fix current language selection if is not allowed for sitemap

Author: Jan Nielsen

src/Libraries/Nop.Core/Http/NopHttpDefaults.cs

@@ -19,4 +19,9 @@ public static partial class NopHttpDefaults
     /// Gets the name of a request item that stores the value that indicates whether the request is being redirected by the generic route transformer
     /// </summary>
     public static string GenericRouteInternalRedirect => "nop.RedirectFromGenericPathRoute";
+
+    /// <summary>
+    /// Gets the name of a request item that stores the value with default language for sitemap.xml
+    /// </summary>
+    public static string ForcedSitemapXmlLanguage => "nop.ForcedSitemapXmlLanguage";
 }

src/Presentation/Nop.Web.Framework/Mvc/Routing/LanguageParameterTransformer.cs

@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Routing;
 using Nop.Core;
+using Nop.Core.Http;
 using Nop.Core.Infrastructure;
 using Nop.Services.Localization;
 
@@ -38,7 +39,11 @@ public LanguageParameterTransformer(IHttpContextAccessor httpContextAccessor,
     /// <returns>The transformed value</returns>
     public string TransformOutbound(object value)
     {
-        //first try to get a language code from the route values
+        // first check if we have forced value for sitemap.xml
+        if (_httpContextAccessor.HttpContext?.Items[NopHttpDefaults.ForcedSitemapXmlLanguage] is string forcedLang && !string.IsNullOrEmpty(forcedLang))
+            return forcedLang;
+        
+        // then try to get a language code from the route values
         var routeValues = _httpContextAccessor.HttpContext.Request.RouteValues;
         if (routeValues.TryGetValue(NopRoutingDefaults.RouteValue.Language, out var routeValue))
         {

src/Presentation/Nop.Web/Factories/SitemapModelFactory.cs

@@ -13,8 +13,10 @@
 using Nop.Core.Domain.Localization;
 using Nop.Core.Domain.News;
 using Nop.Core.Domain.Seo;
+using Nop.Core.Domain.Stores;
 using Nop.Core.Domain.Topics;
 using Nop.Core.Events;
+using Nop.Core.Http;
 using Nop.Core.Infrastructure;
 using Nop.Services.Blogs;
 using Nop.Services.Catalog;
@@ -522,7 +524,7 @@ protected virtual async Task WriteSitemapUrlAsync(XmlWriter writer, SitemapUrlMo
     /// <param name="fullPath">The path and name of the sitemap file</param>
     /// <param name="id">Sitemap identifier</param>
     /// <returns>A task that represents the asynchronous operation</returns>
-    protected virtual async Task GenerateAsync(string fullPath, int id = 0)
+    protected virtual async Task GenerateAsync(string fullPath, int id = 0) 
     {
         //generate all URLs for the sitemap
         var sitemapUrls = await GenerateUrlsAsync();
@@ -603,6 +605,22 @@ protected string GetLocalizedUrl(string currentUrl, Language lang)
         return new Uri(new Uri(scheme), localizedPath).ToString();
     }
 
+    /// <summary>
+    /// Retrieves the list of languages for the given store that are not excluded in the sitemap XML settings,
+    /// if SEO-friendly URLs for languages are enabled.
+    /// </summary>
+    /// <param name="store">The store to retrieve allowed languages for.</param>
+    /// <returns>
+    /// A list of <see cref="Language"/> if SEO-friendly URLs are enabled; otherwise, <c>null</c>.
+    /// </returns>
+    protected async Task<List<Language>> GetAllowedLanguagesAsync(Store store)
+    {
+        return _localizationSettings.SeoFriendlyUrlsForLanguagesEnabled
+            ? (await _languageService.GetAllLanguagesAsync(storeId: store.Id))
+            .Where(lang => !_sitemapXmlSettings.DisallowLanguages.Contains(lang.Id))
+            .ToList()
+            : null;
+    }
     #endregion
 
