CheckBoxLabelExtension

gistfile1.cs

namespace System.Web.Mvc.Html {
    using System.Collections;
    using System;
    using System.Diagnostics.CodeAnalysis;
    using System.Linq;
    using System.Linq.Expressions;

    public static class CheckBoxLabelExtensions {
        public static MvcHtmlString CheckBoxLabel(this HtmlHelper html, string expression) {
            return CheckBoxLabel(html, expression, null);
        }

        public static MvcHtmlString CheckBoxLabel(this HtmlHelper html, string expression, string labelText) {
            return CheckBoxLabelHelper(html, ModelMetadata.FromStringExpression(expression, html.ViewData), expression, labelText);
        }

        [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]
        public static MvcHtmlString CheckBoxLabelFor<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, TValue>> expression) {
            return CheckBoxLabelFor<TModel, TValue>(html, expression, null);
        }

        [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an appropriate nesting of generic types")]
        public static MvcHtmlString CheckBoxLabelFor<TModel, TValue>(this HtmlHelper<TModel> html, Expression<Func<TModel, TValue>> expression, string labelText) {
            return CheckBoxLabelHelper(html, ModelMetadata.FromLambdaExpression(expression, html.ViewData), ExpressionHelper.GetExpressionText(expression), labelText);
        }

        public static MvcHtmlString CheckBoxLabelForModel(this HtmlHelper html) {
            return CheckBoxLabelForModel(html, null);
        }

        public static MvcHtmlString CheckBoxLabelForModel(this HtmlHelper html, string labelText) {
            return CheckBoxLabelHelper(html, html.ViewData.ModelMetadata, String.Empty, labelText);
        }

        internal static MvcHtmlString CheckBoxLabelHelper(HtmlHelper html, ModelMetadata metadata, string htmlFieldName, string labelText = null) {
            string resolvedLabelText = labelText ?? metadata.DisplayName ?? metadata.PropertyName ?? htmlFieldName.Split('.').Last();
            if (String.IsNullOrEmpty(resolvedLabelText)) {
                return MvcHtmlString.Empty;
            }

            TagBuilder label = new TagBuilder("label");
            label.Attributes.Add("for", TagBuilder.CreateSanitizedId(html.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(htmlFieldName)));
            label.InnerHtml = String.Format("<span></span>{0}", resolvedLabelText);

            return new MvcHtmlString(label.ToString(TagRenderMode.Normal));
        }
    }
}