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/*
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
* @authors:
* Marek Kotewicz <marek@ethdev.com>
* @date 2014
*/
var web3 = require('./web3'); // jshint ignore:line
var abi = require('./abi');
/// method signature length in bytes
var ETH_METHOD_SIGNATURE_LENGTH = 4;
/**
* This method should be called when we want to call / transact some solidity method from javascript
* it returns an object which has same methods available as solidity contract description
* usage example:
*
* var abi = [{
* name: 'myMethod',
* inputs: [{ name: 'a', type: 'string' }],
* outputs: [{name: 'd', type: 'string' }]
* }]; // contract abi
*
* var myContract = web3.eth.contract('0x0123123121', abi); // creation of contract object
*
* myContract.myMethod('this is test string param for call').call(); // myMethod call
* myContract.myMethod('this is test string param for transact').transact() // myMethod transact
*
* @param address - address of the contract, which should be called
* @param desc - abi json description of the contract, which is being created
* @returns contract object
*/
var contract = function (address, desc) {
var inputParser = abi.inputParser(desc);
var outputParser = abi.outputParser(desc);
var contract = {};
desc.forEach(function (method) {
contract[method.name] = function () {
var params = Array.prototype.slice.call(arguments);
var parsed = inputParser[method.name].apply(null, params);
var onSuccess = function (result) {
return outputParser[method.name](result);
};
return {
call: function (extra) {
extra = extra || {};
extra.to = address;
return abi.methodSignature(desc, method.name).then(function (signature) {
extra.data = signature.slice(0, 2 + ETH_METHOD_SIGNATURE_LENGTH * 2) + parsed;
return web3.eth.call(extra).then(onSuccess);
});
},
transact: function (extra) {
extra = extra || {};
extra.to = address;
return abi.methodSignature(desc, method.name).then(function (signature) {
extra.data = signature.slice(0, 2 + ETH_METHOD_SIGNATURE_LENGTH * 2) + parsed;
return web3.eth.transact(extra).then(onSuccess);
});
}
};
};
});
return contract;
};
module.exports = contract;
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