jQuery Pocket Reference

The jQuery.ajax() Function

All of jQuery’s Ajax utilities end up invoking jQuery.ajax()—the most complicated function in the entire library. jQuery.ajax() accepts just a single argument: an options object whose properties specify many details about how to perform the Ajax request. A call to jQuery.getScript(url,callback), for example, is equivalent to this jQuery.ajax() invocation:

jQuery.ajax({
    type: "GET",       // The HTTP request method.
    url: url,          // The URL of the data to fetch.
    data: null,        // Don't add any data to the URL.
    dataType:"script", // Execute response as a script.
    success: callback  // Call this function when done.
});

You can set these five fundamental options with jQuery.get() and jQuery.post(). jQuery.ajax() supports quite a few other options, however, if you invoke it directly. The options (including the basic five shown above) are explained in detail below.

Before we dive into the options, note that you can set defaults for any of these options by passing an options object to jQuery.ajaxSetup():

jQuery.ajaxSetup({
    // Abort all Ajax requests after 2 seconds
    timeout: 2000, 
    // Defeat browser cache by adding a timestamp to URL
    cache: false   
});

After running the code above, the specified timeout and cache options will be used for all Ajax requests (including high-level ones like jQuery.get() and the load() method) that do not specify their own values for these options.

While reading about jQuery’s many options and callbacks in the sections that follow, you may find it helpful ...