     #region Methods
@@ -823,27 +841,43 @@ public virtual async Task<SitemapModel> PrepareSitemapModelAsync(SitemapPageMode
     /// </returns>
     public virtual async Task<SitemapXmlModel> PrepareSitemapXmlModelAsync(int id = 0)
     {
-        var language = await _workContext.GetWorkingLanguageAsync();
+        var workingLanguage = await _workContext.GetWorkingLanguageAsync();
         var store = await _storeContext.GetCurrentStoreAsync();
+        
+        // get list of allowed languages (null if multilingual URLs are disabled)
+        var languages = await GetAllowedLanguagesAsync(store);
 
-        var fileName = string.Format(NopSeoDefaults.SitemapXmlFilePattern, store.Id, language.Id, id);
-        var fullPath = _nopFileProvider.GetAbsolutePath(NopSeoDefaults.SitemapXmlDirectory, fileName);
+        // select current language if allowed, fallback to first allowed if needed
+        var language = languages?.FirstOrDefault(lang => lang.Id == workingLanguage?.Id) ?? languages?.FirstOrDefault() ?? workingLanguage;
 
-        if (_nopFileProvider.FileExists(fullPath) && _nopFileProvider.GetLastWriteTimeUtc(fullPath) > DateTime.UtcNow.AddHours(-_sitemapXmlSettings.RebuildSitemapXmlAfterHours))
+        if (language.Id != workingLanguage.Id)
+            _actionContextAccessor.ActionContext.HttpContext.Items[NopHttpDefaults.ForcedSitemapXmlLanguage] = language.UniqueSeoCode.ToLowerInvariant();
+
+        try
         {
+            var fileName = string.Format(NopSeoDefaults.SitemapXmlFilePattern, store.Id, language.Id, id);
+            var fullPath = _nopFileProvider.GetAbsolutePath(NopSeoDefaults.SitemapXmlDirectory, fileName);
+
+            if (_nopFileProvider.FileExists(fullPath) && _nopFileProvider.GetLastWriteTimeUtc(fullPath) > DateTime.UtcNow.AddHours(-_sitemapXmlSettings.RebuildSitemapXmlAfterHours))
+            {
+                return new SitemapXmlModel { SitemapXmlPath = fullPath };
+            }
+
+            //execute task with lock
+            if (!await _locker.PerformActionWithLockAsync(
+                    fullPath,
+                    TimeSpan.FromSeconds(_sitemapXmlSettings.SitemapBuildOperationDelay),
+                    async () => await GenerateAsync(fullPath, id)))
+            {
+                throw new InvalidOperationException();
+            }
+
             return new SitemapXmlModel { SitemapXmlPath = fullPath };
         }
-
-        //execute task with lock
-        if (!await _locker.PerformActionWithLockAsync(
-                fullPath,
-                TimeSpan.FromSeconds(_sitemapXmlSettings.SitemapBuildOperationDelay),
-                async () => await GenerateAsync(fullPath, id)))
+        finally
         {
-            throw new InvalidOperationException();
+            _actionContextAccessor.ActionContext.HttpContext.Items.Remove(NopHttpDefaults.ForcedSitemapXmlLanguage);
         }
-
-        return new SitemapXmlModel { SitemapXmlPath = fullPath };
     }
 
     /// <summary>
@@ -886,10 +920,7 @@ var name when name.Equals(nameof(ProductTag), StringComparison.InvariantCultureI
         var store = await _storeContext.GetCurrentStoreAsync();
 
         var updatedOn = dateTimeUpdatedOn ?? DateTime.UtcNow;
-        var languages = _localizationSettings.SeoFriendlyUrlsForLanguagesEnabled
-            ? (await _languageService.GetAllLanguagesAsync(storeId: store.Id))
-            .Where(lang => !_sitemapXmlSettings.DisallowLanguages.Contains(lang.Id)).ToList()
-            : null;
+        var languages = await GetAllowedLanguagesAsync(store);
 
         if (languages == null || languages.Count == 1)
             return new SitemapUrlModel(url, new List<string>(), updateFreq, updatedOn);