Declaring a Doctrine Repository as a service and injecting it a dependency.

ExampleRepository.php

<?php

namespace Acme\DemoBundle\Repository;

use Acme\DemoBundle\Dependency;
use Doctrine\ORM\EntityRepository;

/**
 * Get this repository directly from the container: it will set the $dependency attribute.
 * If you get it using Doctrine's "getRepository()", don't forget to call setDependency().
 */
class ExampleRepository extends EntityRepository
{
    /**
     * @var Dependency
     */
    private $dependency;

    public function setDependency(Dependency $dependency)
    {
        $this->dependency = $dependency;
    }

    public function findSomething(Directory $directory)
    {
        $dependency = $this->getDependency();

        // Your DQL.
    }

    private function getDependency()
    {
        if (!$this->dependency instanceof Dependency) {
            $message = array(
                'trigger' => 'The "dependency" attribute is NULL.',
                'possibleReason' => 'Did you retrieved this repository using "$doctrine->getRepository()"?',
                'remedy' => 'If so, retrieve it instead directly from the container',
            );
            throw \LogicException(implode(' ', $message));
        }

        return $this->dependency;
    }
}

services.xml

<?xml version="1.0" ?>

<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <services>
        <service id="acme_demo.dependency" class="Acme\DemoBundle\Dependency">
        </service>
        
        <service id="acme_demo.example_repository"
            class="Acme\DemoBundle\Repository\ExampleRepository"
            factory-service="doctrine"
            factory-method="getRepository">
            <argument>AcmeDemoBundle:ExampleRepository</argument>
            <call method="setDependency">
                <argument type="service" id="acme_demo.dependency" />
            </call>
        </service>

        <service id="acme_demo.service" class="Acme\DemoBundle\Service">
            <argument type="service" id="acme_demo.example_repository" />
        </service>
    </services>

</container>