From 8477f4763201a41b515366d88778f983eeb567d3 Mon Sep 17 00:00:00 2001
From: "N. Taylor Mullen" <nimullen@microsoft.com>
Date: Wed, 2 Apr 2014 12:52:59 -0700
Subject: [PATCH] Implement Display HTMLHelper.

Essentially add extension methods and call through to infrastructure.
---
 .../Html/HtmlHelper.cs                        | 19 ++++++++++++
 .../TemplatedHelpers/DisplayExtensions.cs     | 31 +++++++++++++++++++
 .../IHtmlHelperOfT.cs                         | 13 ++++++++
 3 files changed, 63 insertions(+)
 create mode 100644 src/Microsoft.AspNet.Mvc.Rendering/Html/TemplatedHelpers/DisplayExtensions.cs

diff --git a/src/Microsoft.AspNet.Mvc.Rendering/Html/HtmlHelper.cs b/src/Microsoft.AspNet.Mvc.Rendering/Html/HtmlHelper.cs
index 68c0a5863b..7820b4476b 100644
--- a/src/Microsoft.AspNet.Mvc.Rendering/Html/HtmlHelper.cs
+++ b/src/Microsoft.AspNet.Mvc.Rendering/Html/HtmlHelper.cs
@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
+using System.Linq.Expressions;
 using System.Net;
 using System.Reflection;
 using System.Text;
@@ -161,6 +162,24 @@ namespace Microsoft.AspNet.Mvc.Rendering
             return TagBuilder.CreateSanitizedId(name, IdAttributeDotReplacement);
         }
 
+        public virtual HtmlString Display(string expression,
+                                          string templateName,
+                                          string htmlFieldName,
+                                          object additionalViewData)
+        {
+            var templateBuilder = new TemplateBuilder(ViewContext,
+                                                      ViewData,
+                                                      ExpressionMetadataProvider.FromStringExpression(expression, ViewData, MetadataProvider),
+                                                      htmlFieldName ?? ExpressionHelper.GetExpressionText(expression),
+                                                      templateName,
+                                                      readOnly: true,
+                                                      additionalViewData: additionalViewData);
+
+            var templateResult = templateBuilder.Build();
+
+            return new HtmlString(templateResult);
+        }
+
         /// <inheritdoc />
         public virtual HtmlString Name(string name)
         {
diff --git a/src/Microsoft.AspNet.Mvc.Rendering/Html/TemplatedHelpers/DisplayExtensions.cs b/src/Microsoft.AspNet.Mvc.Rendering/Html/TemplatedHelpers/DisplayExtensions.cs
new file mode 100644
index 0000000000..3bab415600
--- /dev/null
+++ b/src/Microsoft.AspNet.Mvc.Rendering/Html/TemplatedHelpers/DisplayExtensions.cs
@@ -0,0 +1,31 @@
+
+namespace Microsoft.AspNet.Mvc.Rendering
+{
+    public static class DisplayExtensions
+    {
+        public static HtmlString Display<T>(this IHtmlHelper<T> html, string expression)
+        {
+            return html.Display(expression, templateName: null, htmlFieldName: null, additionalViewData: null);
+        }
+
+        public static HtmlString Display<T>(this IHtmlHelper<T> html, string expression, object additionalViewData)
+        {
+            return html.Display(expression, templateName: null, htmlFieldName: null, additionalViewData: additionalViewData);
+        }
+
+        public static HtmlString Display<T>(this IHtmlHelper<T> html, string expression, string templateName)
+        {
+            return html.Display(expression, templateName, htmlFieldName: null, additionalViewData: null);
+        }
+
+        public static HtmlString Display<T>(this IHtmlHelper<T> html, string expression, string templateName, object additionalViewData)
+        {
+            return html.Display(expression, templateName, htmlFieldName: null, additionalViewData: additionalViewData);
+        }
+
+        public static HtmlString Display<T>(this IHtmlHelper<T> html, string expression, string templateName, string htmlFieldName)
+        {
+            return html.Display(expression, templateName, htmlFieldName, additionalViewData: null);
+        }
+    }
+}
diff --git a/src/Microsoft.AspNet.Mvc.Rendering/IHtmlHelperOfT.cs b/src/Microsoft.AspNet.Mvc.Rendering/IHtmlHelperOfT.cs
index aa723347c3..79e644bb34 100644
--- a/src/Microsoft.AspNet.Mvc.Rendering/IHtmlHelperOfT.cs
+++ b/src/Microsoft.AspNet.Mvc.Rendering/IHtmlHelperOfT.cs
@@ -11,6 +11,19 @@ namespace Microsoft.AspNet.Mvc.Rendering
     /// <typeparam name="TModel">The <see cref="Type"/> of the model.</typeparam>
     public interface IHtmlHelper<TModel>
     {
+        /// <summary>
+        /// Returns HTML markup for each property in the object that is represented by the expression, using the specified template, HTML field ID, and additional view data.
+        /// </summary>
+        /// <param name="expression">An expression that identifies the object that contains the properties to display.</param>
+        /// <param name="templateName">The name of the template that is used to render the object.</param>
+        /// <param name="htmlFieldName">A string that is used to disambiguate the names of HTML input elements that are rendered for properties that have the same name.</param>
+        /// <param name="additionalViewData">An anonymous object that can contain additional view data that will be merged into the <see cref="ViewDataDictionary{TModel}"/> instance that is created for the template.</param>
+        /// <returns>The HTML markup for each property in the object that is represented by the expression.</returns>
+        HtmlString Display(string expression,
+                           string templateName,
+                           string htmlFieldName,
+                           object additionalViewData);
+
         /// <summary>
         /// Gets or sets the character that replaces periods in the ID attribute of an element.
         /// </summary>