title: How to disable UIAlertController automatic closing when pressing an action button
body: <p>I have an <code>UIAlertController</code> and i'm checking for user input. When the user doesn't type in text field, the OK Action button i added  should give the user a warning and not close the alert view.</p>
  
  <p>I handle the warning but the alert view closes automatically.
  How can i disable the automatic closing?</p>
  
  <p>Thanks.</p>
  
  <p>MY CODE:</p>
  
  <pre><code>    var alert = UIAlertController(title: "change name and phone number", message: nil, preferredStyle: UIAlertControllerStyle.Alert)
      alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default,
          handler: {  action in
              //Add a comment to this line
  
              let nameField: UITextField = alert.textFields![0] as UITextField
              let phoneField: UITextField = alert.textFields![1] as UITextField
              let name = nameField.text
              let phone = phoneField.text
              if name.length == 0 {
                  JLToast.makeText("Please enter name").show()
              } else if phone.length == 0 {
                   JLToast.makeText("Please enter phone number").show()
              } else {
                  self.sendSupportInfo(nameField.text, phone: phoneField.text)
              }
              println("name:: \(nameField.text), phone: \(phoneField.text)")
      }))
      alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Default, handler: nil))
  
      alert.addTextFieldWithConfigurationHandler { (textField) -&gt; Void in
          textField.placeholder = "name"
      }
      alert.addTextFieldWithConfigurationHandler { (textField) -&gt; Void in
          textField.placeholder = "0544-444444"
          textField.keyboardType = UIKeyboardType.PhonePad
      }
      self.presentViewController(alert, animated: true, completion: nil)
  </code></pre>