doctrine / orm

    /**

     * {@inheritdoc}

     */

    public function count(PersistentCollection $collection)

    {

        $association = $collection->getMapping();

        $persister   = $this->uow->getEntityPersister($association->getTargetEntity());

        // only works with single id identifier entities. Will throw an

        // exception in Entity Persisters if that is not the case for the

        // 'mappedBy' field.

        $criteria = [

            $association->getMappedBy()  => $collection->getOwner(),

        ];

        return $persister->count($criteria);

    }

    /**

     * {@inheritdoc}

    /**

     * {@inheritdoc}

     */

    public function slice(PersistentCollection $collection, $offset, $length = null)

    {

        $association = $collection->getMapping();

        $persister   = $this->uow->getEntityPersister($association->getTargetEntity());

        return $persister->getOneToManyCollection($association, $collection->getOwner(), $offset, $length);

    }

    /**

     * {@inheritdoc}

    /**

     * {@inheritDoc}

     */

    public function slice(PersistentCollection $collection, $offset, $length = null)

    {

        $association = $collection->getMapping();

        $persister   = $this->uow->getEntityPersister($association->getTargetEntity());

        return $persister->getManyToManyCollection($association, $collection->getOwner(), $offset, $length);

    }

    /**

     * {@inheritdoc}

     */