reytarovskiy/laravel-feature

A package to manage feature flagging in a Laravel project.

Laravel-Feature

Laravel-Feature is a package fully dedicated to feature toggling in your application, in the easiest way. For Laravel, of course.

It was inspired by the AdEspresso Feature Flag Bundle.

Feature-What?

Feature toggling is basically a way to have full control on the activation of a feature in your applications.

Let's make a couple of examples to give you an idea:

• you just finished to work on the latest feature and you want to push it, but the marketing team wants you to deploy it in a second moment;
• the new killer-feature is ready, but you want to enable it only for a specific set of users;

With Laravel-Feature, you can:

• easily define new features in your application;
• enable/disable features globally;
• enable/disable features for specific users, or for whatever you want;

There are many things to know about feature toggling: take a look to this great article for more info. It's a really nice and useful lecture.

Install

You can install Laravel-Feature with Composer.

$ composer require francescomalatesta/laravel-feature

After that, you need to add the FeatureServiceProvider to the app.php config file.

...
LaravelFeature\Provider\FeatureServiceProvider::class,
...

Now you have to run migrations, to add the tables Laravel-Feature needs.

$ php artisan migrate

... and you're good to go!

Facade

If you want, you can also add the Feature facade to the aliases array in the app.php config file.

...
'Feature' => \LaravelFeature\Facade\Feature::class,
...

If you don't like Facades, inject the FeatureManager class wherever you want!

Config File

By default, you can immediately use Laravel-Feature. However, if you want to tweak some settings, feel free to publish the config file with

$ php artisan vendor:publish --provider="LaravelFeature\Provider\FeatureServiceProvider"

Basic Usage

There are two ways you can use features: working with them globally or specifically for a specific entity.

Globally Enabled/Disabled Features

Declare a New Feature

Let's say you have a new feature that you want to keep hidden until a certain moment. We will call it "page_code_cleaner". Let's add it to our application:

Feature::add('page_code_cleaner', false);

Easy, huh? As you can imagine, the first argument is the feature name. The second is a boolean we specify to define the current status of the feature.

• true stands for the feature is enabled for everyone;
• false stands for the feature is hidden, no one can use it/see it;

And that's all.

Check if a Feature is Enabled

Now, let's imagine a better context for our example. We're building a CMS, and our "page_code_cleaner" is used to... clean our HTML code. Let's assume we have a controller like this one.

class CMSController extends Controller {
    public function getPage($pageSlug) {
        
        // here we are getting our page code from some service
        $content = PageService::getContentBySlug($pageSlug);
        
        // here we are showing our page code
        return view('layout.pages', compact('content'));
    }
}

Now, we want to deploy the new service, but we don't want to make it available for users, because the marketing team asked us to release it the next week. LaravelFeature helps us with this:

class CMSController extends Controller {
    public function getPage($pageSlug) {
        
        // here we are getting our page code from some service
        $content = PageService::getContentBySlug($pageSlug);
        
        // feature flagging here!
        if(Feature::isEnabled('page_code_cleaner')) {
            $content = PageCleanerService::clean($content);
        }
        
        // here we are showing our page code
        return view('layout.pages', compact('content'));
    }
}

Ta-dah! Now, the specific service code will be executed only if the "page_code_cleaner" feature is enabled.

Change a Feature Activation Status

Obviously, using the Feature class we can easily toggle the feature activation status.

// release the feature!
Feature::enable('page_code_cleaner');

// hide the feature!
Feature::disable('page_code_cleaner');

Remove a Feature

Even if it's not so used, you can also delete a feature easily with

Feature::remove('page_code_cleaner');

Warning: be sure about what you do. If you remove a feature from the system, you will stumble upon exceptions if checks for the deleted features are still present in the codebase.

Work with Views

I really love blade directives, they help me writing more elegant code. I prepared a custom blade directive, @feature:

<div>This is an example template div. Always visible.</div>

@feature('my_awesome_feature')
    <p>This paragraph will be visible only if "my_awesome_feature" is enabled!</p>
@endfeature

<div>This is another example template div. Always visible too.</div>

A really nice shortcut!

Enable/Disable Features for Specific Users/Entities

Even if the previous things we saw are useful, LaravelFeature is not just about pushing the on/off button on a feature. Sometimes, business necessities require more flexibility. Think about a Canary Release: we want to rollout a feature only to specific users. Or, maybe, just for one tester user.

Enable Features Management for Specific Users

LaravelFeature makes this possible, and also easier just as adding a trait to our User class.

In fact, all you need to do is to:

• add the LaravelFeature\Featurable\Featurable trait to the User class;
• let the same class implement the FeaturableInterface interface;

...

class User extends Authenticatable implements FeaturableInterface
{
    use Notifiable, Featurable;
    
...

Nothing more! LaravelFeature now already knows what to do.

Status Priority

Please keep in mind that all you're going to read from now is not valid if a feature is already enabled globally. To activate a feature for specific users, you first need to disable it.

