Resolved #176: Allow to change localization and see the result without recompile on development time.

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

@@ -20,13 +20,14 @@ namespace Volo.Abp.Localization
         //TODO: It's better to use decorator pattern for IStringLocalizerFactory instead of getting ResourceManagerStringLocalizerFactory as a dependency.
         public AbpStringLocalizerFactory(
             ResourceManagerStringLocalizerFactory innerFactory,
-            IOptions<AbpLocalizationOptions> abpLocalizationOptions, IServiceProvider serviceProvider)
+            IOptions<AbpLocalizationOptions> abpLocalizationOptions,
+            IServiceProvider serviceProvider)
         {
             _innerFactory = innerFactory;
             _serviceProvider = serviceProvider;
             _abpLocalizationOptions = abpLocalizationOptions.Value;
 
-            _localizerCache = new ConcurrentDictionary<Type, AbpDictionaryBasedStringLocalizer>();;
+            _localizerCache = new ConcurrentDictionary<Type, AbpDictionaryBasedStringLocalizer>();
         }
 
         public virtual IStringLocalizer Create(Type resourceType)
@@ -42,7 +43,8 @@ namespace Volo.Abp.Localization
 
         private AbpDictionaryBasedStringLocalizer CreateAbpStringLocalizer(LocalizationResource resource)
         {
-            resource.Initialize(_serviceProvider);
+            resource.Initialize(_serviceProvider); //TODO: Use CreateScope?
+
             return new AbpDictionaryBasedStringLocalizer(
                 resource,
                 resource.BaseResourceTypes.Select(Create).ToList()

src/Volo.Abp.Localization/Volo/Abp/Localization/ILocalizationDictionary.cs

@@ -29,5 +29,7 @@ namespace Volo.Abp.Localization
         IReadOnlyList<LocalString> GetAllStrings();
 
         void Extend(ILocalizationDictionary dictionary);
+
+        void Clear();
     }
 }

src/Volo.Abp.Localization/Volo/Abp/Localization/ILocalizationDictionaryProvider.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 
 namespace Volo.Abp.Localization
 {
@@ -6,6 +7,8 @@ namespace Volo.Abp.Localization
     {
         IDictionary<string, ILocalizationDictionary> Dictionaries { get; }
 
+        event EventHandler Updated;
+
         void Initialize(LocalizationResourceInitializationContext context);
 
         void Extend(ILocalizationDictionaryProvider dictionaryProvider);

src/Volo.Abp.Localization/Volo/Abp/Localization/LocalizationDictionary.cs

@@ -11,7 +11,7 @@ namespace Volo.Abp.Localization
     {
         /// <inheritdoc/>
         public string CultureName { get; }
-
+        
         /// <inheritdoc/>
         public virtual LocalString this[string name]
         {
@@ -51,6 +51,11 @@ namespace Volo.Abp.Localization
             }
         }
 
+        public void Clear()
+        {
+            _dictionary.Clear();
+        }
+
         /// <inheritdoc/>
         public virtual IEnumerator<LocalString> GetEnumerator()
         {

src/Volo.Abp.Localization/Volo/Abp/Localization/LocalizationDictionaryProviderBase.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 
 namespace Volo.Abp.Localization
@@ -6,6 +7,8 @@ namespace Volo.Abp.Localization
     {
         public IDictionary<string, ILocalizationDictionary> Dictionaries { get; }
 
+        public event EventHandler Updated;
+
         protected LocalizationDictionaryProviderBase()
         {
             Dictionaries = new Dictionary<string, ILocalizationDictionary>();
@@ -35,5 +38,10 @@ namespace Volo.Abp.Localization
                 existingDictionary.Extend(dictionary);
             }
         }
+
+        protected virtual void OnUpdated()
+        {
+            Updated.InvokeSafely(this);
+        }
     }
 }

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

@@ -38,10 +38,30 @@ namespace Volo.Abp.Localization
 
         public virtual void Initialize(IServiceProvider serviceProvider)
         {
+            //TODO: We should refactor here to create a better design!
+
             var context = new LocalizationResourceInitializationContext(serviceProvider);
 
-            DictionaryProvider.Initialize(context);
+            InitializeDictionaryProvider(context);
+            InitializeExtensions(context);
+
+            DictionaryProvider.Updated += (sender, args) =>
+            {
+                InitializeExtensions(context);
+            };
 
+            foreach (var extension in Extensions)
+            {
+                extension.Updated += (sender, args) =>
+                {
+                    InitializeDictionaryProvider(context);
+                    InitializeExtensions(context);
+                };
+            }
+        }
+
+        private void InitializeExtensions(LocalizationResourceInitializationContext context)
+        {
             foreach (var extension in Extensions)
             {
                 extension.Initialize(context);
@@ -49,6 +69,11 @@ namespace Volo.Abp.Localization
             }
         }
 
