Module Development

Add Custom Validation to User Entities for Drupal 8, 9, 10, and 11

Validation happens whenever an entity is created or updated, ensuring data integrity across form submissions, JSON:API requests, and direct entity object manipulation. Drupal's Entity Validation API, consists of constraints, validators, and their integration. As module developer, we'll use this API to enforce custom rules about what constitutes valid data.

In this tutorial, we'll:

  • Learn about the roles of constraints and validators within Drupal's validation system.
  • See how to create and integrate custom validation rules.
  • Apply custom validation to an entity type that enforces specific data integrity rules.

By the end of this tutorial, you should be able to define new constraints and validators, and associate them with entity types.

Drupal Module Developer Guide