Scaffolding: Enable text templates

Part of #4038

.github/dependabot.yml

@@ -18,6 +18,7 @@ updates:
       - dependency-name: Microsoft.Data.SqlClient
       - dependency-name: Microsoft.DotNet.PlatformAbstractions
       - dependency-name: mod_spatialite
+      - dependency-name: Mono.TextTemplating
       - dependency-name: NetTopologySuite*
       - dependency-name: Newtonsoft.Json
       - dependency-name: SQLitePCLRaw*

src/EFCore.Design/Design/DesignTimeServiceCollectionExtensions.cs

@@ -7,6 +7,8 @@
 using Microsoft.EntityFrameworkCore.Migrations.Internal;
 using Microsoft.EntityFrameworkCore.Scaffolding;
 using Microsoft.EntityFrameworkCore.Scaffolding.Internal;
+using Microsoft.EntityFrameworkCore.TextTemplating;
+using Microsoft.EntityFrameworkCore.TextTemplating.Internal;
 
 namespace Microsoft.EntityFrameworkCore.Design;
 
@@ -52,7 +54,9 @@ public static IServiceCollection AddEntityFrameworkDesignTimeServices(
                     .TryAddSingleton(reporter)
                     .TryAddSingleton<IMigrationsCodeGenerator, CSharpMigrationsGenerator>()
                     .TryAddSingleton<IMigrationsCodeGeneratorSelector, MigrationsCodeGeneratorSelector>()
-                    .TryAddSingleton<IModelCodeGenerator, CSharpModelGenerator>()
+                    .TryAddSingleton<ITextTemplating, TextTemplatingService>()
+                    .TryAddSingletonEnumerable<IModelCodeGenerator, TextTemplatingModelGenerator>()
+                    .TryAddSingletonEnumerable<IModelCodeGenerator, CSharpModelGenerator>()
                     .TryAddSingleton<IModelCodeGeneratorSelector, ModelCodeGeneratorSelector>()
                     .TryAddSingleton<ICompiledModelCodeGenerator, CSharpRuntimeModelCodeGenerator>()
                     .TryAddSingleton<ICompiledModelCodeGeneratorSelector, CompiledModelCodeGeneratorSelector>()

src/EFCore.Design/Design/Internal/DatabaseOperations.cs

@@ -96,7 +96,8 @@ public virtual SavedModelFiles ScaffoldContext(
                 UseNullableReferenceTypes = _nullable,
                 ContextDir = MakeDirRelative(outputDir, outputContextDir),
                 ContextName = dbContextClassName,
-                SuppressOnConfiguring = suppressOnConfiguring
+                SuppressOnConfiguring = suppressOnConfiguring,
+                ProjectDir = _projectDir
             });
 
         return scaffolder.Save(

src/EFCore.Design/EFCore.Design.csproj

@@ -60,6 +60,7 @@
   <ItemGroup>
     <PackageReference Include="Humanizer.Core" Version="2.14.1" />
     <PackageReference Include="Microsoft.Extensions.HostFactoryResolver.Sources" PrivateAssets="All" Version="$(MicrosoftExtensionsHostFactoryResolverSourcesVersion)" />
+    <PackageReference Include="Mono.TextTemplating" Version="2.2.1" />
   </ItemGroup>
 
