Doctrine\ORM\UnitOfWork::getCommitOrder PHP Method

    private function getCommitOrder(array $entityChangeSet = null)
    {
        if ($entityChangeSet === null) {
            $entityChangeSet = array_merge(
                    $this->entityInsertions,
                    $this->entityUpdates,
                    $this->entityDeletions
                    );
        }
        
        $calc = $this->getCommitOrderCalculator();
        
        // See if there are any new classes in the changeset, that are not in the
        // commit order graph yet (dont have a node).
        $newNodes = array();
        foreach ($entityChangeSet as $oid => $entity) {
            $className = get_class($entity);         
            if ( ! $calc->hasClass($className)) {
                $class = $this->em->getClassMetadata($className);
                $calc->addClass($class);
                $newNodes[] = $class;
            }
        }

        // Calculate dependencies for new nodes
        foreach ($newNodes as $class) {
            foreach ($class->associationMappings as $assoc) {
                if ($assoc['isOwningSide'] && $assoc['type'] & ClassMetadata::TO_ONE) {
                    $targetClass = $this->em->getClassMetadata($assoc['targetEntity']);
                    if ( ! $calc->hasClass($targetClass->name)) {
                        $calc->addClass($targetClass);
                    }
                    $calc->addDependency($targetClass, $class);
                    // If the target class has mapped subclasses,
                    // these share the same dependency.
                    if ($targetClass->subClasses) {
                        foreach ($targetClass->subClasses as $subClassName) {
                            $targetSubClass = $this->em->getClassMetadata($subClassName);
                            if ( ! $calc->hasClass($subClassName)) {
                                $calc->addClass($targetSubClass);
                            }
                            $calc->addDependency($targetSubClass, $class);
                        }
                    }
                }
            }
        }

        return $calc->getCommitOrder();
    }