Question

I have a button named searchReportButton. On this button click, I need to check session value from server using a ajax web method “Error.aspx/CheckSessionExpiry”.This is done in checkSession javascript function. The checkSession is not returning anything now – instead it is handling the required operation based on the result (redirecting to error page).

1. I need to return the result of ajax web method to the Main Caller. How can we do this return?
2. Do I need to move the remaining code (from Main Caller) into sucsess callback?

Main Caller

searchReportButton.click(function () {

    checkSession();
    //Remainging Code

});

Helper

function checkSession() {

var win = 101;
$.ajax(
        {
            type: "POST",
            url: "Error.aspx/CheckSessionExpiry",
            data: '{"winNumber": "' + win + '"}',
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: handleSessionResult

        }
        );
        }

Result Helper

  function handleSessionResult(result) {


    if (result.hasOwnProperty("d")) 
    {
      result = result.d
    }

    if (result == "ACTIVE") 
    {
      window.location.href("Error.aspx");
      return false;
    }

   //alert(result);

}

REFERENCE:

1. How can I get jQuery to perform a synchronous, rather than asynchronous, Ajax request?
2. $.ajax context option
3. jQuery Ajax Callback does not get Context
4. jQuery pass more parameters into callback

Answer 1

You cannot. Or, to be more specific, you should not. Ajax request is async which means it does not block other JS operations while it’s being proceeded (imagine 5s browser freeze if the server was responding slowly?).

Instead you can pass a success callback, which you already do. Then do anything you wanted in there.

So instead of:

checkSession();
//Remainging Code

you should move the remainging code inside the callback:

function handleSessionResult(result) {
    //... current code
    //Remaining code from the above
}