[DependencyInjection] allow PHP-DSL files to be env-conditional

[nicolas-grekas]

Q	A
Branch?	5.x
Bug fix?	no
New feature?	yes
Deprecations?	no
Tickets	-
License	MIT
Doc PR	-

This PR makes config builders compatible with conditional configuration based on the $env.

See fixture for an example:

use Symfony\Component\DependencyInjection\Tests\Fixtures\AcmeConfig; if ('prod' !== $env) { return; } return static function (AcmeConfig $config) { $config->color('blue'); };

On PHP8, the PR allows using #[When(env: 'prod')]:

use Symfony\Component\DependencyInjection\Attribute\When; use Symfony\Component\DependencyInjection\Tests\Fixtures\AcmeConfig; return #[When(env: 'prod')] function (AcmeConfig $config) { $config->color('blue'); };

Without this patch, such a config file cannot be used if AcmeBundle is not loaded in the current $env.

This is a follow up of https://symfony.com/blog/new-in-symfony-5-3-configure-multiple-environments-in-a-single-file#comment-24521 by @a-menshchikov

[Nyholm]

Just making an observation. This also means we can write:

<?php // config/packages/acme.php use Symfony\Config\AcmeConfig; return static function (AcmeConfig $config) use ($env) { if ('prod' !== $env) { $config->color('red'); } else { $config->color('blue'); } };

Which is the same as:

<?php // config/packages/acme.php use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator; use Symfony\Config\AcmeConfig; return static function (AcmeConfig $config, ContainerConfigurator $container) { if ('prod' !== $container->env()) { $config->color('red'); } else { $config->color('blue'); } };

[Nyholm]

I updated the PR to allow using #[When(env: prod')] on PHP 8:

Wow, that was simpler than I expected. =)

[Nyholm]

Do we need to inject then $env? Or should we just do the PHP8 attributes?

[nicolas-grekas]

We need it for ppl on PHP < 7 at least yes;

[Nyholm]

Since Symfony 4.0 we have the solution to use config/packages/dev/acme.php.

[nicolas-grekas]

True, but that's unrelated feature. Also, we already inject a few variables in the scope. Adding $env next to them just makes sense.

[Nyholm]

Let's move forward. Im happy to discuss removing $env in 6.0 later.