EnumHelper

Helper for working easier with Enum

• Why EnumHelper?
• How to use
• How to install
• Change Logs

Why EnumHelper

In some case, you may need to use Enum type for some properties of your model. But currently MVC Razor does not support Enum type well:

• You need to create SelectList for Enum type before render a DropDownList or ListBox.
• You need to write your own function to change display name of an Enum value.

EnumHelper will help you solve that issue.

How to use

For sample, you have this model:

[Flags]
public enum UserType
{
    Admin = 1,
 
    [EnumDescription("Registered User")]
    RegisterdUser = 2,
 
    [EnumDescription("Guest")]
    Visitor = 4
}

public class UserModel
{
    public UserType userType { get; set; }
    // ...
}

1. Use GetDescription() instead of ToString() if you want to render EnumDescription string to the view:

  @UserModel.userType.GetDescription()

2. If you want to render a list box or drop down list for Enum type, use this function:

  // DropDownList
  @Html.EnumDropDownList("dropdownlistName", UserType.RegisteredUser)

  @Html.EnumDropDownListFor(model => model.userType)
  
  // ListBox
  @Html.EnumListBox("listboxName", UserType.Admin)

  @Html.EnumListBoxFor(model => model.userType)

3. You can add or insert some items into DropDownList/ListBox along with Enum values:

  // add 1 item to DropDownList (item values will be defined automatically)
  @Html.EnumDropDownList("dropdownlistName",
        UserType.RegisteredUser.AddItems("All User Types")

  // insert 2 items into ListBox at position 0 (item values will be defined automatically)
  @Html.EnumListBoxFor(model =>
        model.userType.InsertItems(0, "User Type 1", "User Type 2", "User Type 3"))
  
  // add 2 items whose values are specific into DropDownList:
  @Html.EnumDropDownListFor(model =>
        model.userType.AddItems(
            new EnumItem(128, "User Type A"),
            new EnumItem(256, "User Type B")
        )
  )

  // insert 2 items into ListBox (one of them is in selected state):
  @Html.EnumListBox("listboxName",
        UserType.Visitor.InsertItems(
            0,
            new EnumItem(1024, "This is selected item", true),
            new EnumItem(2048, "This is unselected item", false)
        )
  )

4. Add FlagEnumModel attribute to the action which need to bind Flag Enum type to model.

   Use function HasFlag() to check if added/inserted values are selected.

  public class UserController
  {
      [FlagEnumModel]
      public ActionResult UpdateUser(UserModel model)
      {
          var userType = model.userType;
          
          if (userType.HasFlag(256))
          {
              var result = "User Type B is selected.";
          }
          if (userType == UserType.Admin)
          {
              var result2 = "UserType is admin";
          }
          // ...
      }
  }

How to install

You can install it easily via Nuget: https://www.nuget.org/packages/EnumHelper/

Change Logs

•  Version     	Date            Description
  

•  1.0 Build 3		Jul-11-2013     Fixed bug if property/field type is not Enum
  

•  1.0 Build 2		Jul-08-2013     Fixed bug FlagEnumModelAttribute cannot handle parameters which name is different to 'model'
  

•  1.0				Jul-08-2013     Supported binding enum to model fields.
  

•  1.0 RC 1		Jul-05-2013     Supported binding multi values Enum (Flag Enum) type to Model.
  

•  1.0 Beta 1		Jul-03-2013     Supported main functions for single value Enum type.