title: Detect tap outside tableview cells to perform action
body: <p>I am new to iOS development, i've been following apple intro to iOS and implemented the to-do list app.</p>
  
  <p>I have tableview that shows the list of the current to-do list, and another view controller that allows the user to add a new item in a textfield then add to the list.
  I have a little + on top of my tableview that performs a segue action to the add to-do item view.</p>
  
  <p>I want to be able to perform the same action if the user taps on an empty cell
  I tried to put this code in and it works but I want to put it in the right position so it only triggers when the user hits empty space in the table:</p>
  
  <pre><code>[self performSegueWithIdentifier:@"showAddItem" sender:self];
  </code></pre>
  
  <p>Thank you.</p>
  
  <p><code>- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
  {
      static NSString *cellIdentifier = @"ListPrototypeCell";
      UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath];
      // Configure the cell...
      ABCTodoItem *toDoItem = [self.toDoItems objectAtIndex:indexPath.row];
      cell.textLabel.text = toDoItem.itemName;
      if (toDoItem.completed) {
          cell.accessoryType = UITableViewCellAccessoryCheckmark;
      }
      else
      {
          cell.accessoryType = UITableViewCellAccessoryNone;
      }
      return cell;
  }</code></p>