title: Recursive polymer elements
body: <p>I have a nested array of javascript objects like this:</p>
  
  <pre><code>[
      {id: 1, title: 'hello', parent: 0, children: [
          {id: 3, title: 'hello', parent: 1, children: [
              {id: 4, title: 'hello', parent: 3, children: [
                  {id: 5, title: 'hello', parent: 4},
                  {id: 6, title: 'hello', parent: 4}
              ]},
              {id: 7, title: 'hello', parent: 3}
          ]}
      ]},
      {id: 2, title: 'hello', parent: 0, children: [
          {id: 8, title: 'hello', parent: 2}
      ]}
  ]
  </code></pre>
  
  <p>I'm trying to figure out how to define the template section of a polymer element that will render a nested list like this where you don't know how deep the recursion might go. How could I, for example, render this recursive object as follows using polymer expressions in a template?</p>
  
  <pre><code>&lt;ul&gt;
    &lt;li&gt;hello (1)
      &lt;ul&gt;
        &lt;li&gt;hello (3)
          &lt;ul&gt;
            &lt;li&gt;hello (4)
              &lt;ul&gt;
                &lt;li&gt;hello (5)&lt;/li&gt;
                &lt;li&gt;hello (6)&lt;/li&gt;
              &lt;/ul&gt;
            &lt;/li&gt;
            &lt;li&gt;hello (7)&lt;/li&gt;
          &lt;/ul&gt;
        &lt;/li&gt;
      &lt;/ul&gt;
    &lt;/li&gt;
    &lt;li&gt;hello (2)
      &lt;ul&gt;
        &lt;li&gt;hello (8)&lt;/li&gt;
      &lt;/ul&gt;
    &lt;/li&gt;
  &lt;/ul&gt;
  </code></pre>