AJAX and XML

AJAX and XML examples:

The following example will demonstrate how a web page reads information from an XML file through AJAX:

#This example consists of three parts

l HTML form page

l PHP page

l XML file

HTML form page

When the user selects a CD in the drop-down list above, the function named "showCD()" will be executed. This function is triggered by the "onchange" event:

##After the user selects the drop-down list. Call the showCD() function

ShowCD() function to perform the following steps:

l Check whether a CD is selected

l Create an XMLHttpRequest object

l Create Function executed when the server response is ready

l Send a request to a file on the server

l Please note the parameter (q) added to the end of the URL (containing the contents of the drop-down list)

PHP file

The server page called through JavaScript above is a PHP file named "2.php".

The PHP script loads the XML document, "3.xml", runs the query against the XML file, and returns the results in HTML:

When the CD query is sent from JavaScript to the PHP page, what happens:

l PHP creates the XML DOM object of the "3.xml" file

l Loop through all "artist" elements (nodetypes = 1), find the name that matches the data transmitted by JavaScript

l Find the correct artist included in the CD

l Output the album information and send it To "txtHint" placeholder

XML file

##The file Contains data about CD collection