title: Yii validation rules for an array
body: <p>Is there a way to require an array of elements in the <code>rules()</code> method of a Yii model?
  For example:</p>
  
  <pre><code>public function rules()
  {
     return array(
              array('question[0],question[1],...,question[k]','require'),
     );
  }
  </code></pre>
  
  <p>I have been running into situations where I need to validate several arrays of elements 
  coming from a form and I can't seem to find a good way of going about it other than doing the above. I have the same problem when specifying <code>attributeLables()</code>. If anyone has some advice or a better way of doing this I would really appreciate it.</p>