Topic: [Programmazione] Smart Contracts - page 2. (Read 20994 times)

contract ERC721 {
    
    function totalSupply() public view returns (uint256 total);
    function balanceOf(address _owner) public view returns (uint256 balance);
    function ownerOf(uint256 _tokenId) external view returns (address owner);
    function approve(address _to, uint256 _tokenId) external;
    function transfer(address _to, uint256 _tokenId) external;
    function transferFrom(address _from, address _to, uint256 _tokenId) external;

    event Transfer(address from, address to, uint256 tokenId);
    event Approval(address owner, address approved, uint256 tokenId);
}

string public constant name = "Tokenized Item";
  string public constant symbol = "NFTI";

  struct Token { // Definizione delle informazioni mantenute dal token
    address mintedBy;
    uint64 mintedAt;
    string description; /*Aggiunta allo scopo di rendere più comprensibile l’esempio, in realtà questo potrebbe essere un hash di un link IPFS o maggiori informazioni sul token senza incidere troppo sui costi derivanti dall’utilizzo delle informazioni all’interno dello smart contract*/
  }

  Token[] tokens; // Array dei token in esistenza

   //Mappature
  mapping (uint256 => address) public tokenIndexToOwner; //Token -> User
  mapping (address => uint256) ownershipTokenCount; //User -> Token
  mapping (uint256 => address) public tokenIndexToApproved; //Token -> User approvato a spendere il token

//Evento
  event Mint(address owner, uint256 tokenId, string description);

function _owns(address _claimant, uint256 _tokenId) internal view returns (bool) {
    return tokenIndexToOwner[_tokenId] == _claimant;
  }

  function _approvedFor(address _claimant, uint256 _tokenId) internal view returns (bool) {
    return tokenIndexToApproved[_tokenId] == _claimant;
  }

  function _approve(address _to, uint256 _tokenId) internal {
    tokenIndexToApproved[_tokenId] = _to;

    Approval(tokenIndexToOwner[_tokenId], tokenIndexToApproved[_tokenId], _tokenId);
  }

  function _transfer(address _from, address _to, uint256 _tokenId) internal {
    ownershipTokenCount[_to]++;
    tokenIndexToOwner[_tokenId] = _to;

    if (_from != address(0)) {
      ownershipTokenCount[_from]--;
      delete tokenIndexToApproved[_tokenId];
    }

    Transfer(_from, _to, _tokenId);
  }

 function _mint(address _owner, string description) internal returns (uint256 tokenId) {
    Token memory token = Token({
      mintedBy: _owner,
      mintedAt: uint64(now),
      description: description
    });
    tokenId = tokens.push(token) - 1;

    Mint(_owner, tokenId, description);

    _transfer(0, _owner, tokenId);
  }

 function mint(string description) external returns (uint256) {
    return _mint(msg.sender,description);
  }

  function getToken(uint256 _tokenId) external view returns (address mintedBy, uint64 mintedAt,string description) {
    Token memory token = tokens[_tokenId];

    mintedBy = token.mintedBy;
    mintedAt = token.mintedAt;
    description = token.description;
  }

pragma solidity ^0.4.18;

contract ERC721 {
    
    function totalSupply() public view returns (uint256 total);
    function balanceOf(address _owner) public view returns (uint256 balance);
    function ownerOf(uint256 _tokenId) external view returns (address owner);
    function approve(address _to, uint256 _tokenId) external;
    function transfer(address _to, uint256 _tokenId) external;
    function transferFrom(address _from, address _to, uint256 _tokenId) external;

    event Transfer(address from, address to, uint256 tokenId);
    event Approval(address owner, address approved, uint256 tokenId);
}

contract NFTItem is ERC721 {
 
  string public constant name = "Tokenized Item";
  string public constant symbol = "NFTI";

  /*** DATA TYPES ***/

  struct Token {
    address mintedBy;
    uint64 mintedAt;
    string description;
  }

  Token[] tokens;

  mapping (uint256 => address) public tokenIndexToOwner;
  mapping (address => uint256) ownershipTokenCount;
  mapping (uint256 => address) public tokenIndexToApproved;

  event Mint(address owner, uint256 tokenId, string description);


  /*** INTERNAL FUNCTIONS ***/

  function _owns(address _claimant, uint256 _tokenId) internal view returns (bool) {
    return tokenIndexToOwner[_tokenId] == _claimant;
  }

  function _approvedFor(address _claimant, uint256 _tokenId) internal view returns (bool) {
    return tokenIndexToApproved[_tokenId] == _claimant;
  }

  function _approve(address _to, uint256 _tokenId) internal {
    tokenIndexToApproved[_tokenId] = _to;

    Approval(tokenIndexToOwner[_tokenId], tokenIndexToApproved[_tokenId], _tokenId);
  }

  function _transfer(address _from, address _to, uint256 _tokenId) internal {
    ownershipTokenCount[_to]++;
    tokenIndexToOwner[_tokenId] = _to;

    if (_from != address(0)) {
      ownershipTokenCount[_from]--;
      delete tokenIndexToApproved[_tokenId];
    }

