PersistentObject = Ember.Object + HTML5 Local Storage

persistentObject.js

(function (App) {
    "use strict";

    App.reopen({
        PersistentObject: Ember.Object.extend({
            _impl: null,

            // https://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Storage
            implementationDummy: {
                getItem: function (sKey) {
                    if (!sKey || !this.hasOwnProperty(sKey)) { return null; }
                    return unescape(document.cookie.replace(new RegExp("(?:^|.*;\\s*)" + escape(sKey).replace(/[\-\.\+\*]/g, "\\$&") + "\\s*\\=\\s*((?:[^;](?!;))*[^;]?).*"), "$1"));
                },

                key: function (nKeyId) {
                    return unescape(document.cookie.replace(/\s*\=(?:.(?!;))*$/, "").split(/\s*\=(?:[^;](?!;))*[^;]?;\s*/)[nKeyId]);
                },
                
                setItem: function (sKey, sValue) {
                    if (!sKey) { return; }
                    document.cookie = escape(sKey) + "=" + escape(sValue) + "; expires=Tue, 19 Jan 2038 03:14:07 GMT; path=/";
                    this.length = document.cookie.match(/\=/g).length;
                },
                
                length: document.cookie.match(/\=/g).length,
                
                removeItem: function (sKey) {
                    if (!sKey || !this.hasOwnProperty(sKey)) { return; }
                    document.cookie = escape(sKey) + "=; expires=Thu, 01 Jan 1970 00:00:00 GMT; path=/";
                    this.length--;
                },
                
                hasOwnProperty: function (sKey) {
                    return (new RegExp("(?:^|;\\s*)" + escape(sKey).replace(/[\-\.\+\*]/g, "\\$&") + "\\s*\\=")).test(document.cookie);
                }
            },

            implementationReal: {
                getItem: function (key) {
                    return localStorage.getItem(key);
                },

                setItem: function (key, value) {
                    return localStorage.setItem(key, value);
                },

                removeItem: function (key) {
                    return localStorage.removeItem(key);
                }
            },

            initialize: function () {
                if (Modernizr.localstorage) {
                    this._impl = this.implementationReal;
                } else {
                    this._impl = this.implementationDumy;
                }
            },

            get: function (key) {
                if (!this._impl) {
                    this.initialize();
                }

                return JSON.parse(this._impl.getItem(key));
            },

            set: function (key, value) {
                if (!this._impl) {
                    this.initialize();
                }

                return this._impl.setItem(key, JSON.stringify(value));
            },

            remove: function (key) {
                if (!this._impl) {
                    this.initialize();
                }

                return this._impl.removeItem(key);
            }
        }),
    });

    // If you want access one persistent configuration via followin API:
    // App.get('storage').get('key');
    // App.get('storage').set('key', 'value');
    // App.get('storage').remove('key');

    App.reopen({
        storage: App.PersistentObject.create({})
    });

})(window.App);