FeatureFlagBundle

The FeatureFlagBundle is a bundle to manage features flags in your Symfony applications.

Compatibility

This bundle is tested with at least all maintained Symfony version.

Documentation

Install it

Install extension using composer:

composer require novaway/feature-flag-bundle

If you don't use Flex, enable the bundle in your config/bundles.php file:

<?php

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

Configuration

To configure and register a feature manager you need a factory service. You may also need to change some options to the factory.

# ...
novaway_feature_flag:
    default_manager: default
    managers:
        default:
            factory: 'novaway_feature_flag.factory.array'
            options:
                features:
                    my_feature_1: false
                    my_feature_2: true
                    my_feature3: '%env(bool:FEATURE_ENVVAR)%'

The factories that come with this bundle can be found in the table below.

Factory service id	Options
novaway_feature_flag.factory.array	features

Example configuration

# ...
novaway_feature_flag:
    default_manager: default
    managers:
        default:
            factory: novaway_feature_flag.factory.array
            options:
                features:
                    my_feature_1:
                        enabled: false
                        description: MyFeature1 description text
                    my_feature_2:
                        enabled: true
                        description: MyFeature2 description text
                    my_feature3:
                        enabled: '%env(bool:FEATURE_ENVVAR)%'
                        description: MyFeature3 description text

You can declare multiple managers. Multiple providers is useful if you want to use different storage providers or to isolate your features flags.

# ...
novaway_feature_flag:
    default_manager: manager_foo
    managers:
        manager_foo:
            factory: novaway_feature_flag.factory.array
            options:
                features:
                    my_feature_1:
                        enabled: false
                        description: MyFeature1 description text
                    my_feature_2:
                        enabled: true
                        description: MyFeature2 description text
                    my_feature3:
                        enabled: '%env(bool:FEATURE_ENVVAR)%'
                        description: MyFeature3 description text
        manager_bar:
            factory: novaway_feature_flag.factory.array
            options:
                features:
                    my_feature_4:
                        enabled: false
                        description: MyFeature4 description text
                    my_feature_5: []
                    my_feature_6: ~
                    my_feature_7: false

When several managers are defined, they are registered in the Symfony dependency injection container as services with the following naming convention: novaway_feature_flag.manager.<manager_name>.

For example, the manager_bar is accessible with the following service name: novaway_feature_flag.manager.manager_bar.

Manager storage are also registered in the Symfony dependency injection container as services with the following naming convention: novaway_feature_flag.storage.<manager_name>.

Use it as a service

The bundle adds a global novaway_feature_flag.manager (also bind to FeatureManager) service you can use in your PHP classes.

In the case you have defined several managers, the service use the ChainedFeatureManager class to chain all declared managers.

use Novaway\Bundle\FeatureFlagBundle\Manager\FeatureManager;
// ...

class MyController extends Controller
{
    public function myAction(FeatureManager $featureManager): Response
    {
        if ($featureManager->isEnabled('my_feature_1')) {
            // my_feature_1 is enabled
        }

        if ($featureManager->isDisabled('my_feature_2')) {
            // my_feature_2 is not enabled
        }

        // ...
    }
}

In your Twig templates

You can also check a flag in your templates:

{% if isFeatureEnabled('my_feature_1') %}
    {% include 'feature1_template.html.twig' %}
{% endif %}

{% if isFeatureDisabled('my_feature_2') %}
    {% include 'feature2_template.html.twig' %}
{% endif %}

In the routing configuration

The package allows you to restrict a controller access by adding some configuration in your routing definition.

# app/config/routing.yml
my_first_route:
    path: /my/first/route
    defaults:
        _controller: AppBundle:Default:index
        _features:
            - { feature: my_feature_key, enabled: false } # The action is accessible if "my_feature_key" is disabled

my_second_route:
    path: /my/second-route
    defaults:
        _controller: AppBundle:Default:second
        _features:
            - { feature: foo } # The action is accessible if "foo" is enabled ...
            - { feature: bar, enabled: true } # ... and "bar" feature is also enabled
            - { feature: feature-42, enabled: true, exceptionClass: Symfony\Component\HttpKernel\Exception\BadRequestHttpException } # will throw a BadRequestHttpException if "feature-42" is disabled
            - { feature: feature-44, enabled: true, exceptionFactory: Symfony\Component\HttpKernel\Exception\BadRequestHttpExceptionFactory } # will use the BadRequestHttpExceptionFactory registered factory class to create the exception to be thrown

As a controller attribute

You can also restrict a controller access with attributes, two attributes are available:

• Novaway\Bundle\FeatureFlagBundle\Attribute\FeatureEnabled
• Novaway\Bundle\FeatureFlagBundle\Attribute\FeatureDisabled

#[FeatureEnabled(name: "foo")]
class MyController extends Controller
{
    #[FeatureEnabled(name: "foo", exceptionClass: BadRequestHttpException::class)]
    public function annotationFooEnabledAction(): Response
    {
        return new Response('MyController::annotationFooEnabledAction');
    }

    #[FeatureDisabled(name: "foo", exceptionFactory: MyExceptionFactory::class)]
    public function annotationFooDisabledAction(): Response
    {
        return new Response('MyController::annotationFooDisabledAction');
    }
}

API Controller

The bundle provides an API controller that exposes feature flags via REST endpoints:

• GET /features - Get all feature flags

To enable the API controller, you need to register its routes in your routing configuration:

# config/routes.yaml (or app/config/routing.yml for older Symfony versions)
feature_api:
    resource: '@NovawayFeatureFlagBundle/Resources/config/routing.yml'

You can also register endpoints manually:

features_all:
    path: /features
    defaults:
        _controller: Novaway\Bundle\FeatureFlagBundle\Controller\FeatureApiController::all
    methods: [GET]

The API returns JSON responses with feature flag data including key, description, and enabled status.

Implement your own storage provider

1. First your need to create your storage provider class which implement the Novaway\Bundle\FeatureFlagBundle\Storage\StorageInterface interface
2. Register it in the Symfony dependency injection container
3. Specify the storage you want to use in a manager configuration

novaway_feature_flag:
    manager:
        manager_name:
            storage: your.custom.service.name
            options:
                # arguments need to create the storage service

When you create a storage, the static method create is called to create the storage instance.

License

This library is published under MIT license