OCC-178: User-friendly error if cookies can't be written and thus the shopping cart can't be managed (#333)

* Adding user-friendly error if cookies can't be written

* Updating error message

Author: DemeSzabolcs

src/Modules/OrchardCore.Commerce/Controllers/ShoppingCartController.cs

@@ -1,5 +1,7 @@
 using Lombiq.HelpfulLibraries.OrchardCore.Workflow;
+using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Localization;
 using OrchardCore.Commerce.Abstractions;
 using OrchardCore.Commerce.Activities;
 using OrchardCore.Commerce.Exceptions;
@@ -23,21 +25,24 @@ public class ShoppingCartController : Controller
     private readonly IShoppingCartPersistence _shoppingCartPersistence;
     private readonly IShoppingCartSerializer _shoppingCartSerializer;
     private readonly IEnumerable<IWorkflowManager> _workflowManagers;
+    private readonly IHtmlLocalizer<ShoppingCartController> H;
 
     public ShoppingCartController(
         INotifier notifier,
         IShapeFactory shapeFactory,
         IShoppingCartHelpers shoppingCartHelpers,
         IShoppingCartPersistence shoppingCartPersistence,
         IShoppingCartSerializer shoppingCartSerializer,
-        IEnumerable<IWorkflowManager> workflowManagers)
+        IEnumerable<IWorkflowManager> workflowManagers,
+        IHtmlLocalizer<ShoppingCartController> htmlLocalizer)
     {
         _notifier = notifier;
         _shapeFactory = shapeFactory;
         _shoppingCartHelpers = shoppingCartHelpers;
         _shoppingCartPersistence = shoppingCartPersistence;
         _shoppingCartSerializer = shoppingCartSerializer;
         _workflowManagers = workflowManagers;
+        H = htmlLocalizer;
     }
 
     [HttpGet]
@@ -84,7 +89,18 @@ public async Task<ActionResult> Index(string shoppingCartId = null)
 
     [HttpGet]
     [Route("cart-empty")]
-    public IActionResult Empty() => View();
+    public async Task<ActionResult> Empty()
+    {
+        var trackingConsentFeature = HttpContext.Features.Get<ITrackingConsentFeature>();
+        if (trackingConsentFeature?.CanTrack == false)
+        {
+            await _notifier.ErrorAsync(H["You have to accept cookies in your browser to add items to your shopping " +
+                "cart. If you have privacy-related browser extensions like ad-blockers or cookie blockers, they " +
+                "might be preventing the website from setting cookies, try disabling them."]);
+        }
+
+        return View();
+    }
 
     [HttpPost]
     [ValidateAntiForgeryToken]