title: How can I dynamically hide a button from a view?
body: <p>I would like to dynamically hide a button in one of my views depending on a certain condition.</p>
  
  <p>I tried adding some code to the view controller's <code>-viewWillAppear</code> method, to make the button hidden before displaying the actual view, but I still don't know how to do that.</p>
  
  <p>I have a reference to the button through an IBOutlet, but I'm not sure how to move forward from here. For reference, this is a UIBarButtonItem instance.</p>