Head Rush Ajax

you’re on your way 4

167

asynchronous applications

Checking a coffee maker’s status

Now that you can use the utility functions in text-utils.js, you can easily

check the status of a coffee maker using the getText() function, like this:

function orderCoffee() {

var name = document.getElementById(“name”).value;

var beverage = getBeverage();

var size = getSize();

var coffeemakerStatusDiv1 =

document.getElementById(“coffeemaker1-status”);

var status = getText(coffeemakerStatusDiv1);

if (status == “Idle”) {

// Update the coffee maker’s status

var url = “coffeemaker.php?name=” + escape(name) +

“&size=” + escape(size) +

“&beverage=” + escape(beverage) +

“&coffeemaker=1”;

sendRequest(url);

}

}

This gets the <div> that

holds the status for the rst

coffee maker.

getText() will return the text in

the coffeemaker1-status <div>.

If the rst

coffee maker is

idle, we want to

send the coffee

order to it,

and let it brew

the order.

We still need to

gure out how to

update the coffee

maker’s status, too.

text-utils.js

getText()

getText() will return the text

within a <div>, or any other

element that you give it.

text-utils.js has several

JavaScript functions for working

with the DOM. We’ll cover the

DOM in detail in Chapter 4.

All the code in text-utils.js is in Appendix 2. You

can check it out now, or wait until we’ve talked

more about the DOM in Chapter 4.