title: Recipes for changing the Fetch Request for NSFetchedResultsController and reloading table data
body: <p>From apple doc <a href="http://developer.apple.com/library/ios/#documentation/CoreData/Reference/NSFetchedResultsController_Class/Reference/Reference.html" rel="nofollow noreferrer">Modifying the Fetch Request</a> I see that is possible to change the <code>NSFetchRequest</code> for <code>NSFetchedResultsController</code>. Steps are easy to set up.</p>
  
  <p>After invoking <code>performFetch:</code> I think there is the need to call <code>reloadData</code> on the the table view. How to perform such call?</p>
  
  <p>Reading some stackoverflow topics, I've seen that calling that method should work in most cases. But is there a right way to do it?</p>
  
  <p>In <a href="https://stackoverflow.com/questions/3494095/how-to-switch-uitableviews-nsfetchedresultscontroller-or-its-predicate-progra">How to switch UITableView's NSFetchedResultsController (or its predicate) programmatically?</a>, <strong>TechZen</strong> wrote that:</p>
  
  <blockquote>
    <p>Just make sure to send the tableview itself a beginUpdates before you
    swap controllers and then an endUpdates when you are done. This
    prevents the table from asking for data in the narrow window when the
    FRC are being swapped out. Then call reloadData.</p>
  </blockquote>
  
  <p>Could you explain exactly what does it mean?</p>