web3.js/lib/web3/contract.js

/*
    This file is part of ethereum.js.

    ethereum.js is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    ethereum.js is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with ethereum.js.  If not, see <http://www.gnu.org/licenses/>.
*/
/** 
 * @file contract.js
 * @author Marek Kotewicz <[email protected]>
 * @date 2014
 */

var web3 = require('../web3'); 
var utils = require('../utils/utils');
var coder = require('../solidity/coder');
var SolidityEvent = require('./event');
var SolidityFunction = require('./function');
var AllEvents = require('./allevents');

/**
 * Should be called to encode constructor params
 *
 * @method encodeConstructorParams
 * @param {Array} abi
 * @param {Array} constructor params
 */
var encodeConstructorParams = function (abi, params) {
    return abi.filter(function (json) {
        return json.type === 'constructor' && json.inputs.length === params.length;
    }).map(function (json) {
        return json.inputs.map(function (input) {
            return input.type;
        });
    }).map(function (types) {
        return coder.encodeParams(types, params);
    })[0] || '';
};

/**
 * Should be called to add functions to contract object
 *
 * @method addFunctionsToContract
 * @param {Contract} contract
 * @param {Array} abi
 */
var addFunctionsToContract = function (contract, abi) {
    abi.filter(function (json) {
        return json.type === 'function';
    }).map(function (json) {
        return new SolidityFunction(json, contract.address);
    }).forEach(function (f) {
        f.attachToContract(contract);
    });
};

/**
 * Should be called to add events to contract object
 *
 * @method addEventsToContract
 * @param {Contract} contract
 * @param {Array} abi
 */
var addEventsToContract = function (contract, abi) {
    var events = abi.filter(function (json) {
        return json.type === 'event';
    });

    var All = new AllEvents(events, contract.address);
    All.attachToContract(contract);
    
    events.map(function (json) {
        return new SolidityEvent(json, contract.address);
    }).forEach(function (e) {
        e.attachToContract(contract);
    });
};

/**
 * Should be called to create new ContractFactory
 *
 * @method contract
 * @param {Array} abi
 * @returns {ContractFactory} new contract factory
 */
var contract = function (abi) {
    return new ContractFactory(abi);
};

/**
 * Should be called to check if the contract gets properly deployed on the blockchain.
 *
 * @method checkForContractAddress
 * @param {Object} contract
 * @param {Function} callback
 * @returns {Undefined}
 */
var checkForContractAddress = function(contract, abi, callback){
    var count = 0,
        callbackFired = false;

    // wait for receipt
    var filter = web3.eth.filter('latest', function(e){
        if(!e && !callbackFired) {
            count++;

            // console.log('Checking for contract address', count);

            // stop watching after 50 blocks (timeout)
            if(count > 50) {
                
                filter.stopWatching();
                callbackFired = true;

                if(callback)
                    callback(new Error('Contract transaction couldn\'t be found after 50 blocks'));
                else
                    throw new Error('Contract transaction couldn\'t be found after 50 blocks');


            } else {

                web3.eth.getTransactionReceipt(contract.transactionHash, function(e, receipt){
                    if(receipt && !callbackFired) {

                        web3.eth.getCode(receipt.contractAddress, function(e, code){
                            /*jshint maxcomplexity: 5 */

                            if(callbackFired)
                                return;
                            
                            filter.stopWatching();
                            callbackFired = true;

                            if(code.length > 2) {

                                // console.log('Contract code deployed!');

                                contract.address = receipt.contractAddress;

                                // attach events and methods
                                addFunctionsToContract(contract, abi);
                                addEventsToContract(contract, abi);

                                // call callback for the second time
                                if(callback)
                                    callback(null, contract);

                            } else {
                                if(callback)
                                    callback(new Error('The contract code couldn\'t be stored, please check your gas amount.'));
                                else
                                    throw new Error('The contract code couldn\'t be stored, please check your gas amount.');
                            }
                        });
                    }
                });
            }
        }
    });
};

/**
 * Should be called to create new ContractFactory instance
 *
 * @method ContractFactory
 * @param {Array} abi
 */
var ContractFactory = function (abi) {
    this.abi = abi;
};

/**
 * Should be called to create new contract on a blockchain
 * 
 * @method new
 * @param {Any} contract constructor param1 (optional)
 * @param {Any} contract constructor param2 (optional)
 * @param {Object} contract transaction object (required)
 * @param {Function} callback
 * @returns {Contract} returns contract instance
 */
ContractFactory.prototype.new = function () {
    var _this = this;
    var contract = new Contract(this.abi);

    // parse arguments
    var options = {}; // required!
    var callback;

    var args = Array.prototype.slice.call(arguments);
    if (utils.isFunction(args[args.length - 1])) {
        callback = args.pop();
    }

    var last = args[args.length - 1];
    if (utils.isObject(last) && !utils.isArray(last)) {
        options = args.pop();
    }

    // throw an error if there are no options

    var bytes = encodeConstructorParams(this.abi, args);
    options.data += bytes;


    if(callback) {

        // wait for the contract address adn check if the code was deployed
        web3.eth.sendTransaction(options, function (err, hash) {
            if (err) {
                callback(err);
            } else {
                // add the transaction hash
                contract.transactionHash = hash;

                // call callback for the first time
                callback(null, contract);

                checkForContractAddress(contract, _this.abi, callback);
            }
        });
    } else {
        var hash = web3.eth.sendTransaction(options);
        // add the transaction hash
        contract.transactionHash = hash;
        checkForContractAddress(contract, _this.abi);
    }

    return contract;
};

/**
 * Should be called to get access to existing contract on a blockchain
 *
 * @method at
 * @param {Address} contract address (required)
 * @param {Function} callback {optional)
 * @returns {Contract} returns contract if no callback was passed,
 * otherwise calls callback function (err, contract)
 */
ContractFactory.prototype.at = function (address, callback) {
    var contract = new Contract(this.abi, address);
    // TODO: address is required

    // attach functions
    addFunctionsToContract(contract, this.abi);
    addEventsToContract(contract, this.abi);
    
    if (callback) {
        callback(null, contract);
    } 
    return contract;
};

/**
 * Should be called to create new contract instance
 *
 * @method Contract
 * @param {Array} abi
 * @param {Address} contract address
 */
var Contract = function (abi, address) {
    this.address = address;
};

module.exports = contract;