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Token Contract
pragma solidity ^0.5.0;
import "./ERC20.sol";
import "./ERC20Detailed.sol";
import "./Context.sol";
import "./IERC20.sol";
import "./SafeMath.sol";
contract DemoToken is Context, ERC20, ERC20Detailed {
constructor (
string memory name,
string memory symbol,
uint256 initialSupply
) public ERC20Detailed(name, symbol, 18) {
_mint(_msgSender(), initialSupply);
}
}
Crowdsale Contract
pragma solidity ^0.5.0;
import "./SafeMath.sol";
import "./Crowdsale.sol";
/**
* @title TimedCrowdsale
* @dev Crowdsale accepting contributions only within a time frame.
*/
contract TimedCrowdsale is Crowdsale {
using SafeMath for uint256;
uint256 private _openingTime;
uint256 private _closingTime;
/**
* Event for crowdsale extending
* @param newClosingTime new closing time
* @param prevClosingTime old closing time
*/
event TimedCrowdsaleExtended(uint256 prevClosingTime, uint256 newClosingTime);
/**
* @dev Reverts if not in crowdsale time range.
*/
modifier onlyWhileOpen {
require(isOpen(), "TimedCrowdsale: not open");
_;
}
/**
* @dev Constructor, takes crowdsale opening and closing times.
* @param openingTime Crowdsale opening time
* @param closingTime Crowdsale closing time
*/
constructor (uint256 openingTime, uint256 closingTime) public {
// solhint-disable-next-line not-rely-on-time
require(openingTime >= block.timestamp, "TimedCrowdsale: opening time is before current time");
// solhint-disable-next-line max-line-length
require(closingTime > openingTime, "TimedCrowdsale: opening time is not before closing time");
_openingTime = openingTime;
_closingTime = closingTime;
}
/**
* @return the crowdsale opening time.
*/
function openingTime() public view returns (uint256) {
return _openingTime;
}
/**
* @return the crowdsale closing time.
*/
function closingTime() public view returns (uint256) {
return _closingTime;
}
/**
* @return true if the crowdsale is open, false otherwise.
*/
function isOpen() public view returns (bool) {
// solhint-disable-next-line not-rely-on-time
return block.timestamp >= _openingTime && block.timestamp <= _closingTime;
}
/**
* @dev Checks whether the period in which the crowdsale is open has already elapsed.
* @return Whether crowdsale period has elapsed
*/
function hasClosed() public view returns (bool) {
// solhint-disable-next-line not-rely-on-time
return block.timestamp > _closingTime;
}
/**
* @dev Extend parent behavior requiring to be within contributing period.
* @param beneficiary Token purchaser
* @param weiAmount Amount of wei contributed
*/
function _preValidatePurchase(address beneficiary, uint256 weiAmount) internal onlyWhileOpen view {
super._preValidatePurchase(beneficiary, weiAmount);
}
/**
* @dev Extend crowdsale.
* @param newClosingTime Crowdsale closing time
*/
function _extendTime(uint256 newClosingTime) internal {
require(!hasClosed(), "TimedCrowdsale: already closed");
// solhint-disable-next-line max-line-length
require(newClosingTime > _closingTime, "TimedCrowdsale: new closing time is before current closing time");
emit TimedCrowdsaleExtended(_closingTime, newClosingTime);
_closingTime = newClosingTime;
}
}
pragma solidity ^0.5.0;
import "./SafeMath.sol";
import "./Secondary.sol";
import "./IERC20.sol";
/**
* @title PostDeliveryCrowdsale
* @dev Crowdsale that locks tokens from withdrawal until it ends.
*/
contract PostDeliveryCrowdsale is TimedCrowdsale {
using SafeMath for uint256;
mapping(address => uint256) private _balances;
__unstable__TokenVault private _vault;
constructor() public {
_vault = new __unstable__TokenVault();
}
/**
* @dev Withdraw tokens only after crowdsale ends.
* @param beneficiary Whose tokens will be withdrawn.
*/
function withdrawTokens(address beneficiary) public {
require(hasClosed(), "PostDeliveryCrowdsale: not closed");
uint256 amount = _balances[beneficiary];
require(amount > 0, "PostDeliveryCrowdsale: beneficiary is not due any tokens");
_balances[beneficiary] = 0;
_vault.transfer(token(), beneficiary, amount);
}
/**
* @return the balance of an account.
*/
function balanceOf(address account) public view returns (uint256) {
return _balances[account];
}
/**
* @dev Overrides parent by storing due balances, and delivering tokens to the vault instead of the end user. This
* ensures that the tokens will be available by the time they are withdrawn (which may not be the case if
* `_deliverTokens` was called later).
* @param beneficiary Token purchaser
* @param tokenAmount Amount of tokens purchased
*/
function _processPurchase(address beneficiary, uint256 tokenAmount) internal {
_balances[beneficiary] = _balances[beneficiary].add(tokenAmount);
_deliverTokens(address(_vault), tokenAmount);
}
}
/**
* @title __unstable__TokenVault
* @dev Similar to an Escrow for tokens, this contract allows its primary account to spend its tokens as it sees fit.
* This contract is an internal helper for PostDeliveryCrowdsale, and should not be used outside of this context.
*/
// solhint-disable-next-line contract-name-camelcase
contract __unstable__TokenVault is Secondary {
function transfer(IERC20 token, address to, uint256 amount) public onlyPrimary {
token.transfer(to, amount);
}
}
pragma solidity 0.5.5;
import "./Crowdsale.sol";
contract DemoCrowdsale is Crowdsale, PostDeliveryCrowdsale {
constructor(
uint rate,
address payable wallet,
IERC20 token,
uint openingTime,
uint closingTime
) Crowdsale(rate, wallet, token)
PostDeliveryCrowdsale()
TimedCrowdsale(openingTime, closingTime)
public {}
}
Code to reproduce
Environment