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How to make a default editor template for enums?


How can I make a default editor template for enums? By which I mean: can I do something like this:

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Enum>" %> 
<% -- any code to read the enum and write a dropdown -->

And put this in the EditorTemplates folder under the name Enum.ascx?

Here's a workaround for my problem that I tried, but it's not what I need.

Here is my Enum:

public enum GenderEnum
{
    /// <summary>
    /// Male
    /// </summary>
    [Description("Male Person")]
    Male,

    /// <summary>
    /// Female
    /// </summary>
    [Description("Female Person")]
    Female
}

I made a template called GenderEnum.acsx and put it in the Shared/EditorTemplates folder. Here is the Template:

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<AlefTech.HumanResource.Core.GenderEnum>" %>
<%@ Import Namespace="AlefTech.HumanResource.WebModule.Classes" %>
<%=Html.DropDownListFor(m => m.GetType().Name, Model.GetType()) %>

Of course the method is my own:

public static class HtmlHelperExtension
    {
        public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType)
        {
            List<SelectListItem> list = new List<SelectListItem>();
            Dictionary<string, string> enumItems = enumType.GetDescription();
            foreach (KeyValuePair<string, string> pair in enumItems)
                list.Add(new SelectListItem() { Value = pair.Key, Text = pair.Value });
            return htmlHelper.DropDownListFor(expression, list);
        }

        /// <summary>
        /// return the items of enum paired with its descrtioption.
        /// </summary>
        /// <param name="enumeration">enumeration type to be processed.</param>
        /// <returns></returns>
        public static Dictionary<string, string> GetDescription(this Type enumeration)
        {
            if (!enumeration.IsEnum)
            {
                throw new ArgumentException("passed type must be of Enum type", "enumerationValue");
            }

            Dictionary<string, string> descriptions = new Dictionary<string, string>();
            var members = enumeration.GetMembers().Where(m => m.MemberType == MemberTypes.Field);

            foreach (MemberInfo member in members)
            {
                var attrs = member.GetCustomAttributes(typeof(DescriptionAttribute), false);
                if (attrs.Count() != 0)
                    descriptions.Add(member.Name, ((DescriptionAttribute)attrs[0]).Description);
            }
            return descriptions;
        }

    }

However, even though this worked for me, it is not what I'm asking. Instead, I need the following to work:

Code for Shared\EditorTemplates\Enum.acsx:

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Enum>" %>
<%@ Import Namespace="System.Web.Mvc.Html" %>
<%@ Import Namespace="WhereMyExtentionMethod" %>
<%=Html.DropDownListFor(m => m.GetType().Name, Model.GetType()) %>

With this I wouldn't have to make a template for every enum any more.


Solution

  • Thank you all for your contributions
    Yngvebn, i tried your solution (in your last comment) before, but the only thing i didn't do is the <dynamic>, i used instead <Enum> in generic type.

    at last the solution is :
    create a template named Enum.acsx and put it under the Views\Shared\EditorTemplates

    <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<dynamic>" %>
    <%@ Import Namespace="System.Web.Mvc.Html" %>
    <%@ Import Namespace="the extension methods namespace" %>
    <% Enum model = (Enum)Model; %>
    <%=Html.DropDownList(model.GetType().Name,model.GetType())%>
    

    and in your Entity:

    public class Person
    {
      [UIHint("Enum")]
      public GenderEnum Gender{get;set;}
    }
    
    public Enum GenderEnum
    {
     [Description("Male Person")]
     Male,
     [Description("Female Person")]
     Female
    }
    

    and again there is Extention Methods:

    public static class HtmlHelperExtension
        {
            public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType)
            {
                List<SelectListItem> list = new List<SelectListItem>();
                Dictionary<string, string> enumItems = enumType.GetDescription();
                foreach (KeyValuePair<string, string> pair in enumItems)
                    list.Add(new SelectListItem() { Value = pair.Key, Text = pair.Value });
                return htmlHelper.DropDownListFor(expression, list);
            }
    
            /// <summary>
            /// return the items of enum paired with its descrtioption.
            /// </summary>
            /// <param name="enumeration">enumeration type to be processed.</param>
            /// <returns></returns>
            public static Dictionary<string, string> GetDescription(this Type enumeration)
            {
                if (!enumeration.IsEnum)
                {
                    throw new ArgumentException("passed type must be of Enum type", "enumerationValue");
                }
    
                Dictionary<string, string> descriptions = new Dictionary<string, string>();
                var members = enumeration.GetMembers().Where(m => m.MemberType == MemberTypes.Field);
    
                foreach (MemberInfo member in members)
                {
                    var attrs = member.GetCustomAttributes(typeof(DescriptionAttribute), false);
                    if (attrs.Count() != 0)
                        descriptions.Add(member.Name, ((DescriptionAttribute)attrs[0]).Description);
                }
                return descriptions;
            }
    
        }