title: web MVC - how to report back model's processing result
body: <p>Everyone understands mvc as he wills, but sometimes I do not, at all.<br>
  Currently the majority of my controllers look like this:</p>
  
  <pre><code>&lt;?php
  $input = $_REQUEST['field']
  $model = new Model();
  $status = $model-&gt;launchSpaceShuttle($input);
  
  switch($status)
  {
      case Model::STATUS_LAUNCHED:
          header('Location: Mars');
          break;
  
      case Model::STATUS_INVALID_INPUT:
          echo "Please press the big red button correctly";
          break;
  
      case Model::STATUS_PILOT_IN_HANGOVER:
          ...
          ...
      case etc.
  }
  </code></pre>
  
  <p>This leads to the obvious question:<br>
  Is this how it's supposed to be? Model's returning status codes and controllers deciding how to display and what?<br>
  Because this very much conflicts with the theory about simple, short controllers that act as a really thin wrapper between the input device and the model.</p>
  
  <p><em>bonus case</em>: what about ajax requests if I'm too lazy to create a view ;</p>