Add extensibility point for TH attribute code gen.

- Followed the "decorate" pattern that we use throughout Razor. - Enabled the CSharpCodeBuilder to decorate the CSharpCodeVisitor which exposes a CSharpTagHelperCodeRenderer which is indirectly used to render attribute values. - Fixed up some existing classes that just new'd up the CSharpCodeVisitor class to instead take in the decorated version. #119
aspnet · Sep 25, 2014 · 84e32d5 · 84e32d5
1 parent cfffc06
commit 84e32d5
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Showing 6 changed files with 47 additions and 28 deletions.
diff --git a/src/Microsoft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/CSharpCodeBuilder.cs b/src/Microsoft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/CSharpCodeBuilder.cs
@@ -39,8 +39,12 @@ public override CodeBuilderResult Build()
                         writer.WriteLine("private static object @__o;");
                     }
 
-                    new CSharpHelperVisitor(writer, Context).Accept(Tree.Chunks);
-                    new CSharpTypeMemberVisitor(writer, Context).Accept(Tree.Chunks);
+                    var csharpCodeVisitor = DecorateCSharpCodeVisitor(writer, 
+                                                                      Context, 
+                                                                      new CSharpCodeVisitor(writer, Context));
+
+                    new CSharpHelperVisitor(csharpCodeVisitor, writer, Context).Accept(Tree.Chunks);
+                    new CSharpTypeMemberVisitor(csharpCodeVisitor, writer, Context).Accept(Tree.Chunks);
                     new CSharpDesignTimeHelpersVisitor(writer, Context).AcceptTree(Tree);
                     new CSharpPropertyVisitor(writer, Context).Accept(Tree.Chunks);
 
@@ -55,7 +59,7 @@ public override CodeBuilderResult Build()
                         {
                             new CSharpTagHelperDeclarationVisitor(writer, Context).Accept(Tree.Chunks);
 
-                            new CSharpCodeVisitor(writer, Context).Accept(Tree.Chunks);
+                            csharpCodeVisitor.Accept(Tree.Chunks);
                         }
                     }
                 }
@@ -64,6 +68,13 @@ public override CodeBuilderResult Build()
             return new CodeBuilderResult(writer.GenerateCode(), writer.LineMappingManager.Mappings);
         }
 
+        protected virtual CSharpCodeVisitor DecorateCSharpCodeVisitor([NotNull] CSharpCodeWriter writer,
+                                                                      [NotNull] CodeBuilderContext context,
+                                                                      [NotNull] CSharpCodeVisitor incomingVisitor)
+        {
+            return incomingVisitor;
+        }
+
         protected virtual CSharpCodeWritingScope BuildClassDeclaration(CSharpCodeWriter writer)
         {
             var baseTypeVisitor = new CSharpBaseTypeVisitor(writer, Context);

diff --git a/...crosoft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/CSharpTagHelperCodeRenderer.cs b/...crosoft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/CSharpTagHelperCodeRenderer.cs
@@ -25,9 +25,7 @@ public class CSharpTagHelperCodeRenderer
         private static readonly TagHelperAttributeDescriptorComparer AttributeDescriptorComparer =
             new TagHelperAttributeDescriptorComparer();
 
-        // TODO: The work to properly implement this will be done in: https://github.com/aspnet/Razor/issues/74
-        private readonly TagHelperAttributeValueCodeRenderer _attributeValueCodeRenderer =
-            new TagHelperAttributeValueCodeRenderer();
+        private readonly TagHelperAttributeValueCodeRenderer _attributeValueCodeRenderer;
         private readonly CSharpCodeWriter _writer;
         private readonly CodeBuilderContext _context;
         private readonly IChunkVisitor _bodyVisitor;
@@ -41,12 +39,14 @@ public class CSharpTagHelperCodeRenderer
         /// <param name="context">A <see cref="CodeBuilderContext"/> instance that contains information about 
         /// the current code generation process.</param>
         public CSharpTagHelperCodeRenderer([NotNull] IChunkVisitor bodyVisitor,
+                                           [NotNull] TagHelperAttributeValueCodeRenderer attributeValueCodeRenderer,
                                            [NotNull] CSharpCodeWriter writer,
                                            [NotNull] CodeBuilderContext context)
         {
+            _bodyVisitor = bodyVisitor;
+            _attributeValueCodeRenderer = attributeValueCodeRenderer;
             _writer = writer;
             _context = context;
-            _bodyVisitor = bodyVisitor;
             _tagHelperContext = context.Host.GeneratedClassContext.GeneratedTagHelperContext;
         }
 