+        private void InitializeDictionaryProvider(LocalizationResourceInitializationContext context)
+        {
+            DictionaryProvider.Initialize(context);
+        }
+
         protected virtual void AddBaseResourceTypes()
         {
             var descriptors = ResourceType

src/Volo.Abp.Localization/Volo/Abp/Localization/VirtualFiles/Json/JsonEmbeddedFileLocalizationDictionaryProvider.cs

@@ -17,7 +17,7 @@ namespace Volo.Abp.Localization.VirtualFiles.Json
             return file.Name.EndsWith(".json", StringComparison.OrdinalIgnoreCase);
         }
 
-        protected override ILocalizationDictionary CreateDictionary(string jsonString)
+        protected override ILocalizationDictionary CreateDictionaryFromFileContent(string jsonString)
         {
             return JsonLocalizationDictionaryBuilder.BuildFromJsonString(jsonString); //TODO: Use composition over inheritance!
         }

src/Volo.Abp.Localization/Volo/Abp/Localization/VirtualFiles/VirtualFileLocalizationDictionaryProviderBase.cs

@@ -1,5 +1,7 @@
-using Microsoft.Extensions.DependencyInjection;
+using System;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.FileProviders;
+using Microsoft.Extensions.Primitives;
 using Volo.Abp.Internal;
 using Volo.Abp.VirtualFileSystem;
 
@@ -9,6 +11,8 @@ namespace Volo.Abp.Localization.VirtualFiles
     {
         private readonly string _virtualPath;
 
+        private bool _subscribedForChanges;
+
         protected VirtualFileLocalizationDictionaryProviderBase(string virtualPath)
         {
             _virtualPath = virtualPath;
@@ -17,32 +21,52 @@ namespace Volo.Abp.Localization.VirtualFiles
         public override void Initialize(LocalizationResourceInitializationContext context) //TODO: Extract initialization to a factory..?
         {
             var virtualFileProvider = context.ServiceProvider.GetRequiredService<IVirtualFileProvider>();
-            var directoryContents = virtualFileProvider.GetDirectoryContents(_virtualPath);
 
-            foreach (var file in directoryContents)
+            CreateDictionaries(virtualFileProvider);
+
+            if (!_subscribedForChanges)
+            {
+                ChangeToken.OnChange(() => virtualFileProvider.Watch(_virtualPath.EnsureEndsWith('/') + "**/*.*"), () =>
+                {
+                    CreateDictionaries(virtualFileProvider);
+                    OnUpdated();
+                });
+
+                _subscribedForChanges = true;
+            }
+        }
+
+        private void CreateDictionaries(IFileProvider fileProvider)
+        {
+            Dictionaries.Clear();
+
+            foreach (var file in fileProvider.GetDirectoryContents(_virtualPath))
             {
                 if (file.IsDirectory || !CanParseFile(file))
                 {
                     continue;
                 }
 
-                using (var stream = file.CreateReadStream())
+                var dictionary = CreateDictionaryFromFile(file);
+                if (Dictionaries.ContainsKey(dictionary.CultureName))
                 {
-                    var fileContent = Utf8Helper.ReadStringFromStream(stream);
-
-                    var dictionary = CreateDictionary(fileContent);
-                    if (Dictionaries.ContainsKey(dictionary.CultureName))
-                    {
-                        throw new AbpException($"{file.PhysicalPath} dictionary has a culture name '{dictionary.CultureName}' which is already defined!");
-                    }
-
-                    Dictionaries[dictionary.CultureName] = dictionary;
+                    throw new AbpException($"{file.PhysicalPath} dictionary has a culture name '{dictionary.CultureName}' which is already defined!");
                 }
+                
+                Dictionaries[dictionary.CultureName] = dictionary;
             }
         }
 
         protected abstract bool CanParseFile(IFileInfo file);
 
-        protected abstract ILocalizationDictionary CreateDictionary(string fileContent);
+        protected virtual ILocalizationDictionary CreateDictionaryFromFile(IFileInfo file)
+        {
+            using (var stream = file.CreateReadStream())
+            {
+                return CreateDictionaryFromFileContent(Utf8Helper.ReadStringFromStream(stream));
+            }
+        }
+
+        protected abstract ILocalizationDictionary CreateDictionaryFromFileContent(string fileContent);
     }
 }

src/Volo.Abp.VirtualFileSystem/Volo/Abp/VirtualFileSystem/VirtualFileProvider.cs

@@ -41,7 +41,7 @@ namespace Volo.Abp.VirtualFileSystem
             if (_options.FileSets.PhysicalPaths.Any())
             {
                 var fileProviders = _options.FileSets.PhysicalPaths
-                    .Select(p => new PhysicalFileProvider(p))
+                    .Select(rootPath => new PhysicalFileProvider(rootPath))
                     .Cast<IFileProvider>()
                     .ToList();