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 <marek@ethdev.com>
 * @date 2014
 */

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

/**
 * 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) {
    abi.filter(function (json) {
        return json.type === 'event';
    }).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 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 if no callback was passed,
 * otherwise calls callback function (err, contract)
 */
ContractFactory.prototype.new = function () {
    // 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) {
        var address = web3.eth.sendTransaction(options);
        return this.at(address, callback);
    }
  
    var self = this;
    web3.eth.sendTransaction(options, function (err, address) {
        if (err) {
            callback(err);
        }
        self.at(address, callback); 
    }); 
};

/**
 * 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) {
    // TODO: address is required
    
    if (callback) {
        callback(null, new Contract(this.abi, address));
    } 
    return new Contract(this.abi, address);
};

/**
 * 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;
    addFunctionsToContract(this, abi);
    addEventsToContract(this, abi);
};

module.exports = contract;