Feature Flags for PHP 5.5

This SDK is designed to work with Split, the platform for controlled rollouts, serving features to your users via the Split feature flag to manage your complete customer experience.

Getting started

Running Locally

The repo comes with a PHP 5.5 docker container that includes xdebug and a handful of other nice to have PHP libraries/extensions enabled. To run this locally, the very first thing you would want to do is install the composer dependencies. This is accomplished with run a simple Make command:

$ make install

Once the composer dependencies have been installed you can run the unit tests with another Make command:

$ make test

There are also Make commands to simply bring up/down the docker container and shell into the container:

$ make up
$ make shell
$ make down

Example pseudo usage

try {
    $user = new FeatureFlagUser('[email protected]');
    $flags = (new FeatureFlag())
        ->setUser($user);
       
    if ($flags->exists('my-new-feature')) {
        if ($flags->enabled('my-new-feature')) {
            // feature exists and is turned on for this user
        } else {
            // feature is either turned off for this user
        }
    } else {
        // the feature flag does not exist yet
    }
    
} catch (\Carsdotcom\FeatureFlags\Exceptions\InvalidFeatureFlagUserException $exception) {
    // the user passed was invalid. This could happen if the user identifier wasn't sent during creation
} catch (\Carsdotcom\FeatureFlags\Exceptions\InvalidFeatureFlagException $exception) {
    // if the feature flag we called '$flags->enabled()' did not exist in the system, this exception is thrown 
}

Split.io

Below is a simple example that describes the instantiation and most basic usage of our SDK. Keep in mind that since PHP does not have the ability to share memory between processes the use of the split-synchronizer is mandatory for this SDK.

IMPORTANT: The Split SDK has a constraint of only being able to call the factory method once and get a valid return. Because of this, we can only call initializeSettings() once, any further calls will be ignored.

<?php
use \Carsdotcom\FeatureFlags\Service\SplitIO\SplitFeatureFlag;
use \Carsdotcom\FeatureFlags\Service\SplitIO\SplitFeatureFlagUser;

try {
    $sdkConfig = [
        'log' => [
            'adapter' => 'syslog',
            'level' => 'verbose',
        ],
        'cache' => [
            'adapter' => 'predis',
            'parameters' => [
                'scheme' => 'tcp',
                'host' => 'REDIS_HOST',
                'port' => 'REDIS_PORT',
                'timeout' => 881,
            ],
            'options' => [
                'prefix' => 'development',
            ]
        ],
    ];
    
    $flags = SplitFeatureFlag::getInstance()
        ->initializeSettings(array_merge(['apiKey' => 'API_KEY', $sdkConfig))
        ->setUser(new SplitFeatureFlagUser($ccid = '123'));
       
    if ($flags->exists('my-new-feature') && $flags->enabled('my-new-feature')) {
        // flag exists and is turn on for this user
    else {
        // flag is either off OR doesn't exist
    }
    
} catch (\Carsdotcom\FeatureFlags\Exceptions\InvalidFeatureFlagUserException $exception) {
    // the user passed was invalid. This could happen if the user identifier wasn't sent during creation
} catch (\Carsdotcom\FeatureFlags\Exceptions\InvalidFeatureFlagException $exception) {
    // if the feature flag we called '$flags->enabled()' did not exist in the system, this exception is thrown 
}

Null Feature Flag

This service will always return as if there are no feature flags enabled/exist and never throw any exceptions.

use \Carsdotcom\FeatureFlags\Service\Null\NullFeatureFlag;
use \Carsdotcom\FeatureFlags\Service\Null\NullFeatureFlagUser;

$flags = new NullFeatureFlag();

// any value can be sent to the NullFeatureFlagUser to instantiate it
$flags->setUser(new NullFeatureFlagUser(null));

// will always return an empty array
$flags->all();

// will always return false
$flags->exists('foobar');

// will always return false
$flags->enabled('foobar');

// will always return en empty array
$flags->config('foobar');