public async Task <IActionResult> AddItem(TodoItem newItem) { if (!ModelState.IsValid) { return(RedirectToAction("Index")); } var currentUser = await _userManager.GetUserAsync(User); if (currentUser == null) { return(Challenge()); } var successful = await _todoItemService .AddItemAsync(newItem, currentUser); if (!successful) { return(BadRequest("Could not add item.")); } return(RedirectToAction("Index")); }