title: Angular2 retrieve all elements with class name
body: <p>Can anyone help with how to find 'All' Elements with a particular class name in Angular 2?  I thought it would be trivial but it's giving me more problems that was prepared for. </p>
  
  <pre><code>&lt;span class="classImLookingFor"&gt;foo&lt;/span&gt;
  &lt;span class="classImLookingFor"&gt;Voo&lt;/span&gt;
  &lt;span class="classImLookingFor"&gt;Moo&lt;/span&gt;
  </code></pre>
  
  <p>I thought by doing what I have below would return all the elements with class "classImLookingFor" but it only returns the first instance.  </p>
  
  <pre><code>constructor(private renderer: Renderer){}
  ngAfterViewInit(){
   const el = this.renderer.selectRootElement('.classImLookingFor');
   this.renderer.setElementAttribute(el, 'tabindex', 0);
  }
  </code></pre>
  
  <p>Afterwards, my markup looks like this.</p>
  
  <pre><code>&lt;span class="classImLookingFor" tabindex="0"&gt;foo&lt;/span&gt;
  &lt;span class="classImLookingFor"&gt;Voo&lt;/span&gt;
  &lt;span class="classImLookingFor"&gt;Moo&lt;/span&gt;
  </code></pre>
  
  <p>It seems like I should be able to create a Renderer array, but that doesn't seem to work either. I need to manipulate each element with that class name.   Thanks in Advance</p>