How to add a constructor argument to Symfony Service - php

Question

I create a service that uses FilesystemCache, I don't want to make a new FilesystemCache each time I call the service so I have an argument in the service constructor where I can give an instance.
What I have so far:
Service class:
class MyService
{
private $cache;
private $url;
/**
* MyService constructor.
* #param FilesystemCache $cache
*/
public function __construct(FilesystemCache $cache)
{
$this->cache = $cache;
}
private function data()
{
if ($this->cache->has('data')) {
$data = $this->cache->get('data');
} else {
$data = file_get_contents("my/url/to/data");
}
return $data;
}
}
Config:
services:
# Aliases
Symfony\Component\Cache\Adapter\FilesystemAdapter: '#cache.adapter.filesystem'
# Services
services.myservice:
class: AppBundle\Services\MyService
arguments:
- '#cache.adapter.filesystem'
Where I use the Service:
$myService = $this->container->get('services.myservice');
But what I get is an error:
The definition "services.myservice" has a reference to an abstract definition "cache.adapter.filesystem". Abstract definitions cannot be the target of references.
So, my question is how I have to modify my service or my declaration, or whatever, to be able to do what I want to do: not create an instance each time I call the service.

Answer 1

I highly recommand you to use the cache.app service instead of your own filesystem.cache. Also, you could create your own Adapter.

Answer 2

To make that posible I had to register a new service with the class I want to use in my service constructor. So, my services.yml would be like:
services:
filesystem.cache:
class: Symfony\Component\Cache\Simple\FilesystemCache
services.myservice:
class: AppBundle\Services\MyService
arguments:
- '#filesystem.cache'
and now I'm able to use my service without getting an error.

Answer 3

Using the standard S3.3 autowire setup, this worked for me:
// services.yml
// This basically gives autowire a concrete cache implementation
// No additional parameters are needed
Symfony\Component\Cache\Simple\FilesystemCache:
// And there is no need for any entry for MyService
....
// MyService.php
use Psr\SimpleCache\CacheInterface;
public function __construct(CacheInterface $cache)
This of course will only work if you only have one concrete implementation of CacheInterface in your container.