Using the JSON.NET formatter for normal controllers

Question

When returning Json from a controller (MVC 4 RC) I would like to modify the Json to use camel-casing for the properties and to do this I tried setting the GlobalConfiguration.Formatters.JsonFormatter (not sure if this is correct...don't have the code in front of me), but this does not appear to affect the Json outputted by the Controller.Json method.

After looking around it appears that this approach would only affect Web API controllers, etc. Is this true? Also, is it possible to alter the Controller.Json() method to acheive this?

Answer 1

Like @rouen suggests, created your own JsonDotNetResult.

This is the one I have in my project:

public class JsonNetResult : ActionResult
{
    public Encoding ContentEncoding { get; set; }
    public string ContentType { get; set; }
    public object Data { get; set; }
    public int StatusCode { get; set; }

    public JsonSerializerSettings SerializerSettings { get; set; }

    public JsonNetResult()
    {
        SerializerSettings = new JsonSerializerSettings
        {
            ContractResolver = new CamelCasePropertyNamesContractResolver()
        };
    }

    public override void ExecuteResult(ControllerContext context)
    {
        if (context == null)
            throw new ArgumentNullException("context");

        var response = context.HttpContext.Response;

        response.StatusCode = StatusCode;
        response.ContentType = string.IsNullOrEmpty(ContentType) ? "application/json" : ContentType;

        if ((StatusCode >= 400) && (StatusCode <= 599))
            response.TrySkipIisCustomErrors = true;

        if (ContentEncoding != null)
            response.ContentEncoding = ContentEncoding;

        if (Data == null)
            return;

        var formatting = Formatting.None;

#if DEBUG
        formatting = Formatting.Indented;
#endif

        var writer = new JsonTextWriter(response.Output) { Formatting = formatting };

        var serializer = JsonSerializer.Create(SerializerSettings);
        serializer.Serialize(writer, Data);

        writer.Flush();
    }
}

I then have my own baseController that I inherit from to give me JsonDotNet(object viewModel) type methods.

E.g.

protected JsonNetResult JsonNet(object data = null, int statusCode = (int)HttpStatusCode.OK, string contentType = null)
{
    return new JsonNetResult
               {
                   Data = data,
                   StatusCode = statusCode,
                   ContentType = contentType
               };
}

protected JsonNetResult JsonNetForbidden()
{
    return JsonNet(statusCode: (int)HttpStatusCode.Forbidden);
}

protected JsonNetResult JsonNetNotFound()
{
    return JsonNet(statusCode: (int)HttpStatusCode.NotFound);
}

protected JsonNetResult JsonNetNoContent()
{
    return JsonNet(statusCode: (int)HttpStatusCode.NoContent);
}

protected JsonNetResult JsonNetCreated(object data)
{
    return JsonNet(data, (int)HttpStatusCode.Created);
}

protected JsonNetResult JsonNetReload()
{
    return JsonNet(new { reload = true });
}

protected JsonNetResult JsonNetRedirect(string url = null, string contentType = null)
{
    return JsonNet(new { redirectUrl = url }, contentType: contentType);
}

protected JsonNetResult JsonNetClientError(ErrorDictionary errors)
{
    return JsonNet(new { Errors = errors }, (int)HttpStatusCode.BadRequest);
}

protected JsonNetResult JsonNetUnauthorized()
{
    return JsonNet(null, (int)HttpStatusCode.Unauthorized);
}

protected JsonNetResult JsonNetFlashMessage(string message)
{
    return JsonNet(new { flashMessage = message });
}

Answer 2

There is no way to alter behaviour of default JavaScriptSerializer afaik.

Personally, I use my own JsonDotNetResult (and shortcut method on my BaseController) for all json actions. Not only you can alter its settings in many ways, but the performance is MUCH better with JSON.NET - look here http://james.newtonking.com/archive/2008/10/27/json-net-3-5-beta-1-big-performance-improvements-compact-framework-support-and-more.aspx

Plus there are many little nice bonuses, like automatic resoulution of circular dependencies (always hit it in bigger projects) etc.

Invest your 5 minutes into own JsonDotNetResult, they will be very well spent.