React-modules NPM

react-modules

npm install react-modules babel-template --save

code splitting as a component

import { Modules } from 'react-modules'

<Modules   
  load={require('./App.js')}>{ 
    // or arrays, or objects, whatevs
    App => App ? 
      <div><App /></div> : 
      <span>loading...</span>
}</Modules>

isomorphic / SSR friendly
transpiles to webpack-friendly split points with a plugin(react-modules/babel)
with helpers to preserve server-rendered html until module loads
leverage the structure of your app to efficiently split/load your javascript bundles

api

<Modules load={[require('A'), require('B'), {c: require('C')}]}>{
  ([A, B { c:C }]) => {...}
}</Modules>

load={reqs} - return the required modules with require. with the plugin, this will be converted to webpack code split points.
onError={fn} - catch errors
include={bool} - bypasses the code split
defer={bool} - loads the scripts only in the trasnpiled version
chunkName={str} - optional, acts as third argument to the backing require.ensure() call for named chunks
entry={name} - (experimental) include chunk into name entry. works in tandem with extractEntries() (TODO - accept multiple entries)

html persistence helpers

a set of helpers to preserve server/static-rendered html, until its 'parent' module loads. this is useful when the component is heavy, but you still want to show prerendered html while the chunk loads

preserve(id, DOMelement) : DOMelement
preserved(id) : DOMelement

example -

<Module load={require('./a').default}>{
  A => A ? preserve('myhtml', <div><App/></div>): // on SSR, this will generate html
    preserved('myhtml') || // on browser, use the cached html, until the module loads up
    <span>loading...</span> // if neither available, show loading state
}</Module>

Use sparingly! This will probably break react's checksum algo, but that's the tradeoff you'll need for this behavior.

plugin

react-modules/babel - wraps Modules components' load props with require.ensure boilerplate, generating code splits

extractEntries

extractEntries(filepath) (experimental) - statically analyze module and generate webpack entries

extractResourceMap

extractResourceMap(filepath) (experimental) - statically analyze an app and generate urlpattern -> entries map. works in tandem with react-router@4.