PHP: How to delete a cookie with onclick event from button

Question

I'm trying to create a sign out button with php. I might be going about this the completely wrong way, but anyhow I'm trying to delete a cookie on the click of a button.

    <?php 
    function logOut() {
        setcookie('userDetails[username]',"", time()-1200);
    }



if(isset($_COOKIE["userDetails"])) {
    echo "<table id='rtgLoginBox'>" ;
        echo "<tr>" ;
            echo "<td> Cookie " . $_COOKIE["userDetails"]["username"] . "!";
            echo "<td></td>" ;
        echo "</tr><tr>" ;
            echo "<td><input id='rtgLoginBtn' type='submit' value='Log Out' onclick=\"logOut();\" /></td>" ;
            echo "<td>";
            echo "<td></td>" ;
            echo "<td></td>" ;
        echo "</tr><tr>" ;
            echo "<td></td>" ;
            echo "<td></td>" ;
        echo "</tr>" ;
    echo "</table>" ;
} else {
    echo "<table id='rtgLoginBox'>" ;
        echo "<tr>" ;
            echo "<td><form action='process.php' method='post'>Username:</td>" ;
            echo "<td><input name='usernamein' id='rtgUsernameTxt' type='text' size='20' class='rtgSignUpTxt'/></td>" ;
        echo "</tr><tr>" ;
            echo "<td>Password:</td>" ;
            echo "<td><input name='passwordin' id='rtgPasswordTxt' type='password' size='20' class='rtgSignUpTxt' /></td>" ;
        echo "</tr><tr>" ;
            echo "<td></td>" ;
            echo "<td><input id='rtgLoginBtn' type='submit' value='Log In' />  </form><input id='rtgLoginBtn' type='submit' value='Sign Up' onclick=\"location.href='SignUp.php'\" /></td>" ;
        echo "</tr><tr>" ;
            echo "<td></td>" ;
            echo "<td><a href='mysite.com'><p style='padding:0 !important;'>Forgot Login Details?</p></a></td>" ;
        echo "</tr>" ;
    echo "</table>" ;
    }

    ?>

As far as I've read online, this should work? I also tried putting the function under the echoed table, but this didn't work either.

Answer 1

This code will cause the person to logout if they press the logout button and then redirect them to a new page called whatever.php. You obviously can change that to be whatever you want.

<?php 
    function logOut() {
        setcookie('userDetails[username]',"", time()-1200);
        unset($_COOKIE['userDetails']);
    }

if ('POST' === $_SERVER['REQUEST_METHOD'])
{
    logOut();
    header('Location: /whatever.php');
    exit;
}

if(isset($_COOKIE["userDetails"])) {
    echo "<form action='".htmlspecialchars($_SERVER['PHP_SELF'])."' method='post'><table id='rtgLoginBox'>" ;
        echo "<tr>" ;
            echo "<td> Cookie " . $_COOKIE["userDetails"]["username"] . "!";
            echo "<td></td>" ;
        echo "</tr><tr>" ;
            echo "<td><input id='rtgLoginBtn' type='submit' value='Log Out' /></td>" ;
            echo "<td>";
            echo "<td></td>" ;
            echo "<td></td>" ;
        echo "</tr><tr>" ;
            echo "<td></td>" ;
            echo "<td></td>" ;
        echo "</tr>" ;
    echo "</table></form>" ;
} else {
    echo "<table id='rtgLoginBox'>" ;
        echo "<tr>" ;
            echo "<td><form action='process.php' method='post'>Username:</td>" ;
            echo "<td><input name='usernamein' id='rtgUsernameTxt' type='text' size='20' class='rtgSignUpTxt'/></td>" ;
        echo "</tr><tr>" ;
            echo "<td>Password:</td>" ;
            echo "<td><input name='passwordin' id='rtgPasswordTxt' type='password' size='20' class='rtgSignUpTxt' /></td>" ;
        echo "</tr><tr>" ;
            echo "<td></td>" ;
            echo "<td><input id='rtgLoginBtn' type='submit' value='Log In' />  </form><input id='rtgLoginBtn' type='submit' value='Sign Up' onclick=\"location.href='SignUp.php'\" /></td>" ;
        echo "</tr><tr>" ;
            echo "<td></td>" ;
            echo "<td><a href='mysite.com'><p style='padding:0 !important;'>Forgot Login Details?</p></a></td>" ;
        echo "</tr>" ;
    echo "</table>" ;
    }

    ?>