MVC JsonResult camelCase serialization [duplicate]

Question

This question already has an answer here:

• Proper JSON serialization in MVC 4 3 answers

I am trying to make my action return a JsonResult where all its properties are in camelCase.

I have a simply model:

public class MyModel
{
    public int SomeInteger { get; set; }

    public string SomeString { get; set; }
}

And a simple controller action:

public JsonResult Index()
    {
        MyModel model = new MyModel();
        model.SomeInteger = 1;
        model.SomeString = "SomeString";

        return Json(model, JsonRequestBehavior.AllowGet);
    }

Calling this action method now returns a JsonResult containing the following data:

{"SomeInteger":1,"SomeString":"SomeString"}

For my uses i need the action return the data in camelCase, somehow like this:

{"someInteger":1,"someString":"SomeString"}

Is there any elegant way to do this?

I was looking into possible solutions around here and found MVC3 JSON Serialization: How to control the property names? where they set DataMember definitions to every property of the model, but I do not really want to do this.

Also I found a link where they say that it is possible to solve exactly this kind of issue: http://www.asp.net/web-api/overview/formats-and-model-binding/json-and-xml-serialization#json_camelcasing. It says:

To write JSON property names with camel casing, without changing your data model, set the CamelCasePropertyNamesContractResolver on the serializer:

var json = GlobalConfiguration.Configuration.Formatters.JsonFormatter;
json.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();

One entry on this blog http://frankapi.wordpress.com/2012/09/09/going-camelcase-in-asp-net-mvc-web-api/ also mentiones this solution and states you can simply add it to the RouteConfig.RegisterRoutes to fix this issue. I tried it, but I couldn't make it work.

Do you guys have any idea where I was doing something wrong?

Answer 1

The Json functions of the Controller are just wrappers for creating JsonResults:

protected internal JsonResult Json(object data)
{
    return Json(data, null /* contentType */, null /* contentEncoding */, JsonRequestBehavior.DenyGet);
}

protected internal JsonResult Json(object data, string contentType)
{
    return Json(data, contentType, null /* contentEncoding */, JsonRequestBehavior.DenyGet);
}

protected internal virtual JsonResult Json(object data, string contentType, Encoding contentEncoding)
{
    return Json(data, contentType, contentEncoding, JsonRequestBehavior.DenyGet);
}

protected internal JsonResult Json(object data, JsonRequestBehavior behavior)
{
    return Json(data, null /* contentType */, null /* contentEncoding */, behavior);
}

protected internal JsonResult Json(object data, string contentType, JsonRequestBehavior behavior)
{
    return Json(data, contentType, null /* contentEncoding */, behavior);
}

protected internal virtual JsonResult Json(object data, string contentType, Encoding contentEncoding, JsonRequestBehavior behavior)
{
    return new JsonResult
    {
        Data = data,
        ContentType = contentType,
        ContentEncoding = contentEncoding,
        JsonRequestBehavior = behavior
    };
}

JsonResult internally uses JavaScriptSerializer, so you don't have control about the serialisation process:

public class JsonResult : ActionResult
{
    public JsonResult()
    {
        JsonRequestBehavior = JsonRequestBehavior.DenyGet;
    }

    public Encoding ContentEncoding { get; set; }

    public string ContentType { get; set; }

    public object Data { get; set; }

    public JsonRequestBehavior JsonRequestBehavior { get; set; }

    /// <summary>
    /// When set MaxJsonLength passed to the JavaScriptSerializer.
    /// </summary>
    public int? MaxJsonLength { get; set; }

    /// <summary>
    /// When set RecursionLimit passed to the JavaScriptSerializer.
    /// </summary>
    public int? RecursionLimit { get; set; }

    public override void ExecuteResult(ControllerContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException("context");
        }
        if (JsonRequestBehavior == JsonRequestBehavior.DenyGet &&
            String.Equals(context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase))
        {
            throw new InvalidOperationException(MvcResources.JsonRequest_GetNotAllowed);
        }

        HttpResponseBase response = context.HttpContext.Response;

        if (!String.IsNullOrEmpty(ContentType))
        {
            response.ContentType = ContentType;
        }
        else
        {
            response.ContentType = "application/json";
        }
        if (ContentEncoding != null)
        {
            response.ContentEncoding = ContentEncoding;
        }
        if (Data != null)
        {
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            if (MaxJsonLength.HasValue)
            {
                serializer.MaxJsonLength = MaxJsonLength.Value;
            }
            if (RecursionLimit.HasValue)
            {
                serializer.RecursionLimit = RecursionLimit.Value;
            }
            response.Write(serializer.Serialize(Data));
        }
    }
}

You have to create your own JsonResult and write your own Json Controller functions (if you need / want that). You can create new ones or overwrite existing ones, it is up to you. This link might also interest you.

Answer 2

If you want to return a json string from your action which adheres to camelcase notation what you have to do is to create a JsonSerializerSettings instance and pass it as the second parameter of JsonConvert.SerializeObject(a,b) method.

public string GetSerializedCourseVms()
    {
        var courses = new[]
        {
            new CourseVm{Number = "CREA101", Name = "Care of Magical Creatures", Instructor ="Rubeus Hagrid"},
            new CourseVm{Number = "DARK502", Name = "Defence against dark arts", Instructor ="Severus Snape"},
            new CourseVm{Number = "TRAN201", Name = "Transfiguration", Instructor ="Minerva McGonal"}
        };
        var camelCaseFormatter = new JsonSerializerSettings();
        camelCaseFormatter.ContractResolver = new CamelCasePropertyNamesContractResolver();
        return JsonConvert.SerializeObject(courses, camelCaseFormatter);
    }