sakura/main/messages.php

<?php
/*
 * Sakura Private Messages
 */

// Declare Namespace
namespace Sakura;

// Include components
require_once str_replace(basename(__DIR__), '', dirname(__FILE__)) .'_sakura/sakura.php';

// Add page specific things
$renderData['page'] = [
    'title' => 'Inbox'
];
$renderData['messages'] = Users::getPrivateMessages();

// Print page contents
print Templates::render('main/messages.tpl', $renderData);