Storage polyfill

storage.js

(function (window) {
	'use strict';

	if (window.localStorage && window.sessionStorage) {
		return;
	}

	// initialize if data already stored
	var data = JSON.parse(window.name || '{}');

	var setData = function() {
		window.name = JSON.stringify(data);
	};

	var Storage = function(type) {

		return {
			length: 0,
			clear: function() {
				for (var k in data) {
					// remove all keys with prefix
					if (k && k.indexOf(type) === 0) {
						delete data[type+k];
						this.length--;
					}
				}
				setData();
			},
			getItem: function(key) {
				return (type+key in data) ? data[type+key] : null;
			},
			key: function(i) {
				// not perfect, but works
				var ctr = 0;
				for (var k in data) {
					if (k && (k.indexOf(type) === 0) && (ctr++ === i)) {
						return k.substr(type.length);
					}
				}
				return null;
			},
			removeItem: function(key) {
				if (type+key in data) {
					delete data[type+key];
					this.length--;
					setData();
				}
			},
			setItem: function(key, value) {
				if (!(type+key in data)) {
					this.length++;
				}
				data[type+key] = ''+value; // force the value to a string
				setData();
			}
		};
	};

	// NOTE: local storage is stored with session but better than filling cookies
	if (!window.localStorage) { window.localStorage = new Storage('L$'); }
	if (!window.sessionStorage) { window.sessionStorage = new Storage('S$'); }

})(window);

storage.min.js

(function(b){if(!b.localStorage||!b.sessionStorage){var c=JSON.parse(b.name||"{}"),f=function(){b.name=JSON.stringify(c)},g=function(d){return{length:0,clear:function(){for(var a in c)a&&0===a.indexOf(d)&&(delete c[d+a],this.length--);f()},getItem:function(a){return d+a in c?c[d+a]:null},key:function(a){var b=0,e;for(e in c)if(e&&0===e.indexOf(d)&&b++===a)return e.substr(d.length);return null},removeItem:function(a){d+a in c&&(delete c[d+a],this.length--,f())},setItem:function(a,b){d+a in c||this.length++;
c[d+a]=""+b;f()}}};if(!b.localStorage)b.localStorage=new g("L$");if(!b.sessionStorage)b.sessionStorage=new g("S$")}})(window);