public IActionResult Create()
        {
            CreateClassRoomViewModel model = new CreateClassRoomViewModel
            {
                Categories = this.categoriesService.GetAllAsSelectList(),
                Stages     = this.stagesService.GetAllAsSelectList(),
            };

            return(this.View(model));
        }
        public async Task <IActionResult> Create(CreateClassRoomViewModel inputModel)
        {
            if (!this.ModelState.IsValid)
            {
                inputModel.Categories = this.categoriesService.GetAllAsSelectList();
                inputModel.Stages     = this.stagesService.GetAllAsSelectList();
                return(this.View(inputModel));
            }

            string userId = this.User.FindFirst(ClaimTypes.NameIdentifier).Value;

            await this.roomsService.CreateClassRoomAsync(userId, inputModel.StageId, inputModel.CategoryId);

            return(this.Redirect("/ClassRooms/Index"));
        }