Symfony: Overriding Symfony service ( compiler pass )

I’m on symfony 2.7 and need to override SymfonyComponentAssetUrlPackage

I’ve looked at http://symfony.com/doc/current/cookbook/bundles/override.html and http://symfony.com/doc/current/cookbook/service_container/compiler_passes.html but can’t get it working.

I have made a file in my bundle MyAppCoreBundleOverridesUrlPackage; I registered UrlPackage as a service and added a function:

public function process(ContainerBuilder $container)
{
    $definition = $container->getDefinition('assets.url_package');
    $definition->setClass('MyAppCoreBundleOverridesUrlPackage');
}

The weird thing is, if I call $this->has('assets.url_package') in any controller, it returns false. I did grab it from the services file under Symfony:

<service id="assets.url_package" class="SymfonyComponentAssetUrlPackage" abstract="true">
        <argument /> <!-- base URLs -->
        <argument type="service" /> <!-- version strategy -->
        <argument type="service" id="assets.context" />
    </service>

If I run php app/console debug:container, the UrlPackage from symfony isn’t in there, but, if I change something inside the vendor/*/UrlPackge file, it does work

Can someone point me in the right direction?

Answer

Decorating the service is the thing you’re looking for:

bar:
    public: false
    class: stdClass
    decorates: foo
    arguments: ["@bar.inner"]

You can inject the original service in your own service, and implement the original interface to make them compatible.

http://symfony.com/doc/2.7/service_container/service_decoration.html