BaseStore.js

/**
 * Copyright 2014, Yahoo! Inc.
 * Copyrights licensed under the New BSD License. See the accompanying LICENSE file for terms.
 */
'use strict';

var inherits = require('inherits');
var EventEmitter = require('eventemitter3');
var CHANGE_EVENT = 'change';

/**
 * @class BaseStore
 * @extends EventEmitter
 * @param dispatcher The dispatcher interface
 * @constructor
 */
function BaseStore(dispatcher) {
    this.dispatcher = dispatcher;
    this._hasChanged = false;
    EventEmitter.call(this);
    if (this.initialize) {
        this.initialize();
    }
}

inherits(BaseStore, EventEmitter);

/**
 * Convenience method for getting the store context object.
 * @method getContext
 * @return {Object} Returns the store context object.
 */
BaseStore.prototype.getContext = function getContext() {
    return this.dispatcher.getContext();
};

/**
 * Add a listener for the change event
 * @method addChangeListener
 * @param {Function} callback
 */
BaseStore.prototype.addChangeListener = function addChangeListener(callback) {
    this.on(CHANGE_EVENT, callback);
};

/**
 * Remove a listener for the change event
 * @method removeChangeListener
 * @param {Function} callback
 */
BaseStore.prototype.removeChangeListener = function removeChangeListener(
    callback,
) {
    this.removeListener(CHANGE_EVENT, callback);
};

/**
 * Determines whether the store should dehydrate or not. By default, only dehydrates
 * if the store has emitted an update event. If no update has been emitted, it is assumed
 * that the store is in its default state and therefore does not need to dehydrate.
 * @method shouldDehydrate
 * @returns {boolean}
 */
BaseStore.prototype.shouldDehydrate = function shouldDehydrate() {
    return this._hasChanged;
};

/**
 * Emit a change event
 * @method emitChange
 * @param {*} param=this
 */
BaseStore.prototype.emitChange = function emitChange(param) {
    this._hasChanged = true;
    this.emit(CHANGE_EVENT, param || this);
};

module.exports = BaseStore;