Function storageInitialize

history.js:521–561

* Initializing storage for the custom state's object

()

   * Initializing storage for the custom state's object
   */
  function storageInitialize() {
    var sessionStorage;
    /**
     * sessionStorage throws error when cookies are disabled
     * Chrome content settings when running the site in a Facebook IFrame.
     * see: https://github.com/devote/HTML5-History-API/issues/34
     * and: http://stackoverflow.com/a/12976988/669360
     */
    try {
      sessionStorage = global['sessionStorage'];
      sessionStorage.setItem(sessionStorageKey + 't', '1');
      sessionStorage.removeItem(sessionStorageKey + 't');
    } catch(_e_) {
      sessionStorage = {
        getItem: function(key) {
          var cookie = document.cookie.split(key + "=");
          return cookie.length > 1 && cookie.pop().split(";").shift() || 'null';
        },
        setItem: function(key, value) {
          var state = {};
          // insert one current element to cookie
          if (state[windowLocation.href] = historyObject.state) {
            document.cookie = key + '=' + JSON.stringify(state);
          }
        }
      }
    }

    try {
      // get cache from the storage in browser
      stateStorage = JSON.parse(sessionStorage.getItem(sessionStorageKey)) || {};
    } catch(_e_) {
      stateStorage = {};
    }

    // hang up the event handler to event unload page
    addEvent(eventNamePrefix + 'unload', function() {
      // save current state's object
      sessionStorage.setItem(sessionStorageKey, JSON.stringify(stateStorage));
    }, false);
  }

  /**
   * This method is implemented to override the built-in(native)