Question

I need some help. I’m trying to build a view where I need groups of radiobuttons of enum types.
I have several enum types(classes) like this:

[DataContract(Namespace = Constants.SomeDataContractNamespace)]
public enum OneEnumDataContract
{
    [Display(Name = "Text_None", Description = "Text_None", ResourceType = typeof(TextResource))]
    [EnumMember]
    None = 0,

    [Display(Name = "Text_Medium", Description = "Text_Medium", ResourceType = typeof(TextResource))]
    [EnumMember]
    Medium = 1,

    [Display(Name = "Text_Very", Description = "Text_Very", ResourceType = typeof(TextResource))]
    [EnumMember]
    Very = 2
}

In my model(a datacontract, using WCF) I have this property for the enum datacontract:

    [DataMember(Order = 23)]
    [Display(Name = "EnumValue", Description = "EnumValue_Description", ResourceType = typeof(TextResource))]
    public OneEnumDataContract EnumClass1 { get; set; }

In my view I would try to make the group of radiobuttons like this(with a helper):

@Html.RadioButtonListEnum("EnumList1", Model.EnumClass1)

My helper:

public static MvcHtmlString RadioButtonListEnum<TModel>(this HtmlHelper<TModel> helper, string  NameOfList, object RadioOptions)
    {
        StringBuilder sb = new StringBuilder();
        //som other code for pairing with resourcefile...

        foreach(var myOption in enumTexts.AllKeys)
        {
            sb.Append("<p>");
            sb.Append(enumTexts.GetValues(myOption)[0]);
            sb.Append(helper.RadioButton(NameOfList, System.Convert.ToInt16(myOption)));
            sb.Append("</p>");
        }
        return MvcHtmlString.Create(sb.ToString());
    }

This gives me the first enumvalue in OneEnumDataContract, None, as the parameter RadioOptions.
How can I get all the enumvalues in the datacontract into the helper?

Answer 1

This is one I created recently. It won’t work if you try it on a non-enum but works for my enum needs. I copied bit’s and pieces from different DropDownList helpers like nikeaa posted.

#region RadioButtonList


public static MvcHtmlString RadioButtonListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IDictionary<string, object> htmlAttributes = null) where TModel : class
{
    ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
    String field = ExpressionHelper.GetExpressionText(expression);
    String fieldname = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(field);
    var inputName = fieldname;
    TProperty val = GetValue(htmlHelper, expression);

    var divTag = new TagBuilder("div");
    divTag.MergeAttribute("id", inputName);
    divTag.MergeAttribute("class", "radio");
    foreach (var item in Enum.GetValues(val.GetType()))
    {


        DisplayAttribute[] attr = (DisplayAttribute[])item.GetType().GetField(item.ToString()).GetCustomAttributes(typeof(DisplayAttribute), true);
        if (attr == null || attr.Length == 0 || attr[0].Name != null)
        {
            string name = attr != null && attr.Length > 0 && !string.IsNullOrWhiteSpace(attr[0].Name) ? attr[0].Name : item.ToString();
            var itemval = item;
            var radioButtonTag = RadioButton(htmlHelper, inputName, new SelectListItem { Text = name, Value = itemval.ToString(), Selected = val.Equals(itemval) }, htmlAttributes);

            divTag.InnerHtml += radioButtonTag;
        }
    }


    return new MvcHtmlString(divTag.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);
    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);
}

#endregion

I use it like this

@Html.RadioButtonListFor(m => m.PlayFormat)

You may need to more code to set the correct element name for more complicated uses.

If the enum items have a Display attribute, the name is displayed. Otherwise the enum item is displayed. If the Display name is null, that value is not shown as an option. In this enum, “None” isn’t displayed, “Singles” is displayed from the enum value, “Men’s Doubles” and all the other’s have text from [Display(Name=”Men’s Doubles”)]

public enum PlayFormat
{
    [Display(Name=null)]
    None = 0,
    Singles = 1,
    [Display(Name = "Men's Doubles")]
    MenDoubles = 2,
    [Display(Name = "Women's Doubles")]
    WomenDoubles = 3,
    [Display(Name = "Mixed Doubles")]
    MixedDoubles = 4,
    [Display(Name = "Men's Group")]
    MenGroup = 5,
    [Display(Name = "Women's Group")]
    WomenGroup = 6,
    [Display(Name = "Mixed Group")]
    MixedGroup = 7
}

The page looks like this (except each – is a radio button)

- Singles
- Men's Doubles
- Women's Doubles
- Mixed Doubles
- Men's Group
- Women's Group
- Mixed Group