Symfony prependExtensionConfig with data from a service - symfony

Question

I try to prepend a config array to a different bundle using the prependExtensionConfig from my bundle. All works fine until $config is hardcoded.
My goal is to load the $config values using a service (from the db for example) and than prepend it to the other bundle.
The problem is that the services are not loaded at that moment.
I guess this is a limitation is symfony2.
Any ideas? thx
class MyExtension extends Extension implements PrependExtensionInterface
{
/**
* {#inheritDoc}
*/
public function load(array $configs, ContainerBuilder $container)
{
$configuration = new Configuration();
$config = $this->processConfiguration($configuration, $configs);
$loader = new Loader\YamlFileLoader($container, new FileLocator(__DIR__ . '/../Resources/config'));
$loader->load('services.yml');
}
public function prepend(ContainerBuilder $container)
{
$config = // load config from a service ...
$container->prependExtensionConfig('other_bundle', $config);
}
}

Answer 1

First of all you need to set up your config to take values from parameters section of Service container:
Setup config.yml:
# app/config/config.yml
namespace:
subnamespace:
param1: %param1%
param2: %param2%
Then you need to fill %param1% and %param2% parameters in container with values from database. To do that you need to declare your CompilerPass and add it to the container. After whole container will be loaded (in the compile time) you will have access to all services in it.
Just get the entity manager service and query for needed parameters and register them in container.
Define Compiler pass:
# src/Acme/YourBundle/DependencyInjection/Compiler/ParametersCompilerPass.php
class ParametersCompilerPass implements CompilerPassInterface
{
public function process(ContainerBuilder $container)
{
$em = $container->get('doctrine.orm.default_entity_manager');
$param1 = $em->getRepository('Acme:Params')->find(1);
$param2 = $em->getRepository('Acme:Params')->find(2);
$container->setParameter('param1', $param1);
$container->setParameter('param2', $param2);
}
}
In the bundle definition class you need to add compiler pass to your container
# src/Acme/YourBundle/AcmeYourBundle.php
class AcmeYourBundle extends Bundle
{
public function build(ContainerBuilder $container)
{
parent::build($container);
$container->addCompilerPass(new ParametersCompilerPass(), PassConfig::TYPE_AFTER_REMOVING);
}
}
PassConfig::TYPE_AFTER_REMOVING means that this CompilerPass will be processed almost after all other compiler passes and in this moment you will already have every service injected.