Implementing custom access control for an entity

All entities have a set of handlers that control specific pieces of functionalities. One handler handles access control. When the access handler is not specified, the base \Drupal\Core\Entity\EntityType module will implement \Drupal\Core\Entity\EntityAccessControlHandler as the access handler. By default, this will check whether any modules have implemented hook_entity_create_access or hook_entity_type_create_access and use their opinions. Otherwise, it defaults to the admin permission for the entity type, if implemented.

In this recipe, we will provide an admin permission for our entity and implement the access handler and permission provider available through the Entity API module. We will base this on an entity called Message.

Note

This recipe specifically uses the functionality from the Entity API module because it has been tested and thoroughly reviewed and reduces boilerplate code. Ideally, this will be part of an upcoming minor release...