Question regarding approval of the token

Question

I am trying to make a smart contract where calling a function named transferERC20, you can deposit your erc20 tokens into the smart contract.

Here is the code at the moment:

pragma solidity ^0.5.0;

import "./ERC20.sol";

contract GameTokenERC20 is ERC20{

  function transferERC20(uint _value) public{
    approve(address(this), _value);
   // transfer(address(this), _value);
   emit Approval(msg.sender, address(this), _value);
   transferFrom(msg.sender,address(this), _value);
  }


}

Basically calling the function you should be able to deposit any erc20 token to my contract address.

I have tried to deploy it in remix but metamask doesn't let me set the token that I want to send, it just creates the transaction.

My questions are :

1) If it doesn't work in the remix IDE, should I try it from web3 ? 2) How does the user say which token he wants to send ? I'll have to put a contract address for each token ?

I think I am missing something as the user will just have to deposit the erc20 token inside the contract.

Thanks to all

Answer 1

Since you're transferring from within the token contract itself, you can just do this:

  function transferERC20(uint _value) public {
    transfer(address(this), _value);
  }

msg.sender will be preserved for transfer since this is an internal call.