Email-based PHP chat window - php

Question

I am building a chat/SMS based system I have it sending out the messages but what I need to do is live update the textarea with data from incoming emails without the user reloading (ajax?) I need to pass a number from the main page to fetch.php which gets the emails and creates an array out of emails which have not been read and come from the right sender what I need to do yet is send the number from the main page to the fetch page and return a array of new messages to the main textarea but all the tutorials I have found on ajax seem to require a database and I have no idea how to go about running and returning data on a delay help would be appreciated.
Here is the content of fetch.php:
<?php
error_reporting(E_ALL);
ini_set('display_errors', TRUE);
ini_set('display_startup_errors', TRUE);
/* connect to gmail */
$hostname = '{imap.gmail.com:993/imap/ssl}INBOX';
$username = 'user#gmail.com';
$password = 'passwd';
/* try to connect */
$inbox = imap_open($hostname,$username,$password) or die('Cannot connect to Gmail: ' . imap_last_error());
/* grab emails */
$emails = imap_search($inbox,'ALL');
/* if emails are returned, cycle through each... */
if($emails) {
$messages[] = '';
/* begin output var */
$output = '';
/* put the newest emails on top */
rsort($emails);
/* for every email... */
foreach($emails as $email_number) {
/* get information specific to this email */
$overview = imap_fetch_overview($inbox,$email_number,0);
$message = imap_fetchbody($inbox,$email_number,1);
//print_r($overview);
$Is_sms = strpos($overview[0]->from, "txt.voice.google.com");
if($Is_sms === false) continue;
if($overview[0]->seen != 0) continue;
$pnl = strpos($overview[0]->from, ".");
$pnumber = substr($overview[0]->from, $pnl +2, 10);
if($pnumber != "3303331866") continue;
$messages[] = $message;
//$status = imap_setflag_full($mbox, $mail, "\\Seen \\Flagged", ST_UID);
/* output the email header information */
/*$output.= '<div class="toggler '.($overview[0]->seen ? 'read' : 'unread').'">';
$output.= '<span class="subject">'.$overview[0]->subject.'</span> ';
$output.= '<span class="from">'.$overview[0]->from.'</span>';
//$output.= '<span class="date">on '.$overview[0]->date.'</span>';
$output.= '<span class="pnumber">'.$pnumber.'</span>';
$output.= '</div>';*/
/* output the email body */
//$output.= '<div class="body">'.$message.'</div>';
}
//echo $output;
print_r($messages);
}
/* close the connection */
imap_close($inbox);
The main page is just a to number textbox, a content textarea, a message textbox, and a send button.

Answer 1

The database is required to store the messages for you to fetch later when the AJAX request from a browser needs it. This is because your PHP script does not retain its variables between two subsequent runs and therefor you will need to store the messages somewhere. So it will basically go like this:
Get new message
Place it in some kind of ordered queue where you will be able to fetch everything later than what the client already has.
Send it off to client.
The queue could be numbered with numbers counting upward from the first post, thus allowing clients to specify what the last received message they got was and request everything newer.
BTW, if i did not make it sufficiently clear above, what you said about AJAX requiring a database is somewhat misunderstood. AJAX can function properly without, its just your case that needs some storage and databases are a good way to do it.
Hope that helps :)