ASP.NET MVC 4 return Json resulting in double json or empty data

Question

I am getting either empty Json results or double json results and I don't know why yet?

base line: http://learn.knockoutjs.com/mail?folder=Inbox looks like this in chrome F12: {"id":"Inbox","mails":[{"id":1,......}

My Action:

public ActionResult Mail()
{
    string qs = "";
    foreach (var q in Request.QueryString)
    {

        qs += string.Format("{0}={1}&", q, Request.QueryString[q.ToString()]);
    }
    var proxyRequest = "http://learn.knockoutjs.com/mail?" + qs;
    var request = WebRequest.Create(proxyRequest);
    var response = (HttpWebResponse)request.GetResponse();



    var reader = new StreamReader(response.GetResponseStream());
    var str = reader.ReadToEnd();
    var data = Newtonsoft.Json.JsonConvert.DeserializeObject<dynamic>(str);

    //var json = JsonConvert.SerializeObject(data);  
        // Text Visualization looks good {"id":"Inbox","mails":[{"id":1,"from":"Abb....}
        // no outside quotes, no escaped quotes

        var res = Json(data, JsonRequestBehavior.AllowGet);
        return res;

}

So basically I am proxying the call, but the question is why is the result coming back as either not filled in or double jsoned.

using chrome network trace the result of the above looks like. [[[]],[[[[[]],[[]],[[]],[[]],[[]],...]

valid json, just empty.

when I change the code to look like this

var json = JsonConvert.SerializeObject(data);  
// Text Visualization looks good {"id":"Inbox","mails":[{"id":1,"from":"Abb....}
// no outside quotes, no escaped quotes

var res = Json(json, JsonRequestBehavior.AllowGet);
return res;

Chrome network trace has doubled jsoned the data. "{\"id\":\"Inbox\",\"mails\":[{\"id\":1,\"from\":\"Ab....}"

Since I don't know what the Json actually is, I did newton soft dynamic convert JsonConvert.DeserializeObject

That may be the problem behind my empty response?

Any help would really be appreciated. Thanks

If you're happy with the answer, can you click the check box next to the answer to accept it? — McGarnagle
– McGarnagle, Commented Oct 6, 2012 at 19:29

SLaks · Accepted Answer · 2012-09-12 00:36:23Z

6

Your first method is failing because Json() doesn't understand the dynamic object returned from your JSON reader.
Your second method is failing because Json() is serializing a pre-serialized string.

You can return pre-serialized JSON data using Content(jsonString, "application/json")

answered Sep 12, 2012 at 0:36

SLaks

891k182 gold badges1.9k silver badges2k bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Herb Stahl Over a year ago

I would hope the newtonsoft.json implementation would have an MVC extension to deal with dynamic objects as JsonResults. I know I will forget this in about 6 months. Thanks

CodeFarmer Over a year ago

@SLaks, I think this is a bad practice. Chrome has unpredictable effect to throw out in console.

SLaks Over a year ago

@CodeFarmer: What are you talking about?

Collectives™ on Stack Overflow

ASP.NET MVC 4 return Json resulting in double json or empty data

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related