Symfony控制台ContainerAwareCommand $ this-> getContainer（）产生致命错误

Question

TL;DR

I'm creating console Garbage collector, which should be able to get services from container. It's basic, almost straight from the manual:

<?php
namespace SomeBundle\Console\Command;

use Symfony\Bundle\FrameworkBundle\Command\ContainerAwareCommand,
    Symfony\Component\Console\Input\InputArgument,
    Symfony\Component\Console\Input\InputInterface,
    Symfony\Component\Console\Input\InputOption,
    Symfony\Component\Console\Output\OutputInterface;

class GarbageCollector extends ContainerAwareCommand
{
    protected function configure()
    {
        $this
            ->setName('garbage:collect')
            ->setDescription('Collect garbage')
            ->addArgument(
                'task',
                InputArgument::REQUIRED,
                'What task to execute?'
            )
        ;
    }

    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $task = $input->getArgument('task');

        //...

        $_container = $this->getContainer();
    }
}

Then I'm trying to call it from console via application.php:

#!/usr/bin/env php
<?php
// application.php

require_once __DIR__.'/../vendor/autoload.php';

use SomeBundle\Console\Command\GarbageCollector;
use Symfony\Bundle\FrameworkBundle\Console\Application;

$application = new Application();
$application->add(new GarbageCollector);
$application->run();

Which produces fatal error:

Argument 1 passed to Symfony\Bundle\FrameworkBundle\Console\Application::__construct() must implement interface Symfony\Component\HttpKernel\Kernel Interface, none given

Manual says that only thing I need to do is to extend my class with ContainerAwareCommand, but something missing. I've wrote some crap code to pass Kernel to the Application():

#!/usr/bin/env php
<?php
// application.php

require_once __DIR__.'/../vendor/autoload.php';
require_once __DIR__.'/AppKernel.php';

use SomeBundle\Console\Command\GarbageCollector;
use Symfony\Bundle\FrameworkBundle\Console\Application;
use Symfony\Component\Console\Input\ArgvInput;

$input = new ArgvInput();
$env = $input->getParameterOption(array('--env', '-e'), getenv('SYMFONY_ENV') ?: 'dev');
$debug = getenv('SYMFONY_DEBUG') !== '0' && !$input->hasParameterOption(array('--no-debug', '')) && $env !== 'prod';

$kernel = new AppKernel($env, $debug);
$application = new Application($kernel);
$application->add(new GarbageCollector);
$application->run();

And it works, but feels disgusting.

What do I need to make ContainerAwareCommand implementation of console app? Thanks in advance.

Answer 1

Symfony2 provides via its console runner the ability to call your custom commands and it will handle the injection of the service container. All you need to do is create your command in a registered bundle and it will automatically become available to you. You are initializing your command outside of the framework that is why the container is not available to you unless you manually inject it.

You can reference the cookbook here:

http://symfony.com/doc/current/cookbook/console/console_command.html

You can get a list of all the commands available by running:

php app/console 

On a side note, why are you creating a garbage collector in/for PHP? Just curious because to my understanding memory is freed for you after script execution has ended.