title: How to use validators in InputFilter on array from post?
body: <p>I have a form with an input type='text' name='article[]' .
  I don't know the number of article that can be post because there is a little javascript button where I can add as much I want <i>input name=article[]</i>. </p>
  
  <p>For now, I use Zend\InputFilter\InputFilter but the validators never get the value on the array in my $_POST. </p>
  
  <pre><code>My input : 
  &lt;input name="article[]" class="form-control input-md" type="text" &gt;         
  
  
  My InputFilter :
  class ArticleFormFilter extends InputFilter{
      public function __construct()    {
  
      $this-&gt;add(array(
              'name'       =&gt; 'article[]',
              'required'   =&gt; true,
              'filters' =&gt; array(
                  array(
                      'name'    =&gt; 'Zend\Filter\StripTags',
                  ),
                  array(
                      'name'    =&gt; 'Zend\Filter\StringTrim',
                  ),
              ),
              'validators' =&gt; array(
                  array(
                      'name' =&gt; 'NotEmpty',                       
                  ),
              ),            
          ));
      }
  }
  </code></pre>
  
  <p>If I do it with only one article, using article instead of article[] and no Javascript, it works of course. </p>