Question

I called a web serivce via jQuery AJAX. web service returned ‘True’ as output.
I want to return as return of a function. but it returns undefined.

Where is the source of problem ?
Function IsAuthenticated returns undefined however response.d contains ‘True’ value (its string).

   function IsAuthenticated() {
        //Todo Check If user logined or not from server
       return CallWebService("Server/WebServices/Server.asmx/IsUserLogined", '{}');
    }
    function CallWebService(WebServicePath, parameters) {
        $.ajax({
            type: "POST",
            url: WebServicePath,
            data: parameters,
            async: false,

            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: function (response) {
                alert(response.d);
                if (response.d == 'True') {

                    return true;
                }
                else
                { return false; }
            },
            failure: function (msg) {

                alert("error");

            }
        });

Answer 1

I see that you are using async:false option to make the ajax calls synchronous.

However the success function is still a callback and returning true from the success handler will not return the value as a result of the ajax function call.

You need to capture the output into a local variable and return it.

Try this:

function CallWebService(WebServicePath, parameters) {
    var retValue = null;
        $.ajax({
            type: "POST",
            url: WebServicePath,
            data: parameters,
            async: false,

            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: function (response) {
                alert(response.d);
                if (response.d == 'True') {
                      retValue = true;
                }
                else
                {  retValue =  false; }
            },
            failure: function (msg) {
                alert("error");
            }
        });
        return retValue;
}