Binding::save

public function save(): Result
{
	if (is_null($this->boundEntity) || empty($this->thisIdField))
	{
		// everything was saved at entityObject save
		return new Result();
	}

	$newBindings = $this->get($this->fieldNameMap->getBindings());
	$boundIdsAfterSave = EntityBinding::prepareEntityIDs($this->boundEntityTypeId, $newBindings);

	sort($this->boundIdsBeforeSave);
	sort($boundIdsAfterSave);
	if ($boundIdsAfterSave === $this->boundIdsBeforeSave)
	{
		return new Result();
	}

	$affectedIds = array_unique(array_merge($this->boundIdsBeforeSave, $boundIdsAfterSave));
	if (empty($affectedIds))
	{
		return new Result();
	}

	$query = new Query($this->bindingEntity);

	/** @var Collection $collection */
	$collection =
		$query
			->setSelect([$this->boundEntityIdFieldName, $this->thisIdField, 'IS_PRIMARY'])
			->whereIn($this->boundEntityIdFieldName, $affectedIds)
			->fetchCollection()
	;

	/** @var Array $newPrimaryMap */
	$newPrimaryMap = [];

	foreach ($collection as $object)
	{
		$boundEntityId = $object->require($this->boundEntityIdFieldName);
		$thisId = $object->require($this->thisIdField);
		$isPrimary = $object->require('IS_PRIMARY');

		$primaryDesc = $newPrimaryMap[$boundEntityId] ?? null;

		if (
			is_null($primaryDesc)
			|| $isPrimary && $primaryDesc['isPrimary'] === false
			|| $thisId < $primaryDesc['thisId'] && !$primaryDesc['isPrimary']
		)
		{
			$newPrimaryMap[$boundEntityId] = ['isPrimary' => $isPrimary, 'thisId' => $thisId];
		}
	}

	foreach ($affectedIds as $affectedId)
	{
		if (!isset($newPrimaryMap[$affectedId]))
		{
			//no primary found - set to null
			$newPrimaryMap[$affectedId] = ['isPrimary' => false, 'thisId' => null];
		}
	}

	$result = new Result();
	foreach ($newPrimaryMap as $boundEntityId => $primaryDesc)
	{
		$updateResult =  $this->boundEntity->getDataClass()::update(
			$boundEntityId,
			['fields' => [$this->thisIdField => $primaryDesc['thisId']]],
		);

		if (!$updateResult->isSuccess())
		{
			$result->addErrors($updateResult->getErrors());
		}
	}

	return $result;
}