Inherit from existing resources. Thus we can share common localizations accross modules.

#171.

src/Volo.Abp/Volo/Abp/Localization/AbpDictionaryBasedStringLocalizer.cs

@@ -10,13 +10,16 @@ namespace Volo.Abp.Localization
     {
         public LocalizationResource Resource { get; }
 
-        public LocalizedString this[string name] => GetLocalizedString(name, CultureInfo.CurrentUICulture.Name);
+        public List<IStringLocalizer> BaseLocalizers { get; }
 
-        public LocalizedString this[string name, params object[] arguments] => GetLocalizedStringFormatted(name, CultureInfo.CurrentUICulture.Name, arguments);
+        public virtual LocalizedString this[string name] => GetLocalizedString(name);
 
-        public AbpDictionaryBasedStringLocalizer(LocalizationResource resource)
+        public virtual LocalizedString this[string name, params object[] arguments] => GetLocalizedStringFormatted(name, arguments);
+
+        public AbpDictionaryBasedStringLocalizer(LocalizationResource resource, List<IStringLocalizer> baseLocalizers)
         {
             Resource = resource;
+            BaseLocalizers = baseLocalizers;
         }
 
         public IEnumerable<LocalizedString> GetAllStrings(bool includeParentCultures)
@@ -29,19 +32,38 @@ namespace Volo.Abp.Localization
             return new CultureWrapperStringLocalizer(culture.Name, this);
         }
 
+        protected virtual LocalizedString GetLocalizedStringFormatted(string name, params object[] arguments)
+        {
+            return GetLocalizedStringFormatted(name, CultureInfo.CurrentUICulture.Name, arguments);
+        }
+
         protected virtual LocalizedString GetLocalizedStringFormatted(string name, string cultureName, params object[] arguments)
         {
             var localizedString = GetLocalizedString(name, cultureName);
             return new LocalizedString(name, string.Format(localizedString.Value, arguments), localizedString.ResourceNotFound, localizedString.SearchedLocation);
         }
 
+        protected virtual LocalizedString GetLocalizedString(string name)
+        {
+            return GetLocalizedString(name, CultureInfo.CurrentUICulture.Name);
+        }
+
         protected virtual LocalizedString GetLocalizedString(string name, string cultureName)
         {
             var value = GetLocalizedStringOrNull(name, cultureName);
 
             if (value == null)
             {
-                return new LocalizedString(name, name, true);
+                foreach (var baseLocalizer in BaseLocalizers)
+                {
+                    var baseLocalizedString = baseLocalizer.WithCulture(CultureInfo.GetCultureInfo(cultureName))[name];
+                    if (baseLocalizedString != null && !baseLocalizedString.ResourceNotFound)
+                    {
+                        return baseLocalizedString;
+                    }
+                }
+
+                return new LocalizedString(name, name, resourceNotFound: true);
             }
 
             return value;

src/Volo.Abp/Volo/Abp/Localization/AbpStringLocalizerFactory.cs

@@ -44,12 +44,13 @@ namespace Volo.Abp.Localization
         {
             resource.Initialize(_serviceProvider);
 
-            //Extend dictionary with extensions
             //Wrap reader by wrappers (like db wrapper which implement multitenancy/regions and so on...)
             
             //Notes: Localizer will be cached, so wrappers are responsible to cache/invalidate themselves!
 
-            var localizer = new AbpDictionaryBasedStringLocalizer(resource);
+            var baseLocalizers = resource.BaseResourceTypes.Select(Create).ToList();
+
+            var localizer = new AbpDictionaryBasedStringLocalizer(resource, baseLocalizers);
 
