ObjectManager/Manager service trait test. Allows multiple object Manager classes to use Doctrine's ObjectManager, rather than reimplementing the same functions again and again.

GroupManager.php

<?php

namespace Ibms\CustomerBundle\Entity;

use Doctrine\Common\Persistence\ObjectManager;
use Doctrine\ORM\QueryBuilder;

/**
 * Manages Group objects.
 *
 * @author Tim Nagel <tim@nagel.com.au>
 */
class GroupManager
{
    /**
     * Imports the base Manager trait allowing use of the ObjectManager provided
     * by doctrine.
     */
    use \Infinite\Helper\ManagerTrait;

    /**
     * Manager constructor.
     *
     * @param \Doctrine\Common\Persistence\ObjectManager $objectManager
     * @param string $class
     */
    public function __construct(ObjectManager $objectManager, $class)
    {
        $this->setObjectManager($objectManager, $class);
    }

    /**
     * Overrides the trait's doQueryAll method to provide sorting
     * by the appropriate field.
     *
     * @param \Doctrine\ORM\QueryBuilder $qb
     * @param $alias
     */
    protected function doQueryAll(QueryBuilder $qb, $alias)
    {
        $qb->orderBy(sprintf('%s.name', $alias));
    }

    /**
     * Saves a customer, optionally flushing the ObjectManager to cause a
     * write to occur.
     *
     * @param Customer $customer
     * @param Boolean $flush
     */
    public function save(Group $group, $flush = true)
    {
        $this->doSave($group, $flush);
    }
}

ManagerTrait.php

<?php

namespace Infinite\Helper;

use Doctrine\Common\Persistence\ObjectManager;
use Doctrine\Common\Persistence\ObjectRepository;
use Doctrine\ORM\EntityManager;
use Doctrine\ORM\EntityRepository;
use Doctrine\ORM\QueryBuilder;

/**
 * Contains a grouping of functions related to Manager services and
 * their use of the Doctrine ObjectManager.
 *
 * Provides basic functions like
 *    - queryAll
 *    - find
 *    - findBy
 *    - findOneBy
 *
 * @author Tim Nagel <tim@nagel.com.au>
 */
trait ManagerTrait
{
    /**
     * Persistence Manager.
     *
     * @var ObjectManager|EntityManager
     */
    private $objectManager;

    /**
     * Repository for the Object.
     *
     * @var ObjectRepository|EntityRepository
     */
    private $objectRepository;

    /**
     * @var \Doctrine\ORM\Mapping\ClassMetadata
     */
    private $objectMetadata;

    /**
     * Sets the ObjectManager up. Must be called after the implementing
     * class has getObjectClass set up.
     *
     * @param  \Doctrine\Common\Persistence\ObjectManager $objectManager
     * @param  string                                     $class
     * @throws \LogicException                            when getObjectClass
     */
    protected function setObjectManager(ObjectManager $objectManager, $class)
    {
        $this->objectManager    = $objectManager;
        $this->objectMetadata   = $objectManager->getClassMetadata($class);
        $this->objectRepository = $objectManager->getRepository($class);
    }

    /**
     * Retrieves the object manager.
     *
     * @return ObjectManager|EntityManager
     * @throws \LogicException             when setObjectManager has not been called.
     */
    protected function getObjectManager()
    {
        if (!$this->objectManager) {
            throw new \LogicException(sprintf('Called %s#getObjectManager when %s#setObjectManager has not been called.', __CLASS__, __TRAIT__));
        }

        return $this->objectManager;
    }

    /**
     * Retrieves the object repository for this manager.
     *
     * @return ObjectRepository|EntityRepository
     * @throws \LogicException                   when setObjectManager has not been called.
     */
    protected function getObjectRepository()
    {
        if (!$this->objectRepository) {
            throw new \LogicException(sprintf('Called %s#getObjectRepository when %s#setObjectManager has not been called.', __CLASS__, __TRAIT__));
        }

        return $this->objectRepository;
    }

    /**
     * Retrieves metadata for the object.
     *
     * @return \Doctrine\ORM\Mapping\ClassMetadata
     * @throws \LogicException
     */
    protected function getObjectMetadata()
    {
        if (!$this->objectMetadata) {
            throw new \LogicException(sprintf('Called %s#getObjectMetadata when %s#setObjectManager has not been called.', __CLASS__, __TRAIT__));
        }

        return $this->objectMetadata;
    }

    /**
     * Configures the query builder. Override in the implementing class
     * to specify conditions for queryAll.
     *
     * @param  \Doctrine\ORM\QueryBuilder $qb
     * @param  string                     $alias
     * @return \Doctrine\ORM\QueryBuilder
     */
    protected function doQueryAll(QueryBuilder $qb, $alias)
    {
        return $qb;
    }

    /**
     * Creates a new object that can be consumed by this manager.
     *
     * @return object
     */
    public function create()
    {
        $class = $this->objectRepository->getClassName();

        return new $class;
    }

    /**
     * Finds an object by its identifier.
     *
     * @param  mixed  $id The identifier or array of identifiers
     * @return object
     */
    public function find($id)
    {
        return $this->objectRepository->find($id);
    }

    /**
     * Finds objects by the specified criteria.
     *
     * @param  array       $criteria
     * @param  array|null  $orderBy
     * @param  null        $limit
     * @param  null        $offset
     * @return array|mixed
     */
    public function findBy(array $criteria, array $orderBy = null, $limit = null, $offset = null)
    {
        return $this->objectRepository->findBy($criteria, $orderBy, $limit, $offset);
    }

    /**
     * Finds one object by the specified criteria.
     *
     * @param  array  $criteria
     * @return object
     */
    public function findOneBy(array $criteria)
    {
        return $this->objectRepository->findOneBy($criteria);
    }

    /**
     * Returns a QueryBuilder object to query for all objects.
     *
     * @param string $alias
     */
    public function queryAll($alias = 'e')
    {
        $qb = $this->objectRepository->createQueryBuilder($alias);
        $this->doQueryAll($qb, $alias);

        return $qb;
    }

    /**
     * Checks if the object can be handled by this Manager.
     *
     * @param $object
     * @return bool
     */
    public function handles($object)
    {
        $class = $this->objectRepository->getClassName();

        return $object instanceof $class;
    }

    /**
     * Checks if the object is known to the ObjectManager
     *
     * @return bool
     */
    public function isNew($object)
    {
        return $this->handles($object) && !$this->objectManager->getUnitOfWork()->isInIdentityMap($object);
    }

    /**
     * Persists and optionally flushes an object managed by this
     * manager.
     *
     * To use this method the object implementing this trait
     * should create a save() method that calls this method.
     *
     * @param object $object
     */
    protected function doSave($object)
    {
        $this->objectManager->persist($object);
        $this->objectManager->flush();
    }

    /**
     * Tells the OM about an object that has come from a serialization.
     *
     * @param $object
     */
    public function merge($object)
    {
        $this->objectManager->merge($object);
    }

    /**
     * Begins a transaction to wrap operations.
     */
    protected function begin()
    {
        $this->objectManager->getConnection()->beginTransaction();
    }

    /**
     * Commits a transaction.
     */
    protected function commit()
    {
        $this->objectManager->getConnection()->commit();
    }

    /**
     * Rolls back a transaction.
     */
    protected function rollback()
    {
        $this->objectManager->getConnection()->rollback();
    }

}