How to use a element function in template polymer?
<p>I want to use a function defined in the element. Like this:</p>

<pre><code>&lt;template&gt;
&lt;span onclick="this.parentElement.test();"&gt;&lt;/span&gt;
&lt;/template&gt;

&lt;script&gt;
Polymer({
  is: 'test-ele',
  test: function() {
    console.log('This is a test message.')
  }
})
&lt;/script&gt;
</code></pre>

<p>Is there a similar approach?</p>

<pre><code>&lt;template&gt;
&lt;span onclick="{{{test}}}"&gt;&lt;/span&gt;
&lt;/template&gt;
</code></pre>