web3.js/lib/web3/property.js

144 lines
3.7 KiB
JavaScript

/*
This file is part of web3.js.
web3.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.
web3.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 web3.js. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file property.js
* @author Fabian Vogelsteller <fabian@frozeman.de>
* @author Marek Kotewicz <marek@ethdev.com>
* @date 2015
*/
var utils = require('../utils/utils');
var Property = function (options) {
this.name = options.name;
this.getter = options.getter;
this.setter = options.setter;
this.outputFormatter = options.outputFormatter;
this.inputFormatter = options.inputFormatter;
this.requestManager = null;
};
Property.prototype.setRequestManager = function (rm) {
this.requestManager = rm;
};
/**
* Should be called to format input args of method
*
* @method formatInput
* @param {Array}
* @return {Array}
*/
Property.prototype.formatInput = function (arg) {
return this.inputFormatter ? this.inputFormatter(arg) : arg;
};
/**
* Should be called to format output(result) of method
*
* @method formatOutput
* @param {Object}
* @return {Object}
*/
Property.prototype.formatOutput = function (result) {
return this.outputFormatter && result !== null ? this.outputFormatter(result) : result;
};
/**
* Should be used to extract callback from array of arguments. Modifies input param
*
* @method extractCallback
* @param {Array} arguments
* @return {Function|Null} callback, if exists
*/
Property.prototype.extractCallback = function (args) {
if (utils.isFunction(args[args.length - 1])) {
return args.pop(); // modify the args array!
}
};
/**
* Should attach function to method
*
* @method attachToObject
* @param {Object}
* @param {Function}
*/
Property.prototype.attachToObject = function (obj) {
var proto = {
get: this.buildGet()
};
var names = this.name.split('.');
var name = names[0];
if (names.length > 1) {
obj[names[0]] = obj[names[0]] || {};
obj = obj[names[0]];
name = names[1];
}
Object.defineProperty(obj, name, proto);
obj[asyncGetterName(name)] = this.buildAsyncGet();
};
var asyncGetterName = function (name) {
return 'get' + name.charAt(0).toUpperCase() + name.slice(1);
};
Property.prototype.buildGet = function () {
var property = this;
return function get() {
return property.formatOutput(property.requestManager.send({
method: property.getter
}));
};
};
Property.prototype.buildAsyncGet = function () {
var property = this;
var get = function (callback) {
property.requestManager.sendAsync({
method: property.getter
}, function (err, result) {
callback(err, property.formatOutput(result));
});
};
get.request = this.request.bind(this);
return get;
};
/**
* Should be called to create pure JSONRPC request which can be used in batch request
*
* @method request
* @param {...} params
* @return {Object} jsonrpc request
*/
Property.prototype.request = function () {
var payload = {
method: this.getter,
params: [],
callback: this.extractCallback(Array.prototype.slice.call(arguments))
};
payload.format = this.formatOutput.bind(this);
return payload;
};
module.exports = Property;