public async Task <IActionResult> AddProducts(Activity activity, IEnumerable <Product> products)
{
var productIds = from p in products where p != null select p.Id;
if (products.Count() == 0)
{
return(RedirectToAction(nameof(ActivityController.Products), new { Id = activity.Id }));
}
await _activityService.AddProductsAsync(activity.Id, productIds, User.GetUsername());
return(RedirectToAction(nameof(ActivityController.Products), new { Id = activity.Id }));
}