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

@rnx-kit/react-native-lazy-index

v3.0.1

Published

Hermes/RAM bundle friendly index.js with on-demand loaded modules

Downloads

27

Readme

@rnx-kit/react-native-lazy-index

Build npm version

react-native-lazy-index is a Hermes/RAM bundle friendly, bundle-time generated index.js. Improve your app startup time by only loading features you'll use on demand.

For information on RAM bundles and inline requires, see React Native Performance.

If you use Haul, also take a look at their documentation.

Installation

npm install --save @rnx-kit/react-native-lazy-index

Usage

react-native-lazy-index uses babel-plugin-codegen, so you'll need to configure Babel to include it. The recommended way is to add it to your .babelrc:

 {
   "presets": ["module:metro-react-native-babel-preset"],
   "plugins": [
+    "codegen"
   ]
 }

In your index.js, import @rnx-kit/react-native-lazy-index and pass to it the features that should be lazy loaded. In the example below, we register four entry points:

// @codegen
module.exports = require("@rnx-kit/react-native-lazy-index")({
  SomeFeature: "@awesome-app/some-feature",
  "callable:AnotherFeature": "@awesome-app/another-feature",
  YetAnotherFeature: "@awesome-app/yet-another-feature",
  FinalFeature: "@awesome-app/final-feature",
});

By default, a call to AppRegistry is generated using the key as the app key, and the value is the name of the module containing the app. If the key is prefixed with callable:, a call to BatchedBridge will be generated.

That's it!

Why

With a naive index.js, all features will be loaded when your app starts and React Native is initialized for the first time.

import "@awesome-app/some-feature";
import "@awesome-app/another-feature";
import "@awesome-app/yet-another-feature";
import "@awesome-app/final-feature";

By loading features on demand, we can improve app startup time.

With react-native-lazy-index, we no longer load all features up front. Instead, index.js wraps calls to AppRegistry.registerComponent and BatchedBridge.registerCallableModule, deferring the import of a feature until it is used. Features that are never used, are never loaded.

When you import react-native-lazy-index, something similar to below is generated:

const { AppRegistry } = require("react-native");
const BatchedBridge = require("react-native/Libraries/BatchedBridge/BatchedBridge");

AppRegistry.registerComponent("SomeFeature", () => {
  // We'll import the module the first time "SomeFeature" is accessed.
  require("@awesome-app/some-feature");
  // "SomeFeature" is now overwritten and we can return the real component.
  // Subsequent calls to "SomeFeature" will no longer go through this wrapper.
  return AppRegistry.getRunnable("SomeFeature").componentProvider();
});

BatchedBridge.registerLazyCallableModule("AnotherFeature", () => {
  // We'll import the module the first time "AnotherFeature" is accessed.
  require("@awesome-app/another-feature");
  // "AnotherFeature" is now overwritten and we can return the real component.
  // Subsequent calls to "AnotherFeature" will no longer go through this
  // wrapper.
  return BatchedBridge.getCallableModule("AnotherFeature");
});

AppRegistry.registerComponent("YetAnotherFeature", () => {
  // We'll import the module the first time "YetAnotherFeature" is accessed.
  require("@awesome-app/yet-another-feature");
  // "YetAnotherFeature" is now overwritten and we can return the real
  // component. Subsequent calls to "YetAnotherFeature" will no longer go
  // through this wrapper.
  return AppRegistry.getRunnable("YetAnotherFeature").componentProvider();
});

AppRegistry.registerComponent("FinalFeature", () => {
  // We'll import the module the first time "FinalFeature" is accessed.
  require("@awesome-app/final-feature");
  // "FinalFeature" is now overwritten and we can return the real component.
  // Subsequent calls to "FinalFeature" will no longer go through this wrapper.
  return AppRegistry.getRunnable("FinalFeature").componentProvider();
});

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.

When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.