在Polymer中使用会话存储web中的数据

好吧，我想我明白了。

在就绪函数中，调用存储会话存储的函数：

ready: function(){
    this.setData();
    this.myUser = this.storageUser();
  },
setData: function() {
    sessionStorage.setItem("userData",userData);
  },

然后将会话存储在本地进行对象解析：

storageUser: function(){
    var userData = sessionStorage.getItem("userData");
    var myObject = JSON.parse(userData);
    var userName = [myObject.name + " " + myObject.surname];
    return userName;
  },

这是有原则的。

我知道这是一篇旧帖子，但对于登录此页面的新人来说，这个session storage元素可能会有所帮助。它的行为与local storage完全相同。

    <!--
@license
Copyright (c) 2015 The PlatinumIndustries.pl. All rights reserved.
This code may only be used under the BSD style license.
-->
<link rel="import" href="../polymer/polymer.html">
<!--
Element access to Web Storage API (window.sessionStorage).
Keeps `value` property in sync with sessionStorage.
Value is saved as json by default.
### Usage:
`Ss-sample` will automatically save changes to its value.
    <dom-module id="ls-sample">
      <iron-sessionstorage name="my-app-storage"
        value="{{cartoon}}"
        on-iron-sessionstorage-load-empty="initializeDefaultCartoon"
      ></iron-sessionstorage>
    </dom-module>
    <script>
      Polymer({
        is: 'ls-sample',
        properties: {
          cartoon: {
            type: Object
          }
        },
        // initializes default if nothing has been stored
        initializeDefaultCartoon: function() {
          this.cartoon = {
            name: "Mickey",
            hasEars: true
          }
        },
        // use path set api to propagate changes to sessionstorage
        makeModifications: function() {
          this.set('cartoon.name', "Minions");
          this.set('cartoon.hasEars', false);
        }
      });
    </script>
### Tech notes:
* * `value.*` is observed, and saved on modifications. You must use
    path change notifification methods such as `set()` to modify value
    for changes to be observed.
* * Set `auto-save-disabled` to prevent automatic saving.
* * Value is saved as JSON by default.
* * To delete a key, set value to null
* Element listens to StorageAPI `storage` event, and will reload upon receiving it.
* **Warning**: do not bind value to sub-properties until Polymer
[bug 1550](https://github.com/Polymer/polymer/issues/1550)
is resolved. session storage will be blown away.
`<iron-sessionstorage value="{{foo.bar}}"` will cause **data loss**.
@demo demo/index.html
@hero hero.svg
-->
<dom-module id="iron-sessionstorage"></dom-module>
<script>
  Polymer({
    is: 'iron-sessionstorage',
    properties: {
      /**
       * SessionStorage item key
       */
      name: {
        type: String,
        value: ''
      },
      /**
       * The data associated with this storage.
       * If set to null item will be deleted.
       * @type {*}
       */
      value: {
        type: Object,
        notify: true
      },
      /**
       * If true: do not convert value to JSON on save/load
       */
      useRaw: {
        type: Boolean,
        value: false
      },
      /**
       * Value will not be saved automatically if true. You'll have to do it manually with `save()`
       */
      autoSaveDisabled: {
        type: Boolean,
        value: false
      },
      /**
       * Last error encountered while saving/loading items
       */
      errorMessage: {
        type: String,
        notify: true
      },
      /** True if value has been loaded */
      _loaded: {
        type: Boolean,
        value: false
      }
    },
    observers: [
      '_debounceReload(name,useRaw)',
      '_trySaveValue(autoSaveDisabled)',
      '_trySaveValue(value.*)'
    ],
    ready: function() {
      this._boundHandleStorage = this._handleStorage.bind(this);
    },
    attached: function() {
      window.addEventListener('storage', this._boundHandleStorage);
    },
    detached: function() {
      window.removeEventListener('storage', this._boundHandleStorage);
    },
    _handleStorage: function(ev) {
      if (ev.key == this.name) {
        this._load(true);
      }
    },
    _trySaveValue: function() {
      if (this._doNotSave) {
        return;
      }
      if (this._loaded && !this.autoSaveDisabled) {
        this.debounce('save', this.save);
      }
    },
    _debounceReload: function() {
      this.debounce('reload', this.reload);
    },
    /**
     * Loads the value again. Use if you modify
     * sessionStorage using DOM calls, and want to
     * keep this element in sync.
     */
    reload: function() {
      this._loaded = false;
      this._load();
    },
    /**
     * loads value from session storage
     * @param {boolean=} externalChange true if loading changes from a different window
     */
    _load: function(externalChange) {
      var v = window.sessionStorage.getItem(this.name);
      if (v === null) {
        this._loaded = true;
        this._doNotSave = true;  // guard for save watchers
        this.value = null;
        this._doNotSave = false;
        this.fire('iron-sessionstorage-load-empty', { externalChange: externalChange});
      } else {
        if (!this.useRaw) {
          try { // parse value as JSON
            v = JSON.parse(v);
          } catch(x) {
            this.errorMessage = "Could not parse session storage value";
            console.error("could not parse sessionstorage value", v);
            v = null;
          }
        }
        this._loaded = true;
        this._doNotSave = true;
        this.value = v;
        this._doNotSave = false;
        this.fire('iron-sessionstorage-load', { externalChange: externalChange});
      }
    },
    /**
     * Saves the value to localStorage. Call to save if autoSaveDisabled is set.
     * If `value` is null or undefined, deletes localStorage.
     */
    save: function() {
      var v = this.useRaw ? this.value : JSON.stringify(this.value);
      try {
        if (this.value === null || this.value === undefined) {
          window.sessionStorage.removeItem(this.name);
        } else {
          window.sessionStorage.setItem(this.name, /** @type {string} */ (v));
        }
      }
      catch(ex) {
        // Happens in Safari incognito mode,
        this.errorMessage = ex.message;
        console.error("sessionStorage could not be saved. Safari incoginito mode?", ex);
      }
    }
    /**
     * Fired when value loads from localStorage.
     *
     * @event iron-localstorage-load
     * @param {{externalChange:boolean}} detail -
     *     externalChange: true if change occured in different window.
     */
    /**
     * Fired when loaded value does not exist.
     * Event handler can be used to initialize default value.
     *
     * @event iron-localstorage-load-empty
     * @param {{externalChange:boolean}} detail -
     *     externalChange: true if change occured in different window.
     */
  });
</script>