Head Rush Ajax

131

duplication prohibited

Even though you probably didn’t realize it, the browser did try to tell you

something went wrong. The browser uses a property of your request object,

called status, that you can use to determine whether something went wrong.

Here’s how you can check the status of a request:

Checking the request’s status

function updatePage() {

if (request.readyState == 4) {

if (request.status == 200) {

var customerAddress = request.responseText;

document.getElementById(“address”).value = customerAddress;

} else

alert(“Error! Request status is “ + request.status);

}

}

You’ve seen most of this code

in Chapter 2... this is the

updatePage() callback function.

Here’s a new

property of the

request object.

It reports the

status code

from the server.

The server sends a

status of “200” when

everything is OK.

In case the status isn’t OK, let’s

output an error message to the

screen with the request’s status.

Add the code shown above to your updatePage() function in pizza.html. Now reload your

page in a web browser, and enter a phone number. When you change the phone number eld, and

then move to another eld, what happens? Write down the server’s status code in the blank:

Now x the request URL in getCustomerInfo() so that it points to the correct script on

the Break Neck server. Reload your page, and see what happens. Did you get another status

code? Write down what happened when y