How to tell JSON.NET StringEnumConverter to take DisplayName?

Question

I've got the following model:

public enum Status
{
    [Display(Name = "Awaiting Approval")]
    AwaitingApproval,
    Rejected,
    Accepted,
}

I use this enum in a model like this:

public class Docs
    {
        [Key]
        public int Id { get; set; }
        [JsonConverter(typeof(StringEnumConverter))]
        public Status Status { get; set; }
    }

Now this works fine; the serializer returns the string equivalent of the enum. My question is how to tell JSON.NET to take the Display attribute instead of the string?

Solution 1

You should try using [EnumMember] instead of [Display]. You can also put the [JsonConverter] attribute on the enum itself.

[JsonConverter(typeof(StringEnumConverter))]
public enum Status
{
    [EnumMember(Value = "Awaiting Approval")]
    AwaitingApproval,
    Rejected,
    Accepted,
}

The VB.NET version for the JsonConverter attribute is:

<Newtonsoft.Json.JsonConverter(GetType(Newtonsoft.Json.Converters.StringEnumConverter))>

Solution 2

In WebAPI the best option is to globally convert all enum string in JSON with Description value

1. In Model use this namespace using Newtonsoft.Json.Converters;

   public class Docs
   {
   [Key]
   public int Id { get; set; }
   [JsonConverter(typeof(StringEnumConverter))]
   public Status Status { get; set; }
   }
   

2. In Enum use this namespace using System.Runtime.Serialization; for EnumMember

   public enum Status
   {
   [EnumMember(Value = "Awaiting Approval")]
   AwaitingApproval,
   Rejected,
   Accepted,
   }
   

3. In Global.asax add this code

       protected void Application_Start()
       {
         GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.Converters.Add(new StringEnumConverter());
   
       }
   

It will work fine return enum in JSON using WebAPI.

Solution 3

I tried this and got the error type or namespace enum member could not be found... So you guys might get this error too so you need to use

using System.Runtime.Serialization;

and still you get this error then add a reference like below:

Right click on your project -> Add -> Reference.. -> Assemblies -> Mark System.Runtime.Serialization (i have 4.0.0.0 version ) -> Ok

Now you can proceed like this:

[JsonConverter(typeof(StringEnumConverter))]
public enum Status
{
    [EnumMember(Value = "Awaiting Approval")]
    AwaitingApproval,
    Rejected,
    Accepted,
}

Comments

[Richard B]

This doesn't seem to support i18n scenarios. Can you elaborate and explain if this is indeed accurate, or if there is a way to internationalize the text shown on screen?

[RJ Cuthbertson]

@RichardB you would use the DisplayAttribute for i18n scenarios.