title: Handling deleted id in Firebase
body: <p>I'm building an app with a social network component using Firebase, currently if a user likes a post I create a node in the user document called <code>likes</code> and I add the post id, example: </p>
  
  <pre><code>users: {
      k9EdVpyRJ2R2: {
          likes: {
              E36F50C: true
          }
      }
  }
  </code></pre>
  
  <p>I'm wondering if the post gets deleted should I just handle the deleted post-id on client side when I get the likes ids? or is there a better way to trim the data (or even restructuring it since the app is not live yet)</p>