compiler-passes.md

Compiler Passes

Compiler passes allow the manipulation of service definitions prior to compilation of the service container.

The most common use-cases for using compiler passes:

• Tagging services. This allow you to register those tagged services with another service.

  An example is automatically registering TwigExtension services with the Twig environment.

• Overriding default services. You can customize built-in services, for example, overriding the default RouteCollector service.

Getting started

Define your Compiler Pass. Implement the process method, modifying the ContainerBuilder as necessary.

<?php

namespace Acme\DependencyInjection\Compiler;

use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;

class CustomCompilerPass implements CompilerPassInterface
{
    public function process(ContainerBuilder $container)
    {
        // ...
    }
}

Registering your compiler pass

A Nice application allows the registration of compiler passes through the addCompilerPass method.

Register your custom compiler pass with your application in web/index.php.

<?php

use Nice\Application;
use Acme\DependencyInjection\Compiler\CustomCompilerPass;
// ...

$app = new Application();
$app->addCompilerPass(new CustomCompilerPass());