OpenFeature Provider

OpenFeature is an open standard that provides a vendor-agnostic, community-driven API for feature flagging that works with DevCycle.

DevCycle provides a PHP implementation of the OpenFeature Provider interface, if you prefer to use the OpenFeature API.

Usage

Installation

The OpenFeature Provider is included in the DevCycle SDK for PHP natively. It's compatible with both Cloud, and SDK proxy modes.

To install the bindings via Composer, add the following to composer.json:

{
  "require": {
    "devcycle/php-server-sdk": "*"
  }
}

Then run composer install

Once the composer install is complete, a vendor folder should be generated at the root of your project. Include this at the start of your app index file:

require_once(__DIR__ . '/vendor/autoload.php');

Getting Started

Initialize the DevCycle SDK and set the DevCycleProvider as the provider for OpenFeature:

$options = new DevCycleOptions(true);
$devCycleClient = new DevCycleClient(
    sdkKey: getenv("DEVCYCLE_SERVER_SDK_KEY"),
    dvcOptions: $options);

$api = OpenFeatureAPI::getInstance();
$api->setProvider($devCycleClient->getOpenFeatureProvider());
$openFeatureClient = $api->getClient();

Evaluate a Variable

Use a Variable value by setting the EvaluationContext, then passing the Variable key and default value to one of the OpenFeature flag evaluation methods.

// Create a new user attribute object that can be used by OpenFeature as part of the flag evaluation process.
$user_attributes = new Attributes(array("user_id" => "my-user"));

// Create a new evaluation context for the feature flag evaluations. This context is used to provide user or environment details for flag evaluations in OpenFeature.
$openfeature_context = new EvaluationContext(attributes: $user_attributes);

// Use the OpenFeature client to get the string value of the "string-flag" feature flag.
$flag_value = $openfeature_client->getStringValue("string-flag", "default", $openfeature_context);

Required TargetingKey

For DevCycle SDK to work we require either a targetingKey or user_id to be set on the OpenFeature context. This is used to identify the user as the user_id for a DevCycleUser in DevCycle. Setting the user_id property will take priority over targetingKey.

Context properties to DevCycleUser

The provider will automatically translate known DevCycleUser properties from the OpenFeature context to the DevCycleUser object.

For example all these properties will be set on the DevCycleUser:

$attributes = new Attributes(
    array(
    "user_id" => "test",
    "customData" => array("customkey" => "customValue"),
    "privateCustomData" => array("privateCustomKey" => "privateCustomValue"),
    "email" => "[email protected]",
    "name" => "Name Name",
    "language" => "EN",
    "country" => "CA",
    "appVersion" => "0.0.1",
    "appBuild" => 1,
    "nonSetValueBubbledCustomData" => true,
    "nonSetValueBubbledCustomData2" => "true",
    "nonSetValueBubbledCustomData3" => 1,
    "nonSetValueBubbledCustomData4" => null)
);
$context = new EvaluationContext('user', $attributes);

Context properties that are not known DevCycleUser properties will be automatically added to the CustomData property of the DevCycleUser.

Context Limitations

DevCycle only supports flat JSON Object properties used in the Context. Non-flat properties will throw an exception.

For example nested will be ignored:

$attributes = new Attributes(array("key"=>"value", "number"=>1, "bool"=>true, "nested"=>array("key"=>"value")));
self::$context = new EvaluationContext('user', $attributes);