@@ -363,7 +363,7 @@ private void RenderBufferedAttributeValueAccessor()
 
         private void RenderBufferedAttributeValue(TagHelperAttributeDescriptor attributeDescriptor)
         {
-            RenderAttribute(
+            RenderAttributeValue(
                 attributeDescriptor,
                 valueRenderer: (writer) =>
                 {
@@ -373,7 +373,7 @@ private void RenderBufferedAttributeValue(TagHelperAttributeDescriptor attribute
 
         private void RenderRawAttributeValue(string value, TagHelperAttributeDescriptor attributeDescriptor)
         {
-            RenderAttribute(
+            RenderAttributeValue(
                 attributeDescriptor,
                 valueRenderer: (writer) =>
                 {
@@ -383,7 +383,7 @@ private void RenderRawAttributeValue(string value, TagHelperAttributeDescriptor
 
         private void RenderQuotedAttributeValue(string value, TagHelperAttributeDescriptor attributeDescriptor)
         {
-            RenderAttribute(
+            RenderAttributeValue(
                 attributeDescriptor,
                 valueRenderer: (writer) =>
                 {
@@ -417,8 +417,8 @@ private void BuildBufferedWritingScope(Action renderCode)
             }
         }
 
-        private void RenderAttribute(TagHelperAttributeDescriptor attributeDescriptor,
-                                     Action<CSharpCodeWriter> valueRenderer)
+        private void RenderAttributeValue(TagHelperAttributeDescriptor attributeDescriptor,
+                                          Action<CSharpCodeWriter> valueRenderer)
         {
             _attributeValueCodeRenderer.RenderAttributeValue(attributeDescriptor, _writer, _context, valueRenderer);
         }

diff --git a/...icrosoft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/Visitors/CSharpCodeVisitor.cs b/...icrosoft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/Visitors/CSharpCodeVisitor.cs
@@ -17,18 +17,25 @@ public class CSharpCodeVisitor : CodeVisitor<CSharpCodeWriter>
         private const string TemplateWriterName = "__razor_template_writer";
 
         private CSharpPaddingBuilder _paddingBuilder;
-        private CSharpTagHelperCodeRenderer _tagHelperCodeRenderer;
 
         public CSharpCodeVisitor(CSharpCodeWriter writer, CodeBuilderContext context)
             : base(writer, context)
         {
             _paddingBuilder = new CSharpPaddingBuilder(context.Host);
-            _tagHelperCodeRenderer = new CSharpTagHelperCodeRenderer(this, writer, context);
+            TagHelperRenderer = new CSharpTagHelperCodeRenderer(this, 
+                                                                new TagHelperAttributeValueCodeRenderer(), 
+                                                                writer, 
+                                                                context);
         }
 
+        public CSharpTagHelperCodeRenderer TagHelperRenderer { get; set; }
+
         protected override void Visit(TagHelperChunk chunk)
         {
-            _tagHelperCodeRenderer.RenderTagHelper(chunk);
+            if (TagHelperRenderer != null)
+            {
+                TagHelperRenderer.RenderTagHelper(chunk);
+            }
         }
 
         protected override void Visit(ChunkBlock chunk)

diff --git a/...rosoft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/Visitors/CSharpHelperVisitor.cs b/...rosoft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/Visitors/CSharpHelperVisitor.cs
@@ -9,12 +9,14 @@ public class CSharpHelperVisitor : CodeVisitor<CSharpCodeWriter>
     {
         private const string HelperWriterName = "__razor_helper_writer";
 
