In the first part, we saw how entity validation works in Drupal 8, why it is a separate component and how
Drupal 8 has its entity validation separate and decoupled from the typical validation given by its form API. This is done for a lot of reasons.
There is a lot of literature about entities and their purpose in Drupal 7 context. Most of it has been adopted in Drupal 8 as well.
Drupal 8 allows module developers to write their own customized authentication schemes. In this post, we shall see how we create one.