Contract Name:
ERC20StandardToken
Contract Source Code:
File 1 of 1 : ERC20StandardToken
pragma solidity ^0.4.24;
//ERC20
contract ERC20Ownable {
address public owner;
constructor() public{
owner = msg.sender;
}
modifier onlyOwner {
require(msg.sender == owner);
_;
}
function transferOwnership(address newOwner) onlyOwner public{
if (newOwner != address(0)) {
owner = newOwner;
}
}
}
contract ERC20 {
function transfer(address to, uint256 value) public returns (bool);
function balanceOf(address who) public view returns (uint256);
event Transfer(address indexed from, address indexed to, uint256 value);
}
contract ERC20Token is ERC20,ERC20Ownable {
mapping (address => uint256) balances;
mapping (address => mapping (address => uint256)) allowed;
event Transfer(
address indexed _from,
address indexed _to,
uint256 _value
);
event Approval(
address indexed _owner,
address indexed _spender,
uint256 _value
);
//Fix for short address attack against ERC20
modifier onlyPayloadSize(uint size) {
assert(msg.data.length == size + 4);
_;
}
function balanceOf(address _owner) constant public returns (uint256) {
return balances[_owner];
}
function transfer(address _to, uint256 _value) onlyPayloadSize(2*32) public returns (bool){
require(balances[msg.sender] >= _value && _value > 0);
balances[msg.sender] -= _value;
balances[_to] += _value;
emit Transfer(msg.sender, _to, _value);
return true;
}
function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
require(balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0);
balances[_to] += _value;
balances[_from] -= _value;
allowed[_from][msg.sender] -= _value;
emit Transfer(_from, _to, _value);
return true;
}
function approve(address _spender, uint256 _value) public {
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
}
/* Approves and then calls the receiving contract */
function approveAndCall(address _spender, uint256 _value, bytes _extraData) public returns (bool success) {
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
//call the receiveApproval function on the contract you want to be notified. This crafts the function signature manually so one doesn't have to include a contract in here just for this.
//receiveApproval(address _from, uint256 _value, address _tokenContract, bytes _extraData)
//it is assumed that when does this that the call *should* succeed, otherwise one would use vanilla approve instead.
//require(_spender.call(bytes4(keccak256("receiveApproval(address,uint256,address,bytes)")), abi.encode(msg.sender, _value, this, _extraData)));
require(_spender.call(abi.encodeWithSelector(bytes4(keccak256("receiveApproval(address,uint256,address,bytes)")),msg.sender, _value, this, _extraData)));
return true;
}
function allowance(address _owner, address _spender) constant public returns (uint256) {
return allowed[_owner][_spender];
}
}
contract ERC20StandardToken is ERC20Token {
uint256 public totalSupply;
string public name;
uint256 public decimals;
string public symbol;
bool public mintable;
constructor(address _owner, string _name, string _symbol, uint256 _decimals, uint256 _totalSupply, bool _mintable) public {
require(_owner != address(0));
owner = _owner;
decimals = _decimals;
symbol = _symbol;
name = _name;
mintable = _mintable;
totalSupply = _totalSupply;
balances[_owner] = totalSupply;
emit Transfer(address(0), _owner, totalSupply);
}
function mint(uint256 amount) onlyOwner public {
require(mintable);
require(amount >= 0);
balances[msg.sender] += amount;
totalSupply += amount;
}
function burn(uint256 _value) onlyOwner public returns (bool) {
require(balances[msg.sender] >= _value && totalSupply >=_value && _value > 0);
balances[msg.sender] -= _value;
totalSupply -= _value;
emit Transfer(msg.sender, 0x0, _value);
return true;
}
}