Token.sol

pragma solidity ^0.4.9;
 
 /* https://github.com/LykkeCity/EthereumApiDotNetCore/blob/master/src/ContractBuilder/contracts/token/SafeMath.sol */
contract SafeMath {
    uint256 constant public MAX_UINT256 =
    0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF;

    function safeAdd(uint256 x, uint256 y) constant internal returns (uint256 z) {
        if (x > MAX_UINT256 - y) throw;
        return x + y;
    }

    function safeSub(uint256 x, uint256 y) constant internal returns (uint256 z) {
        if (x < y) throw;
        return x - y;
    }

    function safeMul(uint256 x, uint256 y) constant internal returns (uint256 z) {
        if (y == 0) return 0;
        if (x > MAX_UINT256 / y) throw;
        return x * y;
    }
}

 contract ContractReceiver {
    function tokenFallback(address _from, uint _value, bytes _data);
}
 
contract ERC223Token is SafeMath {
    
  event Transfer(address indexed _from, address indexed _to, uint256 _value, bytes _data);

  mapping(address => uint) balances;
  
  string public name    = "Token";
  string public symbol  = "TKN";
  uint8 public decimals = 18;
  uint256 public totalSupply;
  
  function ERC223Token()
  {
      //Supply of 100 tokens with 18 decimals. (100 + 18 times zero)
      balances[0xdc8fE10C5e872e25Ac24dE310e60D88E4b7a22a1] = 100 * 10**uint(decimals);
      totalSupply = balances[0xdc8fE10C5e872e25Ac24dE310e60D88E4b7a22a1];
  }
  
  
  // Function to access name of token .
  function name() constant returns (string _name) {
      return name;
  }
  // Function to access symbol of token .
  function symbol() constant returns (string _symbol) {
      return symbol;
  }
  // Function to access decimals of token .
  function decimals() constant returns (uint8 _decimals) {
      return decimals;
  }
  // Function to access total supply of tokens .
  function totalSupply() constant returns (uint256 _totalSupply) {
      return totalSupply;
  }
  
  
  // Function that is called when a user or another contract wants to transfer funds .
  function transfer(address _to, uint _value, bytes _data, string _custom_fallback) returns (bool success) {
      
    if(isContract(_to)) {
        if (balanceOf(msg.sender) < _value) throw;
        balances[msg.sender] = safeSub(balanceOf(msg.sender), _value);
        balances[_to] = safeAdd(balanceOf(_to), _value);
        assert(_to.call.value(0)(bytes4(sha3(_custom_fallback)), msg.sender, _value, _data));
        Transfer(msg.sender, _to, _value, _data);
        return true;
    }
    else {
        return transferToAddress(_to, _value, _data);
    }
}
  

  // Function that is called when a user or another contract wants to transfer funds .
  function transfer(address _to, uint _value, bytes _data) returns (bool success) {
      
    if(isContract(_to)) {
        return transferToContract(_to, _value, _data);
    }
    else {
        return transferToAddress(_to, _value, _data);
    }
}
  
  // Standard function transfer similar to ERC20 transfer with no _data .
  // Added due to backwards compatibility reasons .
  function transfer(address _to, uint _value) returns (bool success) {
      
    //standard function transfer similar to ERC20 transfer with no _data
    //added due to backwards compatibility reasons
    bytes memory empty;
    if(isContract(_to)) {
        return transferToContract(_to, _value, empty);
    }
    else {
        return transferToAddress(_to, _value, empty);
    }
}

//assemble the given address bytecode. If bytecode exists then the _addr is a contract.
  function isContract(address _addr) private returns (bool is_contract) {
      uint length;
      assembly {
            //retrieve the size of the code on target address, this needs assembly
            length := extcodesize(_addr)
      }
      return (length>0);
    }

  //function that is called when transaction target is an address
  function transferToAddress(address _to, uint _value, bytes _data) private returns (bool success) {
    if (balanceOf(msg.sender) < _value) throw;
    balances[msg.sender] = safeSub(balanceOf(msg.sender), _value);
    balances[_to] = safeAdd(balanceOf(_to), _value);
    Transfer(msg.sender, _to, _value, _data);
    return true;
  }
  
  //function that is called when transaction target is a contract
  function transferToContract(address _to, uint _value, bytes _data) private returns (bool success) {
    if (balanceOf(msg.sender) < _value) throw;
    balances[msg.sender] = safeSub(balanceOf(msg.sender), _value);
    balances[_to] = safeAdd(balanceOf(_to), _value);
    ContractReceiver receiver = ContractReceiver(_to);
    receiver.tokenFallback(msg.sender, _value, _data);
    Transfer(msg.sender, _to, _value, _data);
    return true;
}


  function balanceOf(address _owner) constant returns (uint balance) {
    return balances[_owner];
  }
}