interface ModerationHandlerInterface

interface ModerationHandlerInterface {
    
    /**
     * Determines if an entity should be moderated.
     *
     * At the workflow level, moderation is enabled or disabled for entire entity
     * types or bundles. After a bundle has been enabled, there maybe be further
     * decisions each entity type may make to evaluate if a given entity is
     * appropriate to be included in a moderation workflow. The handler is only
     * consulted after the user has configured the associated entity type and
     * bundle to be included in a moderation workflow.
     *
     * Returning FALSE will remove the moderation state field widget from the
     * associated entity form and opt out of all moderation related entity
     * semantics, such as creating new revisions and changing the publishing
     * status of a revision.
     *
     * @param \Drupal\Core\Entity\ContentEntityInterface $entity
     *   The entity we may be moderating.
     *
     * @return bool
     *   TRUE if this entity should be moderated, FALSE otherwise.
     */
    public function isModeratedEntity(ContentEntityInterface $entity);
    
    /**
     * Operates on moderated content entities preSave().
     *
     * @param \Drupal\Core\Entity\ContentEntityInterface $entity
     *   The entity to modify.
     * @param bool $default_revision
     *   Whether the new revision should be made the default revision.
     * @param bool $published_state
     *   Whether the state being transitioned to is a published state or not.
     */
    public function onPresave(ContentEntityInterface $entity, $default_revision, $published_state);
    
    /**
     * Alters entity forms to enforce revision handling.
     *
     * @param array $form
     *   An associative array containing the structure of the form.
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   The current state of the form.
     * @param string $form_id
     *   The form id.
     *
     * @see hook_form_alter()
     */
    public function enforceRevisionsEntityFormAlter(array &$form, FormStateInterface $form_state, $form_id);
    
    /**
     * Alters bundle forms to enforce revision handling.
     *
     * @param array $form
     *   An associative array containing the structure of the form.
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   The current state of the form.
     * @param string $form_id
     *   The form id.
     *
     * @see hook_form_alter()
     */
    public function enforceRevisionsBundleFormAlter(array &$form, FormStateInterface $form_state, $form_id);

}