Symfony 4.2 - How to decorate the UrlGenerator - php

Question

I want to decorate the Symfony UrlGenerator class.
Symfony\Component\Routing\Generator\UrlGenerator: ~
my.url_generator:
class: AppBundle\Service\UrlGenerator
decorates: Symfony\Component\Routing\Generator\UrlGenerator
arguments: ['#my.url_generator.inner']
public: false
I've added this to the services.yml but my AppBundle\Service\UrlGenerator class is ignored:
I tried the following configuration again.
config/services.yaml
parameters:
locale: 'en'
router.options.generator_class: AppBundle\Service\UrlGenerator
router.options.generator_base_class: AppBundle\Service\UrlGenerator
Still it doesn't work
How to decorate the UrlGenerator in Symfony 4.2?

Answer 1

The right answer is : you shouldn't decorate UrlGeneratorInterface.
You have to decorate 'router' service. Check here : https://github.com/symfony/symfony/issues/28663
** services.yml :
services:
App\Services\MyRouter:
decorates: 'router'
arguments: ['#App\Services\MyRouter.inner']
** MyRouter.php :
<?php
namespace App\Services;
use Symfony\Component\Routing\RequestContext;
use Symfony\Component\Routing\RouterInterface;
class MyRouter implements RouterInterface
{
/**
* #var RouterInterface
*/
private $router;
/**
* MyRouter constructor.
* #param RouterInterface $router
*/
public function __construct(RouterInterface $router)
{
$this->router = $router;
}
/**
* #inheritdoc
*/
public function generate($name, $parameters = [], $referenceType = self::ABSOLUTE_PATH)
{
// Your code here
return $this->router->generate($name, $parameters, $referenceType);
}
/**
* #inheritdoc
*/
public function setContext(RequestContext $context)
{
$this->router->setContext($context);
}
/**
* #inheritdoc
*/
public function getContext()
{
return $this->router->getContext();
}
/**
* #inheritdoc
*/
public function getRouteCollection()
{
return $this->router->getRouteCollection();
}
/**
* #inheritdoc
*/
public function match($pathinfo)
{
return $this->router->match($pathinfo);
}
}

Answer 2

I believe the issue is that UrlGenerator service name is Symfony\Component\Routing\Generator\UrlGeneratorInterface, and not Symfony\Component\Routing\Generator\UrlGenerator (cf. this code).
Secondly, when you decorate a service, the decorator will take the service name. So you should not need to modify router.options.generator_class.
Try with this configuration:
my.url_generator:
class: AppBundle\Service\UrlGenerator
decorates: Symfony\Component\Routing\Generator\UrlGeneratorInterface
arguments: ['#my.url_generator.inner']
Setting public to false is likely not needed, as on Symfony4/Flex it should be the default value.
Update for comments:
decorated service may look like this:
class MyUrlGenerator implements UrlGeneratorInterface
{
private $originalUrlGenerator;
public function __construct(UrlGeneratorInterface $innerUrlGenerator)
{
$this->originalUrlGenerator = $innerUrlGenerator;
}
public function generate($name, $parameters = [], $referenceType = self::ABSOLUTE_PATH)
{
// Maybe add your custom logic here...
// or completely override base method
return $this->originalUrlGenerator->generate($name, $parameters, $referenceType);
}
}

Answer 3

I believe you have to decorate the Symfony\Component\Routing\Generator\UrlGeneratorInterface, because the services should depend on the interface and not on a specific implementation (class).