ERC223 with ERC20 backwards compatibility

ERC20.sol

pragma solidity ^0.4.10;

import 'browser/SafeMath.sol';

contract ERC20 {
  uint256 public totalSupply;
  function name() constant returns (string _name);
  function symbol() constant returns (string _symbol);
  function decimals() constant returns (uint8 _decimals);
  function totalSupply() constant returns (uint256 _totalSupply);
  function balanceOf(address who) public view returns (uint256);
  function allowance(address owner, address spender) public view returns (uint256);
  function transferFrom(address from, address to, uint256 value) public returns (bool);
  function approve(address spender, uint256 value) public returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
  event Approval(address indexed owner, address indexed spender, uint256 value);
}

ERC223.sol

pragma solidity ^0.4.10;

import 'browser/StandardToken.sol';

contract ERC223 is StandardToken {
    function transfer(address to, uint value, bytes data);
    event Transfer(address indexed from, address indexed to, uint value, bytes indexed data);
}

ERC223ReceivingContract.sol

pragma solidity ^0.4.10;

 /**
 * @title Contract that will work with ERC223 tokens.
 */
 
contract ERC223ReceivingContract { 
/**
 * @dev Standard ERC223 function that will handle incoming token transfers.
 *
 * @param _from  Token sender address.
 * @param _value Amount of tokens.
 * @param _data  Transaction metadata.
 */
    function tokenFallback(address _from, uint _value, bytes _data);
}

ERC223Token.sol

pragma solidity ^0.4.10;

import 'browser/ERC223.sol';
import 'browser/ERC223ReceivingContract.sol';

contract ERC223Token is ERC223 {

  function transfer(address _to, uint _value) {
    uint codeLength;
    bytes memory empty;

    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);
    }
    Transfer(msg.sender, _to, _value, empty);
}

  function transfer(address _to, uint _value, bytes _data) {
    // Standard function transfer similar to ERC20 transfer with no _data .
    // Added due to backwards compatibility reasons .
    uint codeLength;

    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);
    }
    Transfer(msg.sender, _to, _value, _data);
  }
}

MyToken.sol

pragma solidity ^0.4.10;

import 'browser/ERC223Token.sol';

contract MyToken is StandardToken {
    string public name = "MyToken";
    string public symbol = "MYT";
    uint8 public decimals = 8;
    uint256 public totalSupply = 10000;

    function MyToken() {
        balances[msg.sender] = totalSupply;
    }
    
    function name() constant returns (string _name) {
    return name;
  }

  function symbol() constant returns (string _symbol) {
    return symbol;
  }

  function decimals() constant returns (uint8 _decimals) {
    return decimals;
  }

  function totalSupply() constant returns (uint256) {
    return totalSupply;
  }
}

SafeMath.sol

pragma solidity ^0.4.10;


/**
 * @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;
  }
}

StandardToken.sol

pragma solidity ^0.4.10;

import 'browser/ERC20.sol';

contract StandardToken is ERC20 {

  using SafeMath for uint256;
  mapping(address => uint256) balances;
  mapping (address => mapping (address => uint256)) internal allowed;

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of.
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) public view returns (uint256 balance) {
    return balances[_owner];
  }

  /**
   * @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) {
    require(_to != address(0));
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);
    balances[_from] = SafeMath.sub(balances[_from], _value);
    balances[_to] = SafeMath.add(balances[_to], _value);
    allowed[_from][msg.sender] = SafeMath.sub(allowed[_from][msg.sender], _value);
    Transfer(_from, _to, _value);
    return true;
  }

  function approve(address _spender, uint256 _value) public returns (bool) {
    allowed[msg.sender][_spender] = _value;
    Approval(msg.sender, _spender, _value);
    return true;
  }

  function allowance(address _owner, address _spender) public view returns (uint256) {
    return allowed[_owner][_spender];
  }

  function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
    allowed[msg.sender][_spender] = SafeMath.add(allowed[msg.sender][_spender], _addedValue);
    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] = SafeMath.sub(oldValue, _subtractedValue);
    }
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

}