What's this?!
This is a very little package with React hooks wrapping time-related vanilla Javascript functions,
so you can use them with minimal effort in your React apps without having to worry about manual
clean up, or writing boilerplate to pause/resume intervals etc.
Feature Overview
- Hooks for all timing-related vanilla JS functions like:
- …and additional utility hooks for common tasks like
- throttling:
useThrottledState()
, useThrottle()
, useDebounce()
- GFX/animation/rendering:
useAnimationFrameLoop()
- reactive counters:
useCounter()
, useCountdown()
, useTimer()
- time:
useClock()
- async effects:
useTimeoutEffect()
, useIdleCallbackEffect()
- Reactive intervals: intervals can be controlled via pause, resume, start or stop
- A versatile API: customizable settings, many hook "flavors" depending on the use-case.
- Automatic clean-ups of pending timers, intervals etc. on unmount
- Callbacks are automatically memoized
- Full Typescript support
- Very lightweight (no transitive dependencies!)
- Tree-shakable — You only bundle what you use!
Installation
npm i react-timing-hooks
yarn add react-timing-hooks
Documentation
https://ericlambrecht.github.io/react-timing-hooks/
How to migrate
https://ericlambrecht.github.io/react-timing-hooks/migrations/
Some Examples
A "status logger" with useInterval()
import { useInterval } from 'react-timing-hooks'
const StatusLogger = () => {
const logUpdates = () => console.log('status update')
const { start, pause, resume, isPaused } = useInterval(logUpdates, 1000)
return <div>
<button onClick={start}>Do stuff</button>
<button onClick={isPaused ? resume : pause}>Toggle Status Updates</button>
</div>
}
Throttle a button click with useThrottle()
import { useThrottle } from 'react-timing-hooks'
const HelloWorld = () => {
const [result, setResult] = useState(null)
const updateResult = () => setResult(extremeMegaCalculation())
const onButtonClick = useThrottle(updateResult, 1000)
return <div>
<button onClick={onButtonClick}>Spam me!</button>
<p>Result: {result}</p>
</div>
}
Display the user's browsing time using useTimer()
import { useTimer } from 'react-timing-hooks'
const BrowsingTime = () => {
const [elapsedSeconds] = useTimer(0, { startOnMount: true })
return <span>
You've been browsing this page for {elapsedSeconds} seconds.
</span>
}
Display the current time with useClock()
import { useTimeout } from 'react-timing-hooks'
const Clock = () => {
const [currentTime] = useClock()
return <span>{currentTime}</span>
}
A canvas renderer using useAnimationFrameLoop()
import { useAnimationFrameLoop } from 'react-timing-hooks'
const Renderer = () => {
const delta = useRef(0)
const canvasRef = useRef(null)
const canvas = canvasRef.current
const context = canvas.getContext('2d')
const updateCanvas = (d) => {
context.fillStyle = '#000000'
context.fillRect(d, d, context.canvas.width, context.canvas.height)
}
const { start, stop, isStopped } = useAnimationFrameLoop(() => {
delta.current += 1
updateCanvas(delta.current)
})
return <>
<canvas ref={canvasRef} {...props}/>
<button onClick={isStopped ? start : stop}>
{isStopped ? "Start rendering" : "Stop rendering"}
</button>
</>
}
Why does this exist?
I was once working for a company where the project required lots of timeouts and such. I quickly noticed that
writing a timeout or anything similar requires a lot of boilerplate (if you don't do it quick and dirty).
Dan Abramov showcased this in one of his blogposts a while a go.
This library is supposed to give you easy access to those time-related functionalities while keeping your code clean and concise.
You will not have to manually clean up timers or intervals.
Another common use-case is pausing/resuming or starting/stopping intervals (or loops). This lib offers
callbacks for that. So pausing is really just a matter of calling a pause()
function for example.
Many frequent use cases also have their own utility hook, like useThrottle
, useCountdown
or useAnimationFrameLoop
to make things even easier.
Needless to say, every hook is already tested and typed (so you don't have to).
Some "Before-/After-Code"
A simple interval that increments a counter on every second and can be manually started upon user input:
Before
import { useEffect, useState } from 'react'
const Counter = () => {
const [counter, setCounter] = useState(0)
const [startInterval, setStartInterval] = useState(false)
const intervalId = useRef(null)
useEffect(() => {
if (startInterval) {
intervalId.current = setInterval(() => setCounter(c => c + 1), 1000)
}
}, [startInterval])
useEffect(() => {
return function onUnmount() {
if (intervalId.current !== null) {
clearInterval(intervalId.current)
}
}
}, [intervalId])
return <>
<button onClick={() => setStartInterval(true)}>Start counting</button>
<p>{counter}</p>
</>
}
After
import { useState } from 'react'
import { useInterval } from 'react-timing-hooks'
const Counter = () => {
const [counter, setCounter] = useState(0)
const { start } = useInterval(() => setCounter(c => c + 1), 1000)
return <>
<button onClick={start}>Start counting</button>
<p>{counter}</p>
</>
}
Well,… actually, there is even a shorter way using the utility hook useTimer()
🙈
After After
import { useCounter } from 'react-timing-hooks'
const Counter = () => {
const [counter, { start }] = useTimer(0)
return <>
<button onClick={start}>Start counting</button>
<p>{counter}</p>
</>
}
Another example: You might have a timeout that runs under a certain condition. In this case a cleanup
has to be done in a separate useEffect
call that cleans everything up (but only on unmount).
Before
import { useEffect } from 'react'
const TimeoutRenderer = ({ depA, depB }) => {
const [output, setOutput] = useState(null)
const timeoutId = useRef(null)
useEffect(() => {
if (depA && depB) {
timeoutId.current = setTimeout(() => setOutput('Hello World'), 1000)
}
}, [depA, depB])
useEffect(() => {
return function onUnmount() {
if (timeoutId.current !== null) {
clearTimeout(timeoutId.current)
}
}
}, [timeoutId])
return output ? (
<div>{output}</div>
) : null
}
After
import { useState } from 'react'
import { useTimeoutEffect } from 'react-timing-hooks'
const TimeoutRenderer = ({ depA, depB }) => {
const [output, setOutput] = useState(null)
useTimeoutEffect((timeout, clearAll) => {
if (depA && depB) {
timeout(() => setOutput('Hello World'), 1000)
}
}, [depA, depB])
return output ? (
<div>{output}</div>
) : null
}
In this case react-timing-hooks
automatically took care of cleaning up the timeout for you (if the component is mounted for less than a second for instance).
Memoization
You don't have to worry about memoization of your callbacks (by using useCallback
) for example. React Timing Hooks is taking care of that for you. So even if you pass a simple inline arrow function to one of these hooks, the return value (if there is one) will not change on every render but instead stay the same (i.e. it will be memoized).
This means something like this is safe to do:
const [foo, setFoo] = useState(null)
const onFooChange = useTimeout(() => console.log('foo changed one second ago!'), 1000)
useEffect(() => {
onFooChange()
}, [foo, onFooChange])
Bundle Size
The whole lib is tree-shakable, i.e. only hooks you actually use end up in your bundle.
So far, we also do not use any transitive dependencies. So don't worry about the bundle size.
But check for yourself: https://bundlephobia.com/result?p=react-timing-hooks
Contributing
see CONTRIBUTING.md