Drupal Module

Drupal 7 global variables vs. Drupal 8 services

Several Drupal 7 global values like global $language and global $user are also now accessed via services in Drupal 8 (and not global variables).

Drupal::languageManager()->getCurrentLanguage() and Drupal::currentUser()

Two ways to get the currentUser data:

1) Procedural code
$user = \Drupal::currentUser();
ksm($user->id());

(or)

2) OO code access the @current_user service, via dependency injection (DI)
$service = \Drupal::service('thirstysix.ex');
ksm($service->DisplayUserId());

Boost Module uses on Drupal?

Boost provides static page caching for Drupal enabling a very significant performance and scalability boost for sites that receive mostly anonymous traffic. For shared hosting this is your best option in terms of improving performance. On dedicated servers, you may want to consider Varnish instead.