Entity Field types, Data types
Drupal is a CMS (Content Management System) open-source written in PHP. Drupl 8 is the latest version of Drupal successor of Drupal 7 popular for its security, flexibility and scalability, used on the complex high traffic web applications as well as small showcase sites. Drupal 8 is comes with over 200 new features and improvements including native full responsive support, multilingual support, REST Full web service. Drupal 8 was created in PHP using Symfony 2 Framework and TWIG templating system.
This web site is a set of tutorials help to new Drupal 8 developers and persons who want to be a Drupal 8 developer or a webmaster. The level of the tutorials are start from very basic (beginners) and can be very complex (Experts). I hope the site is useful for you and you are welcome to share your knowledge, ideas and experience. Thank you.
To set Drupal System variables you can use the $settings (on Drupal 8) and $conf (On Drupal 7) array of setting.php file.
$settings['file_public_path'] = '/path/to/dir/public';
Create a custom module (here : example)
For active themes by route you first have to define a service in your $module.services.yml file: