title: Polymer custom element attribute access or send
body: <p>I'm searching for a way to access an attribute on a Polymer custom element from the DOM
  or to send data from Polymer.register to the DOM.</p>
  
  <p>This really simple element below takes two values and multiplies them, placing the result in its <code>result</code> attribute.</p>
  
  <p>How can I access this result from the outside?</p>
  
  <pre><code>&lt;element attributes='value times result' name='value-box'&gt;
    &lt;template&gt;
      &lt;p&gt;{{result}}&lt;/p&gt;
    &lt;/template&gt;
  
    &lt;script&gt;
      Polymer.register(this, {
        ready: function() {
          if (this.value != null &amp;&amp; this.times != null) {
            this.result = this.value * this.times;
          }
        }
      });
    &lt;/script&gt;
  &lt;/element&gt;
  </code></pre>