How to make a default editor template for enums in MVC 4?

Question

We know that if we define a template for a base type, that template could serve also for the derived types (if any other template was not used to override it).

As we can't inherit an Enum, nor enums are considered inherited from the Enum, so neither the Enum.cshtml template in the Views\Shared\EditorTemplates will not be active for different custom enum properties of the objects, like this one:

public enum Role
{
    Admin,
    User,
    Guest
}

I already saw some answers on this topic for ASP in general, but I am wondering if in MVC 4 there are some improvements on this subject?

PS. I mean without use any explicit template attribution (like @Html.EditorFor(model => model.Role, "Enum") or [UIHint("Enum")])

PPS. I am novice in MVC, so I'll appreciate your simple answers.

I'm a little confused what you're asking for. So simply defining an Editor Template for Enum, i.e. Enum.cshtml, is insufficient? — asymptoticFault, Oct 02 '13 at 14:36
Could you give an example of the desired generated html from your enum ? — Raphaël Althaus, Oct 02 '13 at 16:47

score 7 · Accepted Answer · edited Nov 15 '16 at 16:08

7

K. Scott Allen has a nice article about this.

edited Nov 15 '16 at 16:08

Stacked

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answered Oct 02 '13 at 16:57

lajjne

699
5
15

Good article. But need to include `Nullable` enum model types – FindOutIslamNow May 30 '18 at 09:59

score 1 · Answer 2 · answered Sep 01 '17 at 09:17

In MVC 5, you can add a template to Views->Shared->EditorTemplates containing this code:

@model Enum
@{
    var optionLabel = ViewData["optionLabel"] as string;
    var htmlAttributes = ViewData["htmlAttributes"];
}
@Html.EnumDropDownListFor(m => m, optionLabel, htmlAttributes)

Example usage:

@Html.EditorFor(model => model.PropertyType, 
                new { 
                       htmlAttributes = new { @class = "form-control" },
                       optionLabel = "Select" 
                    })

In MVC 4, you don't have the EnumDropDownListFor extension, but you could roll your own, which I did previously like this:

public static MvcHtmlString DropDownListFor<TModel, TEnum>
   (this HtmlHelper<TModel> htmlHelper, 
    Expression<Func<TModel, TEnum>> expression, 
    string optionLabel = null, object htmlAttributes = null)
{
    //This code is based on the blog - it's finding out if it nullable or not
    Type metaDataModelType = ModelMetadata
       .FromLambdaExpression(expression, htmlHelper.ViewData).ModelType;
    Type enumType = Nullable.GetUnderlyingType(metaDataModelType) ?? metaDataModelType;

    if (!enumType.IsEnum)
        throw new ArgumentException("TEnum must be an enumerated type");  


    IEnumerable<SelectListItem> items = Enum.GetValues(enumType).Cast<TEnum>()
       .Select(e => new SelectListItem
               {
                  Text = e.GetDisplayName(),
                  Value = e.ToString(),
                  Selected = e.Equals(ModelMetadata
                     .FromLambdaExpression(expression, htmlHelper.ViewData).Model)
               });

    return htmlHelper.DropDownListFor(
        expression,
        items,
        optionLabel,
        htmlAttributes
        );
}

References:

http://stackoverflow.com/questions/79126/create-generic-method-constraining-t-to-an-enum

http://blogs.msdn.com/b/stuartleeks/archive/2010/05/21/asp-net-mvc-creating-a-dropdownlist-helper-for-enums.aspx

Christian · Answer 3 · 2021-03-31T13:39:48.027

0

Also; there is:

@Html.EnumDropDownListFor(model => model.Role, new { @class = ".." })

Role being the enum of course :)

edited Mar 31 '21 at 13:39

answered Mar 31 '21 at 13:15

Christian

394
2
17

How to make a default editor template for enums in MVC 4?

3 Answers3

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