npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

@eppo/react-native-sdk

v3.2.0

Published

Eppo React Native SDK

Downloads

17,141

Readme

Eppo React Native SDK

Test and lint SDK

Eppo is a modular flagging and experimentation analysis tool. Eppo's React Native SDK is built to make assignments for single user client applications that run in a web browser. Before proceeding you'll need an Eppo account.

Features

  • Feature gates
  • Kill switches
  • Progressive rollouts
  • A/B/n experiments
  • Mutually exclusive experiments (Layers)
  • Dynamic configuration

Installation

npm install @eppo/react-native-sdk

Quick start

Begin by initializing a singleton instance of Eppo's client. Once initialized, the client can be used to make assignments anywhere in your app.

Initialize once

import { init } from "@eppo/react-native-sdk";

await init({ apiKey: "<SDK-KEY-FROM-DASHBOARD>" });

Assign anywhere

import * as EppoSdk from "@eppo/react-native-sdk";

const eppoClient = EppoSdk.getInstance();
const user = getCurrentUser();

const variation = eppoClient.getBooleanAssignment('show-new-feature', user.id, { 
  'country': user.country,
  'device': user.device,
}, false);

Assignment functions

Every Eppo flag has a return type that is set once on creation in the dashboard. Once a flag is created, assignments in code should be made using the corresponding typed function:

getBoolAssignment(...)
getNumericAssignment(...)
getIntegerAssignment(...)
getStringAssignment(...)
getJSONAssignment(...)

Each function has the same signature, but returns the type in the function name. For booleans use getBooleanAssignment, which has the following signature:

getBooleanAssignment: (
  flagKey: string,
  subjectKey: string,
  subjectAttributes: Record<string, any>,
  defaultValue: boolean,
) => boolean

Initialization options

The init function accepts the following optional configuration arguments.

| Option | Type | Description | Default | | ------ | ----- | ----- | ----- | | assignmentLogger | IAssignmentLogger | A callback that sends each assignment to your data warehouse. Required only for experiment analysis. See example below. | null | | requestTimeoutMs | number | Timeout in milliseconds for HTTPS requests for the experiment configurations. | 5000 | | numInitialRequestRetries | number | Number of additional times the initial configurations request will be attempted if it fails. This is the request typically synchronously waited (via await) for completion. A small wait will be done between requests. | 1 | | pollAfterSuccessfulInitialization | boolean | Poll for new configurations (every 30 seconds) after successfully requesting the initial configurations. | false | | pollAfterFailedInitialization | boolean | Poll for new configurations even if the initial configurations request failed. | false | | throwOnFailedInitialization | boolean | Throw an error (reject the promise) if unable to fetch initial configurations during initialization. | true | | numPollRequestRetries | number | If polling for updated configurations after initialization, the number of additional times a request will be attempted before giving up. Subsequent attempts are done using an exponential backoff. | 7 |

Assignment logger

To use the Eppo SDK for experiments that require analysis, pass in a callback logging function to the init function on SDK initialization. The SDK invokes the callback to capture assignment data whenever a variation is assigned. The assignment data is needed in the warehouse to perform analysis.

The code below illustrates an example implementation of a logging callback using Segment, but you can use any system you'd like. The only requirement is that the SDK receives a logAssignment callback function. Here we define an implementation of the Eppo IAssignmentLogger interface containing a single function named logAssignment:

import { IAssignmentLogger } from "@eppo/react-native-sdk";
import { AnalyticsBrowser } from "@segment/analytics-next";

// Connect to Segment (or your own event-tracking system)
const analytics = AnalyticsBrowser.load({ writeKey: "<SEGMENT_WRITE_KEY>" });

const assignmentLogger: IAssignmentLogger = {
  logAssignment(assignment) {
    analytics.track({
      userId: assignment.subject,
      event: "Eppo Randomized Assignment",
      type: "track",
      properties: { ...assignment },
    });
  },
};

Avoiding duplicated assignment logs

Eppo's SDK uses an internal cache to ensure that duplicate assignment events are not logged to the data warehouse. While Eppo's analytic engine will automatically deduplicate assignment records, this internal cache prevents firing unnecessary events and can help minimize costs associated with event logging.

Philosophy

Eppo's SDKs are built for simplicity, speed and reliability. Flag configurations are compressed and distributed over a global CDN (Fastly), typically reaching end users in under 15ms. Those configurations are then cached locally, ensuring that each assignment is made instantly. Each SDK is as light as possible, with evaluation logic at around 25 simple lines of code. The simple typed functions listed above are all developers need to know about, abstracting away the complexity of the underlying set of features.