Por retiro seguro, me refiero a que si una venta colectiva no alcanza el objetivo, qué área del código envía los tokens a los inversores. Estoy realmente perplejo.
pragma solidity ^0.4.16;
interface token {
function transfer(address receiver, uint amount);
}
contract Crowdsale {
address public beneficiary;
uint public fundingGoal;
uint public amountRaised;
uint public deadline;
uint public price;
token public tokenReward;
mapping(address => uint256) public balanceOf;
bool fundingGoalReached = false;
bool crowdsaleClosed = false;
event GoalReached(address recipient, uint totalAmountRaised);
event FundTransfer(address backer, uint amount, bool isContribution);
/**
* Constrctor function
*
* Setup the owner
*/
function Crowdsale(
address ifSuccessfulSendTo,
uint fundingGoalInEthers,
uint durationInMinutes,
uint etherCostOfEachToken,
address addressOfTokenUsedAsReward
) {
beneficiary = ifSuccessfulSendTo;
fundingGoal = fundingGoalInEthers * 1 ether;
deadline = now + durationInMinutes * 1 minutes;
price = etherCostOfEachToken * 1 ether;
tokenReward = token(addressOfTokenUsedAsReward);
}
/**
* Fallback function
*
* The function without name is the default function that is called whenever anyone sends funds to a contract
*/
function () payable {
require(!crowdsaleClosed);
uint amount = msg.value;
balanceOf[msg.sender] += amount;
amountRaised += amount;
tokenReward.transfer(msg.sender, amount / price);
FundTransfer(msg.sender, amount, true);
}
modifier afterDeadline() { if (now >= deadline) _; }
/**
* Check if goal was reached
*
* Checks if the goal or time limit has been reached and ends the campaign
*/
function checkGoalReached() afterDeadline {
if (amountRaised >= fundingGoal){
fundingGoalReached = true;
GoalReached(beneficiary, amountRaised);
}
crowdsaleClosed = true;
}
/**
* Withdraw the funds
*
* Checks to see if goal or time limit has been reached, and if so, and the funding goal was reached,
* sends the entire amount to the beneficiary. If goal was not reached, each contributor can withdraw
* the amount they contributed.
*/
function safeWithdrawal() afterDeadline {
if (!fundingGoalReached) {
uint amount = balanceOf[msg.sender];
balanceOf[msg.sender] = 0;
if (amount > 0) {
if (msg.sender.send(amount)) {
FundTransfer(msg.sender, amount, false);
} else {
balanceOf[msg.sender] = amount;
}
}
}
if (fundingGoalReached && beneficiary == msg.sender) {
if (beneficiary.send(amountRaised)) {
FundTransfer(beneficiary, amountRaised, false);
} else {
//If we fail to send the funds to beneficiary, unlock funders balance
fundingGoalReached = false;
}
}
}
}
Estas son las partes relevantes:
modifier afterDeadline() { if (now >= deadline) _; }
y
function safeWithdrawal() afterDeadline {
if (!fundingGoalReached) {
uint amount = balanceOf[msg.sender];
balanceOf[msg.sender] = 0;
if (amount > 0) {
if (msg.sender.send(amount)) {
FundTransfer(msg.sender, amount, false);
} else {
balanceOf[msg.sender] = amount;
}
}
}
if (fundingGoalReached && beneficiary == msg.sender) {
if (beneficiary.send(amountRaised)) {
FundTransfer(beneficiary, amountRaised, false);
} else {
//If we fail to send the funds to beneficiary, unlock funders balance
fundingGoalReached = false;
}
}
}
El modificador verifica si el crowdsale ha terminado. Si no ha terminado, safeWithdrawal
sale sin hacer nada. safeWithdrawal
luego verifica si se alcanzó el objetivo de financiación. Si no se alcanzó, verifica si la dirección de envío depositó algo. Si el remitente depositó, entonces se devuelve el saldo y el saldo en el contrato se establece en 0.
La segunda mitad de SafeWithdrawal se refiere al grupo que puso en marcha la ICO. Si se alcanzó el objetivo de financiación y la dirección de envío es beneficiary
(el grupo que recibe los fondos), entonces enviará los fondos. Luego, si el envío falla, desbloquea los fondos para los contribuyentes.
amountRaised
supera cierta cantidad.
libertad bloqueada
N. Hyatt
libertad bloqueada
msg.sender.send
es donde se envían los fondos.N. Hyatt