ASP.NET MVC JsonResult Date Format

Question

I have a controller action that effectively simply returns a JsonResult of my model. So, in my method I have something like the following:

return new JsonRes         


        

Answer 1

I found that creating a new JsonResult and returning that is unsatisfactory - having to replace all calls to return Json(obj) with return new MyJsonResult { Data = obj } is a pain.

---

So I figured, why not just hijack the JsonResult using an ActionFilter:

public class JsonNetFilterAttribute : ActionFilterAttribute
{
    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        if (filterContext.Result is JsonResult == false)
        {
            return;
        }

        filterContext.Result = new JsonNetResult(
            (JsonResult)filterContext.Result);
    }

    private class JsonNetResult : JsonResult
    {
        public JsonNetResult(JsonResult jsonResult)
        {
            this.ContentEncoding = jsonResult.ContentEncoding;
            this.ContentType = jsonResult.ContentType;
            this.Data = jsonResult.Data;
            this.JsonRequestBehavior = jsonResult.JsonRequestBehavior;
            this.MaxJsonLength = jsonResult.MaxJsonLength;
            this.RecursionLimit = jsonResult.RecursionLimit;
        }

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

            var isMethodGet = string.Equals(
                context.HttpContext.Request.HttpMethod, 
                "GET", 
                StringComparison.OrdinalIgnoreCase);

            if (this.JsonRequestBehavior == JsonRequestBehavior.DenyGet
                && isMethodGet)
            {
                throw new InvalidOperationException(
                    "GET not allowed! Change JsonRequestBehavior to AllowGet.");
            }

            var response = context.HttpContext.Response;

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

            if (this.ContentEncoding != null)
            {
                response.ContentEncoding = this.ContentEncoding;
            }

            if (this.Data != null)
            {
                response.Write(JsonConvert.SerializeObject(this.Data));
            }
        }
    }
}

---

This can be applied to any method returning a JsonResult to use JSON.Net instead:

[JsonNetFilter]
public ActionResult GetJson()
{
    return Json(new { hello = new Date(2015, 03, 09) }, JsonRequestBehavior.AllowGet)
}

which will respond with

{"hello":"2015-03-09T00:00:00+00:00"}

as desired!

---

You can, if you don't mind calling the is comparison at every request, add this to your FilterConfig:

// ...
filters.Add(new JsonNetFilterAttribute());

and all of your JSON will now be serialized with JSON.Net instead of the built-in JavaScriptSerializer.