Question

I want to protect a website from being accessed until a user has agreed to something. The basic idea is that at the top of each page it will check if the cookie exists if not then exit and include a php page that contains the message and two buttons one which will create the cookie and the other simply moving them off the site e.g. google.com

EDIT:

This is what I ended up with:

The warning include would look something like this:

 <?php

function pageURL() {
    $pageURL = 'http';
     if ($_SERVER["HTTPS"] == "on") {
        $pageURL .= "s";
    }
     $pageURL .= "://";
     if ($_SERVER["SERVER_PORT"] != "80") {
          $pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
     } 
    else {
          $pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
     }
 return $pageURL;
}

$pageRedirect = pageURL();

    if (
        isset($_POST['agree_button']) && ($_POST['agree_button'] == 'I agree')
    ) {
        setcookie('agreed', 'true');
        header("Location:$pageRedirect",303);
    }
?>


<form action="<?php echo pageURL(); ?>" method="post">
    <p>INSERT MESSAGE HERE (User must agree)</p>
    <input type="submit" value="I agree" name="agree_button" />
    <input type="button" value="I disagree" />
</form>

and the at the top of pages something like this:

<?php

    if(!isset($_COOKIE['agreed']) || ($_COOKIE['agreed'] != 'true'))
    {
        include('warning.php'); exit;
    }

?>

Answer 1

i would do it client-side…

<script src="js/jquery.cookie.js" type="text/javascript"></script>
<form>
    <p>INSERT MESSAGE HERE (User must agree)</p>
    <input type="submit" value="I agree" onclick="$.cookie('agreed', 'true'); location.href='/'" />
    <input type="button" value="I disagree" />
</form>

and the check would be…

if (
    !isset($_COOKIE['agreed'])||
    ($_COOKIE['agreed'] != 'true')
) {
    include('warning.php');
    exit;
}

if you want to set the cookie on server side, you need to…

<?php
    if (
        isset($_POST['agree_button'])&&
        ($_POST['agree_button'] == 'I agree')
    ) {
        setcookie('agreed', 'true');
        header('Location: /'); // redirect to main page
    }
?>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
    <p>INSERT MESSAGE HERE (User must agree)</p>
    <input type="submit" value="I agree" name="agree_button" />
    <input type="button" value="I disagree" />
</form>

see setcookie() man page