNT}) (I use web3.js, if you use other ways, maybe there will be some differences)