@Html.DisplayName(), .DisplayText(), .Id(), .Name(), `.Value(…

…)` return `string`

- fixes #566
- allows compositions such as `@Html.Label("property", Html.Id("property"))`
- adjust XML comments to match
- add missing XML comments to `HtmlHelperValueExtensions`
- correct typos in `DisplayText()` and `ValidationMessageFor()` comments
- also increase XML comment consistency for changed methods

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

@@ -258,17 +258,16 @@ public HtmlString DisplayForModel(string templateName,
         }
 
         /// <inheritdoc />
-        public HtmlString DisplayName(string expression)
+        public string DisplayName(string expression)
         {
             var metadata = ExpressionMetadataProvider.FromStringExpression(expression, ViewData, MetadataProvider);
             return GenerateDisplayName(metadata, expression);
         }
 
         /// <inheritdoc />
-        public HtmlString DisplayText(string name)
+        public string DisplayText(string name)
         {
             var metadata = ExpressionMetadataProvider.FromStringExpression(name, ViewData, MetadataProvider);
-
             return GenerateDisplayText(metadata);
         }
 
@@ -305,7 +304,7 @@ public HtmlString Hidden(string name, object value, object htmlAttributes)
         }
 
         /// <inheritdoc />
-        public HtmlString Id(string name)
+        public string Id(string name)
         {
             return GenerateId(name);
         }
@@ -328,10 +327,10 @@ public HtmlString ListBox(string name, IEnumerable<SelectListItem> selectList, o
         }
 
         /// <inheritdoc />
-        public virtual HtmlString Name(string name)
+        public virtual string Name(string name)
         {
             var fullName = ViewData.TemplateInfo.GetFullHtmlFieldName(name);
-            return new HtmlString(Encode(fullName));
+            return fullName;
         }
 
         /// <inheritdoc />
@@ -585,7 +584,7 @@ public HtmlString TextBox(string name, object value, string format, IDictionary<
         }
 
         /// <inheritdoc />
-        public HtmlString Value([NotNull] string name, string format)
+        public string Value([NotNull] string name, string format)
         {
             return GenerateValue(name, value: null, format: format, useViewData: true);
         }
@@ -701,7 +700,7 @@ protected virtual HtmlString GenerateCheckBox(ModelMetadata metadata, string nam
                 htmlAttributes: htmlAttributeDictionary);
         }
 
-        protected virtual HtmlString GenerateDisplayName([NotNull] ModelMetadata metadata, string htmlFieldName)
+        protected virtual string GenerateDisplayName([NotNull] ModelMetadata metadata, string htmlFieldName)
         {
             // We don't call ModelMetadata.GetDisplayName here because
             // we want to fall back to the field name rather than the ModelType.
@@ -713,12 +712,12 @@ protected virtual HtmlString GenerateDisplayName([NotNull] ModelMetadata metadat
                     string.IsNullOrEmpty(htmlFieldName) ? string.Empty : htmlFieldName.Split('.').Last();
             }
 
-            return new HtmlString(Encode(resolvedDisplayName));
+            return resolvedDisplayName;
         }
 
-        protected virtual HtmlString GenerateDisplayText(ModelMetadata metadata)
+        protected virtual string GenerateDisplayText(ModelMetadata metadata)
         {
-            return new HtmlString(metadata.SimpleDisplayText);
+            return metadata.SimpleDisplayText ?? string.Empty;
         }
 
         protected HtmlString GenerateDropDown(ModelMetadata metadata, string expression,
@@ -845,9 +844,9 @@ protected virtual HtmlString GenerateHidden(
                 htmlAttributes: htmlAttributeDictionary);
         }
 
-        protected virtual HtmlString GenerateId(string expression)
+        protected virtual string GenerateId(string expression)
         {
-            return new HtmlString(Encode(ViewData.TemplateInfo.GetFullHtmlFieldName(expression)));
+            return ViewData.TemplateInfo.GetFullHtmlFieldName(expression);
         }
 
         protected virtual HtmlString GenerateLabel([NotNull] ModelMetadata metadata,
@@ -1344,7 +1343,7 @@ protected virtual HtmlString GenerateValidationMessage(string expression,
             return builder.ToHtmlString(TagRenderMode.Normal);
         }
 
-        protected virtual HtmlString GenerateValue(string name, object value, string format, bool useViewData)
+        protected virtual string GenerateValue(string name, object value, string format, bool useViewData)
         {
             var fullName = ViewData.TemplateInfo.GetFullHtmlFieldName(name);
             var attemptedValue = (string)GetModelStateValue(fullName, typeof(string));
@@ -1375,7 +1374,7 @@ protected virtual HtmlString GenerateValue(string name, object value, string for
                 resolvedValue = FormatValue(value, format);
             }
 
-            return new HtmlString(Encode(resolvedValue));
+            return resolvedValue;
         }
 
         protected virtual IEnumerable<ModelClientValidationRule> GetClientValidationRules(

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

@@ -88,14 +88,14 @@ public HtmlString DisplayFor<TValue>([NotNull] Expression<Func<TModel, TValue>>
         }
 
