// Example URI for DELETE: todos/1
        public async Task <IActionResult> Index(int pId)
        {
            var lIndexCardBox = _context.IndexCardBoxes.Single(x => x.Id == pId);

            if (lIndexCardBox == null)
            {
                return(NotFound()); // returns an 404 page not found
            }

            IUser lUser = base.GetCurrentUser(_context);

            // check if box belongs to authenticated user
            if (IndexCardBox.UserIsOwnerOfIndexCardBox(pId, lUser, _context) == false)
            {
                return(Forbid());
            }

            // delete all index cards and uploads
            // loop all indexcards
            var lIndexCards       = _context.IndexCards.Select(x => x).Where(x => x.IndexCardBoxId == pId);
            var lIndexCardsAsList = lIndexCards.ToList <IIndexCard>();

            foreach (IIndexCard lIndexCard in lIndexCardsAsList)
            {
                // removed dependen uploaded files
                IndexCard.RemoveAllUploadedFiles(lIndexCard, _env.WebRootPath);
            }

            // remove all indexcards
            _context.IndexCards.RemoveRange(lIndexCards);
            _context.SaveChanges();

            // remove box
            _context.IndexCardBoxes.Remove(lIndexCardBox);
            _context.SaveChanges();

            return(Json(lIndexCardBox));
        }
        // Example URI for DELETE: todos/1
        public IActionResult Index(int pId)
        {
            var lIndexCard = _context.IndexCards.Single(x => x.Id == pId);

            if (lIndexCard == null)
            {
                return(NotFound()); // returns an 404 page not found
            }

            // checkk if index card belongs to user
            if (UserIsOwnerOfIndexCard(lIndexCard) == false)
            {
                return(Forbid());
            }

            // remove uploaded files
            IndexCard.RemoveAllUploadedFiles(lIndexCard, _env.WebRootPath);

            _context.Remove(lIndexCard);
            _context.SaveChanges();

            return(Json(lIndexCard));
        }