How to Override any Part of a Bundle

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How to Override any Part of a Bundle

This document is a quick reference for how to override different parts of third-party bundles.


Routing is never automatically imported in Symfony2. If you want to include the routes from any bundle, then they must be manually imported from somewhere in your application (e.g. app/config/routing.yml).

The easiest way to "override" a bundle's routing is to never import it at all. Instead of importing a third-party bundle's routing, simply copying that routing file into your application, modify it, and import it instead.


Assuming the third-party bundle involved uses non-service controllers (which is almost always the case), you can easily override controllers via bundle inheritance. For more information, see How to use Bundle Inheritance to Override parts of a Bundle. If the controller is a service, see the next section on how to override it.

Services & Configuration

In order to override/extend a service, there are two options. First, you can set the parameter holding the service's class name to your own class by setting it in app/config/config.yml. This of course is only possible if the class name is defined as a parameter in the service config of the bundle containing the service. For example, to override the class used for Symfony's translator service, you would override the translator.class parameter. Knowing exactly which parameter to override may take some research. For the translator, the parameter is defined and used in the Resources/config/translation.xml file in the core FrameworkBundle:

  • YAML
  • XML
  • PHP
# app/config/config.yml
    translator.class:      Acme\HelloBundle\Translation\Translator

Secondly, if the class is not available as a parameter, you want to make sure the class is always overridden when your bundle is used, or you need to modify something beyond just the class name, you should use a compiler pass:

// src/Acme/DemoBundle/DependencyInjection/Compiler/OverrideServiceCompilerPass.php
namespace Acme\DemoBundle\DependencyInjection\Compiler;

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

class OverrideServiceCompilerPass implements CompilerPassInterface
    public function process(ContainerBuilder $container)
        $definition = $container->getDefinition('original-service-id');

In this example you fetch the service definition of the original service, and set its class name to your own class.

See How to work with Compiler Passes in Bundles for information on how to use compiler passes. If you want to do something beyond just overriding the class - like adding a method call - you can only use the compiler pass method.

Entities & Entity mapping

Due to the way Doctrine works, it is not possible to override entity mapping of a bundle. However, if a bundle provides a mapped superclass (such as the User entity in the FOSUserBundle) one can override attributes and associations. Learn more about this feature and its limitations in the Doctrine documentation.


In order to override a form type, it has to be registered as a service (meaning it is tagged as "form.type"). You can then override it as you would override any service as explained in How to Override any Part of a Bundle. This, of course, will only work if the type is referred to by its alias rather than being instantiated, e.g.:

$builder->add('name', 'custom_type');

rather than:

$builder->add('name', new CustomType());

Validation metadata

In progress...


Translations are not related to bundles, but to domains. That means that you can override the translations from any translation file, as long as it is in the correct domain.


The last translation file always wins. That mean that you need to make sure that the bundle containing your translations is loaded after any bundle whose translations you're overriding. This is done in AppKernel.

The file that always wins is the one that is placed in app/Resources/translations, as those files are always loaded last.

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.