Hello i have my form and i want to implement this method for preventing double submitting on forms or going back The simple code:
<?php
// start session
session_start();
// create unique token
$form_token = uniqid();
// commit token to session
$_SESSION['user_token'] = $form_token;
?>
<!doctype html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Prevent multiple POSTs </title>
</head>
<body>
<form action="submit.php" method="post">
<input type="text" name="bar" />
<input type="hidden" name="user_token" value="<?php echo $_SESSION['user_token']; ?>" />
<input type="submit" value="Submit" />
</form>
</body>
</html>
And here the submit.php code:
<?php
session_start();
//We check if the token of the page and session match!
if($_POST['user_token'] == $_SESSION['user_token']) {
$message = 'Your download is <a href="foobar.xls"> Here </a> ';
} else {
$message = 'Your request has expired, please go back and resubmit!';
}
echo "We say: " . $message;
// invalidate the token so it expires on view, important!
unset($_SESSION['user_token']);
?>
I uploaded this script to my server but whenever i click the submit button i get the same answer the We say: Your download is Here echo , why this i checked if my cookies are created and yes they exists as they should ,
i want that users that have submitted the form once , to cant do that another time until a refresh or setting a maximum time that these cookies can exists and than delete them so that the user after for eg 10 min can submit another form if he want so
Any help will greatly be welcomed. Thanks in advance. Updatet
