title: TabBar app - load data before showing view
body: <p>I am making an app based on tabBar menu at the bottom. The initial view is a simple view with button, textfields, labels and so forth.
  The second tab/view is a tableView where the data for the cells are retrieve from a server in appDelegate when app starts. But if the user presses the second tab before the data is downloaded, well then then tableView is empty. </p>
  
  <p>How can i ensure that the user can not press the second tab before the data for tableView has been downloaded?
  Or must I show a temporary view with a spinner or something like that?</p>
  
  <p>Please note that I am using storyboards.</p>