Symfony2. Force a service to get instanced - php

Question

I'm working with symfony 2.8, I'm facing a situation where a service must be instanced even if it is not requested somewhere.
Why ? Because this Core service configure tagged services that are transfered by method calling into Core ( I did this in a compiler pass ).
And then, if I request one of these tagged services without request Core, it will not be configured and then be unusable.
Here is the compiler pass :
$coreDefinition = $container->findDefinition(
'app.improvements.core'
);
$taggedAppliers = $container->findTaggedServiceIds('app.improvement.applier');
foreach ($taggedAppliers as $id => $tags) {
$coreDefinition->addMethodCall(
'registerApplier',
[new Reference($id)]
);
}
$taggedImprovements = $container->findTaggedServiceIds(
'app.improvement'
);
// Only method found to initialize improvements.
foreach ($taggedImprovements as $id => $tags) {
$coreDefinition->addMethodCall(
'registerImprovement',
[new Reference($id)]
);
}
To sum up, the Appliers registers Improvement and Core registers Appliers. The core associate improvements with appliers because each improvement must be registered in a specific applier that the core stores.
The problem I that when I only request a Applier, its improvements are not registered into it because the core isn't instancied.
Thank you.

Answer 1

Design problems aside, the easiest way to instantiate a service is to use an event listener. In your case you would listen for the kernel.request and pull your service from the container.
class RequestListener
{
public function onKernelRequest(GetResponseEvent $event)
{
$event->getKernel()->getContainer()->get('service_id');
}
}