title: loading image asynchronously in viewDidLoad, with activity indicator
body: <p>When i'm switching from a view (by clicking on a cell in a table) to a view that displays some images, i'm loading a couple of images from a couple of urls.</p>
  
  <p>I want to display an activity indicator animation while the loading occurs. </p>
  
  <p>I'm doing this loading in viewDidLoad of the new view.</p>
  
  <p>If i'm loading the images synchronously, then (not surprisingly) the animation doesn't work since the request is blocking...
  If i'm loading the images asynchronously, then (also not surprisingly) the view is opened with blanks instead of images, without waiting for the images to be fetched, which i don't want.</p>
  
  <p>I tried to put all that in the segue code that transforms from the old view to the new one, because i hoped that the view will be switched only after the loading will complete but it didn't matter.</p>
  
  <p><strong>How can I enjoy both worlds?</strong> how can i not block the app, display the animation, but transition to the next view only when all the images have been loaded?</p>