title: Autolayouts : How to create collapse/Expand dynamic view swift 3/4
body: <p>I have a problem that I can't create a view that can collapse it's contents that may be dynamic height , i know it's easy to collapse it with height <strong>constant = 0</strong> , but i can't figure out how to make it expand again as the content of that view is dynamic and sub-itmes may be added later </p>
  
  <p>I want that behavior </p>
  
  <p><a href="https://i.stack.imgur.com/F9i8K.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/F9i8K.gif" alt="enter image description here"></a></p>