Slim framework used in a class

api.php

<?php

session_start();

define('WWW_ROOT', dirname(__FILE__) . DIRECTORY_SEPARATOR);

require_once WWW_ROOT . 'includes' .    DIRECTORY_SEPARATOR . 'functions.php';
require_once WWW_ROOT . 'classes' .     DIRECTORY_SEPARATOR . 'Config.php';
require_once(WWW_ROOT . 'dao' .         DIRECTORY_SEPARATOR . 'UserDAO.php');
require_once(WWW_ROOT . 'dao' .         DIRECTORY_SEPARATOR . 'EventDAO.php');
require_once(WWW_ROOT . 'dao' .         DIRECTORY_SEPARATOR . 'RegistrationDAO.php');
require_once(WWW_ROOT . 'Slim' .        DIRECTORY_SEPARATOR . 'Slim.php');

class api {
    private $app;
    private $userDao;
    private $eventDao;
    private $registrationDao;
    private $feedback = array("status" => "error", "response" => "Invalid or no parameters given.");

    function __construct() {
        $this->userDao = new UserDAO();
        $this->eventDao = new EventDAO();
        $this->registrationDao = new RegistrationDAO();

        $this->app = new Slim();

        $this->app->get('/', array($this, 'index'));
        $this->app->post('/users/login', array($this, 'login'));
        $this->app->post('/users/register', array($this, 'addUser'));

        $this->app->get('/events', array($this, 'events'));
        $this->app->get('/events/id', array($this, 'eventById'));
        $this->app->post('/events/add', array($this, 'addEvent'));
        $this->app->post('/events/update/id', array($this, 'updateEventById'));
        $this->app->get('/events/delete/id', array($this, 'deleteEventById'));

        $this->app->get("/registrations/eventid", array($this, 'registrationById'));
        $this->app->get("/registrations/delete/id", array($this, 'registrationDeleteById'));
        $this->app->post("/registrations/add", array($this, 'addRegistration'));

        $this->app->run();
    }

    public function index() {
        $this->display();
    }

    public function addRegistration() {
        $request = $this->app->request()->post();

        $this->feedback = array("status" => "success", "response" => $this->registrationDao->addRegistrationForEvent($request));

        $this->display();
    }

    public function addEvent() {
        $request = $this->app->request()->post();

        $this->feedback = array("status" => "success", "response" => $this->eventDao->addEvent($request));

        $this->display();
    }

    public function updateEventById() {
        $request = $this->app->request()->post();

        if(isset($_POST['id']))
            $this->feedback = array("status" => "success", "response" => $this->eventDao->updateEvent($_POST['id'], $request));

        $this->display();
    }

    public function deleteEventById() {
        if(isset($_GET['id']) && isset($_GET['api-key']))
            $this->feedback = array("status" => "success", "response" => $this->feedback = $this->eventDao->deleteEventById($_GET['id'], $_GET['api-key']));

        $this->display();
    }

    public function registrationDeleteById() {
        if(isset($_GET['id']))
            $this->feedback = array("status" => "success", "response" => $this->feedback = $this->registrationDao->deleteRegistrationForEvent($_GET['id']));

        $this->display();
    }

    public function events() {
        if(isset($_GET['api-key']))
            $this->feedback = $this->eventDao->getEventsByUser($_GET['api-key']);

        $this->display();
    }

    public function registrationById() {
        if(isset($_GET['id']))
            $this->feedback = array("status" => "success", "response" => $this->registrationDao->getRegistrationsForEvent($_GET['id']));

        $this->display();
    }

    public function eventById() {
        if(isset($_GET['id']) && isset($_GET['api-key']))
            $this->feedback = $this->eventDao->getEventById($_GET['id'], $_GET['api-key']);

        $this->display();
    }

    public function addUser() {
        $request = $this->app->request()->post();

        $this->feedback = array("status" => "success", "response" => $this->userDao->addUser($request));

        $this->display();
    }

    public function login() {
        $request = $this->app->request()->post();

        $this->feedback = array("status" => "success", "response" => $this->userDao->login($request));

        $this->display();
    }

    public function display() {
        die(json_encode($this->feedback));
    }
}

new api();