-        private CSharpCodeVisitor _codeVisitor;
+        private CSharpCodeVisitor _csharpCodeVisitor;
 
-        public CSharpHelperVisitor(CSharpCodeWriter writer, CodeBuilderContext context)
+        public CSharpHelperVisitor([NotNull] CSharpCodeVisitor csharpCodeVisitor,
+                                   [NotNull] CSharpCodeWriter writer,
+                                   [NotNull] CodeBuilderContext context)
             : base(writer, context)
         {
-            _codeVisitor = new CSharpCodeVisitor(writer, context);
+            _csharpCodeVisitor = csharpCodeVisitor;
         }
 
         protected override void Visit(HelperChunk chunk)
@@ -46,7 +48,7 @@ protected override void Visit(HelperChunk chunk)
             Context.TargetWriterName = HelperWriterName;
 
             // Generate children code
-            _codeVisitor.Accept(chunk.Children);
+            _csharpCodeVisitor.Accept(chunk.Children);
 
             Context.TargetWriterName = currentTargetWriterName;
 

diff --git a/...ft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/Visitors/CSharpTypeMemberVisitor.cs b/...ft.AspNet.Razor/Generator/Compiler/CodeBuilder/CSharp/Visitors/CSharpTypeMemberVisitor.cs
@@ -9,10 +9,12 @@ public class CSharpTypeMemberVisitor : CodeVisitor<CSharpCodeWriter>
     {
         private CSharpCodeVisitor _csharpCodeVisitor;
 
-        public CSharpTypeMemberVisitor(CSharpCodeWriter writer, CodeBuilderContext context)
+        public CSharpTypeMemberVisitor([NotNull] CSharpCodeVisitor csharpCodeVisitor, 
+                                       [NotNull] CSharpCodeWriter writer, 
+                                       [NotNull] CodeBuilderContext context)
             : base(writer, context)
         {
-            _csharpCodeVisitor = new CSharpCodeVisitor(writer, context);
+            _csharpCodeVisitor = csharpCodeVisitor;
         }
 
         protected override void Visit(TypeMemberChunk chunk)

diff --git a/src/Microsoft.AspNet.Razor/TagHelpers/TagHelperAttributeValueCodeRenderer.cs b/src/Microsoft.AspNet.Razor/TagHelpers/TagHelperAttributeValueCodeRenderer.cs
@@ -2,9 +2,6 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using System.Diagnostics;
-using System.Linq;
-using System.Reflection;
 using Microsoft.AspNet.Razor.Generator;
 using Microsoft.AspNet.Razor.Generator.Compiler.CSharp;
 
@@ -31,10 +28,10 @@ public class TagHelperAttributeValueCodeRenderer
         /// Writes the string: "new MyPropertyType(...)" to the output where the "..." is rendered by calling the
         /// <paramref name="renderAttributeValue"/> <see cref="Action"/>.
         /// </remarks>
-        public void RenderAttributeValue([NotNull] TagHelperAttributeDescriptor attributeDescriptor,
-                                         [NotNull] CSharpCodeWriter writer,
-                                         [NotNull] CodeBuilderContext context,
-                                         [NotNull] Action<CSharpCodeWriter> renderAttributeValue)
+        public virtual void RenderAttributeValue([NotNull] TagHelperAttributeDescriptor attributeDescriptor,
+                                                 [NotNull] CSharpCodeWriter writer,
+                                                 [NotNull] CodeBuilderContext context,
+                                                 [NotNull] Action<CSharpCodeWriter> renderAttributeValue)
         {
             renderAttributeValue(writer);
         }