PHP jQuery Long Polling Chat Application
- by Tejas Jadhav
I've made a simple PHP jQuery Chat Application with Short Polling (AJAX Refresh). Like, every 2 - 3 seconds it asks for new messages. But, I read that Long Polling is a better approach for Chat applications. So, I went through some Long Polling scripts.
I made like this:
Javascript:
$("#submit").click(function(){
$.ajax({
url: 'chat-handler.php',
dataType: 'json',
data: {action : 'read', message : 'message'}
});
});
var getNewMessage = function() {
$.ajax({
url: 'chat-handler.php',
dataType: 'json',
data: {action : 'read', message : 'message'},
function(data){
alert(data);
}
});
getNewMessage();
}
$(document).ready(getNewMessage);
PHP
<?php
$time = time();
while ((time() - $time) < 25) {
$data = $db->getNewMessage ();
if (!empty ($data)) {
echo json_encode ($data);
break;
}
usleep(1000000); // 1 Second
}
?>
The problem is, once getNewMessage() starts, it executes unless it gets some response (from chat-handler.php). It executes recursively. But if someone wants to send a message in between, then actually that function ($("#submit").click()) never executes as getNewMessage() is still executing. So is there any workaround?
