Observers::processAfterSave

public function processAfterSave(Item $itemBeforeSave, Item $item, Context $context = null): FieldAfterSaveResult
{
	$previousObservers = $itemBeforeSave->remindActual($this->getName());
	$currentObservers = $item->get($this->getName());

	$addedObservers = array_diff($currentObservers, $previousObservers);
	$removedObservers = array_diff($previousObservers, $currentObservers);

	$this->integrationClassName::onEntityModification(
		$item->getEntityTypeId(),
		$item->getId(),
		[
			'CURRENT_FIELDS' => $item->getData(),
			'PREVIOUS_FIELDS' => $itemBeforeSave->getData(Values::ACTUAL),
			'ADDED_OBSERVER_IDS' => $addedObservers,
			'REMOVED_OBSERVER_IDS' => $removedObservers,
		]
	);

	return parent::processAfterSave($itemBeforeSave, $item, $context);
}