mcs/class/System.Web.Mvc3/Mvc/Html/LabelExtensions.cs

   1 namespace System.Web.Mvc.Html {
   2     using System;
   3     using System.Diagnostics.CodeAnalysis;
   4     using System.Linq;
   5     using System.Linq.Expressions;
   6
   7     public static class LabelExtensions {
   8         public static MvcHtmlString Label(this HtmlHelper html, string expression) {
   9             return Label(html,
  10                          expression,
  11                          null);
  12         }
  13
  14         public static MvcHtmlString Label(this HtmlHelper html, string expression, string labelText) {
  15             return LabelHelper(html,
  16                                ModelMetadata.FromStringExpression(expression, html.ViewData),
  17                                expression,
  18                                labelText);
  19         }
  20
  21         [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]
  22         public static MvcHtmlString LabelFor<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, TValue>> expression) {
  23             return LabelFor<TModel, TValue>(html, expression, null);
  24         }
  25
  26         [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]
  27         public static MvcHtmlString LabelFor<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, TValue>> expression, string labelText) {
  28             return LabelHelper(html,
  29                                ModelMetadata.FromLambdaExpression(expression, html.ViewData),
  30                                ExpressionHelper.GetExpressionText(expression),
  31                                labelText);
  32         }
  33
  34         public static MvcHtmlString LabelForModel(this HtmlHelper html) {
  35             return LabelForModel(html, null);
  36         }
  37
  38         public static MvcHtmlString LabelForModel(this HtmlHelper html, string labelText) {
  39             return LabelHelper(html, html.ViewData.ModelMetadata, String.Empty, labelText);
  40         }
  41
  42         internal static MvcHtmlString LabelHelper(HtmlHelper html, ModelMetadata metadata, string htmlFieldName, string labelText = null) {
  43             string resolvedLabelText = labelText ?? metadata.DisplayName ?? metadata.PropertyName ?? htmlFieldName.Split('.').Last();
  44             if (String.IsNullOrEmpty(resolvedLabelText)) {
  45                 return MvcHtmlString.Empty;
  46             }
  47
  48             TagBuilder tag = new TagBuilder("label");
  49             tag.Attributes.Add("for", TagBuilder.CreateSanitizedId(html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(htmlFieldName)));
  50             tag.SetInnerText(resolvedLabelText);
  51             return tag.ToMvcHtmlString(TagRenderMode.Normal);
  52         }
  53     }
  54 }