AJAX Tutorial
AJAX
AJAX is a developers dream, because you can:
Update a web page without reloading the page
Request data from a server - after the page has loaded
Receive data from a server - after the page has loaded
Send data to a server - in the background
Try it Yourself Examples in Every Chapter
In every chapter, you can edit the examples online, and click on a button to view the result.
AJAX Example Explained
HTML Page
<!DOCTYPE html>
<html>
<body>
<div id="demo"><h2>Let AJAX change this text</h2></div>
<button type="button" onclick="loadDoc()">Change Content</button>
</body>
</html>
The HTML page contains a <div> section and a <button>.
The <div> section is used to display information from a server.
The <button> calls a function (if it is clicked).
The function requests data from a web server and displays it:
Function loadDoc()
function loadDoc() {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (xhttp.readyState == 4 && xhttp.status == 200) {
document.getElementById("demo").innerHTML = xhttp.responseText;
}
};
xhttp.open("GET", "ajax_info.txt", true);
xhttp.send();
}
