EntityHandlerInterface.php

<?php

namespace Drupal\Core\Entity;

use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Defines an interface for entity handlers.
 *
 * This interface can be implemented by entity handlers that require
 * dependency injection.
 *
 * @ingroup entity_api
 */
interface EntityHandlerInterface {
    
    /**
     * Instantiates a new instance of this entity handler.
     *
     * This is a factory method that returns a new instance of this object. The
     * factory should pass any needed dependencies into the constructor of this
     * object, but not the container itself. Every call to this method must return
     * a new instance of this object; that is, it may not implement a singleton.
     *
     * @param \Symfony\Component\DependencyInjection\ContainerInterface $container
     *   The service container this object should use.
     * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
     *   The entity type definition.
     *
     * @return static
     *   A new instance of the entity handler.
     */
    public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type);

}