title: UICollectionView Approach for having expandable comments/replies
body: <p>I have a collectionView as the following :</p>
  
  <p><a href="https://i.stack.imgur.com/pS5Hw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pS5Hw.png" alt=""></a></p>
  
  <p><code>UICollectionView</code> with multiple sections, section 2 is comments and it has rows of each comment,
  now I want when i press a comment it displays its replies.. <strong>and hide ALL other opened replies</strong></p>
  
  <ul>
  <li>I tried appending replies in collectionView array ( Appending below the actual comment index )</li>
  </ul>
  
  <p>I'm good until i want to collapse the replies again ? I did the following :</p>
  
  <ul>
  <li>I saved the original array without appended replies and reused it for everytime i append replies, so it basically adds replies to a clean array</li>
  </ul>
  
  <p>but the issue here with identifying where to append replies (which index) because the index is returned wrong after the append of first replies</p>
  
  <p>TL;DR what's the best approach for doing this in UICollectionView using objective c?</p>