How can I make a JavaScript synchronous call to the server? [duplicate]

Question

Possible Duplicate:
How can I get jQuery to perform a synchronous, rather than asynchronous, AJAX request?

I have a method that returns initialization data. It first checks the sessionStorage. If it doesn't find the data there, it makes a call to the server to get the data. Here's the code:

function getInitializationData() {

// Check local storage (cache) prior to making a server call.
// Assume HTML 5 browser because this is an Intranet application.
if (!sessionStorage.getItem("initialData")) {

    // The browser doesn't have the initialization data,
    // so the client will call the server to get the data.
    // Note: the initialization data is complex but 
    // HTML 5 storage only stores strings. Thus, the
    // code has to convert into a string prior to storage.
    $.ajax({
        url: "../initialization.x",
        type: "POST",
        dataType: "json",
        timeout: 10000,
        error: handleError,
        success: function(data) { sessionStorage.setItem("initialData", JSON.stringify(data)); } 
    });
}

// convert the string back to a complex object
return JSON.parse(sessionStorage.getItem("initialData"));
}

The problem is that the success function almost always gets executed after the method returns. How can I make the server call synchronous such that the success function must execute prior to the return statement of the getInitializationData method?

Answer 1

Use async: false

function getInitializationData() {

// Check local storage (cache) prior to making a server call.
// Assume HTML 5 browser because this is an Intranet application.
if (!sessionStorage.getItem("initialData")) {

    // The browser doesn't have the initialization data,
    // so the client will call the server to get the data.
    // Note: the initialization data is complex but 
    // HTML 5 storage only stores strings. Thus, the
    // code has to convert into a string prior to storage.
    $.ajax({
        url: "../initialization.x",
        type: "POST",
        dataType: "json",
        timeout: 10000,
        async: false,
        error: handleError,
        success: function(data) { sessionStorage.setItem("initialData", JSON.stringify(data)); } 
    });
}

// convert the string back to a complex object
return JSON.parse(sessionStorage.getItem("initialData"));
}