PHP-AJAX Chat/Shoutbox Example

AJAX and PHP combined together in a simple chat message server.  This uses XMLHTTPRequest to call itself with the appropriate GET variables to trigger a read or write to a server-side file named chit-chat.dat

 
<?php
$filename = 'chit-chat.dat';
 
if(isset($_GET['msg'])){
$msg = sanitize($_GET['msg']);
$conv = file_get_contents($filename);
file_put_contents($filename,$conv.$msg);
exit;
}
if(isset($_GET['conv'])){
$conv = file_get_contents($filename);
echo $conv;
exit;
}
function sanitize($var){
//sanitize here
return $var;
}
?>
 

<script type="text/javascript">
 
function createXMLHttpRequest() {
if (typeof XMLHttpRequest != "undefined") {
return new XMLHttpRequest();
} else if (typeof ActiveXObject != "undefined") {
return new ActiveXObject("Microsoft.XMLHTTP");
} else {
throw new Error("XMLHttpRequest not supported");
}
}
 
function sendMsg(msg){
request = createXMLHttpRequest();
request.open("GET", "index.php?msg="+msg, true);
request.onreadystatechange = function() {
//
}
request.send(null);
}
function rcvMsg(){
request = createXMLHttpRequest();
request.open("GET", "index.php?conv=1", true);
request.onreadystatechange = function() {
if (request.readyState == 4 && request.status == 200) {
var node = document.createTextNode(request.responseText);
document.getElementById("output").appendChild(node);
}
}
request.send(null);
}
rcvMsg();</script>
 
<div id="output">
 
</div>
<input type="text" id="msg_form"><input type="submit" value="send" onClick="sendMsg(document.getElementById('msg_form').value);rcvMsg();">

source: hawkenterprises

PHP-AJAX+Chat%2FShoutbox+Example addthis