title: What is the best way to bypass devise authorization for a specific record marked public
body: <p>I'm using devise and cancan in a Rails 3.2 project. I have an <strong>event</strong> model with a
  boolean flag <strong>public</strong>. If the event is marked as <strong>public => true</strong> then I want anybody, signed in or not to be able to access the record with</p>
  
  <pre><code>GET /events/:id
  </code></pre>
  
  <p>If it is marked as <strong>public => false</strong> then a series of cancan abilities will decide authorization and access to the above resource.</p>
  
  <p>What is the best pattern for achieving this?</p>