Make <vc:widget> work in theme and plugin views again

.ai/skills/theme-creation.md

@@ -84,7 +84,8 @@ Do not use this skill for changes to `Grand.Web/Views` themselves — that is `.
 16. Add `Views/{ThemeName}/_ViewStart.cshtml`.
 17. Copy **only** the views the theme actually changes. Everything else resolves through the fallback locations. Each copied view is a file that must be re-reconciled on every upgrade.
 18. A copied view keeps the same `@model`, the same route names, and the same storefront data attributes — `data-cart-action`, product IDs, quick-view URLs, wishlist, compare, add-to-cart, image `alt` / `title` / `loading`.
-19. Keep widget zones (`@await Component.InvokeAsync("Widget", new { widgetZone = "..." })`) present in copied views. Dropping a zone silently disables every installed widget on that page.
+19. Keep widget zones (`<vc:widget widget-zone="..." />` or `@await Component.InvokeAsync("Widget", new { widgetZone = "..." })`) present in copied views. Dropping a zone silently disables every installed widget on that page.
+    A `<vc:...>` tag only works for a view component in an assembly the theme registers with `@addTagHelper`, which here is `Grand.Web.Common` (`<vc:widget>`). A theme cannot reference `Grand.Web` (`GRAND001`), so every other `<vc:...>` copied from a `Grand.Web` view, such as `<vc:related-products>`, renders as an empty unknown element with no build error. Rewrite those as `@await Component.InvokeAsync("RelatedProducts", new { productId = Model.Id })`.
 20. A theme must not change view models, controller actions, or route definitions. If a theme needs different data, the change belongs in `Grand.Web`, not the theme.
 
 #### Assets

src/Core/Grand.Infrastructure/Caching/Constants/CommonCacheKey.cs

@@ -217,4 +217,18 @@ public static partial class CacheKey
     public static string PAGES_PATTERN_KEY => "Grand.pages.";
 
     #endregion
+
+    #region Widgets
+
+    /// <summary>
+    ///     Key for widget info
+    /// </summary>
+    /// <remarks>
+    ///     {0} : current store ID
+    ///     {1} : customer groups
+    ///     {2} : widget zone
+    /// </remarks>
+    public static string WIDGET_MODEL_KEY => "Grand.pres.widget-{0}-{1}-{2}";
+
+    #endregion
 }

src/Plugins/Theme.Nordic/Views/Nordic/Product/ProductLayout.Simple.cshtml

@@ -236,10 +236,10 @@
                         </gn-tabs>
                     </div>
                 </div>
-                <vc:products-also-purchased product-id="@Model.Id" product-thumb-picture-size="null"></vc:products-also-purchased>
-                <vc:related-products product-id="@Model.Id" product-thumb-picture-size="null"></vc:related-products>
-                <vc:similar-products product-id="@Model.Id" product-thumb-picture-size="null"></vc:similar-products>
-                <vc:recommended-products product-id="@Model.Id" product-thumb-picture-size="null"></vc:recommended-products>
+                @await Component.InvokeAsync("ProductsAlsoPurchased", new { productId = Model.Id })
+                @await Component.InvokeAsync("RelatedProducts", new { productId = Model.Id })
+                @await Component.InvokeAsync("SimilarProducts", new { productId = Model.Id })
+                @await Component.InvokeAsync("RecommendedProducts", new { productId = Model.Id })
                 @if (Model.RenderCaptcha)
                 {
                     <partial name="Partials/Captcha"/>

src/Tests/Grand.Web.Tests/Components/WidgetViewComponentTests.cs → src/Tests/Grand.Web.Common.Tests/Components/WidgetViewComponentTests.cs

@@ -4,14 +4,14 @@
 using Grand.Infrastructure.Caching;
 using Grand.Infrastructure.Configuration;
 using Grand.Mediator;
-using Grand.Web.Components;
+using Grand.Web.Common.Components;
 using Grand.Web.Models.Cms;
 using Microsoft.AspNetCore.Mvc.ViewComponents;
 using Microsoft.Extensions.Caching.Memory;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Moq;
 
-namespace Grand.Web.Tests.Components;
+namespace Grand.Web.Common.Tests.Components;
 
 [TestClass]
 public class WidgetViewComponentTests

src/Web/Grand.Web/Components/Widget.cs → src/Web/Grand.Web.Common/Components/WidgetViewComponent.cs

@@ -2,12 +2,11 @@
 using Grand.Domain.Customers;
 using Grand.Infrastructure;
 using Grand.Infrastructure.Caching;
-using Grand.Web.Common.Components;
-using Grand.Web.Events.Cache;
+using Grand.Infrastructure.Caching.Constants;
 using Grand.Web.Models.Cms;
 using Microsoft.AspNetCore.Mvc;
 
-namespace Grand.Web.Components;
+namespace Grand.Web.Common.Components;
 
 public class WidgetViewComponent : BaseViewComponent
 {
@@ -24,7 +23,7 @@ public WidgetViewComponent(IContextAccessor contextAccessor, ICacheBase cacheBas
 
     public async Task<IViewComponentResult> InvokeAsync(string widgetZone, object additionalData = null)
     {
-        var cacheKey = string.Format(CacheKeyConst.WIDGET_MODEL_KEY, _contextAccessor.StoreContext.CurrentStore.Id,
+        var cacheKey = string.Format(CacheKey.WIDGET_MODEL_KEY, _contextAccessor.StoreContext.CurrentStore.Id,
             string.Join(",", _contextAccessor.WorkContext.CurrentCustomer.GetCustomerGroupIds()),
             widgetZone);
 

src/Web/Grand.Web.Models/Cms/WidgetModel.cs → src/Web/Grand.Web.Common/Models/Cms/WidgetModel.cs

@@ -1,10 +1,11 @@
 using Grand.Infrastructure.Models;
 
+//the namespace stays from Grand.Web.Models: storefront and theme _ViewImports import it
 namespace Grand.Web.Models.Cms;
 
 public class WidgetModel : BaseModel
 {
     public string WidgetZone { get; set; }
     public string ViewComponentName { get; set; }
     public object AdditionalData { get; set; }
-}
+}

src/Web/Grand.Web/Events/Cache/CacheKeyConst.cs

@@ -288,16 +288,6 @@ public static class CacheKeyConst
     /// </remarks>
     public const string SITEMAP_PAGE_MODEL_KEY = "Grand.pres.sitemap.page-{0}-{1}-{2}";
 
-    /// <summary>
-    ///     Key for widget info
-    /// </summary>
-    /// <remarks>
-    ///     {0} : current store ID
-    ///     {1} : customer groups
-    ///     {2} : widget zone
-    /// </remarks>
-    public const string WIDGET_MODEL_KEY = "Grand.pres.widget-{0}-{1}-{2}";
-
     /// <summary>
     ///     Key for caching
     /// </summary>