[Ethereum] Send all Tokens and Eth to a Address automatically

contract-designerc-20soliditytokens

I have few child wallets and a parent wallet.
Whenever these child wallets get incoming ERC20 tokens or ETH. I want to send them automatically to the parent wallet.

I know I can do below to send the entire eth balance.

beneficiary.transfer(this.balance);

How can I do it for erc20 tokens.

Thanks in advance.

Best Answer

You are looking to effectively 'forward' your balance. A way to go about doing this is using a contract similar to the one highlighted Here.

pragma solidity ^0.4.18;

/**
 * Contract that will forward any incoming Ether to its creator
 */
contract Forwarder {
  // Address to which any funds sent to this contract will be forwarded
  address public destinationAddress;

  /**
   * Create the contract, and set the destination address to that of the creator
   */
  function Forwarder() public {
    destinationAddress = msg.sender;
  }

  /**
   * Default function; Gets called when Ether is deposited, and forwards it to the destination address
   */
  function() payable public {
        destinationAddress.transfer(msg.value);
  }

  /**
   * It is possible that funds were sent to this address before the contract was deployed.
   * We can flush those funds to the destination address.
   */
  function flush() public {
    destinationAddress.transfer(this.balance);
  }

}

Related Solutions

Contract Development – How to Send ERC20 Tokens from Contract

.send() function sends Ethereum from contract balance, not tokens. So you need to call token transfer function.

Also I advise you to always you send() function within require() because send() doesn't throw exception and your debug process could be harder.

Additionally, why does the contract not have to sign the transaction as a user would?

Because contract can't execute it's own functions by itself. All functions can be triggered only when real user send signed transaction with correct data field (contains information about calling function and arguments) to Ethereum network.

Solidity – How to Send ERC20 Automatically from Contract to Beneficiary Upon Receiving

Your code will send the ether sent to the contract to the owner. make your fallback public.

function () payable public {
       owner.transfer(msg.value);
    }

This won't work for tokens sent to the contract. You will need to use the method approveAndCall on the ERC20. Problem is that not all ERC20 contracts implement approveAndCall.

If the function is implemented as described in the ethereum ERC20 standard wiki, your users should execute the function approveAndCall (see link above) in the token contract.

You should implement the following function in your contract.

function receiveApproval(address from, uint256 tokens, address token, bytes data) public {
    TokenERC20 tokenInstance =  TokenERC20(token);
    tokenInstance.transferFrom(from, owner, tokens);
}

As you can see, the annoying part here is that simply transferring the tokens to the contract won't work, because your contract will not know about the transfer and you will have to implement a function to manually check the balance and send the available tokens to your account. That is why the users will have to do approveAndCall which approve a number of tokens of a particular user to be moved by you and then calls you contract to let it know about the transfer.

Hope this helps.

Best Answer

Related Solutions

Contract Development – How to Send ERC20 Tokens from Contract

Solidity – How to Send ERC20 Automatically from Contract to Beneficiary Upon Receiving

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