Symfony console - displaying help for command with no arguments - php

Question

I'm developing a pretty simple Symfony console application. It has just one command with one argument, and a few options.
I followed this guide to create an extension of the Application class.
This is the normal usage for the app, and it works fine:
php application <argument>
This also works fine (argument with options):
php application.php <argument> --some-option
If someone runs php application.php without any arguments or options, I want it to run as though the user had run php application.php --help.
I do have a working solution but it isn't optimal and is perhaps slightly brittle. In my extended Application class, I overrode the run() method as follows:
/**
* Override parent method so that --help options is used when app is called with no arguments or options
*
* #param InputInterface|null $input
* #param OutputInterface|null $output
* #return int
* #throws \Exception
*/
public function run(InputInterface $input = null, OutputInterface $output = null)
{
if ($input === null) {
if (count($_SERVER["argv"]) <= 1) {
$args = array_merge($_SERVER["argv"], ["--help"]);
$input = new ArgvInput($args);
}
}
return parent::run($input, $output);
}
By default, Application::run() is called with a null InputInterface, so here I figured I could just check the raw value of the arguments and forcefully add a help option to pass to the parent method.
Is there a better way to achieve this?

Answer 1

I managed to work out a solution which didn't involve touching the Application class at all. To call the help command from within another command:
/**
* #param InputInterface $input
* #param OutputInterface $output
* #return int
* #throws \Symfony\Component\Console\Exception\ExceptionInterface
*/
protected function outputHelp(InputInterface $input, OutputInterface $output)
{
$help = new HelpCommand();
$help->setCommand($this);
return $help->run($input, $output);
}

Answer 2

To do a specific action depending on command, you can use an EventListener which is called when the onConsoleCommand is fired.
The listener class should work as follows :
<?php
namespace AppBundle\EventListener;
use Symfony\Component\Console\Event\ConsoleCommandEvent;
use Symfony\Component\Console\Command\HelpCommand;
class ConsoleEventListener
{
public function onConsoleCommand(ConsoleCommandEvent $event)
{
$application = $event->getCommand()->getApplication();
$inputDefinition = $application->getDefinition();
if ($inputDefinition->getArgumentCount() < 2) {
$help = new HelpCommand();
$help->setCommand($event->getCommand());
return $help->run($event->getInput(), $event->getOutput());
}
}
}
The service declaration :
services:
# ...
app.console_event_listener:
class: AppBundle\EventListener\ConsoleEventListener
tags:
- { name: kernel.event_listener, event: console.command, method: onConsoleCommand }