Hacking Gmail

How Gmail Works

B

y now you’ve learned how to use Gmail with some flair, and

you can change the way it looks to a certain extent. Now

you have to look into exactly how it works. You already

know that the majority of the Gmail functionality is enacted

client-side — that is, on the browser, rather than at the server —

and is done with JavaScript. This chapter describes exactly how

this works and how you can exploit it.

What the Devil Is Going On?

Before revealing just what’s happening, let’s recap. In Chapter 4

you used the DOM inspector inside Firefox to help you dissect

the HTML, and this will help you again. So, as before, open up

Gmail in Firefox, and open the DOM inspector.

You already know that the main document is made of two frames,

the first made of many subframes and the second one with noth-

ing but a huge chunk of JavaScript. Figure 5-1 shows you that in

the DOM inspector.

Using the DOM inspector’s right-click menu Copy as XML

function, you can grab the text of the script and copy it to a text

editor. Ordinarily, I would include this code as a listing right

here, but when I cut and pasted it into the manuscript of this

book, it added another 120 pages in a single keystroke. This does

not bode well, especially as Google has tried as hard as it can to

format the JavaScript as tightly as possible. This saves bandwidth

but doesn’t help anyone else read what Google is doing. We’ll

reach that problem in a page or two.

̨Getting at the code

̨The interface

̨XMLHttpRequest

̨Packet sniffing

The Basics

interface

̨Decoding the data

chapter

in this chapter