title: iOS UiCollectionView - reloadData using custom UiCollectionViewLayout
body: <p>I'm trying to use a custom UiCollectionViewLayout but I have a little problem. 
  In my project I want to load some JSON information and present it in a UICollectionView. I need to load the information from WEB and then (when everything is loaded) I need to reload my Collection View.
  If I use the <code>UICollectionViewFlowLayout</code> everything works great. However, when I try to use my own layout, the <code>reloadData</code> doesn't work properly and nothing happens.</p>
  
  <p>I'm reloading the data with an async task:</p>
  
  <pre><code>dispatch_async(dispatch_get_main_queue(), ^{ 
  
              [self.newsCollectionView reloadData];
  
          });
  </code></pre>
  
  <p>Thanks</p>