System.ArgumentException: Invalid JSON primitive error

Question

I am getting "System.ArgumentException: Invalid JSON primitive: pagenum" when I return "sdata" in the following code:

 function getPageData() {
pagenum = parseInt(eSc("#resultsBtn").attr("data-pagenum"));
if (pageName === "Home") {
    scrollPath = "/Home/GetResults/";
    sdata = { "pagenum": pagenum, "sortType": sortType };
}
else if (pageName === "Search") {
    scrollPath = "/SearchAjax/GetResultsKeyword/";
    sdata = { "pagenum": pagenum, "sortType": sortType, "keyword": keyword };
}
else if (pageName === "Cat") {
    scrollPath = "/SearchAjax/GetResultsCategory/";
    sdata = { "pagenum": pagenum, "sortType": sortType, "ID": categoryId, "Level": level };
}
else if (pageName === "Merchant") {
    scrollPath = "/SearchAjax/GetResultsMerchant/";
    sdata = { "pagenum": pagenum, "sortType": sortType, "ID": merchantId };
}

}

and the init function on pageload:

 function init(a, b, c, d, e, f, g) {
getPageData();
eSc.ajax({
    type: 'POST',
    url: scrollPath,
    data: sdata,
    success: function (data) {
        eSc("#moreResults").html(data);
    }
});

}

users dont see an issue and the correct data is still returned, yet I am getting an error email every time someone loads more data from our site in production (doesnt happen in development so its hard to troubleshoot). When inspecting in firebug, I see the correct data is passed. So why am I still getting this error?!

Any tips as to why this might be happening?

Answer 1

function init(a, b, c, d, e, f, g) {
getPageData();
eSc.ajax({
    type: 'POST',
    url: scrollPath,
    contentType: 'application/json',
    dataType: 'json',
    data: JSON.stringify(sdata ),
    success: function (data) {
        eSc("#moreResults").html(data);
    }
});

pass sData in json format, using JSON.stringify to format data in json format.

It works in my case. Hope it work in your case.

Answer 2

            var param = "{'type': '" + type + "'}";
            var paramSfy = JSON.stringify({ type: type})
            var src = '/Physical_Inventory/Home/runZeroQtyDLIUpdate';
            $.ajax({
                type: "POST",
                url: src,
                dataType: "json",
                contentType: "application/json; charset=utf-8",
                data: paramSfy,

What I noticed is,

if you are using contentType: "application/json; charset=utf-8" then the data is expected as a string:

"{ "Param" : "Value" }"

this is best accomplished by using the JSON.stringify function.

if you don't set a content type then the default is, "application/x-www-form-urlencoded; charset=UTF-8" If you use this content type, then the param and value are embeded into the url, and the data can be set in ajax like so:

data: {Param : Value},