    /**
     * @author Ed Spencer
     *
     * 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',

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