EnumUtil Class For ASP.NET MVC - Generates HTML Select, HTML Radio From Enum Code

EnumUtil.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Web;

namespace SolutionName.Helpers
{
    public static class EnumUtil
    {
        /*
        How to use?
        
        if you have enum like
        
        public enum LeaveStatus
        {
            [Display(Name = "Accepted Leave!")]
            Accepted = 1,

            [Display(Name = "Refused By Manager")]
            Refused = 2,

            [Display(Name = "Waiting Manager Approval")]
            Pending = 3
        }
        
        - Display the name of enum item
        LeaveStatus.Pending.GetDisplayName()
        
        - convert to dictionary
        foreach (KeyValuePair<int, string> item in EnumUtil.AsDictionary( typeof(LeaveStatus) ))
        {
            // use item.Key, item.Value to access current dictionary items
        }
        
        - To generate Html Select Code
        @EnumUtil.HtmlSelect( typeof(LeaveStatus), "fieldName" )
        
        - To generate Html Radio Code
        @EnumUtil.HtmlRadio( typeof(LeaveStatus), "fieldName" )
        
        */
        
        // Get DisplayName attribute of the Enum
        public static string GetDisplayName(this Enum enumVal)
        {
            var displayAttr = enumVal.GetType()
                                    .GetMember(enumVal.ToString())
                                    .First()
                                    .GetCustomAttributes(false)
                                    .OfType<DisplayAttribute>()
                                    .FirstOrDefault();

            string result = string.Empty;
            if (displayAttr != null)
            {
                result = displayAttr.Name;
            }

            return result;
        }

        /// <summary>
        /// Exports Enum as a Dictionary Val => DisplayName
        /// </summary>
        /// <typeparam name="T">Enum Type</typeparam>
        /// <returns></returns>
        public static Dictionary<int, string> AsDictionary(Type enumType)
        {
            Dictionary<int, string> dt = new Dictionary<int, string>();

            foreach (Enum item in Enum.GetValues(enumType))
            {
                dt.Add(Convert.ToInt32(item), item.GetDisplayName());
            }

            return dt;
        }

        /// <summary>
        /// generates HTML select code for Enum Type
        /// </summary>
        /// <typeparam name="T">typeof(EnumName)</typeparam>
        /// <param name="inputName">the name of the HTML select</param>
        /// <param name="id">ID for Javascript of css usage</param>
        /// <returns></returns>
        public static IHtmlString HtmlSelect(Type enumType, string inputName, string id = "", string cssClass="form-control")
        {
            StringBuilder builder = new StringBuilder();
            builder.Append($"<select class='{cssClass}' name='{inputName}' id='{id}'>");
            
            foreach (KeyValuePair<int, string> item in EnumUtil.AsDictionary(enumType))
            {
                builder.Append($"<option value='{item.Key}'>{item.Value}</option>");
            }

            builder.Append("</select>");

            return new HtmlString(builder.ToString());
        }

        /// <summary>
        /// generates HTML radio List code for Enum Type
        /// </summary>
        /// <param name="enumType">typeof(EnumName)</param>
        /// <param name="inputName">the name of the input</param>
        /// <param name="inputClass">css class name</param>
        /// <returns></returns>
        public static IHtmlString HtmlRadio(Type enumType, string inputName, int defaultValue=0, string inputClass="")
        {
            StringBuilder builder = new StringBuilder();
            bool firstItemNotChecked = true;
            foreach (KeyValuePair<int, string> item in EnumUtil.AsDictionary(enumType))
            {
                builder.Append("<label>");
                builder.Append($"<input type='radio' name='{inputName}' id='{inputName}_{item.Key}' class='{inputClass}' value='{item.Key}' ");
                if (firstItemNotChecked && defaultValue == 0)
                {
                    builder.Append("checked='checked' ");
                    firstItemNotChecked = false;
                }

                // check the radio with default value
                if (defaultValue != 0 && item.Key == defaultValue)
                {
                    builder.Append("checked='checked' ");
                }

                builder.Append($"/> {item.Value}</label>");
            }

            return new HtmlString(builder.ToString());
        }
    }
}