Add `Name()`, `NameFor()`, and `NameForModel()` helper methods

- `Name()` is a `virtual` instance method to allow useful derivation
- `NameFor()` is an instance method to avoid adding `GetExpressionName()`
  to the public surface; either method could be `virtual`
- `NameForModel()` is an extension method because it's not usefully overridden
- use `Name*()` in sample

samples/MvcSample.Web/Views/Shared/MyView.cshtml

@@ -4,6 +4,11 @@
     Layout = "/Views/Shared/_Layout.cshtml";
     ViewBag.Title = "Home Page";
     string nullValue = null;
+
+    ViewBag.Anon = new
+    {
+        Address = new { Street = "123 Fake St.", City = "Redmond", State = "WA", Country = "USA", },
+    };
 }
 
 @functions {
@@ -53,6 +58,46 @@
         <p>You can easily find a web hosting company that offers the right mix of features and price for your applications.</p>
         <p><a class="btn btn-default" href="http://go.microsoft.com/fwlink/?LinkId=301867">Learn more &raquo;</a></p>
     </div>
+</div>
+
+<div class="row">
+    <div style="float: left; border: 5px solid blue;">
+        <table>
+            <tr>
+                <td>
+                    <label class="control-label col-md-2">ForModel</label>
+                </td>
+                <td>
+                    '@Html.NameForModel()'
+                </td>
+            </tr>
+            <tr>
+                <td>
+                    <label class="control-label col-md-2">Name</label>
+                </td>
+                <td>
+                    '@Html.Name("Name")'
+                </td>
+            </tr>
+            <tr>
+                <td>
+                    <label class="control-label col-md-2">m.Address</label>
+                </td>
+                <td>
+                    '@Html.NameFor(m => m.Address)'
+                </td>
+            </tr>
+            <tr>
+                <td>
+                    <label class="control-label col-md-2">Anon.Address.Street</label>
+                </td>
+                <td>
+                    '@Html.Name("Anon.Address.Street")'
+                </td>
+            </tr>
+        </table>
+    </div>
+
     <div style="float: right; border: 5px solid red;">
         @await Component.InvokeAsync("Tags", 15)
     </div>

src/Microsoft.AspNet.Mvc.Rendering/Html/HtmlHelper.cs

@@ -130,6 +130,15 @@ namespace Microsoft.AspNet.Mvc.Rendering
             return TagBuilder.CreateSanitizedId(name, IdAttributeDotReplacement);
         }
 
+        /// <inheritdoc />
+        [SuppressMessage("Microsoft.Naming", "CA1719:ParameterNamesShouldNotMatchMemberNames",
+            MessageId = "1#", Justification = "This is a shipped API.")]
+        public virtual HtmlString Name(string name)
+        {
+            var fullName = ViewData.TemplateInfo.GetFullHtmlFieldName(name);
+            return new HtmlString(Encode(fullName));
+        }
+
         public async Task<HtmlString> PartialAsync([NotNull] string partialViewName, object model, ViewDataDictionary viewData)
         {
             using (var writer = new StringWriter(CultureInfo.CurrentCulture))

src/Microsoft.AspNet.Mvc.Rendering/Html/HtmlHelperOfT.cs

@@ -1,5 +1,7 @@
 using System;
-using Microsoft.AspNet.Abstractions;
+using System.Diagnostics.CodeAnalysis;
+using System.Linq.Expressions;
+using Microsoft.AspNet.Mvc.Rendering.Expressions;
 
 namespace Microsoft.AspNet.Mvc.Rendering
 {
@@ -36,5 +38,21 @@ namespace Microsoft.AspNet.Mvc.Rendering
 
             base.Contextualize(viewContext);
         }
+
+        /// <inheritdoc />
+        [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures",
+            Justification = "This is an appropriate nesting of generic types")]
+        [SuppressMessage("Microsoft.Design", "CA1011:ConsiderPassingBaseTypesAsParameters",
+            Justification = "Users cannot use anonymous methods with the LambdaExpression type")]
+        public HtmlString NameFor<TProperty>([NotNull] Expression<Func<TModel, TProperty>> expression)
+        {
+            var expressionName = GetExpressionName(expression);
+            return Name(expressionName);
+        }
+
+        protected string GetExpressionName<TProperty>([NotNull] Expression<Func<TModel, TProperty>> expression)
+        {
+            return ExpressionHelper.GetExpressionText(expression);
+        }
     }
 }

src/Microsoft.AspNet.Mvc.Rendering/HtmlHelperNameExtensions.cs

@@ -0,0 +1,19 @@
+
+namespace Microsoft.AspNet.Mvc.Rendering
+{
+    /// <summary>
+    /// Name-related extensions for <see cref="HtmlHelper"/> and <see cref="HtmlHelper{T}"/>.
+    /// </summary>
+    public static class HtmlHelperNameExtensions
+    {
+        /// <summary>
+        /// Gets the full HTML field name for the current model.
+        /// </summary>
+        /// <param name="htmlHelper">The <see cref="HtmlHelper"/> instance that this method extends.</param>
+        /// <returns>An <see cref="HtmlString"/> that represents HTML markup.</returns>
+        public static HtmlString NameForModel<TModel>([NotNull] this IHtmlHelper<TModel> htmlHelper)
+        {
+            return htmlHelper.Name(string.Empty);
+        }
+    }
+}

src/Microsoft.AspNet.Mvc.Rendering/IHtmlHelperOfT.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq.Expressions;
 using System.Threading.Tasks;
 
 namespace Microsoft.AspNet.Mvc.Rendering
@@ -50,6 +51,21 @@ namespace Microsoft.AspNet.Mvc.Rendering
         /// <returns>The ID of the HTML element.</returns>
         string GenerateIdFromName(string name);
 
+        /// <summary>
+        /// Gets the full HTML field name for the given expression <paramref name="name"/>.
+        /// </summary>
+        /// <param name="name">Name of an expression, relative to the current model.</param>
+        /// <returns>An <see cref="HtmlString"/> that represents HTML markup.</returns>
+        HtmlString Name(string name);
+
+        /// <summary>
+        /// Gets the full HTML field name for the given <paramref name="expression"/>.
+        /// </summary>
+        /// <typeparam name="TProperty">The <see cref="Type"/> the <paramref name="expression"/> returns.</typeparam>
+        /// <param name="expression">An expression, relative to the current model.</param>
+        /// <returns>An <see cref="HtmlString"/> that represents HTML markup.</returns>
+        HtmlString NameFor<TProperty>([NotNull] Expression<Func<TModel, TProperty>> expression);
+
         /// <summary>
         /// Wraps HTML markup in an <see cref="HtmlString"/>, which will enable HTML markup to be
         /// rendered to the output without getting HTML encoded.
@@ -66,7 +82,6 @@ namespace Microsoft.AspNet.Mvc.Rendering
         /// <returns>An <see cref="HtmlString"/> that represents HTML markup.</returns>
         HtmlString Raw(object value);
 
-        
         /// <summary>
         /// Returns a partial view in string format.
         /// </summary>