         /// <inheritdoc />
-        public HtmlString DisplayNameFor<TValue>([NotNull] Expression<Func<TModel, TValue>> expression)
+        public string DisplayNameFor<TValue>([NotNull] Expression<Func<TModel, TValue>> expression)
         {
             var metadata = GetModelMetadata(expression);
             return GenerateDisplayName(metadata, ExpressionHelper.GetExpressionText(expression));
         }
 
         /// <inheritdoc />
-        public HtmlString DisplayNameForInnerType<TInnerModel, TValue>(
+        public string DisplayNameForInnerType<TInnerModel, TValue>(
             [NotNull] Expression<Func<TInnerModel, TValue>> expression)
         {
             var metadata = ExpressionMetadataProvider.FromLambdaExpression<TInnerModel, TValue>(
@@ -113,7 +113,7 @@ public HtmlString DisplayNameForInnerType<TInnerModel, TValue>(
         }
 
         /// <inheritdoc />
-        public HtmlString DisplayTextFor<TValue>([NotNull] Expression<Func<TModel, TValue>> expression)
+        public string DisplayTextFor<TValue>([NotNull] Expression<Func<TModel, TValue>> expression)
         {
             return GenerateDisplayText(GetModelMetadata(expression));
         }
@@ -144,7 +144,7 @@ public HtmlString HiddenFor<TProperty>([NotNull] Expression<Func<TModel, TProper
         }
 
         /// <inheritdoc />
-        public HtmlString IdFor<TProperty>([NotNull] Expression<Func<TModel, TProperty>> expression)
+        public string IdFor<TProperty>([NotNull] Expression<Func<TModel, TProperty>> expression)
         {
             return GenerateId(GetExpressionName(expression));
         }
@@ -172,7 +172,7 @@ public HtmlString ListBoxFor<TProperty>(
         }
 
         /// <inheritdoc />
-        public HtmlString NameFor<TProperty>([NotNull] Expression<Func<TModel, TProperty>> expression)
+        public string NameFor<TProperty>([NotNull] Expression<Func<TModel, TProperty>> expression)
         {
             var expressionName = GetExpressionName(expression);
             return Name(expressionName);
@@ -242,7 +242,7 @@ public HtmlString ValidationMessageFor<TProperty>([NotNull] Expression<Func<TMod
         }
 
         /// <inheritdoc />
-        public HtmlString ValueFor<TProperty>(Expression<Func<TModel, TProperty>> expression, string format)
+        public string ValueFor<TProperty>(Expression<Func<TModel, TProperty>> expression, string format)
         {
             var metadata = GetModelMetadata(expression);
             return GenerateValue(ExpressionHelper.GetExpressionText(expression), metadata.Model, format,

src/Microsoft.AspNet.Mvc.Core/Rendering/HtmlHelperDisplayNameExtensions.cs

@@ -15,21 +15,19 @@ public static class HtmlHelperDisplayNameExtensions
         /// <summary>
         /// Gets the display name for the current model.
         /// </summary>
-        /// <returns>An <see cref="HtmlString"/> that represents HTML markup.</returns>
-        public static HtmlString DisplayNameForModel([NotNull] this IHtmlHelper htmlHelper)
+        /// <returns>The display name.</returns>
+        public static string DisplayNameForModel([NotNull] this IHtmlHelper htmlHelper)
         {
             return htmlHelper.DisplayName(string.Empty);
         }
 
         /// <summary>
-        /// Gets the display name for the model.
+        /// Gets the display name.
         /// </summary>
         /// <param name="htmlHelper">The <see cref="IHtmlHelper{T}"/> instance that this method extends.</param>
         /// <param name="expression">An expression that identifies the object that contains the display name.</param>
-        /// <returns>
-        /// The display name for the model.
-        /// </returns>
-        public static HtmlString DisplayNameFor<TInnerModel, TValue>(
+        /// <returns>The display name.</returns>
+        public static string DisplayNameFor<TInnerModel, TValue>(
             [NotNull] this IHtmlHelper<IEnumerable<TInnerModel>> htmlHelper,
             [NotNull] Expression<Func<TInnerModel, TValue>> expression)
         {

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

@@ -12,18 +12,18 @@ public static class HtmlHelperNameExtensions
         /// 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([NotNull] this IHtmlHelper htmlHelper)
+        /// <returns>The name.</returns>
+        public static string NameForModel([NotNull] this IHtmlHelper htmlHelper)
         {
             return htmlHelper.Name(string.Empty);
         }
 
         /// <summary>
-        /// Gets the full HTML field id for the current model.
+        /// Gets the full HTML field Id 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 IdForModel([NotNull] this IHtmlHelper htmlHelper)
+        /// <returns>The Id of the HTML element.</returns>
+        public static string IdForModel([NotNull] this IHtmlHelper htmlHelper)
         {
             return htmlHelper.Id(string.Empty);
         }

src/Microsoft.AspNet.Mvc.Core/Rendering/HtmlHelperValueExtensions.cs

@@ -8,24 +8,47 @@ namespace Microsoft.AspNet.Mvc.Rendering
 {
     public static class HtmlHelperValueExtensions
     {
-        public static HtmlString Value([NotNull] this IHtmlHelper htmlHelper, string name)
+        /// <summary>
+        /// Returns the model value for the given expression <paramref name="name"/>.
+        /// </summary>
+        /// <param name="htmlHelper">The <see cref="HtmlHelper"/> instance that this method extends.</param>
+        /// <param name="name">Name of an expression, relative to the current model.</param>
+        /// <returns>The value.</returns>
+        public static string Value([NotNull] this IHtmlHelper htmlHelper, string name)
         {
             return htmlHelper.Value(name, format: null);
         }
 