    Transfer(_from, _to, _tokenId);
  }

  function _mint(address _owner, string description) internal returns (uint256 tokenId) {
    Token memory token = Token({
      mintedBy: _owner,
      mintedAt: uint64(now),
      description: description
    });
    tokenId = tokens.push(token) - 1;

    Mint(_owner, tokenId, description);

    _transfer(0, _owner, tokenId);
  }


  /*** ERC721 IMPLEMENTATION ***/

  function totalSupply() public view returns (uint256) {
    return tokens.length;
  }

  function balanceOf(address _owner) public view returns (uint256) {
    return ownershipTokenCount[_owner];
  }

  function ownerOf(uint256 _tokenId) external view returns (address owner) {
    owner = tokenIndexToOwner[_tokenId];

    require(owner != address(0));
  }

  function approve(address _to, uint256 _tokenId) external {
    require(_owns(msg.sender, _tokenId));

    _approve(_to, _tokenId);
  }

  function transfer(address _to, uint256 _tokenId) external {
    require(_to != address(0));
    require(_to != address(this));
    require(_owns(msg.sender, _tokenId));

    _transfer(msg.sender, _to, _tokenId);
  }

  function transferFrom(address _from, address _to, uint256 _tokenId) external {
    require(_to != address(0));
    require(_to != address(this));
    require(_approvedFor(msg.sender, _tokenId));
    require(_owns(_from, _tokenId));

    _transfer(_from, _to, _tokenId);
  }

  function tokensOfOwner(address _owner) external view returns (uint256[]) {
    uint256 balance = balanceOf(_owner);

    if (balance == 0) {
      return new uint256[](0);
    } else {
      uint256[] memory result = new uint256[](balance);
      uint256 maxTokenId = totalSupply();
      uint256 idx = 0;

      uint256 tokenId;
      for (tokenId = 1; tokenId <= maxTokenId; tokenId++) {
        if (tokenIndexToOwner[tokenId] == _owner) {
          result[idx] = tokenId;
          idx++;
        }
      }
    }

    return result;
  }

  function mint(string description) external returns (uint256) {
    return _mint(msg.sender,description);
  }

  function getToken(uint256 _tokenId) external view returns (address mintedBy, uint64 mintedAt,string description) {
    Token memory token = tokens[_tokenId];

    mintedBy = token.mintedBy;
    mintedAt = token.mintedAt;
    description = token.description;
  }
}

mapping (address => uint256) public locked;

   event Lock(address indexed _owner, uint256 _value);
    event Unlock(address indexed _owner, uint256 _value);

   function lock(uint256 _value) public returns (bool success){
        require(safeSub(balances[msg.sender], locked[msg.sender]) >= _value); // New check for token availability - Makkara
        locked[msg.sender] = _value;
        emit Lock(msg.sender, _value); // Raise event for locked tokens.
        return true;
    }
    
    function locked() public view returns (uint256 _value){
        return locked[msg.sender];
    }
    
    function unlock(uint256 _value) public returns (bool success){
        require(locked[msg.sender] >= _value);
        locked[msg.sender]-=_value;
        return true;
    }

// Abstract contract for the full ERC 20 Token standard
// https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md
pragma solidity ^0.4.21;

contract SafeMath {
  function safeMul(uint256 a, uint256 b) internal returns (uint256) {
    uint256 c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function safeSub(uint256 a, uint256 b) internal returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  function safeAdd(uint256 a, uint256 b) internal returns (uint256) {
    uint256 c = a + b;
    assert(c>=a && c>=b);
    return c;
  }

  function assert(bool assertion) internal {
    if (!assertion) throw;
  }
}

contract EIP20Interface {
    /* This is a slight change to the ERC20 base standard.
    function totalSupply() constant returns (uint256 supply);
    is replaced with:
    uint256 public totalSupply;
    This automatically creates a getter function for the totalSupply.
    This is moved to the base contract since public getter functions are not
    currently recognised as an implementation of the matching abstract
    function by the compiler.
    */
    /// total amount of tokens
    uint256 public totalSupply;

    /// @param _owner The address from which the balance will be retrieved
    /// @return The balance
    function balanceOf(address _owner) public view returns (uint256 balance);

    /// @notice send `_value` token to `_to` from `msg.sender`
    /// @param _to The address of the recipient
    /// @param _value The amount of token to be transferred
    /// @return Whether the transfer was successful or not
    function transfer(address _to, uint256 _value) public returns (bool success);

    /// @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from`
    /// @param _from The address of the sender
    /// @param _to The address of the recipient
    /// @param _value The amount of token to be transferred
    /// @return Whether the transfer was successful or not
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success);

    /// @notice `msg.sender` approves `_spender` to spend `_value` tokens
    /// @param _spender The address of the account able to transfer the tokens
    /// @param _value The amount of tokens to be approved for transfer
    /// @return Whether the approval was successful or not
    function approve(address _spender, uint256 _value) public returns (bool success);

    /// @param _owner The address of the account owning tokens
    /// @param _spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens allowed to spent
    function allowance(address _owner, address _spender) public view returns (uint256 remaining);

