MVC 5 invalid JSON primitive

Question

I am trying to write a auto-complete with ajax in MVC5 but no matter what I try I get the error invalid JSON primitive. When I enter the url manually localhost:5088/GetData?inpt=[query] I am able to see the return json.

From what I understand online , I am giving the "data:" parameter wrong. I tried putting them in "" but it didn't work.

My Controller :

  public  JsonResult GetData(string inpt)
        {
            try
            {
                var node = //some values here , cause its too long I deleted it 
                foreach (var node in q)
                {
                    string scity = node.Attribute("CityName").Value.ToUpper(new CultureInfo("tr-TR", false));
                    string ccity = node.Attribute("CityCode").Value;
                    string ccode = node.Attribute("CountryCode").Value;
                    if (ccity != oldcity)
                    {
                        result.Add(new HavaAlani { SehirAdi = scity, HavaAlaniKodu = ccity, HavaAlaniAdi = scity + ", " + ccode, Sehirmi = true });
                        oldcity = ccity;
                    }
                    result.Add(new HavaAlani { SehirAdi = scity, HavaAlaniKodu = node.Attribute("Code").Value, HavaAlaniAdi = node.Value, Sehirmi = false });
                }
            }
            catch
            {

            }

            return Json(result, JsonRequestBehavior.AllowGet);
        }
    }

My JS :

    $('input.suggestBox').each(function () {
    //$(this).jsonSuggest(air.Lines);
    $(this).autocomplete({
        source: function (request, response) {
            $.ajax({
                url: "dataAl/GetData",
                data: { inpt: request.term },
                dataType: "json",
                type: "POST",
                contentType: "application/json; charset=utf-8",
                dataFilter: function (data) { return data; },
                success: function (data) {
                    response($.map(data.d, function (item) {
                        return {
                            code: item.HavaAlaniKodu,
                            value: item.HavaAlaniAdi,
                            iscity: item.Sehirmi
                        }
                    }))
                },
                error: function (XMLHttpRequest, textStatus, errorThrown) {
                    alert(XMLHttpRequest.responseText);
                }
            });
        },
        minLength: 2
    }).data("ui-autocomplete")._renderItem = function (ul, item) {
        var cls = "airport";
        if (item.iscity)
            cls = "city";
        return $("<li></li>")
                .data("item.autocomplete", item)
                .append("<span class='span-" + cls + "'></span>")
                .append("<a class='ui-autocomplete-" + cls + "'>" + item.value + " (" + item.code + ")" + "</a>")
                .appendTo(ul);
    };

});

Answer 1

Comment was getting a bit long so adding this as an answer-

The first thing to try would be modifying your content type per this post: MVC JSON method returning invalid JSON to JQuery?

Try "application/json".

also wrap your data object in

  JSON.stringify()

If that doesn't work can you tell me where result is coming from in your action - I'm not seeing the declaration. Also add a break point and ensure that you can step into that method.