Debug AJAX with Firebug
Sometimes it can be difficult to debug AJAX applications, because it is asynchronous in nature the response is not normally displayed unless you provide provisions otherwise. Creating debugging systems such as debugging code, places to display the debugging information, etc, can be time consuming and detracts focus from the job at hand.
The method described below does not only apply to AJAX but to Flash and Flex as-well, it can be very helpful any time you are sending and receiving HTTP requests, synchronously or asynchronously.
A really simple and easy way to get debugging information; is to monitor the HTTP requests coming and going when you are sending your AJAX requests. So what’s the easiest way to do this? Why install Firebug of-course!
The NET tab in Firebug allows for monitoring of the coming and going requests in real time. When sending a POST request you can view the post data being sent, you can also view the server response. For instance if your request called hi.php and sent the post data; “say hi” then hi.php replied with the data “Hi from hi.php!”, Firebug would display the “say hi” post data and also the “Hi from hi.php!” response.
Firebug also offers excellent and intricate benchmarking facilities which allow you to optimize your web pages to a great extent. Anyone who doesnt use Firebug should start to use it right now!