localStorage polyfill

localStorage-polyfill.js

// Polyfill localStorage for older browsers
(function () {
  'use strict';
  if (!window.localStorage) {
    window.localStorage = {
      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: 0,
      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);
      }
    };
    window.localStorage.length = (document.cookie.match(/\=/g) || window.localStorage).length;
  }
}());