Chris@18: <?php
Chris@18: 
Chris@18: namespace Drupal\Core\Entity;
Chris@18: 
Chris@18: /**
Chris@18:  * Defines methods for an entity that supports synchronization.
Chris@18:  */
Chris@18: interface SynchronizableInterface extends EntityInterface {
Chris@18: 
Chris@18:   /**
Chris@18:    * Sets the status of the synchronization flag.
Chris@18:    *
Chris@18:    * @param bool $status
Chris@18:    *   The status of the synchronization flag.
Chris@18:    *
Chris@18:    * @return $this
Chris@18:    */
Chris@18:   public function setSyncing($status);
Chris@18: 
Chris@18:   /**
Chris@18:    * Returns whether this entity is being changed as part of a synchronization.
Chris@18:    *
Chris@18:    * If you are writing code that responds to a change in this entity (insert,
Chris@18:    * update, delete, presave, etc.), and your code would result in a change to
Chris@18:    * this entity itself, a configuration change (whether related to this entity,
Chris@18:    * another entity, or non-entity configuration), you need to check and see if
Chris@18:    * this entity change is part of a synchronization process, and skip executing
Chris@18:    * your code if that is the case.
Chris@18:    *
Chris@18:    * For example, \Drupal\node\Entity\NodeType::postSave() adds the default body
Chris@18:    * field to newly created node type configuration entities, which is a
Chris@18:    * configuration change. You would not want this code to run during an import,
Chris@18:    * because imported entities were already given the body field when they were
Chris@18:    * originally created, and the imported configuration includes all of their
Chris@18:    * currently-configured fields. On the other hand,
Chris@18:    * \Drupal\field\Entity\FieldStorageConfig::preSave() and the methods it calls
Chris@18:    * make sure that the storage tables are created or updated for the field
Chris@18:    * storage configuration entity, which is not a configuration change, and it
Chris@18:    * must be done whether due to an import or not. So, the first method should
Chris@18:    * check $entity->isSyncing() and skip executing if it returns TRUE, and the
Chris@18:    * second should not perform this check.
Chris@18:    *
Chris@18:    * @return bool
Chris@18:    *   TRUE if the configuration entity is being created, updated, or deleted
Chris@18:    *   through a synchronization process.
Chris@18:    */
Chris@18:   public function isSyncing();
Chris@18: 
Chris@18: }