optgroup in mvc 3

Question

Hi Everybody,

I have this:

[code]
public static class GroupDropListExtensions
{
    public static MvcHtmlString GroupDropList(this HtmlHelper helper, string name, IEnumerable<GroupDropListItem> data, int? SelectedValue, object htmlAttributes)
    {
        if (data == null && helper.ViewData != null)
            data = helper.ViewData.Eval(name) as IEnumerable<GroupDropListItem>;
        if (data == null) return new MvcHtmlString(string.Empty);

        var select = new TagBuilder("select");

        if (htmlAttributes != null)
            select.MergeAttributes(new RouteValueDictionary(htmlAttributes));

        select.GenerateId(name);
        select.MergeAttribute("name", name);

        var optgroupHtml = new StringBuilder();
        var groups = data.ToList();
        foreach (var group in data)
        {
            var groupTag = new TagBuilder("optgroup");
            groupTag.Attributes.Add("label", helper.Encode(group.Name));
            var optHtml = new StringBuilder();
            foreach (var item in group.Items)
            {
                var option = new TagBuilder("option");
                option.Attributes.Add("value", helper.Encode(item.Value));
                if (SelectedValue != 0 && item.Value == SelectedValue)
                    option.Attributes.Add("selected", "selected");
                option.InnerHtml = helper.Encode(item.Text);
                optHtml.AppendLine(option.ToString(TagRenderMode.Normal));
            }
            groupTag.InnerHtml = optHtml.ToString();
            optgroupHtml.AppendLine(groupTag.ToString(TagRenderMode.Normal));
        }
        select.InnerHtml = optgroupHtml.ToString();
        return new MvcHtmlString(select.ToString(TagRenderMode.Normal));
    }

    /*
    public static object GroupDropList(this HtmlHelper helper, string weekid, IEnumerable<GroupDropListItem> getWeekNumbers, object selectedValue)
    {
       

    }
     */
}

public class GroupDropListItem
{
    public string Name { get; set; }
    public List<OptionItem> Items { get; set; }
}

public class OptionItem
{
    public string Text { get; set; }
    public int Value { get; set; }
}
[/code]

and the extension method that will use the class:

[code]
 public static IEnumerable<GroupDropListItem> GetWeekNumbers(this HtmlHelper helper /*Dictionary<int, DateTime> dayOfWeek*/  /*,DateTime allWeeks*/ /*int selectID*/)
        {
            var janFirst = new DateTime(DateTime.Today.Year, 1, 1);
            //beware different cultures.
            var firstWeek = janFirst.AddDays(1 - (int)(janFirst.DayOfWeek));
            int j = -1;
            foreach (var x1 in Enumerable.Range(0, 52).Select(i => new
            {
                weekStart = firstWeek.AddDays(i * 7),
                Tuesday = firstWeek.AddDays(i * 3)
            }).TakeWhile(x => x.weekStart.Year <= janFirst.Year).Select(x => new
            {
                x.weekStart,

                tuesday = x.weekStart.AddDays(3),
                weekFinish = x.weekStart.AddDays(6)
            }).SkipWhile(x => x.weekFinish < janFirst.AddDays(1)))
            {
                j++;
                yield return new GroupDropListItem(
                                 {
                                     List<GroupDropListItem> = new
                                                 {
                                                     Maandag = firstWeek.AddDays(j*7).ToShortDateString(),
                                                     //.OrderBy(item => item.ToString(CultureInfo.InvariantCulture)),
                                                     Dindsdag = x1.weekStart.AddDays(1).ToShortDateString(),
                                                     Wendsday = x1.weekStart.AddDays(2).ToShortDateString(),
                                                     Thursday = x1.weekStart.AddDays(3).ToShortDateString(),
                                                     Fryday = x1.weekStart.AddDays(4).ToShortDateString(),
                                                     Saterday = x1.weekStart.AddDays(5).ToShortDateString(),
                                                     Sunday = x1.weekStart.AddDays(6).ToShortDateString(),
                                                     //vrijdag = x1.weekStart.AddDays(6).ToShortDateString(),
                                                     //weekNum = j + 1
                                                 }.ToString(),



                                     Name  = (j + 1).ToString(CultureInfo.InvariantCulture);//.ToString(CultureInfo.InvariantCulture))

                                 });

            }

            //return helper.DropDownList()
        }//end method
[/code]

and for the view:

[code]
<div class="editor-field">
                       
                       
                                  
                        @Html.GroupDropList("weekId",  (IEnumerable<GroupDropListItem>) Html.GetWeekNumbers(), new {onchange = "Selectedchange();"})
                        @Html.ValidationMessageFor(model => model != null && model.Week != null ? model.Week.WeekNumber : null)
                    </div>
[/code]

But how to get the helper class: GroupDropListExtensions

integrated in the othter helper method:

GetWeekNumbers.

THX for helping