             //TODO: Wrap with DB provider or other premium sources
 

src/Volo.Abp/Volo/Abp/Localization/LocalizationResource.cs

@@ -10,19 +10,12 @@ namespace Volo.Abp.Localization
 
         public string DefaultCultureName { get; set; }
 
-        public ILocalizationDictionaryProvider DictionaryProvider
-        {
-            get => _dictionaryProvider;
-            set
-            {
-                Check.NotNull(value, nameof(value));
-                _dictionaryProvider = value;
-            }
-        }
-        private ILocalizationDictionaryProvider _dictionaryProvider;
+        public ILocalizationDictionaryProvider DictionaryProvider { get; }
 
         public List<ILocalizationDictionaryProvider> Extensions { get; }
 
+        public List<Type> BaseResourceTypes { get; }
+
         public LocalizationResource([NotNull] Type resourceType, [NotNull] string defaultCultureName, [NotNull] ILocalizationDictionaryProvider dictionaryProvider)
         {
             Check.NotNull(resourceType, nameof(resourceType));
@@ -33,6 +26,7 @@ namespace Volo.Abp.Localization
             DefaultCultureName = defaultCultureName;
             DictionaryProvider = dictionaryProvider;
 
+            BaseResourceTypes = new List<Type>();
             Extensions = new List<ILocalizationDictionaryProvider>();
         }
 

src/Volo.Abp/Volo/Abp/Localization/LocalizationResourceExtensions.cs

@@ -0,0 +1,18 @@
+using System;
+using JetBrains.Annotations;
+
+namespace Volo.Abp.Localization
+{
+    public static class LocalizationResourceExtensions
+    {
+        public static LocalizationResource InheritFrom([NotNull] this LocalizationResource resource, [NotNull] params Type[] baseResourceTypes)
+        {
+            Check.NotNull(resource, nameof(resource));
+            Check.NotNull(baseResourceTypes, nameof(baseResourceTypes));
+
+            resource.BaseResourceTypes.AddRange(baseResourceTypes);
+
+            return resource;
+        }
+    }
+}

src/Volo.Abp/Volo/Abp/Localization/LocalizationResourceListExtensions.cs

@@ -6,7 +6,7 @@ namespace Volo.Abp.Localization
 {
     public static class LocalizationResourceListExtensions
     {
-        public static void AddJson<TResource>([NotNull] this LocalizationResourceDictionary resourceDictionary, [NotNull] string defaultCultureName)
+        public static LocalizationResource AddJson<TResource>([NotNull] this LocalizationResourceDictionary resourceDictionary, [NotNull] string defaultCultureName)
         {
             Check.NotNull(resourceDictionary, nameof(resourceDictionary));
             Check.NotNull(defaultCultureName, nameof(defaultCultureName));
@@ -18,7 +18,7 @@ namespace Volo.Abp.Localization
                 throw new AbpException("There is already a resource with given type: " + resourceType.AssemblyQualifiedName);
             }
 
-            resourceDictionary[resourceType] = new LocalizationResource(
+            return resourceDictionary[resourceType] = new LocalizationResource(
                 resourceType,
                 defaultCultureName,
                 new JsonEmbeddedFileLocalizationDictionaryProvider(

test/Volo.Abp.Tests/Volo.Abp.Tests.csproj

@@ -12,8 +12,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <EmbeddedResource Include="Volo\Abp\Localization\SourceExt\*.json" />
-    <EmbeddedResource Include="Volo\Abp\Localization\Source\*.json" />
+    <EmbeddedResource Include="Volo\Abp\Localization\**\*.json" />
   </ItemGroup>
 
   <ItemGroup>

test/Volo.Abp.Tests/Volo/Abp/Localization/AbpLocalization_Tests.cs

@@ -2,6 +2,8 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Localization;
 using Shouldly;
+using Volo.Abp.Localization.Base.CountryNames;
+using Volo.Abp.Localization.Base.Validation;
 using Volo.Abp.Localization.Source;
 using Volo.Abp.Localization.SourceExt;
 using Volo.Abp.Modularity;
@@ -58,7 +60,7 @@ namespace Volo.Abp.Localization
 
             using (AbpCultureHelper.Use("tr"))
             {
-                _localizer["SeeYou"].Value.ShouldBe("See you"); //Not defined in tr
+                _localizer["SeeYou"].Value.ShouldBe("See you"); //Not defined in tr, getting from default lang
             }
 
             using (AbpCultureHelper.Use("it"))
@@ -67,6 +69,30 @@ namespace Volo.Abp.Localization
             }
         }
 
