title: Yii - How to use scenarios to validate only visible form fields?
body: <p>I have a multi-step form that will be submitted on the final step.
  The user should be able to go back and forward as he/she pleases.
  So, I believe I have to use the same form, but visually split it, using css and js.</p>
  
  <p>Upon each "next" button click, I wish to validate the form using <em>Yii Scenarios</em> rules defined.</p>
  
  <p>I'm trying to think on an approach to trigger the validation, only on visible fields (for that single step).</p>
  
  <p>My thought:</p>
  
  <ol>
  <li>Create the model and activeform</li>
  <li>Create the <em>scenarios</em> that should be triggered based on a <em>flag</em></li>
  <li>On each "next" click, send an ajax call, that will be consumed by
  the <em>controller</em>, and than sent to the <em>model</em>, and use it as a flag to
  trigger a <em>scenario</em>.</li>
  </ol>
  
  <p>Does this makes sense? Or is there a better approach for doing this?</p>