title: How to trigger Ajax ( <iron-ajax > ) call in polymer?
body: <p>I just want to trigger the ajax inside some javascript function</p>
  
  <p>My code is here:</p>
  
  <pre><code>&lt;template is="dom-bind" id="app"&gt; 
  &lt;iron-ajax auto url="{{ path('polymer_get_file') }}" handle-as="json" last-response="{{ '{{attachmentResponse}}' }}"&gt;
  &lt;/iron-ajax&gt;
    &lt;vaadin-grid items="{{attachmentResponse.results' }}"&gt;
      &lt;table&gt;
        &lt;colgroup&gt;
          &lt;col name="index"&gt;
          &lt;col name="file"/&gt;
          &lt;col sortable name="file"/&gt;
          &lt;col name="type"/&gt; 
        &lt;/colgroup&gt; 
      &lt;/table&gt;
    &lt;/vaadin-grid&gt;&lt;/template&gt;&lt;script&gt; function onClick (){
     // Here i need to trigger iron-ajax } &lt;/script&gt;
  </code></pre>