Refactor languages.

framework/src/Volo.Abp.AspNetCore.Mvc.UI.Theme.Basic/Themes/Basic/Components/Toolbar/LanguageSwitch/LanguageSwitchViewComponent.cs

@@ -1,10 +1,7 @@
-using System.Collections.Generic;
-using System.Globalization;
+using System.Globalization;
 using System.Linq;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Mvc;
-using Microsoft.Extensions.Options;
 using Volo.Abp.Localization;
 
 namespace Volo.Abp.AspNetCore.Mvc.UI.Theme.Basic.Themes.Basic.Components.Toolbar.LanguageSwitch
@@ -21,7 +18,10 @@ namespace Volo.Abp.AspNetCore.Mvc.UI.Theme.Basic.Themes.Basic.Components.Toolbar
         public async Task<IViewComponentResult> InvokeAsync()
         {
             var languages = await _languageProvider.GetLanguagesAsync();
-            var currentLanguage = FindCurrentLanguage(languages);
+            var currentLanguage = languages.FindByCulture(
+                CultureInfo.CurrentCulture.Name,
+                CultureInfo.CurrentUICulture.Name
+            );
 
             var model = new LanguageSwitchViewComponentModel
             {
@@ -31,14 +31,5 @@ namespace Volo.Abp.AspNetCore.Mvc.UI.Theme.Basic.Themes.Basic.Components.Toolbar
             
             return View("~/Themes/Basic/Components/Toolbar/LanguageSwitch/Default.cshtml", model);
         }
-
-        private LanguageInfo FindCurrentLanguage(IReadOnlyList<LanguageInfo> languages)
-        {
-            return languages.FirstOrDefault(l =>
-                       l.CultureName == CultureInfo.CurrentCulture.Name &&
-                       l.UiCultureName == CultureInfo.CurrentUICulture.Name)
-                   ?? languages.FirstOrDefault(l => l.CultureName == CultureInfo.CurrentCulture.Name)
-                   ?? languages.FirstOrDefault(l => l.UiCultureName == CultureInfo.CurrentUICulture.Name);
-        }
     }
 }

framework/src/Volo.Abp.AspNetCore/Microsoft/AspNetCore/Builder/AbpApplicationBuilderExtensions.cs

@@ -98,14 +98,8 @@ namespace Microsoft.AspNetCore.Builder
                 return new RequestCulture(firstLanguage.CultureName, firstLanguage.UiCultureName);
             }
 
-            if (!defaultLanguage.Contains(";"))
-            {
-                return new RequestCulture(defaultLanguage, defaultLanguage);
-            }
-
-            var splitted = defaultLanguage.Split(';');
-            return new RequestCulture(splitted[0], splitted[1]);
-
+            var (cultureName, uiCultureName) = LocalizationSettingHelper.ParseLanguageSetting(defaultLanguage);
+            return new RequestCulture(cultureName, uiCultureName);
         }
     }
 }

framework/src/Volo.Abp.Localization/Volo/Abp/Localization/ILanguageInfo.cs

@@ -0,0 +1,13 @@
+namespace Volo.Abp.Localization
+{
+    public interface ILanguageInfo
+    {
+        string CultureName { get; }
+
+        string UiCultureName { get; }
+
+        string DisplayName { get; }
+
+        string FlagIcon { get; }
+    }
+}

framework/src/Volo.Abp.Localization/Volo/Abp/Localization/LanguageInfo.cs

@@ -4,7 +4,7 @@ using JetBrains.Annotations;
 namespace Volo.Abp.Localization
 {
     [Serializable]
-    public class LanguageInfo
+    public class LanguageInfo : ILanguageInfo
     {
         [NotNull]
         public virtual string CultureName { get; protected set; }

framework/src/Volo.Abp.Localization/Volo/Abp/Localization/LanguageInfoExtensions.cs

@@ -0,0 +1,27 @@
+using System.Collections.Generic;
+using System.Linq;
+using JetBrains.Annotations;
+
+namespace Volo.Abp.Localization
+{
+    public static class LanguageInfoExtensions
+    {
+        public static T FindByCulture<T>(
+            [NotNull] this IEnumerable<T> languages,
+            [NotNull] string cultureName,
+            [CanBeNull] string uiCultureName = null)
+        where T : class, ILanguageInfo
+        {
+            if (uiCultureName == null)
+            {
+                uiCultureName = cultureName;
+            }
+
+            var languageList = languages.ToList();
+
+            return languageList.FirstOrDefault(l => l.CultureName == cultureName && l.UiCultureName == uiCultureName)
+                   ?? languageList.FirstOrDefault(l => l.CultureName == cultureName)
+                   ?? languageList.FirstOrDefault(l => l.UiCultureName == uiCultureName);
+        }
+    }
+}

framework/src/Volo.Abp.Localization/Volo/Abp/Localization/LocalizationSettingHelper.cs

@@ -0,0 +1,25 @@
+using JetBrains.Annotations;
+
+namespace Volo.Abp.Localization
+{
+    public static class LocalizationSettingHelper
+    {
+        /// <summary>
+        /// Gets a setting value like "en-US;en" and returns as splitted values like ("en-US", "en").
+        /// </summary>
+        /// <param name="settingValue"></param>
+        /// <returns></returns>
+        public static (string cultureName, string uiCultureName) ParseLanguageSetting([NotNull] string settingValue)
+        {
+            Check.NotNull(settingValue, nameof(settingValue));
+
+            if (!settingValue.Contains(";"))
+            {
+                return (settingValue, settingValue);
+            }
+
+            var splitted = settingValue.Split(';');
+            return (splitted[0], splitted[1]);
+        }
+    }
+}