Entity Validation API

Entity Validation API in Drupal 8.

Entity Validation API overview

In Drupal 8 Entity validation is moved to a separate Entity validation API and decoupled from form validation.

Providing a custom validation constraint

Todo: Document how a validation constraint can be provided.

Supported validation constraints [TBD]

List supported validation constraints and their settings. Also, document type-specific default constraints added in automatically here.