title: Local notifications repeat interval using calendar triggers
body: <p>I'm setting up some local notifications as reminders.
  So far I've been able to set a non repeating notification which triggers from a date picked from a datePicker.</p>
  
  <pre><code>let dateformatter = DateFormatter()
      dateformatter.dateStyle = DateFormatter.Style.medium
      dateformatter.timeStyle = DateFormatter.Style.short
      let dateFromString = dateformatter.date(from: selectDateTextField.text!)
      let fireDateOfNotification: Date = dateFromString!
  
      //if permission allowed
      let content = UNMutableNotificationContent()
      content.title = notifTitleTextField.text!
      content.body = notifNoteTextView.text
      content.sound = UNNotificationSound.default()
  
      let triggerDate = Calendar.current.dateComponents([.year,.month,.day,.hour,.minute,.second,], from: fireDateOfNotification)
      let trigger = UNCalendarNotificationTrigger(dateMatching: triggerDate,
                                                  repeats: false)
      //Schedule the Notification
      let titleNospace = notifTitleTextField.text?.replacingOccurrences(of: " ", with: "")
      let identifier = titleNospace
      let request = UNNotificationRequest(identifier: identifier!, content: content, trigger: trigger)
      self.center.add(request, withCompletionHandler: { (error) in
          if let error = error {
              print(error.localizedDescription)
          }
      })
  </code></pre>
  
  <p>Now i would like the user to pick from a list (or a Picker) the repeating interval (hourly, daily, weekly, monthly, yearly or every x days).
  Is there a simple way to do so or i need to create a custom class?
  is it correct to make it through a series of if else statement? (it seems to me a bit off, doesn't really seems to be the correct way)
  Thanks.</p>