Optgroup in DropDownlistFor MVC 4 Not Support Mvc validation - asp.net-mvc

Question

public static MvcHtmlString DropDownGroupListFor<TModel, TValue>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TValue>> expression, IEnumerable<GroupedSelectListItem> selectList, string defaultText, object htmlAttributes, bool isDisabled)
{
if (isDisabled)
{
IDictionary<string, object> htmlAttributeMerge = new RouteValueDictionary(htmlAttributes);
htmlAttributeMerge.Add("disabled", "disabled");
return DropDownGroupListFor(htmlHelper,expression, selectList, defaultText, htmlAttributeMerge);
}
else
{
return DropDownGroupListFor(htmlHelper, expression, selectList, defaultText, htmlAttributes);
}
}
// Helper methods
private static IEnumerable<GroupedSelectListItem> GetSelectData(this HtmlHelper htmlHelper, string name)
{
object o = null;
if (htmlHelper.ViewData != null)
{
o = htmlHelper.ViewData.Eval(name);
}
if (o == null)
{
throw new InvalidOperationException(
String.Format(
CultureInfo.CurrentCulture,
"Missing Select Data",
name,
"IEnumerable<GroupedSelectListItem>"));
}
IEnumerable<GroupedSelectListItem> selectList = o as IEnumerable<GroupedSelectListItem>;
if (selectList == null)
{
throw new InvalidOperationException(
String.Format(
CultureInfo.CurrentCulture,
"Wrong Select DataType",
name,
o.GetType().FullName,
"IEnumerable<GroupedSelectListItem>"));
}
return selectList;
}
internal static string ListItemToOption(GroupedSelectListItem item)
{
TagBuilder builder = new TagBuilder("option")
{
InnerHtml = HttpUtility.HtmlEncode(item.Text)
};
if (item.Value != null)
{
builder.Attributes["value"] = item.Value;
}
if (item.Selected)
{
builder.Attributes["selected"] = "selected";
}
return builder.ToString(TagRenderMode.Normal);
}
private static MvcHtmlString SelectInternal(this HtmlHelper htmlHelper, string optionLabel, string name, IEnumerable<GroupedSelectListItem> selectList, bool allowMultiple, IDictionary<string, object> htmlAttributes)
{
name = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(name);
if (String.IsNullOrEmpty(name))
{
throw new ArgumentException("Null Or Empty", "name");
}
bool usedViewData = false;
// If we got a null selectList, try to use ViewData to get the list of items.
if (selectList == null)
{
selectList = GetSelectData(htmlHelper, name);
usedViewData = true;
}
object defaultValue = (allowMultiple) ? htmlHelper.GetModelStateValue(name, typeof(string[])) : htmlHelper.GetModelStateValue(name, typeof(string));
// If we haven't already used ViewData to get the entire list of items then we need to
// use the ViewData-supplied value before using the parameter-supplied value.
if (!usedViewData)
{
if (defaultValue == null)
{
defaultValue = htmlHelper.ViewData.Eval(name);
}
}
if (defaultValue != null)
{
IEnumerable defaultValues = (allowMultiple) ? defaultValue as IEnumerable : new[] { defaultValue };
IEnumerable<string> values = from object value in defaultValues select Convert.ToString(value, CultureInfo.CurrentCulture);
HashSet<string> selectedValues = new HashSet<string>(values, StringComparer.OrdinalIgnoreCase);
List<GroupedSelectListItem> newSelectList = new List<GroupedSelectListItem>();
foreach (GroupedSelectListItem item in selectList)
{
item.Selected = (item.Value != null) ? selectedValues.Contains(item.Value) : selectedValues.Contains(item.Text);
newSelectList.Add(item);
}
selectList = newSelectList;
}
// Convert each ListItem to an <option> tag
StringBuilder listItemBuilder = new StringBuilder();
// Make optionLabel the first item that gets rendered.
if (optionLabel != null)
{
listItemBuilder.AppendLine(ListItemToOption(new GroupedSelectListItem() { Text = optionLabel, Value = String.Empty, Selected = false }));
}
foreach (var group in selectList.GroupBy(i => i.GroupKey))
{
string groupName = selectList.Where(i => i.GroupKey == group.Key).Select(it => it.GroupName).FirstOrDefault();
listItemBuilder.AppendLine(string.Format("<optgroup label=\"{0}\" value=\"{1}\">", groupName, group.Key));
foreach (GroupedSelectListItem item in group)
{
listItemBuilder.AppendLine(ListItemToOption(item));
}
listItemBuilder.AppendLine("</optgroup>");
}
TagBuilder tagBuilder = new TagBuilder("select")
{
InnerHtml = listItemBuilder.ToString()
};
foreach (var htmlAttribute in htmlAttributes)
{
tagBuilder.MergeAttribute(
htmlAttribute.Key.Replace('_', '-'),
(string)htmlAttribute.Value
);
}
tagBuilder.MergeAttributes(htmlAttributes);
tagBuilder.MergeAttribute("name", name, true /* replaceExisting */);
tagBuilder.GenerateId(name);
if (allowMultiple)
{
tagBuilder.MergeAttribute("multiple", "multiple");
}
// If there are any errors for a named field, we add the css attribute.
ModelState modelState;
if (htmlHelper.ViewData.ModelState.TryGetValue(name, out modelState))
{
if (modelState.Errors.Count > 0)
{
tagBuilder.AddCssClass(HtmlHelper.ValidationInputCssClassName);
}
}
return MvcHtmlString.Create(tagBuilder.ToString());
}
internal static object GetModelStateValue(this HtmlHelper helper, string key, Type destinationType)
{
ModelState modelState;
if (helper.ViewData.ModelState.TryGetValue(key, out modelState))
{
if (modelState.Value != null)
{
return modelState.Value.ConvertTo(destinationType, null /* culture */);
}
}
return null;
}
#Html.DropDownGroupListFor(m => m.id, Model.list, null, new { #class
= "form-control"})
this the whole code Validation On Id But validtion not work,validation is server side when click on button to submit validtion not fire why?