I followed the doc of 4.2. MicroKernelTrait throws error

[featuriz]

I'm following a doc of symonfy 4.2 MicroKernelTrait
Dated: Jan 10 2019 08:45 AM India ISD.
This causing 2 error.

(1/2) ArgumentCountError

Too few arguments to function Symfony\Component\HttpKernel\Kernel::__construct(), 0 passed in /home/sudhakar/SudhakarK/NB/2019/FZFW/vendor/symfony/http-kernel/Controller/ControllerResolver.php on line 133 and exactly 2 expected

(2/2) InvalidArgumentException

Controller "Kernel" has required constructor arguments and does not exist in the container. Did you forget to define such a service?

How to reproduce:
I followd the turorial of the mentioned page with 4.2 symfony version.

The error is when running http://localhost:8000/random/10
But http://localhost:8000/ works

Thanks.

[featuriz]

The same error is spotted here

Here the solution is creating a service.
But in learning starting point creating a service for newcome is ??? not good.

[featuriz]

I solved this problem with this code. But I don't know this is correct or not . But now its working. I added the construct()

`<?php

use Symfony\Bundle\FrameworkBundle\Kernel\MicroKernelTrait;
use Symfony\Component\Config\Loader\LoaderInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Kernel as BaseKernel;
use Symfony\Component\Routing\RouteCollectionBuilder;

require DIR . '/vendor/autoload.php';

class Kernel extends BaseKernel
{
use MicroKernelTrait;

public function __construct(){
    parent::__construct('dev', true);
}

public function registerBundles()
{
    return array(
        new Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
    );
}

protected function configureContainer(ContainerBuilder $c, LoaderInterface $loader)
{
    // PHP equivalent of config/packages/framework.yaml
    $c->loadFromExtension('framework', array(
        'secret' => 'S0ME_SECRET',
    ));
}

protected function configureRoutes(RouteCollectionBuilder $routes)
{
    // kernel is a service that points to this class
    // optional 3rd argument is the route name
    $routes->add('/random/{limit}', 'Kernel::randomNumber');
}

public function randomNumber($limit)
{
    return new JsonResponse(array(
        'number' => random_int(0, $limit),
    ));
    // return new Response("WElcome");
}

}

$kernel = new Kernel('dev', true);
$request = Request::createFromGlobals();
$response = $kernel->handle($request);
$response->send();
$kernel->terminate($request, $response);`

[xabbuh]

The issue is the route configuration:

protected function configureRoutes(RouteCollectionBuilder $routes)
{
    // kernel is a service that points to this class
    // optional 3rd argument is the route name
    $routes->add('/random/{limit}', 'Kernel::randomNumber');
}

The controller resolver does not pick the service from the container but tries to instantiate the Kernel class here which then fails as no arguments will be passed.

@featuriz Can you confirm that changing the route configuration to $routes->add('/random/{limit}', 'kernel::randomNumber'); solves this?

[featuriz]

The issue is the route configuration:

protected function configureRoutes(RouteCollectionBuilder $routes)
{
    // kernel is a service that points to this class
    // optional 3rd argument is the route name
    $routes->add('/random/{limit}', 'Kernel::randomNumber');
}

The controller resolver does not pick the service from the container but tries to instantiate the Kernel class here which then fails as no arguments will be passed.

@featuriz Can you confirm that changing the route configuration to $routes->add('/random/{limit}', 'kernel:randomNumber'); solves this?

No Its Not working. I have used this in the previous post itself.

Yes you are Right. I found that the error is in 2nd argument. It can't find the method in the same file.

[xabbuh]

Are you sure? In the previous post you use Kernel (notice the uppercased K and two colons).

[guillaumesmo]

Had the same issue, using kernel in lowercase fixed it for me indeed, both with single and double semicolons. Which one is the preferred solution? I'll make a PR

[xabbuh]

Thank you for the confirmation @guillaumesmo! Let's use two colons as we use this notation everywhere else too (I updated my comment above accordingly).