usage.md

Quickstart

You can define your features in your config files. Just give your feature a name and the active or inactive flag.

Minimal example with two features:

flagception:

    # Your Features (optional you left it empty)
    features:
    
        # Feature name as key
        feature_123:
            # Default flag if inactive or active (default: false)
            default: true
            
        feature_abc:
            default: false

Now you can check the feature state in twig templates, controllers or services.

Twig usage

{% if feature('feature_123') %}
    {# Execute if feature is active ... #}
{% endif %}

Service usage

# FooService.php

class FooService
{
    /**
     * @var FeatureManagerInterface
     */
    private $manager;

    /**
     * @param FeatureManagerInterface $manager
     * Service id: flagception.manager.feature_manager
     */
    public function __construct(FeatureManagerInterface $manager)
    {
        $this->manager = $manager;
    }
    
    public function do()
    {
        // ...
        if ($this->manager->isActive('feature_123')) {
            // ...
        }
        // ...
    }
}

Controller usage

// src/AppBundle/Controller/BlogController.php
namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;

class BlogController extends Controller
{
    /**
     * @Route("/blog/{page}", name="blog_list", defaults={"_feature": "feature_123"})
     */
    public function listAction($page)
    {
        // ...
    }

    /**
     * @Route("/blog/{slug}", name="blog_show")
     */
    public function showAction($slug)
    {
        // ...
    }
}

Annotation usage

# FooController.php

use Flagception\Bundle\FlagceptionBundle\Annotations\Feature;

/**
 * @Feature("feature_123")
 */
class FooController
{

    /**
     * @Feature("feature_789")
     */
    public function barAction()
    {
    }

    public function fooAction()
    {
    }
}

If you request an action with inactive feature flag, you will get a NotFoundHttpException.

Take a look to the detail documentation for Twig, Route or Annotation usage.

Feature names

You can name your features as you like. But we recommend using snake case. Especially because Symfony normalizes values from your YML or XML into snake case (see here). Your feature "flag-a" becomes "flag_a". So you have to check for "flag_a" everywhere in your code, even if you've actually maintained "flag-a" in your YML / XML. Consider this with your feature naming.

Constraint usage

In some cases will you need more instead of a simple true / false. So you can define constraints to enable or disable a feature. A constraint should return true or false.

An example:

# config.yml

flagception:
    features:      
    
        # This feature will only be active, if the current user has id 12
        feature_123:
            default: false
            constraint: 'user_id === 12'     
            
        # This feature will only be active, if the user_role array contains "ROLE_ADMIN"
        feature_abc:
            default: false
            constraint: '"ROLE_ADMIN" in user_role'   
                    
        # This feature will only be active between 8am and 6pm.
        # OR if the user_role array contains "ROLE_ADMIN"
        feature_abc:
            default: false
            constraint: '(date("H") > 8 and date("H") < 18) or "ROLE_ADMIN" in user_role'

You can extend constraints with your own variables and functions. Read the constraint documentation for more details.