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Pass Query String Value into jQuery Ajax Call in ASP.NET

I have a webMethod with a single argument I am trying to call via jQuery Ajax. Now the argument is supposed to be the query string of the url in which I am making the ajax call. I don't know how to pass the query string as an argument into the method from the jQuery ajax. My Code is as follows
C# Method
[WebMethod]
public static string FollowUser(string userId)
{
//Code to follow user
//returns a string value
}
jQuery Ajax
$(document).ready(function() {
$("#btnFollow").click(function() {
$.ajax({
type: "POST",
url: "Default.aspx/FollowUser",
data: //how do I pass the query string here
contentType: "application/json; charset=utf-8", datatype: "json",
context: this,
success: function(msg) {
//I'm doing some stuff here
}
},
error: function(response) {
alert(response.d);
}
});
});
});
Someone help me out. Thanks.

You need to pass the data as part of the the URL or change the method to GET. When submitting an aJax post with data you are sending the data as part of the request body (form data). This won't be as a query string attribute but part of the content. Instead change the URL To include the data. Example.
Default.aspx/FollowUser?userId=user1
changing to a GET method will force the post parameters to be part of the query string instead.

Cannot pass large json string to another Page with asp.net c# and knockoutjs

I got a problem while working with knockoutJs and asp.net c#.
When I passed a json string from page to another popup page using jquery ajax and knockoutJs for printing.
The problem occur:
When the Json string is small. It works fine, the popup page shows string data in table.
However, when the json string is large. It doesn't work anymore. The error occurs with message:
"Uncaught Sys.ArgumentException: Sys.ArgumentException: Cannot deserialize. The data does not correspond to valid JSON.
Parameter name: data"
Here is my code:
$.ajax({
type: "POST",
url: 'InProgressBrief.aspx/PrintReport',
data: ko.toJSON({ reportData: ko.toJSON(InProgressBriefs.Briefs) }),
async: false,
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function () {
window.open("PrintInProgressBrief.aspx?month=" + InProgressBriefs.Month() + "&year=" + InProgressBriefs.Year(), "", "status=0,toolbar=0,width=1000,height=900");
}
})
Here is my webMethod
[WebMethod]
public static void PrintReport(string reportData)
{
PSCDialog.DataShare = reportData;
}
The popup page recieves the Json tring:
if (PSCDialog.DataShare != null)
return PSCDialog.DataShare as string;
In the popup page UI, I set the knockoutjs variable, my UI javascript code is something like follow:
var InProgressBriefs = {
Briefs: ""
;
$(function(){
InProgressBriefs.Briefs = Sys.Serialization.JavaScriptSerializer.deserialize('<%=ReportJSONData%>');
ko.applyBindings(InProgressBriefs, $('#mainDivPrint')[0]);
})
Would anyone please tell me what is the problem here? I will appreciate your help alot.
Thank you in advance.

One thing that's a little suspicious is the line
data: ko.toJSON({ reportData: ko.toJSON(InProgressBriefs.Briefs) }),
When that's deserialized, you wind up with reportData being a JSON-encoded string rather than a native object. I doubt that's what you want. More likely what you need is
data: ko.toJSON({ reportData: ko.toJS(InProgressBriefs.Briefs) }),
which serializes only once.

How can I call a method that are in my code-behind via Javascript or Jquery

I have the follow line in my Javascript code
credenciadausuario = '<%= getCredenciada() %>';
In my code-behind I have this method
public string getCredenciada()
{
Utilidade.QuebraToken tk = new Utilidade.QuebraToken();
string credenciada = tk.CarregaToken(1, Request.Cookies["token"].Value);
return credenciada;
}
but when I put the debugger in my javascript code, the credenciadausuario variable, receives the string "<%= getCredenciada() %>" and not the return of my method. How can I call my method that are in my code-behind via javascript or jquery ?

It seems all you want to do in your code is get the value of a cookie. Why not do that in JavaScript on the client?

IF possible make use of ajax and do call the method, that will do you task.
check this post : http://pranayamr.blogspot.com/2012/01/calling-server-side-function-from.html
Cs File (codebehind)
[WebMethod]
public static string IsExists(string value)
{
//code to check uniqe value call to database to check this
return "True";
}
Javascript
function IsExists(pagePath, dataString)
{
$.ajax({
type:"POST",
url: pagePath,
data: dataString,
contentType:"application/json; charset=utf-8",
dataType:"json",
error:
function(XMLHttpRequest, textStatus, errorThrown) {
alert("Error");
},
success:
function(result) {
alert( result.d);
}
}
});}
var pagePath = window.location.pathname + "/IsExists";
var dataString = "{ 'value':'ab" }";
IsExists(pagePath, dataString);

This article from Encosia is excellent. It shows how to call a method in your code behind using jQuery ajax.
http://encosia.com/using-jquery-to-directly-call-aspnet-ajax-page-methods/
In your code behind you have to give the method the [WebMethod] attribute:
public partial class _Default : Page
{
[WebMethod]
public static string GetDate()
{
return DateTime.Now.ToString();
}
}
To call that method using jQuery you would use the following:
$.ajax({
type: "POST",
url: "PageName.aspx/GetDate",
data: "{}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function(msg) {
// Do something interesting here.
}
});

Well, to actually CALL your code-behind methods from Javascript, you would have to use ajax. JQuery has a nice $.ajax wrapper for that.
But I think you just want to include some value into the js code once, while it's being generated and sent to the browser. In that case, you need to use a file type which ASP.NET recognizes as a dynamic file.
The easiest would be to put JS code (in a <script> tag) into .ascx files. Then <%= getCredenciada() %> will be executed and will return an actual string which will be rendered into javascript code.
Then, of course, you should include such a control to the page as a regular ASP.NET control.
And I am not saying this is the best way to achieve what you want. Sometimes it's just the fastest.

