Localized enum strings in SelectList - asp.net-mvc-3

Question

In my MVC3 app. I'm using select list to populate combo box with enum values like this
<div class="editor-field">
#Html.DropDownListFor(x => x.AdType, new SelectList(Enum.GetValues(typeof(MyDomain.Property.AdTypeEnum))), " ", new { #class = "dxeButtonEdit_Glass" })
</div>
MyDomain.Property looks like this
public enum AdTypeEnum
{
Sale = 1,
Rent = 2,
SaleOrRent = 3
};
How can I use my localized strings to localize these enums?

Answer 1

You could write a custom attribute:
public class LocalizedNameAttribute: Attribute
{
private readonly Type _resourceType;
private readonly string _resourceKey;
public LocalizedNameAttribute(string resourceKey, Type resourceType)
{
_resourceType = resourceType;
_resourceKey = resourceKey;
DisplayName = (string)_resourceType
.GetProperty(_resourceKey, BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Public)
.GetValue(null, null);
}
public string DisplayName { get; private set; }
}
and a custom DropDownListForEnum helper:
public static class DropDownListExtensions
{
public static IHtmlString DropDownListForEnum<TModel, TProperty>(
this HtmlHelper<TModel> htmlHelper,
Expression<Func<TModel, TProperty>> expression,
string optionLabel,
object htmlAttributes
)
{
if (!typeof(TProperty).IsEnum)
{
throw new Exception("This helper can be used only with enum types");
}
var enumType = typeof(TProperty);
var fields = enumType.GetFields(
BindingFlags.Static | BindingFlags.GetField | BindingFlags.Public
);
var values = Enum.GetValues(enumType).OfType<TProperty>();
var items =
from value in values
from field in fields
let descriptionAttribute = field
.GetCustomAttributes(
typeof(LocalizedNameAttribute), true
)
.OfType<LocalizedNameAttribute>()
.FirstOrDefault()
let displayName = (descriptionAttribute != null)
? descriptionAttribute.DisplayName
: value.ToString()
where value.ToString() == field.Name
select new { Id = value, Name = displayName };
var metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
var enumObj = metadata;
var selectList = new SelectList(items, "Id", "Name", metadata.Model);
return htmlHelper.DropDownListFor(expression, selectList, optionLabel, htmlAttributes);
}
}
And then it's easy:
Model:
public enum AdTypeEnum
{
[LocalizedName("Sale", typeof(Messages))]
Sale = 1,
[LocalizedName("Rent", typeof(Messages))]
Rent = 2,
[LocalizedName("SaleOrRent", typeof(Messages))]
SaleOrRent = 3
}
public class MyViewModel
{
public AdTypeEnum AdType { get; set; }
}
Controller:
public class HomeController : Controller
{
public ActionResult Index()
{
return View(new MyViewModel
{
AdType = AdTypeEnum.SaleOrRent
});
}
}
View:
#model MyViewModel
#Html.DropDownListForEnum(
x => x.AdType,
" ",
new { #class = "foo" }
)
Finally you should create a Messages.resx file which will contain the necessary keys (Sale, Rent and SaleOrRent). And if you want to localize you simply define a Messages.xx-XX.resx with the same keys for a different culture and swap the current thread culture.