store.js

/*******************************************************************************
********************************************************************************
**                                                                            **
**  Copyright (c) 2012 Catch.com, Inc.                                        **
**                                                                            **
**  Licensed under the Apache License, Version 2.0 (the "License");           **
**  you may not use this file except in compliance with the License.          **
**  You may obtain a copy of the License at                                   **
**                                                                            **
**      http://www.apache.org/licenses/LICENSE-2.0                            **
**                                                                            **
**  Unless required by applicable law or agreed to in writing, software       **
**  distributed under the License is distributed on an "AS IS" BASIS,         **
**  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  **
**  See the License for the specific language governing permissions and       **
**  limitations under the License.                                            **
**                                                                            **
********************************************************************************
*******************************************************************************/

goog.provide('mvc.Store');

goog.require('goog.events');
goog.require('goog.object');
goog.require('mvc.Model');



/**
 * @constructor
 * @param {function(new:mvc.Model)=} opt_defaultModel type to return if
 * a model is not found in get.
 */
mvc.Store = function(opt_defaultModel) {
  this.cache_ = {};
  this.default_ = opt_defaultModel || mvc.Model;
};


/**
 * takes two arguments. The model's id (or leave out to create a new model)
 * and the type of model to create if none found in cache
 *
 * @param {string=} opt_input the model's id.
 * @param {function(new:mvc.Model)=} opt_model type of model to create.
 * @return {mvc.Model} model from the store or new model.
 */
mvc.Store.prototype.get = function(opt_input, opt_model) {
  if (this.cache_[opt_input])
    return this.cache_[opt_input];
  var modelConstructor = opt_model || this.default_;
  var model = new modelConstructor();
  if (opt_input)
    model.set('id', opt_input, true);
  this.cache_[opt_input || model.cid_] = model;
  var list = goog.events.listen(model, goog.events.EventType.CHANGE,
      function() {
        var id = model.get('id');
        if (id) {
          this.cache_[id] = model;
          delete this.cache_[model.cid_];
          goog.events.unlistenByKey(list);
        }
      }, false, this);
  return model;
};


/**
 * this is used to setup the store from cache
 *
 * @param {mvc.Model|Array.<mvc.Model>} models to set in store.
 */
mvc.Store.prototype.set = function(models) {
  if (!goog.isArrayLike(models)) {
    models = [models];
  }
  goog.array.forEach(/** @type {Array} */(models), function(model) {
    this.cache_[model.get('id') || model.getCid()] = model;
  }, this);
};