j4nr6n/feature-flag-bundle

Installation

Make sure Composer is installed globally, as explained in the installation chapter of the Composer documentation.

Open a command console, enter your project directory and execute:

$ composer require j4nr6n/feature-flag-bundle

Applications that don't use Symfony Flex

Enable the bundle by adding it to the list of registered bundles in the config/bundles.php file of your project:

// config/bundles.php

return [
    // ...
    j4nr6n\FeatureFlagBundle\FeatureFlagBundle::class => ['all' => true],
];

Using The Bundle

A voter is an easy way to isolate the code for a given feature, but can also be used to "vote" on more than one feature.

// src/FeatureFlag/MyFeatureVoter.php

// ...
use j4nr6n\FeatureFlagBundle\FeatureVoterInterface;

class MyFeatureVoter implements FeatureVoterInterface
{
    public function supports(string $featureFlag): bool
    {
        return $featureFlag === 'my_new_feature';
    }

    public function isEnabled(string $featureFlag, array $context = []): bool
    {
        // ...
    }
}

You can create as many feature voters as you want. Remember though, if any single registered voter returns true. The final result will be true.

In Controllers

// src/Controller/DefaultController.php

// ...
use j4nr6n\FeatureFlagBundle\FeatureCheckerInterface;

class DefaultController extends AbstractController
{
    // ...
    
    #[Route(name: 'app_default_homepage', methods: [Request::METHOD_GET])]
    public function homepage(FeatureCheckerInterface $featureChecker): Response
    {
        return $featureChecker->isEnabled('new_homepage', ['user' => $this->getUser()])
            ? $this->render('default/new_homepage.html.twig')
            : $this->render('default/homepage.html.twig');
    }
}

In Services

// src/Service/SomeService.php

// ...
use j4nr6n/FeatureFlagBundle\FEatureCheckerInterface;

class SomeService
{
    public function __construct(
        private readonly FeatureCheckerInterface $featureChecker
    ) {
    }
    
    public function someMethod() {
        return $this->featureChecker->isEnabled('new_feature')
            ? // Let them experience our greatness!
            : // Not yet...
    }
}

In Twig

{% include feature_is_enabled('fancy_widget')
    ? '_fancy_widget.html.twig'
    : '_plain_widget.html.twig'
%}

Feature Checkers

If feature voters aren't working out, you can also create your own feature "checker". See the Feature Checker documentation for more information.