Laravel-Feature first checks if the feature is enabled globally, then it goes down at entity-level.

Enable/Disable a Feature for a Specific User

$user = Auth::user();

// now, the feature "my.feature" is enabled ONLY for $user!
Feature::enableFor('my.feature', $user);

// now, the feature "my.feature" is disabled for $user!
Feature::disableFor('my.feature', $user);

Check if a Feature is Enabled for a Specific User

$user = Auth::user();

if(Feature::isEnabledFor('my.feature', $user)) {
    
    // do amazing things!
    
}

Other Notes

LaravelFeature also provides a Blade directive to check if a feature is enabled for a specific user. You can use the @featurefor blade tags:

@featurefor('my.feature', $user)
    
    // do $user related things here!
    
@endfeaturefor

Advanced Things

Ok, now that we got the basics, let's raise the bar!

Enable Features Management for Other Entities

As I told before, you can easily add features management for Users just by using the Featurable trait and implementing the FeaturableInterface in the User model. However, when structuring the relationships, I decided to implement a many-to-many polymorphic relationship. This means that you can add feature management to any model!

Let's make an example: imagine that you have a Role model you use to implement a basic roles systems for your users. This because you have admins and normal users.

So, you rolled out the amazing killer feature but you want to enable it only for admins. How to do this? Easy. Recap:

• add the Featurable trait to the Role model;
• be sure the Role model implements the FeaturableInterface;

Let's think the role-user relationship as one-to-many one.

You will probably have a role() method on your User class, right? Good. You already know the rest:

// $role is the admin role!
$role = Auth::user()->role;

...

Feature::enableFor('my.feature', $role);

...

if(Feature::isEnabledFor('my.feature', $role)) {

    // this code will be executed only if the user is an admin!
    
}

Scan Directories for Features

One of the nice bonuses of the package that inspired me when making this package, is the ability to "scan" views, find @feature declarations and then add these scanned features if not already present on the system.

I created a simple artisan command to do this.

$ php artisan feature:scan

The command will use a dedicated service to fetch the resources/views folder and scan every single Blade view to find @feature directives. It will then output the search results.

Try it, you will like it!

Note: if you have published the config file, you will be able to change the list of scanned directories.

Using a Custom Features Repository

Imagine that you want to change the place or the way you store features. For some crazy reason, you want to store it on a static file, or on Dropbox.

Now, Eloquent doesn't have a Dropbox driver, so you can't use this package. Bye.

Just joking! When making this package, I wanted to be sure to create a fully reusable logic if the developer doesn't want to use Eloquent anymore.

To do this, I created a nice interface for the Job, and created some bindings in the Laravel Service Container. Nothing really complex, anyway.

The interface I am talking about is FeatureRepositoryInterface.

<?php

namespace LaravelFeature\Domain\Repository;

use LaravelFeature\Domain\Model\Feature;
use LaravelFeature\Featurable\FeaturableInterface;

interface FeatureRepositoryInterface
{
    public function save(Feature $feature);

    public function remove(Feature $feature);

    public function findByName($featureName);

    public function enableFor($featureName, FeaturableInterface $featurable);

    public function disableFor($featureName, FeaturableInterface $featurable);

    public function isEnabledFor($featureName, FeaturableInterface $featurable);
}

This interface has some methods. Let's quickly explain them:

• save: this method is used to save a new feature on the system if not already present;
• remove: this method is used to remove a feature from the system;
• findByName: this method is used to find a feature from the system, given its name;
• enableFor: used to enable a feature for a specific Featurable entity;
• disableFor: used to disable a feature for a specific Featurable entity;
• isEnabledFor: used to check if a feature is enabled for a specific Featurable entity;

So, you will need to create a new DropboxFeatureRepository that implements FeatureRepositoryInterface, with all the methods you just saw.

Finally, you will have to change the repository binding in the features.php config file:

'repository' => LaravelFeature\Repository\EloquentFeatureRepository::class

will become...

'repository' => My\Wonderful\DropboxFeatureRepository::class

Done! By the way, don't forget to let the entities you need to implement the FeaturableInterface.

<?php

namespace LaravelFeature\Featurable;

interface FeaturableInterface
{
    public function hasFeature($featureName);
}

The only method, here, is hasFeature. It's used to define if the given feature is enabled for that entity, or not.

To have a better idea of the mechanism, feel free to look to the EloquentFeatureRepository class and the Featurable trait I built for the Eloquent implementation.

Change log

Please see CHANGELOG for more information on what has changed recently.

Testing

You can start tests with a simple:

$ phpunit

or, also

$ composer test

There are two separate test suites:

• Unit;
• Integration;

$ phpunit --testsuite=unit
$ phpunit --testsuite=integration

Contributing

Please see CONTRIBUTING and CONDUCT for details.

Security

If you discover any security related issues, please email francescomalatesta@live.it instead of using the issue tracker.

Credits

• Francesco Malatesta
• All Contributors

License

The MIT License (MIT). Please see License File for more information.