+        [Fact]
+        public void Should_Get_From_Inherited_Texts()
+        {
+            using (AbpCultureHelper.Use("en"))
+            {
+                _localizer["USA"].Value.ShouldBe("United States of America"); //Inherited from CountryNames/en.json
+                _localizer["ThisFieldIsRequired"].Value.ShouldBe("This field is required"); //Inherited from Validation/en.json
+            }
+
+            using (AbpCultureHelper.Use("tr"))
+            {
+                _localizer["USA"].Value.ShouldBe("Amerika Birleşik Devletleri"); //Inherited from CountryNames/tr.json
+            }
+        }
+
+        [Fact]
+        public void Should_Override_Inherited_Text()
+        {
+            using (AbpCultureHelper.Use("en"))
+            {
+                _localizer["MaxLenghtErrorMessage", 42].Value.ShouldBe("This field's length can be maximum of '42' chars"); //Overriden in Source/en.json
+            }
+        }
+
         [Fact]
         public void Should_Get_Localized_Text_If_Defined_In_Requested_Culture()
         {
@@ -84,7 +110,15 @@ namespace Volo.Abp.Localization
             {
                 services.Configure<AbpLocalizationOptions>(options =>
                 {
-                    options.Resources.AddJson<LocalizationTestResource>("en");
+                    options.Resources.AddJson<LocalizationTestValidationResource>("en");
+                    options.Resources.AddJson<LocalizationTestCountryNamesResource>("en");
+                    
+                    options.Resources.AddJson<LocalizationTestResource>("en")
+                        .InheritFrom(
+                            typeof(LocalizationTestValidationResource),
+                            typeof(LocalizationTestCountryNamesResource)
+                        );
+
                     options.Resources.ExtendWithJson<LocalizationTestResource, LocalizationTestResourceExt>();
                 });
             }

test/Volo.Abp.Tests/Volo/Abp/Localization/Base/CountryNames/LocalizationTestCountryNamesResource.cs

@@ -0,0 +1,7 @@
+namespace Volo.Abp.Localization.Base.CountryNames
+{
+    public sealed class LocalizationTestCountryNamesResource
+    {
+        
+    }
+}

test/Volo.Abp.Tests/Volo/Abp/Localization/Base/CountryNames/en.json

@@ -0,0 +1,6 @@
+{
+  "culture": "en",
+  "texts": {
+    "USA": "United States of America"
+  }
+}

test/Volo.Abp.Tests/Volo/Abp/Localization/Base/CountryNames/tr.json

@@ -0,0 +1,6 @@
+{
+  "culture": "tr",
+  "texts": {
+    "USA": "Amerika Birleşik Devletleri"
+  }
+}

test/Volo.Abp.Tests/Volo/Abp/Localization/Base/Validation/LocalizationTestValidationResource.cs

@@ -0,0 +1,7 @@
+namespace Volo.Abp.Localization.Base.Validation
+{
+    public sealed class LocalizationTestValidationResource
+    {
+        
+    }
+}

test/Volo.Abp.Tests/Volo/Abp/Localization/Base/Validation/en.json

@@ -0,0 +1,7 @@
+{
+  "culture": "en",
+  "texts": {
+    "ThisFieldIsRequired": "This field is required",
+    "MaxLenghtErrorMessage": "This field can be maximum of '{0}' chars"
+  }
+}

test/Volo.Abp.Tests/Volo/Abp/Localization/Source/en.json

@@ -3,6 +3,7 @@
   "texts": {
     "Hello <b>{0}</b>.": "Hello <b>{0}</b>.",
     "Car": "Car",
-    "CarPlural": "Cars"
+    "CarPlural": "Cars",
+    "MaxLenghtErrorMessage": "This field's length can be maximum of '{0}' chars"
   }
 }