@harnessio/ff-javascript-client-sdk

Harness Feature Flags Client SDK for JavaScript

Basic library for integrating CF into javascript applications.

Install

npm i @harnessio/ff-javascript-client-sdk

or

yarn add @harnessio/ff-javascript-client-sdk

Usage

import { initialize, Event } from '@harnessio/ff-javascript-client-sdk'

Initialize SDK with api key and target information.

// Replace with your SDK Key
const FF_SDK_KEY = "2c2a12a1-6599-406e-96c4-031a51c8a51b"

const cf = initialize(FF_SDK_KEY, {
    identifier: YOUR-TARGET-IDENTIFIER,      // Target identifier
    name: YOUR-TARGET-NAME,                  // Optional target name
    attributes: {                            // Optional target attributes
      email: '[e-mail]'
    }
  }, {
    baseUrl: 'http://40.20.100.200/api/1.0', // Replace with your Feature Flags server
  });

Listening to events from the cf instance.

cf.on(Event.READY, flags => {
  // Event happens when connection to server is established
  // flags contains all evaluations against SDK key
})

cf.on(Event.CHANGED, flagInfo => {
  // Event happens when a changed event is pushed
  // flagInfo contains information about the updated feature flag
})

cf.on(Event.DISCONNECTED, () => {
  // Event happens when connection is disconnected
})

cf.on(Event.ERROR, () => {
  // Event happens when connection some error has occurred
})

Getting value for a particular feature flag

const value = cf.variation("dark-theme", false) // second argument is default value when variation does not exist

Cleaning up

Remove a listener of an event by cf.off.

cf.off(Event.ERROR, YOUR-CLOSURE)

Remove all listeners:

cf.off()

On closing your application, call cf.close() to close the event stream.

cf.close();

License

Apache version 2.