Contract Name:
VMembersCoin
Contract Source Code:
File 1 of 1 : VMembersCoin
pragma solidity ^0.4.24;
contract owned {
address public owner;
constructor() public {
owner = msg.sender;
}
modifier onlyOwner {
require(msg.sender == owner);
_;
}
function transferOwnership(address newOwner) onlyOwner public {
owner = newOwner;
}
}
contract ERC223ReceivingContract {
function tokenFallback(address _from, uint _value, bytes _data) public;
}
contract ERC20CompatibleToken is owned {
using SafeMath for uint;
// Public variables of the token
string public name;
string public symbol;
uint8 public decimals = 18;
uint256 public totalSupply;
mapping(address => uint) balances; // List of user balances.
event Transfer(address indexed from, address indexed to, uint value);
event Approval(address indexed owner, address indexed spender, uint256 value);
mapping (address => mapping (address => uint256)) internal allowed;
mapping (address => bool) public frozenAccount;
/**
* Constrctor function
*
* Initializes contract with initial supply tokens to the creator of the contract
*/
constructor(
uint256 initialSupply,
string memory tokenName,
string memory tokenSymbol
) public {
totalSupply = initialSupply * 10 ** uint256(decimals); // Update total supply with the decimal amount
balances[msg.sender] = totalSupply; // Give the creator all initial tokens
name = tokenName; // Set the name for display purposes
symbol = tokenSymbol; // Set the symbol for display purposes
}
/**
* @dev Transfer tokens from one address to another
* @param _from address The address which you want to send tokens from
* @param _to address The address which you want to transfer to
* @param _value uint256 the amount of tokens to be transferred
*/
function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
uint codeLength;
bytes memory empty;
require(_to != address(0));
require(_value <= balances[_from]);
require(_value <= allowed[_from][msg.sender]);
require(!frozenAccount[_from]); // Check if sender is frozen
require(!frozenAccount[_to]); // Check if recipient is frozen
assembly {
// Retrieve the size of the code on target address, this needs assembly .
codeLength := extcodesize(_to)
}
if(codeLength>0) {
ERC223ReceivingContract receiver = ERC223ReceivingContract(_to);
receiver.tokenFallback(_from, _value, empty);
}
balances[_from] = balances[_from].sub(_value);
balances[_to] = balances[_to].add(_value);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
emit Transfer(_from, _to, _value);
return true;
}
/**
* @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
*
* @param _spender The address which will spend the funds.
* @param _value The amount of tokens to be spent.
*/
function approve(address _spender, uint256 _value) public returns (bool) {
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}
/**
* @dev Function to check the amount of tokens that an owner allowed to a spender.
* @param _owner address The address which owns the funds.
* @param _spender address The address which will spend the funds.
* @return A uint256 specifying the amount of tokens still available for the spender.
*/
function allowance(address _owner, address _spender) public view returns (uint256) {
return allowed[_owner][_spender];
}
/**
* approve should be called when allowed[_spender] == 0. To increment
* allowed value is better to use this function to avoid 2 calls (and wait until
* the first transaction is mined)
* From MonolithDAO Token.sol
*/
function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
uint oldValue = allowed[msg.sender][_spender];
if (_subtractedValue > oldValue) {
allowed[msg.sender][_spender] = 0;
} else {
allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
}
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
/* This generates a public event on the blockchain that will notify clients */
event FrozenFunds(address target, bool frozen);
/// @notice `freeze? Prevent | Allow` `target` from sending & receiving tokens
/// @param target Address to be frozen
/// @param freeze either to freeze it or not
function freezeAccount(address target, bool freeze) onlyOwner public {
frozenAccount[target] = freeze;
emit FrozenFunds(target, freeze);
}
}
contract ERC223Interface {
function balanceOf(address who) public constant returns (uint);
function transfer(address to, uint value) public;
function transfer(address to, uint value, bytes data) public;
event Transfer(address indexed from, address indexed to, uint value, bytes data);
}
/**
* @title SafeMath
* @dev Math operations with safety checks that throw on error
*/
library SafeMath {
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
uint256 c = a * b;
assert(c / a == b);
return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
// assert(b > 0); // Solidity automatically throws when dividing by 0
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a);
return a - b;
}
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
assert(c >= a);
return c;
}
}
/**
* @title VMembers Coin Main Contract
* @dev Reference implementation of the ERC223 standard token.
*/
contract VMembersCoin is owned, ERC223Interface, ERC20CompatibleToken {
using SafeMath for uint;
mapping (address => bool) public frozenAccount;
/* Initializes contract with initial supply tokens to the creator of the contract */
constructor(
uint256 initialSupply,
string memory tokenName,
string memory tokenSymbol
) ERC20CompatibleToken(initialSupply, tokenName, tokenSymbol) public {}
/**
* @dev Transfer the specified amount of tokens to the specified address.
* Invokes the `tokenFallback` function if the recipient is a contract.
* The token transfer fails if the recipient is a contract
* but does not implement the `tokenFallback` function
* or the fallback function to receive funds.
*
* @param _to Receiver address.
* @param _value Amount of tokens that will be transferred.
* @param _data Transaction metadata.
*/
function transfer(address _to, uint _value, bytes _data) public {
// Standard function transfer similar to ERC20 transfer with no _data .
// Added due to backwards compatibility reasons .
uint codeLength;
require(!frozenAccount[msg.sender]); // Check if sender is frozen
require(!frozenAccount[_to]); // Check if recipient is frozen
assembly {
// Retrieve the size of the code on target address, this needs assembly .
codeLength := extcodesize(_to)
}
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
if(codeLength>0) {
ERC223ReceivingContract receiver = ERC223ReceivingContract(_to);
receiver.tokenFallback(msg.sender, _value, _data);
}
emit Transfer(msg.sender, _to, _value);
return ;
}
/**
* @dev Transfer the specified amount of tokens to the specified address.
* This function works the same with the previous one
* but doesn't contain `_data` param.
* Added due to backwards compatibility reasons.
*
* @param _to Receiver address.
* @param _value Amount of tokens that will be transferred.
*/
function transfer(address _to, uint _value) public {
uint codeLength;
bytes memory empty;
require(!frozenAccount[msg.sender]); // Check if sender is frozen
require(!frozenAccount[_to]); // Check if recipient is frozen
assembly {
// Retrieve the size of the code on target address, this needs assembly .
codeLength := extcodesize(_to)
}
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
if(codeLength>0) {
ERC223ReceivingContract receiver = ERC223ReceivingContract(_to);
receiver.tokenFallback(msg.sender, _value, empty);
}
emit Transfer(msg.sender, _to, _value);
return ;
}
/**
* @dev Returns balance of the `_owner`.
*
* @param _owner The address whose balance will be returned.
* @return balance Balance of the `_owner`.
*/
function balanceOf(address _owner) public constant returns (uint balance) {
return balances[_owner];
}
/* This generates a public event on the blockchain that will notify clients */
event FrozenFunds(address target, bool frozen);
/// @notice `freeze? Prevent | Allow` `target` from sending & receiving tokens
/// @param target Address to be frozen
/// @param freeze either to freeze it or not
function freezeAccount(address target, bool freeze) onlyOwner public {
frozenAccount[target] = freeze;
emit FrozenFunds(target, freeze);
return ;
}
}