Using jQuery AJAX to call ASP.NET function in control code-behind instead of page code-behind

I have a user control that I'm creating that is using some AJAX in jQuery.
I need to call a function in the code-behind of my control, but every example I find online looks like this:
$("input").click(function() {
$.ajax({
type: "POST",
url: "Default.aspx/GetResult",
data: "{}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function(result) {
//do something
}
});
});
This works fine if I have the method in the Default.aspx page. But I don't want to have the function there, I need the function in the code-behind of my control. How can I modify the url property to call the correct function?
I tried:
url: "GetResult"
but that didn't work.

The way to handle this is to have the webmethod in your page, then just pass the values directly to a control method with the same signature in your control - there is no other way to do this.
In other words, ALL the page method does is call the usercontrol method so it is really small. IF you have the same signature for multiple child controls, you could pass a parameter to tell the page method which one to call/use.
EDIT: Per request (very very simple example). You can find other examples with more complex types being passed to the server side method. for instance see my answer here: Jquery .ajax async postback on C# UserControl
Example:
Page method: note the "static" part.
[WebMethod]
public static string GetServerTimeString()
{
return MyNamespace.UserControls.Menu.ucHelloWorld();
}
User Control Method:
public static string ucHelloWorld()
{
return "howdy from myUserControl.cs at: " + DateTime.Now.ToString();
}
Client ajax via jquery:
$(document).ready(function()
{
/***************************************/
function testLoadTime(jdata)
{
$("#timeResult").text(jdata);
};
$("#testTimeServerButton").click(function()
{
//alert("beep");
$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
data: "{}",
dataFilter: function(data)
{
var msg;
if (typeof (JSON) !== 'undefined' &&
typeof (JSON.parse) === 'function')
msg = JSON.parse(data);
else
msg = eval('(' + data + ')');
if (msg.hasOwnProperty('d'))
return msg.d;
else
return msg;
},
url: "MyPage.aspx/GetServerTimeString",
success: function(msg)
{
testLoadTime(msg);
}
});
});
});
Note: the dataFilter: function(data)... part of the ajax is so that it works with 2.0 and 3.5 asp.net ajax without changing the client code.

You can't...WebMethods have to be in WebServices or Pages, they cannot be inside UserControls.
Think about it a different way to see the issue a bit clearer...what's the URL to a UserControl? Since there's no way to access them you can't get at the method directly. You could try another way perhaps, maybe a proxy method in your page?

Using PageMethods with jQuery

Simply put I want to call public static methods decorated with WebMethod attribute inside my code-behind C# file from jquery.ajax to get some json and other simple stuff (in different functions). But instead I'm getting whole page :'(
I'm not using asp.net AJAX though I'm developing for .NET 3.5 framework and using VS 2008. (There are some restrictions from client)
Please let me know if I can use page-methods with using asp.net ajax or If not what is other simple solution?

After much deliberations I found the problem. I was using jquery's editable plugin. This was source of the problem. When jeditable calls jquery's ajax it sets ajax options like this:
var ajaxoptions = {
type: 'POST',
data: submitdata,
url: settings.target,
success: function(result, status) {
if (ajaxoptions.dataType == 'html') {
$(self).html(result);
}
self.editing = false;
callback.apply(self, [result, settings]);
if (!$.trim($(self).html())) {
$(self).html(settings.placeholder);
}
},
error: function(xhr, status, error) {
onerror.apply(form, [settings, self, xhr]);
}
};
so it was sending the things as simple html and to use this with page methods we need to setup the things so that it sends as json. So we need to add something to the settings like this:
var ajaxoptions = {
type: 'POST',
data: submitdata,
url: settings.target,
dataType: 'json', //Data Type
contentType: 'application/json; charset=utf-8', //Content Type
//....other settings
};
So I put two new properties in settings dataType and contentType and changed above to this:
var ajaxoptions = {
type: 'POST',
data: submitdata,
url: settings.target,
dataType: settings.dataType,
contentType: settings.contentType,
//....other settings
};
Now another problem arised :( it was sending data (from submitdata property) as normal query-string which asp.net does not accept with json requests. So I had to use jquery's json plugin and change the way data is sent in ajax using following test on dataType:
if (settings.dataType == "json") {
if ($.toJSON) {
submitdata = $.toJSON(submitdata);
}
}
and it works like breeze!!!

Russ Cam posted this link in response to another question (so if this helps, go up vote his answer ;)):
Using jQuery to directly call ASP.NET AJAX Page Methods

Dave Ward has a series of posts that use jQuery directly with ASP.Net PageMethods, no MS Ajax UpdatePanel required. In particular this post will get you started.

I am not sure but i think WebMethods are accessible only through asp.net AJAX. I may be wrong though, because we dont use it that way at all. We do it in a slightly different way.
We have built a aspx page which accepts all our AJAX requests and passes them to the subsequent methods.
Server side code
If Not (Request("method") Is Nothing) Then
method = Request("method")
username = HttpContext.Current.User.Identity.Name.ToString
Select Case UCase(method)
Case "GETPROJECTS"
Response.ContentType = "text/json"
Response.Write(GetProjects(Request("cid"), Request("status")))
Exit Select
end select
end if
Client Side code [using jquery]
$.ajaxSetup({
error: function(xhr, msg) { alert(xhr, msg) },
type: "POST",
url: "Ajax.aspx",
beforeSend: function() { showLoader(el); },
data: { method: 'GetProjects', cid: "2", status:"open"},
success: function(msg) {
var data = JSON.parse(msg);
alert(data.Message);
},
complete: function() { hideLoader(el); }
});
Hope this helps.