How to access EntityManager into a RabbitMQBundle custom producer class? - php

Question

I am using RabbitMQBundle in a Symfony 2.8 project, and I would like to use a custom producer class which persists an entity (Message) in database before publishing the RabbitMQ message.
I defined the custom producer class in config.yml:
old_sound_rabbit_mq:
...
producers:
myproducer:
class: AppBundle\Services\GenericProducer
connection: default
exchange_options: {name: 'my_exchange', type: direct}
And the custom Producer class:
<?php
namespace AppBundle\Services;
use AppBundle\Entity\Message;
use OldSound\RabbitMqBundle\RabbitMq\Producer;
/**
* Customised Producer, that publishes AMQP Messages
* but also:
* - writes an entry in the Message table
*/
class GenericProducer extends Producer
{
/**
* Entity Manager
*/
protected $em;
public function setEntityManager($entityManager)
{
$this->em = $entityManager;
return $this;
}
/**
* Publishes the message and merges additional properties with basic properties
* And also:
* - writes an entry in the Message table
*
* #param string $action
* #param array $parameters
* #param string $routingKey
* #param array $additionalProperties
* #param array|null $headers
*/
public function publish($action, $parameters = array() , $routingKey = '', $additionalProperties = array(), array $headers = null)
{
$message = new Message();
$message->setAction($action)
->setParameters($parameters);
$this->em->persist($message);
$this->em->flush();
$msgBody = array(
'action' => $action,
'parameters' => $parameters
);
parent::publish($msgBody, $routingKey, $additionalProperties, $headers);
}
}
How can I make a call to GenericProducer->setEntityManager, as the producer is not defined in services.yml, like other services ?
Is there another way to achieve this ?
Thanks for your time.

Answer 1

the producer service definition is generated dynamically by the bundle in the Dependency Injection Extension of the bundle.
You can either try to decorate the existing service or create a compiler pass where you fetch the existing service and extend it by calling the setEntityManager function.

Answer 2

Following #lordrhodos suggestion, I decorated the producer service generated by RabbitMQBundle. Here is the complete code:
config.yml (nothing special to do):
old_sound_rabbit_mq:
...
producers:
myproducer:
connection: default
exchange_options: {name: 'my_exchange', type: direct}
services.yml (here you define a decorating service):
app.decorating_myproducer_producer:
class: AppBundle\Services\GenericProducer
decorates: old_sound_rabbit_mq.myproducer_producer
arguments: ['#
app.decorating_myproducer_producer.inner', '#doctrine.orm.entity_manager']
public: false
decorator class:
<?php
namespace AppBundle\Services;
use AppBundle\Entity\Message;
use OldSound\RabbitMqBundle\RabbitMq\Producer;
/**
* Customised Producer, that publishes AMQP Messages
* but also:
* - writes an entry in the Message table
*/
class GenericProducer extends Producer
{
/**
* #var Producer
*/
protected $producer;
/**
* #var EntityManager
*/
protected $em;
/**
* GenericProducer constructor.
* #param Producer $producer
* #param EntityManager $entityManager
*/
public function __construct(Producer $producer, EntityManager $entityManager)
{
$this->producer = $producer;
$this->em = $entityManager;
}
/**
* Publishes the message and merges additional properties with basic properties
* And also:
* - writes an entry in the Message table
*
* #param string $action
* #param array $parameters
* #param string $routingKey
* #param array $additionalProperties
* #param array|null $headers
*/
public function publish($action, $parameters = array() , $routingKey = '', $additionalProperties = array(), array $headers = null)
{
$message = new Message();
$message->setAction($action)
->setParameters($parameters);
$this->em->persist($message);
$this->em->flush();
$msgBody = array(
'action' => $action,
'parameters' => $parameters
);
$this->producer->publish(serialize($msgBody), $routingKey, $additionalProperties, $headers);
}
}
Finally, call the original producer from a controller:
$this->get('old_sound_rabbit_mq.myproducer_producer')->publish('wait', ['time' => 30]);