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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 Java implementation of the OpenFeature Provider interface, if you prefer to use the OpenFeature API.

Maven GitHub

Installation​

The Provider implementation is built into the Java SDK.

Maven​

You can use the Java SDK in your Maven project by adding the following to your pom.xml:

<dependency>
    <groupId>com.devcycle</groupId>
    <artifactId>java-server-sdk</artifactId>
    <version>LATEST</version>
    <scope>compile</scope>
</dependency>
info

Refer to the latest version of the SDK on maven central if you would not prefer Maven or Gradle to pull the latest version automatically by using +

Gradle​

Alternatively you can use the SDK in your Gradle project by adding the following to build.gradle:

implementation("com.devcycle:java-server-sdk:+")

Usage​

Start by creating and configuring the DevCycleLocalClient. Once the DevCycle client is configured, call the getOpenFeatureProvider() function to obtain the OpenFeature provider and set it into the OpenFeature API.

import com.devcycle.sdk.server.local.api.DevCycleLocalClient;
import com.devcycle.sdk.server.local.model.DevCycleLocalOptions;
import dev.openfeature.sdk.*;

public class OpenFeatureExample {
    public static void main(String[] args) {
        // Initialize DevCycle Client
        DevCycleLocalOptions options = DevCycleLocalOptions.builder().build();
        DevCycleLocalClient devCycleClient = new DevCycleLocalClient(System.getenv("DEVCYCLE_SERVER_SDK_KEY"), options);

        // Set the provider into the OpenFeature API
        OpenFeatureAPI api = OpenFeatureAPI.getInstance();
        api.setProvider(devCycleClient.getOpenFeatureProvider());

        // Get the OpenFeature client
        Client openFeatureClient = api.getClient();
    }
}

Evaluate a Variable​

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

// Retrieve a boolean flag from the OpenFeature client
Boolean variableValue = openFeatureClient.getBooleanValue("boolean-flag", false, new MutableContext("user-1234"));

NOTE: use DevCycleCloudClient \ DevCycleCloudOptions for Cloud Bucketing mode.

Required Targeting Key​

For DevCycle SDK to work we require either a targeting key or user_id attribute to be set on the OpenFeature context. This value is used to identify the user as the user_id property for a DevCycleUser in DevCycle.

Mapping Context Properties to DevCycleUser​

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

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

MutableContext context = new MutableContext("test-1234");
context.add("email", "email@devcycle.com");
context.add("name", "name");
context.add("country", "CA");
context.add("language", "en");
context.add("appVersion", "1.0.11");
context.add("appBuild", 1000);

Map<String,Object> customData = new LinkedHashMap<>();
customData.put("custom", "value");
context.add("customData", Structure.mapToStructure(customData));

Map<String,Object> privateCustomData = new LinkedHashMap<>();
privateCustomData.put("private", "data");
context.add("privateCustomData", Structure.mapToStructure(privateCustomData));

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

DevCycle allows the following data types for custom data values: boolean, integer, double, float, and String. Other data types will be ignored.

JSON Flag Limitations​

The OpenFeature spec for JSON flags allows for any type of valid JSON value to be set as the flag value.

For example the following are all valid default value types to use with OpenFeature:

// Invalid JSON values for the DevCycle SDK, will return defaults
openFeatureClient.getObjectValue("json-flag", new Value(new ArrayList<String>(Arrays.asList("value1", "value2"))));
openFeatureClient.getObjectValue("json-flag", new Value(610));
openFeatureClient.getObjectValue("json-flag", new Value(false));
openFeatureClient.getObjectValue("json-flag", new Value("string"));
openFeatureClient.getObjectValue("json-flag", new Value());

However, these are not valid types for the DevCycle SDK, the DevCycle SDK only supports JSON Objects (as Map<String,Object>):


Map<String,Object> defaultJsonData = new LinkedHashMap<>();
defaultJsonData.put("default", "value");
openFeatureClient.getObjectValue("json-flag", new Value(Structure.mapToStructure(defaultJsonData)));

This is enforced both for both the flag values and the default values supplied to the getObjectValue() method. Invalid types will trigger a dev.openfeature.sdk.exceptions.TypeMismatchError exception.