Has anyone implement RadioButtonListFor<T> for ASP.NET MVC?

Question

There was an Html.RadioButtonList extension method in ASP.NET MVC Futures. Has anyone found a code for a strongly typed version RadioButtonListFor<T>. It would look like this in a view:

<%= Html.RadioButtonListFor(model=>model.Item,Model.ItemList) %> 

Answer 1

Here is the usage in the aspx page

    <%= Html.RadioButtonListFor(m => m.GenderRadioButtonList)%> 

Here is the view model

public class HomePageViewModel {     public enum GenderType     {         Male,         Female     }     public RadioButtonListViewModel<GenderType> GenderRadioButtonList { get; set; }      public HomePageViewModel()     {         GenderRadioButtonList = new RadioButtonListViewModel<GenderType>         {             Id = "Gender",             SelectedValue = GenderType.Male,             ListItems = new List<RadioButtonListItem<GenderType>>             {                 new RadioButtonListItem<GenderType>{Text = "Male", Value = GenderType.Male},                 new RadioButtonListItem<GenderType>{Text = "Female", Value = GenderType.Female}             }         };     } } 

Here's the view model used for radio button lists

public class RadioButtonListViewModel<T> {     public string Id { get; set; }     private T selectedValue;     public T SelectedValue     {         get { return selectedValue; }         set         {             selectedValue = value;             UpdatedSelectedItems();         }     }      private void UpdatedSelectedItems()     {         if (ListItems == null)             return;          ListItems.ForEach(li => li.Selected = Equals(li.Value, SelectedValue));     }      private List<RadioButtonListItem<T>> listItems;     public List<RadioButtonListItem<T>> ListItems     {         get { return listItems; }         set         {             listItems = value;             UpdatedSelectedItems();         }     } }  public class RadioButtonListItem<T> {     public bool Selected { get; set; }      public string Text { get; set; }      public T Value { get; set; }      public override string ToString()     {         return Value.ToString();     } } 

Here's the extension methods for RadioButtonListFor

public static class HtmlHelperExtensions {     public static string RadioButtonListFor<TModel, TRadioButtonListValue>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, RadioButtonListViewModel<TRadioButtonListValue>>> expression) where TModel : class     {         return htmlHelper.RadioButtonListFor(expression, null);     }      public static string RadioButtonListFor<TModel, TRadioButtonListValue>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, RadioButtonListViewModel<TRadioButtonListValue>>> expression, object htmlAttributes) where TModel : class     {         return htmlHelper.RadioButtonListFor(expression, new RouteValueDictionary(htmlAttributes));     }      public static string RadioButtonListFor<TModel, TRadioButtonListValue>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, RadioButtonListViewModel<TRadioButtonListValue>>> expression, IDictionary<string, object> htmlAttributes) where TModel : class     {         var inputName = GetInputName(expression);          RadioButtonListViewModel<TRadioButtonListValue> radioButtonList = GetValue(htmlHelper, expression);          if (radioButtonList == null)             return String.Empty;          if (radioButtonList.ListItems == null)             return String.Empty;          var divTag = new TagBuilder("div");         divTag.MergeAttribute("id", inputName);         divTag.MergeAttribute("class", "radio");         foreach (var item in radioButtonList.ListItems)         {             var radioButtonTag = RadioButton(htmlHelper, inputName, new SelectListItem{Text=item.Text, Selected = item.Selected, Value = item.Value.ToString()}, htmlAttributes);              divTag.InnerHtml += radioButtonTag;         }          return divTag + htmlHelper.ValidationMessage(inputName, "*");     }      public static string GetInputName<TModel, TProperty>(Expression<Func<TModel, TProperty>> expression)     {         if (expression.Body.NodeType == ExpressionType.Call)         {             var methodCallExpression = (MethodCallExpression)expression.Body;             string name = GetInputName(methodCallExpression);             return name.Substring(expression.Parameters[0].Name.Length + 1);          }         return expression.Body.ToString().Substring(expression.Parameters[0].Name.Length + 1);     }      private static string GetInputName(MethodCallExpression expression)     {         // p => p.Foo.Bar().Baz.ToString() => p.Foo OR throw...          var methodCallExpression = expression.Object as MethodCallExpression;         if (methodCallExpression != null)         {             return GetInputName(methodCallExpression);         }         return expression.Object.ToString();     }      public static string RadioButton(this HtmlHelper htmlHelper, string name, SelectListItem listItem,                          IDictionary<string, object> htmlAttributes)     {         var inputIdSb = new StringBuilder();         inputIdSb.Append(name)             .Append("_")             .Append(listItem.Value);          var sb = new StringBuilder();          var builder = new TagBuilder("input");         if (listItem.Selected) builder.MergeAttribute("checked", "checked");         builder.MergeAttribute("type", "radio");         builder.MergeAttribute("value", listItem.Value);         builder.MergeAttribute("id", inputIdSb.ToString());         builder.MergeAttribute("name", name + ".SelectedValue");         builder.MergeAttributes(htmlAttributes);         sb.Append(builder.ToString(TagRenderMode.SelfClosing));         sb.Append(RadioButtonLabel(inputIdSb.ToString(), listItem.Text, htmlAttributes));         sb.Append("<br>");          return sb.ToString();     }      public static string RadioButtonLabel(string inputId, string displayText,                                  IDictionary<string, object> htmlAttributes)     {         var labelBuilder = new TagBuilder("label");         labelBuilder.MergeAttribute("for", inputId);         labelBuilder.MergeAttributes(htmlAttributes);         labelBuilder.InnerHtml = displayText;          return labelBuilder.ToString(TagRenderMode.Normal);     }       public static TProperty GetValue<TModel, TProperty>(HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression) where TModel : class     {         TModel model = htmlHelper.ViewData.Model;         if (model == null)         {             return default(TProperty);         }         Func<TModel, TProperty> func = expression.Compile();         return func(model);     } }