   <ItemGroup>

src/EFCore.Design/Properties/DesignStrings.resx

@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!--
-    Microsoft ResX Schema
-
+  <!-- 
+    Microsoft ResX Schema 
+    
     Version 2.0
-
-    The primary goals of this format is to allow a simple XML format
-    that is mostly human readable. The generation and parsing of the
-    various data types are done through the TypeConverter classes
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
     associated with the data types.
-
+    
     Example:
-
+    
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-
-    There are any number of "resheader" rows that contain simple
+                
+    There are any number of "resheader" rows that contain simple 
     name/value pairs.
-
-    Each data row contains a name, and value. The row also contains a
-    type or mimetype. Type corresponds to a .NET class that support
-    text/value conversion through the TypeConverter architecture.
-    Classes that don't support this are serialized and stored with the
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
     mimetype set.
-
-    The mimetype is used for serialized objects, and tells the
-    ResXResourceReader how to depersist the object. This is currently not
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
     extensible. For a given mimetype the value must be set accordingly:
-
-    Note - application/x-microsoft.net.object.binary.base64 is the format
-    that the ResXResourceWriter will generate, however the reader can
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
     read any of the formats listed below.
-
+    
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with
+    value   : The object must be serialized with 
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-
+    
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with
+    value   : The object must be serialized with 
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array
+    value   : The object must be serialized into a byte array 
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
@@ -189,6 +189,9 @@
   <data name="DuplicateMigrationName" xml:space="preserve">
     <value>The name '{migrationName}' is used by an existing migration.</value>
   </data>
+  <data name="EncodingIgnored" xml:space="preserve">
+    <value>The encoding '{encoding}' specified in the output directive will be ignored. EF Core always scaffolds files using the encoding 'utf-8'.</value>
+  </data>
   <data name="ErrorConnecting" xml:space="preserve">
     <value>An error occurred while accessing the database. Continuing without the information provided by the database. Error: {message}</value>
   </data>
@@ -378,6 +381,9 @@ Change your target project to the migrations project by using the Package Manage
   <data name="UnhandledEnumValue" xml:space="preserve">
     <value>Unhandled enum value '{enumValue}'.</value>
   </data>
+  <data name="UnknownDirectiveProcessor" xml:space="preserve">
+    <value>Failed to resolve type for directive processor {name}.</value>
+  </data>
   <data name="UnknownLiteral" xml:space="preserve">
     <value>Cannot scaffold C# literals of type '{literalType}'. The provider should implement CoreTypeMapping.GenerateCodeLiteral to support using it at design time.</value>
   </data>
@@ -420,4 +426,4 @@ Change your target project to the migrations project by using the Package Manage
   <data name="WritingSnapshot" xml:space="preserve">
     <value>Writing model snapshot to '{file}'.</value>
   </data>
-</root>
+</root>

src/EFCore.Design/Scaffolding/IModelCodeGeneratorSelector.cs

@@ -16,5 +16,16 @@ public interface IModelCodeGeneratorSelector
     /// </summary>
     /// <param name="language">The programming language.</param>
     /// <returns>The <see cref="IModelCodeGenerator" />.</returns>
+    [Obsolete("Use the overload that takes ModelCodeGenerationOptions instead.")]
     IModelCodeGenerator Select(string? language);
+
+    /// <summary>
+    ///     Selects an <see cref="IModelCodeGenerator" /> service for a given set of options.
+    /// </summary>
+    /// <param name="options">The options.</param>
+    /// <returns>The <see cref="IModelCodeGenerator" />.</returns>
+    IModelCodeGenerator Select(ModelCodeGenerationOptions options)
+#pragma warning disable CS0618 // Type or member is obsolete
+        => Select(options.Language);
+#pragma warning restore CS0618
 }

src/EFCore.Design/Scaffolding/Internal/ModelCodeGeneratorSelector.cs

@@ -13,14 +13,22 @@ namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal;
 /// </summary>
 public class ModelCodeGeneratorSelector : LanguageBasedSelector<IModelCodeGenerator>, IModelCodeGeneratorSelector
 {
+    private readonly IEnumerable<TemplatedModelGenerator> _templatedModelGenerators;
+
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
     ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
     ///     any release. You should only use it directly in your code with extreme caution and knowing that
     ///     doing so can result in application failures when updating to a new Entity Framework Core release.
     /// </summary>
     public ModelCodeGeneratorSelector(IEnumerable<IModelCodeGenerator> services)
-        : base(services)
-    {
-    }
+        : base(services.Except(services.OfType<TemplatedModelGenerator>()).ToList())
+        => _templatedModelGenerators = services.OfType<TemplatedModelGenerator>().ToList();
+
+    /// <inheritdoc />
+    public virtual IModelCodeGenerator Select(ModelCodeGenerationOptions options)
+        => _templatedModelGenerators
+                .Where(g => options.ProjectDir != null && g.HasTemplates(options.ProjectDir))
+                .LastOrDefault()
+            ?? Select(options.Language);
 }

src/EFCore.Design/Scaffolding/Internal/ReverseEngineerScaffolder.cs

@@ -114,7 +114,7 @@ public virtual ScaffoldedModel ScaffoldModel(
                 : DefaultDbContextName;
         }
 
-        var codeGenerator = ModelCodeGeneratorSelector.Select(codeOptions.Language);
+        var codeGenerator = ModelCodeGeneratorSelector.Select(codeOptions);
 
         return codeGenerator.GenerateModel(model, codeOptions);
     }