-        public static HtmlString ValueFor<TModel, TProperty>(
+        /// <summary>
+        /// Returns the model value for the given <paramref name="expression"/>.
+        /// </summary>
+        /// <param name="htmlHelper">The <see cref="HtmlHelper"/> instance that this method extends.</param>
+        /// <param name="expression">An expression, relative to the current model.</param>
+        /// <returns>The value.</returns>
+        public static string ValueFor<TModel, TProperty>(
             [NotNull] this IHtmlHelper<TModel> htmlHelper,
             [NotNull] Expression<Func<TModel, TProperty>> expression)
         {
             return htmlHelper.ValueFor(expression, format: null);
         }
 
-        public static HtmlString ValueForModel([NotNull] this IHtmlHelper htmlHelper)
+        /// <summary>
+        /// Returns the model value for the current model.
+        /// </summary>
+        /// <param name="htmlHelper">The <see cref="HtmlHelper"/> instance that this method extends.</param>
+        /// <returns>The value.</returns>
+        public static string ValueForModel([NotNull] this IHtmlHelper htmlHelper)
         {
             return ValueForModel(htmlHelper, format: null);
         }
 
-        public static HtmlString ValueForModel([NotNull] this IHtmlHelper htmlHelper, string format)
+        /// <summary>
+        /// Returns the model value for the current model.
+        /// </summary>
+        /// <param name="htmlHelper">The <see cref="HtmlHelper"/> instance that this method extends.</param>
+        /// <param name="format">The optional format string to apply to the value.</param>
+        /// <returns>The value.</returns>
+        public static string ValueForModel([NotNull] this IHtmlHelper htmlHelper, string format)
         {
             return htmlHelper.Value(string.Empty, format);
         }

src/Microsoft.AspNet.Mvc.Core/Rendering/IHtmlHelper.cs

@@ -162,17 +162,16 @@ HtmlString Display(
         /// <returns>
         /// The display name.
         /// </returns>
-        HtmlString DisplayName(string expression);
+        string DisplayName(string expression);
 
-        /// Returns the HtmlString corresponding to the property in the model specified by the name.
+        /// <summary>
+        /// Gets the display text for the specified expression <paramref name="name"/>.
         /// </summary>
-        /// <param name="name">
-        /// The string which identifies the object for which the HtmlString should be returned.</param>
+        /// <param name="name">Name of an expression, relative to the current model.</param>
         /// <returns>
-        /// New <see cref="HtmlString"/> containing the display text. If the value is null,
-        /// then it returns the ModelMetadata.NullDisplayText.
+        /// The display text. If the value is null, returns <see cref="ModelMetadata.NullDisplayText"/>.
         /// </returns>
-        HtmlString DisplayText(string name);
+        string DisplayText(string name);
 
         /// <summary>
         /// Returns a single-selection HTML {select} element using the specified name of the form field,
@@ -262,11 +261,11 @@ HtmlString DropDownList(
         HtmlString Hidden(string name, object value, object htmlAttributes);
 
         /// <summary>
-        /// Gets the Id of the given string.
+        /// Gets the HTML element Id for the specified expression <paramref name="name"/>.
         /// </summary>
-        /// <param name="name">The string which identifies the object for which the Id should be returned.</param>
-        /// <returns>New <see cref="HtmlString"/> containing the Id.</returns>
-        HtmlString Id(string name);
+        /// <param name="name">Name of an expression, relative to the current model.</param>
+        /// <returns>The Id of the HTML element.</returns>
+        string Id(string name);
 
         /// <summary>
         /// Returns an HTML label element and the property name of the property that is represented by the specified
@@ -294,11 +293,11 @@ HtmlString DropDownList(
         HtmlString ListBox(string name, IEnumerable<SelectListItem> selectList, object htmlAttributes);
 
         /// <summary>
-        /// Gets the full HTML field name for the given expression <paramref name="name"/>.
+        /// Gets the full HTML element 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);
+        /// <returns>The name.</returns>
+        string Name(string name);
 
         /// <summary>
         /// Returns a partial view in string format.
@@ -475,7 +474,7 @@ HtmlString ValidationSummary(
         /// </summary>
         /// <param name="name">Name of an expression, relative to the current model.</param>
         /// <param name="format">The optional format string to apply to the value.</param>
-        /// <returns>An <see cref="HtmlString"/> that represents HTML markup.</returns>
-        HtmlString Value([NotNull] string name, string format);
+        /// <returns>The value.</returns>
+        string Value([NotNull] string name, string format);
     }
 }