<?php
  
require_once('kirby.php');
  
// setup the database
c::set('db.host', 'localhost');
c::set('db.user', 'root');
c::set('db.password', 'password');
c::set('db.name', 'database');
  
// select all users from an imaginary user table
$users = db::select('users', '*');
  
// build a list of encoded email addresses
// with a fallback for users without an email address
foreach($users AS $user) {
    echo str::email( a::get($user, 'email', 'no email') );
} 
  
?>

<?php

require_once('kirby.php');

if(get('submit')) {

    $email = get('email');

    if(!v::email($email)) {
        echo 'That is not a valid email address';
    } else {
        db::insert('newsletter', array('email' => $email));
        go('/success');
    }

}

?>
<form>
  <input type="text" name="email" />
  <input type="submit" name="submit" value="Subscribe" />
</form>