web/app/inc.php

<?php
/*
    This is the main file to be included on every page.
    It will act as a front controller of our application.
      _____
     /     \
    | () () |
     \  ^  /
      |||||
      |||||

    Tread carefully
*/

// Disable type coercion
declare(strict_types=1);

// Autoloader
spl_autoload_register(function ($class_name) {
    require __DIR__ . '/core/' . $class_name . '.php';
});

/* === App Setup === */

// Displays a custom page on error or exception 
new ErrorHandler;

// Grab configuration file
$config   = (
    new Config(__DIR__ . '/config.php')
)->config;

// Start database connection
$database = new Database($config['database']);

// Session wrapper
$session  = new Session;

// Handles current user session
$user     = new User($session, $database);

// THIS IS IMPORTANT!!
// Without it, everyone will have access to any page without having to be logged in.
// Decides if the user is allowed to view current page
new AccessControl($user, $config['root_url']);

$app = new App(
    $config,
    $database,
    $session,
    $user
);

// We will use $app instead
unset(
    $config,
    $database,
    $session,
    $user
);

return $app;