RxJS Hooks and Suspense: The Ultimate Guide

Why Hooks

“This” isn’t the way

Time travelling

Get on the Hook

Why RxJS in Hooks

Observable Hooks

import React from 'react'
import { useObservableState } from 'observable-hooks'
import { timer } from 'rxjs'
import { switchMap, mapTo, startWith } from 'rxjs/operators'
const App = () => {
const [isTyping, updateIsTyping] = useObservableState(
event$ => event$.pipe(
switchMap(() =>
return (
<input type="text" onKeyDown={updateIsTyping} />
<p>{isTyping ? 'Good you are typing.' : 'Why stop typing?'}</p>
Pomodoro Timer Example


Render-as-You-Fetch (using Suspense)
// api.js
import { ObservableResource } from 'observable-hooks'
const postResource$$ = new Subject()export const postsResource = new ObservableResource(postResource$$.pipe(
switchMap(id => fakePostsXHR(id))
export function fetchPosts(id) {
// App.jsx
import { useObservableSuspense } from 'observable-hooks'
import { postsResource, fetchPosts } from './api'fetchPosts('crimx')function ProfilePage() {
return (
<Suspense fallback={<h1>Loading posts...</h1>}>
<ProfileTimeline />
function ProfileTimeline() {
// Try to read posts, although they might not have loaded yet
const posts = useObservableSuspense(postsResource)
return (
{posts.map(post => (
<li key={post.id}>{post.text}</li>



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