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?

• Dave Ward: You might find this post helpful if you're curious about why using JSON.stringify solves the problem: encosia.com/asmx-scriptservice-mistake-invalid-json-primitive

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},

Answer 3

jQuery serializes $.ajax()'s data parameter using the URL encoded scheme, regardless of what Content-Type is specified. I recommend to use the content type in ajax:

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

Also you need to use quotes in data parameter. In your version it's a JavaScript object literal instead of JSON string.

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 +'}';
}

I hope it helps.

• Ortal: great, however i am getting the following error (even though the response is correct in firebug)
• Ortal: sorry, hit enter too soon: "great, however i am getting the following error (even though the response is correct in firebug) "SyntaxError: JSON.parse: unexpected character" i tried commenting out the contentTupe (I am not getting json back) and have the same issue."
• tildy: I edited the code, because + sign were missing. Please , try it now.