Backbone model using localstorage as an auxiliary storage mechanism (giving you session-esque properties in the frontend). Uses Require.js, just strip if back if you don't use it. Recommendation is to call loadFromStorage() in initialize() method and call saveToStorage() when the model changes.

localStorage.js

define(['backbone'],
  function(Backbone) {
  	return Backbone.Model.extend({
 
			_storage: localStorage || {setItem: function() {}, getItem: function() {return {};}},
 
			saveToStorage: function() {
				this._storage.setItem(this._getKey(), JSON.stringify(this.toJSON()));
			},
 
			loadFromStorage: function() {
				var value = this._storage.getItem(this._getKey());
				return value && JSON.parse(value);
			},
			_getKey: function() {
				if (!this._storageKey) {
					throw new Error("Key not defined for local storage model.");
				}
				return this._storageKey;
			}
 
	});
});