public IActionResult Add3DPen(ThreeDPenBindingModel threeDPenModel)
        {
            if (!ModelState.IsValid)
            {
                return(View(threeDPenModel));
            }

            this.threeDPens.Create(
                threeDPenModel.Make,
                threeDPenModel.Price,
                threeDPenModel.Description,
                threeDPenModel.ImageUrl,
                this.userManager.GetUserId(User));

            return(RedirectToAction("All3DPens"));
        }
        public IActionResult Edit3DPen(int id, ThreeDPenBindingModel threeDPenModel)
        {
            if (!ModelState.IsValid)
            {
                return(View(threeDPenModel));
            }

            var threeDPenExists = this.threeDPens.Exists(id);

            if (!threeDPenExists)
            {
                return(NotFound());
            }

            this.threeDPens.EditPen(
                id,
                threeDPenModel.Make,
                threeDPenModel.Price,
                threeDPenModel.Description,
                threeDPenModel.ImageUrl);

            return(RedirectToAction("All3DPens"));
        }