joshuaestes/feature-toggle

RTFD

This library allows you to easily add and modify various features to your code while in development. Please read the information below on instructions on how to use this library as well as how to customize and add to it for your own needs.

Concepts

• Features are all unique and allows you to enable or disable each feature.
• Toggles are the logic behind whether a feature is enabled or not.
• Repositories allow you to persist features.

Installation

To install, just add to your composer.json file.

"require": {
    "joshuaestes/feature-toggle": "~0.1"
},

Usage

use JoshuaEstes\Component\FeatureToggle\FeatureBuilder;

$feature = FeatureBuilder::create('enable_a_cool_new_feature')
    ->getFeature();

if ($feature->isEnabled()) {
    // code for when the feature is enabled
} else {
    // code for when the feature is disabled
}

By default the feature is disabled. You will need to enabled the feature. You are able to do this two different ways.

use JoshuaEstes\Component\FeatureToggle\Toggle\FeatureToggleGeneric;

$feature = FeatureBuilder::create('enable_a_cool_new_feature')
    ->setToggle(
        new FeatureToggleGeneric(
            array(
                'enabled' => true
            )
        )
    )
    ->getFeature();

This will now enabled the feature, when you call isEnabled() it will return true. The other way to enable a feature is like so:

$feature = FeatureBuilder::create('enable_a_cool_new_feature')
    ->getFeature();

$feature->setToggle(
    new FeatureToggleGeneric(
        array(
            'enabled' => true
        )
    )
);

Feature Container

The feature container is used to put all your features into one place where you can easily loop through them.

use JoshuaEstes\Component\FeatureToggle\FeatureContainer;
use JoshuaEstes\Component\FeatureToggle\Feature;

$container = new FeatureContainer();
$feature = FeatureBuilder::create('enable_a_cool_new_feature')
    ->getFeature();

$container->addFeature($feature);

$coolNewFeature = $container->getFeature('enable_a_cool_new_feature');

$thisIsNull = $container->getFeature('does_not_compute');

$thisIsFalse = $container->hasFeature('enable_that_sweet_new_feature');
$thisIsTrue  = $container->hasFeature('enable_a_cool_new_feature');

$numberOfFeatures = count($container);

foreach ($container as $f) {
    // @var FeatureInterface $f
    var_dump($f->isEnabled());
}

You can read the source code for more methods that you can call, such as removeFeature and clearFeatures.

Creating Custom Features

All features must implement the FeatureInterface.

In most situations you will only need to use the default Feature, however in some situations you might want to create your own.

Creating Custom Toggles

All toggles must implement the FeatureToggleInterface.

By creating a custom toggle, you can change the logic for figuring out if a feature is enable or not. Some ideas for custom toggles include:

• IP Based, can enable a feature if the user is on an internal network.
• Username, or something similar.
• Collection, a collection of toggles where it checks for any or all to be enable.
• Gradual, where you can release a feature to x% of a user base.

Creating a custom toggle based on username

You can create a custom feature toggle with ease.

use JoshuaEstes\Component\FeatureToggle\Toggle\FeatureToggle;
use JoshuaEstes\Component\FeatureToggle\FeatureInterface;

class FeatureToggleUsername extends FeatureToggle
{
    protected $user;

    public function setUser($user)
    {
        $this->user = $user;
    }

    protected function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setRequired(
            array(
                'username'
            )
        );
    }

    public function isEnabled(FeatureInterface $feature)
    {
        return $this->options['username'] == $this->user->getUsername();
    }
}

Now that we have the toggle, we just need to create the toggle and assign it to a feature object.

use JoshuaEstes\Component\FeatureToggle\FeatureBuilder;

$toggle = new FeatureToggleUsername(
    array(
        'username' => 'joshua',
    )
);
$toggle->setUser($user);

$feature = FeatureBuilder::create('enable_for_joshua')
    ->setToggle($toggle)
    ->getFeature();

That's all there is to it! Note that the $user variable needs to be defined and must have a method getUsername. This feature will return true only for the user with the username joshua and will return false for all other users.

Creating Custom Repository

All toggles must implement the RepositoryInterface.

Creating custom repositories allow you to store the states of the features in anything from a database to a flat file store. Some ideas are:

• MySQL
• MongoDB
• SQLite

Testing

php vendor/bin/phing -f build/build.xml phpunit