How to create a service and inject the request content and query string as arguments?

Question

I'm attempting to write my own wrapper around request parameters, so I can reuse the same parameter class throughout the system (e.g. in commands), where the request stack is not available. Currently, several services have a request wrapper injected, which itself has the RequestStack injected.

What I hope to achieve is to, in services.yml, define that the service App\Util\Parameters should be injected with the values of $queryString and $content from the below example:

class SomeService {

    public function __construct(Symfony\Component\HttpFoundation\RequestStack $stack)
    {
        $request = $stack->getCurrentRequest();
        ...
        $queryString = $request->getQueryString();
        $content = $request->getContent();
        ...

So, in services.yml, I'm hoping to do something like:

# psuedo-config..!
App\Util\Parameters:
  arguments:
    $content: ['requestStack.currentRequest.getContent']
    $queryString: ['requestStack.currentRequest.getQueryString']

Given the following class:

namespace App\Util;

class Parameters {
    public function __construct(protected mixed $content = [], protected string $queryString = "")
    {
    ...

My hope is that in other parts of the system, where the RequestStack is not available, I could do something like the following to override the injection,

$params = new Parameters(['foo' => 'bar']);

but in cases where the Parameters service is injected, the values would instead be populated from the request.

Answer 1

You would need to create a service factory.

App\Util\Parameters:
  factory: '@App\Util\ParameterFactory'

And then the factory:

class ParameterFactory {

    public function __construct(private RequestStack $stack)
    {}

    public function __invoke(): Parameters {
        $request = $this->stack->getCurrentRequest();
        
        $queryString = $request->getQueryString();
        $content = $request->getContent();

        return new Parameters($content, $queryString);
    }

}