Head Rush Ajax

148

Chapter 3

1

Let’s say that Jim wants to get a caffeine x. He enters his name into the web

form, selects Large and Mocha, and then clicks “Order Coffee”. This causes

your JavaScript to run, which then sends a request to the rst coffee maker.

2

While the rst coffee maker is brewing coffee for Jim, Mary decides she

needs some cappucino to keep her going. Good thing this is an asynchronous

application—she can order a drink from the second coffee maker, even

though the server is still brewing coffee in response to Jim’s earlier request.

The rst coffee

maker is working

on Jim’s order,

and we’ve updated

the status of the

coffee maker.

Make Jim a large mocha

using the rst coffee maker

Clicking on “Order Coffee”

causes the Javascript to send

a request to the server to

brew a cup of coffee.

The server is

still busy brewing

coffee for Jim...

coffeemaker.php

coffeemaker.php

How is the coffee maker going to work?

You should have a good idea of what you’ll need to build the coffee-making

app. Now you just need to be sure you know what the app will do. Before

diving into the actual HTML and JavaScript, let’s take a closer look at how

the coffee maker will handle requests to make a cup of coffee.

JavaScript

Jim enters in

his name and

coffee order.

Since coffee maker 2 is idle, and

this is an asynchronous app, Mary

can place her own coffee order.

JavaScript

Make Mary a medium

cappucino using the second ...