Question

I’m trying to create a sort of chatbox system with PHP/MySql and AJAX but I’m having difficulties running my script in IE. I tested it in Google Chrome and it worked just fine. But when I test it in IE, the AJAX function that should get all messages from the database each 3 seconds, doesn’t work properly. It does call the PHP script each 3 seconds and put the responseText into a div (displaying all messages found each 3 seconds). But the messages shown, are the same always ( untill I close the page and re-run the script ). Also when a new message is added to the database, it does not show up. It seems as if the responseText isn’t ‘updating’. These are my scripts:

(AJAX)

function getMessages(messengerid, repeat)
{
var xmlhttp;
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    document.getElementById("messages").innerHTML=xmlhttp.responseText;
    document.getElementById("messages").scrollTop = document.getElementById("messages").scrollHeight;
    }
  }
xmlhttp.open("GET","modules/get_messages.php?key=abcIUETH85i236t246jerst3487Jh&id="+messengerid,true);
xmlhttp.send();
if(repeat) {
    setTimeout("getMessages("+messengerid+", 1);", 3000);
}
}

(PHP/MySql)

<?php
$key = "abcIUETH85i236t246jerst3487Jh";

if( ($_GET['key'] == $key OR defined('IS_INTERNAL')) AND (int)$_GET['id'] > 0) {

    include_once("../config.php");
    include_once("../class/system.class.php");

    $sys = new system($template_name);

    if(!$sys->connect($db)) {
        exit();
    }

    $messages = $sys->getEntries("messages", " WHERE messenger_id = '".(int)$_GET['id']."' ORDER BY id ASC ");
    $messenger    = $sys->getEntries("messengers", " WHERE id = '".(int)$_GET['id']."' LIMIT 1");

    $user1 = $sys->getEntries("accounts", " WHERE id = '".$messenger[0]['account_id1']."' ");
    $user2 = $sys->getEntries("accounts", " WHERE id = '".$messenger[0]['account_id2']."' ");

    $displaynames[$user1[0]['id']] = $user1[0]['displayname'];
    $displaynames[$user2[0]['id']] = $user2[0]['displayname'];

    foreach($messages AS $key => $message) {

    if(is_numeric($key)) {              
    ?>
    <div class="message">
        <b><?=$displaynames[$message['account_id']];?>  (<?=date("h:m:s", $message['timestamp']);?>) says:</b> <br />
        <?=nl2br($message['message_content']);?>
    </div>
    <?php
    }
    }


}

?>

Any help would be much appreciated!
Thanks in advance.

Best Regards,
Skyfe.

Answer 1

Your response is being cached. One way to fix this is to append a unique parameter in your request URL, such as the current timestamp.