title: Zend Custom ViewScript for Form not rendering file element
body: <p>I created a custom viewscript for a zend form. In the form, there is a file element. When I run the code <code>echo $this-&gt;element-&gt;elementname-&gt;renderViewHelper()</code> it works fine on all elements except the file element. When I run the following code on my file element within my custom viewscript, i get the following error: <code>Uncaught exception 'Zend_Form_Element_Exception' with message 'Decorator by name ViewHelper does not exist'</code></p>
  
  <pre><code>&lt;?php if($this-&gt;element-&gt;avatarimage-&gt;hasErrors()):?&gt;
          &lt;div class="control-group error"&gt;
      &lt;?php else: ?&gt;
          &lt;div class="control-group"&gt;
      &lt;?php endif;?&gt;
          &lt;label for="avatarimage" class="control-label"&gt;Avatar Image&lt;/label&gt;
          &lt;div class="controls"&gt;
              &lt;?php echo $this-&gt;element-&gt;avatarimage-&gt;renderViewHelper();?&gt;
              &lt;?php if($this-&gt;element-&gt;avatarimage-&gt;hasErrors()):
                      $messages = $this-&gt;element-&gt;avatarimage-&gt;getMessages();
                      $messages = array_values($messages);
                      $message  = $messages[0];
                      echo '&lt;span class="help-inline"&gt;'.$message.'&lt;/span&gt;';
                  endif;
              ?&gt;              
          &lt;/div&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>How can I incorporate my file element into my custom form viewscript?</p>