How to call a Controller from a Service in Symfony 5+?

Sometimes you need to call a Controller from a Service class in Symfony Framework. To do that, you can call a controller from a service by injecting the Symfony\Component\HttpKernel\KernelInterface interface into your service, and then using it to create a sub-request to the controller.

Here are the steps to follow:

1. Inject Symfony\Component\HttpKernel\KernelInterface into your service:

// src/Service/MyService.php

namespace App\Service;

use Symfony\Component\HttpKernel\KernelInterface;

class MyService
{
    private $kernel;

    public function __construct(KernelInterface $kernel)
    {
        $this->kernel = $kernel;
    }

    // ...
}

2. Create a sub-request to the controller:

// src/Service/MyService.php

namespace App\Service;

use Symfony\Component\HttpKernel\KernelInterface;
use Symfony\Component\HttpFoundation\Request;

class MyService
{
    private $kernel;

    public function __construct(KernelInterface $kernel)
    {
        $this->kernel = $kernel;
    }

    public function myMethod()
    {
//    * @param string               $uri        The URI
//    * @param string               $method     The HTTP method ('GET', 'POST, etc.)
//    * @param array                $parameters The query (GET) or request (POST) parameters
//    * @param array                $cookies    The request cookies ($_COOKIE)
//    * @param array                $files      The request files ($_FILES)
//    * @param array                $server     The server parameters ($_SERVER)
//    * @param string|resource|null $content    The raw body data

        $request = Request::create($uri, $method, $params, $cookies, $files, $server);
        $response = $this->kernel->handle($request, HttpKernelInterface::SUB_REQUEST);
        
        return $response->getContent();
    }
}

In the example above, we created a sub-request to the controller using the Request::create() method and passing the route of the controller as the first argument. We then passed the created request to the handle() method of the kernel, along with the HttpKernelInterface::SUB_REQUEST flag to indicate that we're making a sub-request.

The handle() method returns a Symfony\Component\HttpFoundation\Response object, which we can use to get the content of the response by calling the getContent() method

Read more about Symfony's HTTP Foundation Component