$container['view'] = function ($container) {
    $view = new SlimViewsTwig(
        $container['settings']['view']['template_path'],
        $container['settings']['view']['twig'],
        [
            'debug' => true // This line should enable debug mode
        ]
    );

    $basePath = rtrim(str_ireplace('index.php', '', $container['request']->getUri()->getBasePath()), '/');
    $view->addExtension(new SlimViewsTwigExtension($container['router'], $basePath));

    $view->addExtension(new Twig_Extension_Debug());

    return $view;
};

$container['validate_sanitize'] = function ($container)
{
    $class_path = $container->get('settings')['class_path'];
    require $class_path . 'ValidateSanitize.php';
    $validator = new ValidateSanitize();
    return $validator;
};

$container['hash_password'] = function($container)
{
    $class_path = $container->get('settings')['class_path'];
    require $class_path . 'HashPassword.php';
    $hash = new HashPassword();
    return $hash;
};

$app->post('/register', function(Request $request, Response $response)
{
    $arr_tainted_params = $request->getParsedBody();

    $sanitizer_validator = $this→get('validate_sanitize'); //here for example
    $password_hasher = $this->get('hash_password');

    $tainted_email = $arr_tainted_params['email'];
    $tainted_username = $arr_tainted_params['username'];
    $tainted_password = $arr_tainted_params['password'];

    $model = $this->get('model');
    $sql_wrapper = $this->get('sql_wrapper');
    $sql_queries = $this->get('sql_queries');
    $db_handle = $this->get('dbase');

    $cleaned_email = $sanitizer_validator->sanitize_input($tainted_email, FILTER_SANITIZE_EMAIL);
    $cleaned_username = $sanitizer_validator->sanitize_input($tainted_username, FILTER_SANITIZE_STRING);
    $cleaned_password = $sanitizer_validator->sanitize_input($tainted_password, FILTER_SANITIZE_STRING);
 });

<?php

require 'routes/change_password.php';
require 'routes/forgot_password.php';
require 'routes/homepage.php';
require 'routes/login.php';
require 'routes/logout.php';
require 'routes/register.php';

<?php

session_start();

require __DIR__ . '/../vendor/autoload.php';

$settings = require __DIR__ . '/app/settings.php'; //an array of options containing database configurations and the path to twig templates

$container = new SlimContainer($settings); //not sure what this does

require __DIR__ . '/app/dependencies.php';

$app = new SlimApp($container);

require __DIR__ . '/app/routes.php';

$app→run();