title: Get DOM element from FormControl, Angular 2
body: <p>My custom form validator gets FormControl argumet and I want to get access to native DOM element. How can I get DOM element using FormControl object?</p>
  
  <pre><code>fileValidator(control: FormControl):{[key: string]: boolean}{
  ...
  }
  </code></pre>
  
  <p>I need property files from input type="file" element.</p>