ASP.Net Web API + JSend

CamelCaseStringEnumConverter.cs

using Newtonsoft.Json.Converters;

namespace Web.Core
{
    public class CamelCaseStringEnumConverter : StringEnumConverter
    {
        public CamelCaseStringEnumConverter()
        {
            CamelCaseText = true;
        }
    }
}

JSendMessageHandler.cs

using System.Linq;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using System.Web.Http;

namespace Web.Core
{
    public class JSendMessageHandler : DelegatingHandler
    {
        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
            return base.SendAsync(request, cancellationToken)
                .ContinueWith(t =>
                {
                    if (request.Headers.Accept.All(a => a.MediaType != "application/json"))
                        return t.Result;
                    if (t.Result.Content != null && t.Result.Content.Headers.ContentType.MediaType != "application/json")
                        return t.Result;

                    object responseObject;
                    t.Result.TryGetContentValue(out responseObject);
                    if (t.Exception != null)
                    {
                        return request.CreateResponse(new JSendPayload
                        {
                            Status = JSendStatus.Error,
                            Message = t.Exception.Message,
                            Data = responseObject ?? t.Exception
                        });
                    }
                    if (t.IsCanceled)
                    {
                        return request.CreateResponse(new JSendPayload
                        {
                            Status = JSendStatus.Fail,
                            Message = "Operation Cancelled",
                            Data = responseObject ?? t.Exception
                        });
                    }
                    var errorContent = t.Result.Content as ObjectContent<HttpError>;
                    if (errorContent != null)
                    {
                        return request.CreateResponse(new JSendPayload
                        {
                            Status = JSendStatus.Error,
                            Message = t.Result.ReasonPhrase,
                            Code = (int)t.Result.StatusCode,
                            Data = responseObject
                        });
                    }
                    return request.CreateResponse(new JSendPayload
                    {
                        Status = JSendStatus.Success,
                        Data = responseObject
                    });
                }, cancellationToken);
        }
    }
}

JSendPayload.cs

using Newtonsoft.Json;

namespace Web.Core
{
    public class JSendPayload
    {
        [JsonConverter(typeof(CamelCaseStringEnumConverter))]
        public JSendStatus Status { get; set; }
        public object Data { get; set; }
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public string Message { get; set; }
        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
        public int? Code { get; set; }
    }
}

JSendStatus.cs

namespace Web.Core
{
    public enum JSendStatus
    {
        Success,
        Fail,
        Error
    }
}

WebApiConfig.cs

using System.Web.Http;
using Web.Core;
using Newtonsoft.Json.Serialization;

namespace Web
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            config.MapHttpAttributeRoutes();

            config.Formatters.JsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
            config.MessageHandlers.Add(new JSendMessageHandler());
        }
    }
}