    /// @notice `msg.sender` locks the amount of `_value` tokens
    /// @param _value The amount of tokens to be locked
    /// @return Whether the lock was successful or not
    function lock(uint256 _value) public returns (bool success);
    
    /// @notice `msg.sender` check the amount of tokens locked
    /// @return The amount of tokens locked
    function locked() public view returns (uint256 _value);

    /// @notice `msg.sender` unlocks the amount of `_value` tokens
    /// @param _value The amount of tokens to be unlocked
    /// @return Whether the unlock was successful or not
    function unlock(uint256 _value) returns (bool success);

    // solhint-disable-next-line no-simple-event-func-name
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
    event Lock(address indexed _owner, uint256 _value);
    event Unlock(address indexed _owner, uint256 _value);
}


contract EIP20 is EIP20Interface, SafeMath {

    uint256 constant private MAX_UINT256 = 2**256 - 1;
    mapping (address => uint256) public balances;
    mapping (address => mapping (address => uint256)) public allowed;
    mapping (address => uint256) public locked;
    /*
    NOTE:
    The following variables are OPTIONAL vanities. One does not have to include them.
    They allow one to customise the token contract & in no way influences the core functionality.
    Some wallets/interfaces might not even bother to look at this information.
    */
    string public name;                   //fancy name: eg Simon Bucks
    uint8 public decimals;                //How many decimals to show.
    string public symbol;                 //An identifier: eg SBX

    function EIP20(
        uint256 _initialAmount,
        string _tokenName,
        uint8 _decimalUnits,
        string _tokenSymbol
    ) public {
        balances[msg.sender] = _initialAmount * 10 ** uint256(_decimalUnits);               // Give the creator all initial tokens
        totalSupply = _initialAmount * 10 ** uint256(_decimalUnits);                        // Update total supply
        name = _tokenName;                                   // Set the name for display purposes
        decimals = _decimalUnits;                            // Amount of decimals for display purposes
        symbol = _tokenSymbol;                               // Set the symbol for display purposes
        locked[msg.sender] = 0;  //Initialize locked tokens for the creator - Makkara
    }

    function transfer(address _to, uint256 _value) public returns (bool success) {
        require(safeSub(balances[msg.sender], locked[msg.sender]) >= _value); // New check for token availability - Makkara
        balances[msg.sender] -= _value;
        balances[_to] += _value;
        emit Transfer(msg.sender, _to, _value); //solhint-disable-line indent, no-unused-vars
        return true;
    }

    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        uint256 allowance = allowed[_from][msg.sender];
        require(safeSub(balances[_from], locked[_from]) >= _value && allowance >= _value);
        balances[_to] += _value;
        balances[_from] -= _value;
        if (allowance < MAX_UINT256) {
            allowed[_from][msg.sender] -= _value;
        }
        emit Transfer(_from, _to, _value); //solhint-disable-line indent, no-unused-vars
        return true;
    }

    function balanceOf(address _owner) public view returns (uint256 balance) {
        return balances[_owner];
    }

    function approve(address _spender, uint256 _value) public returns (bool success) {
        require(safeSub(balances[msg.sender], locked[msg.sender]) >= _value); // New check for token availability - Makkara
        allowed[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value); //solhint-disable-line indent, no-unused-vars
        return true;
    }

    function allowance(address _owner, address _spender) public view returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }
    
    function lock(uint256 _value) public returns (bool success){
        require(safeSub(balances[msg.sender], locked[msg.sender]) >= _value); // New check for token availability - Makkara
        locked[msg.sender] = _value;
        emit Lock(msg.sender, _value); // Raise event for locked tokens.
        return true;
    }
    
    function locked() public view returns (uint256 _value){
        return locked[msg.sender];
    }
    
    function unlock(uint256 _value) public returns (bool success){
        require(locked[msg.sender] >= _value);
        locked[msg.sender]-=_value;
        emit Unlock(msg.sender, _value); // Raise event for unlocked tokens.
        return true;
    }
    
}

   function () payable{

        // Qui dentro poi usi msg.sender per sapere chi e' il destinatario dei token e msg.value per calcolare quanti token spedirgli


        LogReceivedFunds(msg.sender, msg.value);


    }

function pay() payable
        public
        returns(bool success)
    {
        //Operazioni ...

        LogReceivedFunds(msg.sender, msg.value);
        return true;
    }

function checkOwnershipEvents() {
                  document.getElementById("response3").innerHTML = ""
                 
                  var pf = web3.eth.contract(scAbi).at(scAddress);
                  // watch for an event with {some: 'args'}
                  var myEvent = pf.ProofOfOwnership({ some: 'args' }, { fromBlock: 0, toBlock: 'latest' });
                  // would get all past logs again.
                  var myResults = myEvent.get(function (error, logs) {
                      console.log(logs);
                      var event1;
                      for (var i = 0; i < logs.length ; i++) {
                          event1 = JSON.stringify(logs[i].args);
                          document.getElementById("response3").innerHTML += 'Proof of ownership received: ' + JSON.stringify(event1) + '
'
                      }
                  });
              }