/**
 * The LocalStorageProxy uses the new HTML5 localStorage API to save {@link Ext.data.Model Model}
 * data locally on the client browser. HTML5 localStorage is a key-value store (e.g. cannot save
 * complex objects like JSON), so LocalStorageProxy automatically serializes and deserializes data
 * when saving and retrieving it.
 *
 * localStorage is extremely useful for saving user-specific information without needing to build
 * server-side infrastructure to support it. Let's imagine we're writing a Twitter search
 * application and want to save the user's searches locally so they can easily perform a saved
 * search again later. We'd start by creating a Search model:
 *
 *     Ext.define('Search', {
 *         fields: ['id', 'query'],
 *         extend: 'Ext.data.Model',
 *         proxy: {
 *             type: 'localstorage',
 *             id: 'twitter-Searches'
 *         }
 *     });
 *
 * Our Search model contains just two fields - id and query - plus a Proxy definition. The only
 * configuration we need to pass to the LocalStorage proxy is an {@link #id}. This is important
 * as it separates the Model data in this Proxy from all others. The localStorage API puts all data
 * into a single shared namespace, so by setting an id we enable LocalStorageProxy to manage
 * the saved Search data.
 *
 * Saving our data into localStorage is easy and would usually be done with a
 * {@link Ext.data.Store Store}:
 *
 *     // our Store automatically picks up the LocalStorageProxy defined on the Search model
 *     var store = Ext.create('Ext.data.Store', {
 *         model: "Search"
 *     });
 *
 *     // loads any existing Search data from localStorage
 *     store.load();
 *
 *     // now add some Searches
 *     store.add({ query: 'Sencha Touch' });
 *     store.add({ query: 'Ext JS' });
 *
 *     // finally, save our Search data to localStorage
 *     store.sync();
 *
 * The LocalStorageProxy automatically gives our new Searches an id when we call store.sync().
 * It encodes the Model data and places it into localStorage. We can also save directly
 * to localStorage, bypassing the Store altogether:
 *
 *     var search = Ext.create('Search', { query: 'Sencha Animator' });
 *
 *     // uses the configured LocalStorageProxy to save the new Search to localStorage
 *     search.save();
 *
 * # Limitations
 *
 * If this proxy is used in a browser where local storage is not supported, the constructor
 * will throw an error. A local storage proxy requires a unique ID which is used as a key in which
 * all record data are stored in the local storage object.
 *
 * It's important to supply this unique ID as it cannot be reliably determined otherwise. If no id
 * is provided but the attached store has a storeId, the storeId will be used. If neither option
 * is presented the proxy will throw an error.
 */
Ext.define('Ext.data.proxy.LocalStorage', {
    extend: 'Ext.data.proxy.WebStorage',
    alias: 'proxy.localstorage',
    alternateClassName: 'Ext.data.LocalStorageProxy',

    getStorageObject: function() {
        return window.localStorage;
    }
});