Instantly share code, notes, and snippets.

View Dataloader.js
// The `loader` prop is a Dataloader instance
class Dataloader extends React.Component {
state = {data: null, isLoaded: false};
componentWillMount() {
componentWillReceiveProps(nextProps) {
if ( !== || this.props.loader !== nextProps.loader) {
this.setState({isLoaded: false});

Demo: Coordinating async React with non-React views

tl;dr I built a demo illustrating what it might look like to add async rendering to Facebook's commenting interface, while ensuring it appears on the screen simultaneous to the server-rendered story.

A key benefit of async rendering is that large updates don't block the main thread; instead, the work is spread out and performed during idle periods using cooperative scheduling.

But once you make something async, you introduce the possibility that things may appear on the screen at separate times. Especially when you're dealing with multiple UI frameworks, as is often the case at Facebook.

How do we solve this with React?

View prefetch.js
function prefetch(getKey, getValue, getInitialValue, propName) {
const inFlight = new Set();
const cache = new Map();
return ChildComponent => {
return class extends React.Component {
state = {value: getInitialValue(this.props)};
componentWillReceiveProps(nextProps) {
const key = getKey(nextProps);
if (cache.has(key)) {
// Use cached value
View app.js
// getComponent is a function that returns a promise for a component
// It will not be called until the first mount
function asyncComponent(getComponent) {
return class AsyncComponent extends React.Component {
static Component = null;
state = { Component: AsyncComponent.Component };
componentWillMount() {
if (!this.state.Component) {
getComponent().then(Component => {
View SassMeister-input.scss
// ----
// libsass (v3.2.5)
// ----
.foo :global(.some-ovid-class) .bar {
color: blue;
View app.js
const history = createHistory();
const router = createReactRouter(routes);
history.listen((location => {
router.match(location, (err, state, redirectInfo) => {
// Integrate with external state library (Redux), or render directly
<RouterComponent {...state} />;
View gist:1168dd2c3cbd8e4cb477
function reactRouter(router) {
return (reducer, initialState) => next => {
const baseStore = next(reducer, initialState);
function storeIsInSyncWithRouter() {
//... blah blah implementation details
// Apply router middleware which intercepts TRANSITION_TO actions
const wrappedDispatch = routerMiddleware(router)()(baseStore.dispatch);
View flux.js
* Basic proof of concept.
* - Hot reloadable
* - Stateless stores
* - Stores and action creators interoperable with Redux.
import React, { Component } from 'react';
export default function dispatch(store, atom, action) {
View gist:c7eb7ac45617d9332b60
import Flummox from 'flummox';
import { Map } from 'immutable';
// Instead of a constructor, just wrap flux creation inside a function
export default function createFlux() {
const flux = new Flummox();
// Actions are the same. Just pass an object instead of a class.
const thingActions = flux.createActions('things', {
incrementSomething(amount) {
View gist:dfbac9ed62474e1be605
const flux = new Flux();
flux.createActions('foobar', {
foo() {
return 'bar';
bar() {
return 'baz';