Harness CF React Native SDK
Overview
Harness is a feature management platform that helps teams to build better software and to test features quicker.
Setup
To install SDK, declare a dependency to project's package.json
file:
"ff-react-native-client-sdk": "0.0.1",
Or using npm install:
$ npm install --save ff-react-native-client-sdk
For iOS, run the following commands from project root folder
$ cd ios
$ pod install
Then, you may import package to your project. The SDK is used via single instance exported from index.d.ts
module
import cfClientInstance from 'ff-react-native-client-sdk';
Initialization
cfClientInstance
is base instance that provides all the features of SDK. It is initialized with instances of CfConfiguration
and CfTarget
. All configuration fields are optional and if omitted they will be populated with default values by SDK.
import cfClientInstance, {CfConfiguration, CfTarget} from 'ff-react-native-client-sdk';
const client = cfClientInstance;
const cfConfiguration = new CfConfiguration();
cfConfiguration.streamEnabled = true;
const cfTarget = new CfTarget();
cfTarget.identifier = 'Harness'
const apiKey = "YOUR_API_KEY";
const result = await cfClientInstance.initialize(apiKey, cfConfiguration, cfTarget);
cfTarget
represents a desired target for which we want features to be evaluated. identifier
is mandatory field.
"YOUR_API_KEY"
is an authentication key, needed for access to Harness services.
Your Harness SDK is now initialized. Congratulations!!!
Public API Methods
The Public API exposes a few methods that you can utilize:
-
async initialize(apiKey: string, config: CfConfiguration, target:CfTarget)
-
boolVariation(evalutionId: string, defaultValue?: boolean)
-
stringVariation(evalutionId: string, defaultValue?:string)
-
numberVariation(evalutionId: string, defaultValue?:number)
-
jsonVariation(evalutionId: string, defaultValue: any)
-
registerEventsListener(listener: (type: string, flags: any) => void)
-
unregisterListener(listener: (type: string, flags: any) => void)
-
destroy()
Fetch evaluation's value
It is possible to fetch a value for a given evaluation. Evaluation is performed based on different type. In case there is no evaluation with provided id, the default value is returned.
Use appropriate method to fetch the desired Evaluation of a certain type.
boolVariation(evaluationId: string, defaultValue?: boolean)
let evaluation = await client.boolVariation("demo_bool_evaluation", false)
numberVariation(evaluationId: string, defaultValue?:number)
let numberEvaluation = await client.numberVariation("demo_number_evaluation", 0)
stringVariation(evaluationId: string, defaultValue?:string)
let stringEvaluation = await client.stringVariation("demo_string_evaluation", "default");
jsonVariation(evaluationId: string, defaultValue?: any)
let jsonEvaluation = await client.jsonVariation("demo_json_evaluation", {});
Register for events
This method provides a way to register a listener for different events that might be triggered by SDK, indicating specific change in SDK itself.
client.registerEventsListener((type, flags) => {
});
Each type will return a corresponding value as shown in the table below.
event type | returns |
---|
"start" | null |
"end" | null |
"evaluation_polling" | List |
"evaluation_change" | EvaluationResponse |
| |
Visit documentation for complete list of possible types and values they provide.
To avoid unexpected behaviour, when listener is not needed anymore, a caller should call
client.unregisterListener(eventsListener)
This way the sdk will remove desired listener from internal list.
Shutting down the SDK
To avoid potential memory leak, when SDK is no longer needed (when the app is closed, for example), a caller should call this method
client.destroy()