How to work with app-localstorage-document in Polymer
<p>I am trying to figure out how to set and retrieve a value in the app-localstorage-document. I worked before with the iron-meta element and did it like so:<br></p>

<pre><code>      &lt;iron-meta id="meta" key="id" value="{{meta}}"&gt;&lt;/iron-meta&gt;          

      Polymer({
         is: 'login-form',
         properties: {
           meta: {
            type: String,
            value: ''
           },
         },

         getValue: function() {
           this.meta = '100'
           var savedValue = this.$.meta.byKey('id');
           console.log(savedValue);
         }

      });
</code></pre>

<p>But when I try something similar with the app-localstorage-document it just returns:<br> Promise {[[PromiseStatus]]: "resolved", [[PromiseValue]]: undefined}<br>
I cant find any example on how to work with this element. Maybe someone can help me out here.<br></p>

<pre><code>      &lt;app-localstorage-document id="meta" key="id" data="{{meta}}" storage="window.localStorage"&gt;&lt;/app-localstorage-document&gt;

         Polymer({
          is: 'login-form',
           properties: {
             meta: {
               type: String,
               value: ''
             },
           },

           getValue: function() {
             this.$.meta.setStoredValue('id', '50');
             var savedValue = this.$.meta.getStoredValue('id');
             console.log(savedValue);
           }
         });
</code></pre>