!types

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.

$3

* Hooks for all timing-related vanilla JS functions like:
* setInterval() –> [useInterval()][interval-api] | [MDN][interval-mdn]
* setTimeout() –> [useTimeout()][timeout-api] | [MDN][timeout-mdn]
* requestAnimationFrame() –> [useAnimationFrame()][raf-api] | [MDN][raf-mdn]
* requestIdleCallback() –> [useIdleCallback()][idle-cb-api] | [MDN][idle-cb-mdn]
* …and additional [utility hooks][all-hooks] for common tasks like
* throttling: useThrottledState(), useThrottle(), useDebounce()
* GFX/animation/rendering: useAnimationFrameLoop()
* reactive counters: useCounter(), useCountdown(), useTimer()
* time: useClock()
* async effects: useTimeoutEffect(), useIdleCallbackEffect()
* oscillation: useOscillator()
* 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

``bash

via npm

npm i react-timing-hooks

via yarn

yarn add react-timing-hooks
`

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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()
`jsx harmony
import { useInterval } from 'react-timing-hooks'

const StatusLogger = () => {
const logUpdates = () => console.log('status update')
// could also be intialized with { startOnMount: true } to immediately start the interval
const { start, pause, resume, isPaused } = useInterval(logUpdates, 1000)

return

Do stuff
Toggle Status Updates

}
`
----

#### Throttle a button click with useThrottle()

`jsx harmony
import { useThrottle } from 'react-timing-hooks'

const HelloWorld = () => {
const [result, setResult] = useState(null)
const updateResult = () => setResult(extremeMegaCalculation())

const onButtonClick = useThrottle(updateResult, 1000)

return

Spam me!

Result: {result}

}
`
----

#### Display the user's browsing time using useTimer()
`jsx harmony
import { useTimer } from 'react-timing-hooks'

const BrowsingTime = () => {
const [elapsedSeconds] = useTimer(0, { startOnMount: true })
return
You've been browsing this page for {elapsedSeconds} seconds.

}
`
----

#### Display the current time with useClock()
`jsx harmony
import { useTimeout } from 'react-timing-hooks'

const Clock = () => {
// This will show a time like 1:13:56 PM (supports localized formats as well).
// The displayed time will update every second
const [currentTime] = useClock()
return {currentTime}
}
`
----

#### A canvas renderer using useAnimationFrameLoop()

`jsx harmony
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 <>


{isStopped ? "Start rendering" : "Stop rendering"}


}
`

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).

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A simple interval that increments a counter on every second and can be manually started upon user input:

#### Before

`jsx harmony
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 <>
setStartInterval(true)}>Start counting

{counter}

}
`

#### After

`jsx harmony
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 <>
Start counting

{counter}

}
`

Well,… actually, there is even a shorter way using the utility hook useTimer() 🙈

#### After After

`jsx harmony
import { useCounter } from 'react-timing-hooks'

const Counter = () => {
const [counter, { start }] = useTimer(0)

return <>
Start counting

{counter}

}
`
----

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

`jsx harmony
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 ? (

{output}

) : null
}
`

#### After

`jsx harmony
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)
}
// you could even add more timeouts in this effect
// without any more boilerplate
}, [depA, depB])

return output ? (

{output}

) : 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).

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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:

`javascript
const [foo, setFoo] = useState(null)
const onFooChange = useTimeout(() => console.log('foo changed one second ago!'), 1000)

// the following effect will run only when "foo" changes, just as expected.
// "onFooChange" is memoized and safe to use in a dependency array.
useEffect(() => {
onFooChange()
}, [foo, onFooChange])
``

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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

[timeout-mdn]: https://developer.mozilla.org/en-US/docs/Web/API/setTimeout
[interval-mdn]: https://developer.mozilla.org/en-US/docs/Web/API/setInterval
[raf-mdn]: https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame
[idle-cb-mdn]: https://developer.mozilla.org/en-US/docs/Web/API/Window/requestIdleCallback
[timeout-api]: https://ericlambrecht.github.io/react-timing-hooks/callbacks/useTimeout.html
[interval-api]: https://ericlambrecht.github.io/react-timing-hooks/loops-and-intervals/
[raf-api]: https://ericlambrecht.github.io/react-timing-hooks/loops-and-intervals/useAnimationFrameLoop.html
[idle-cb-api]: https://ericlambrecht.github.io/react-timing-hooks/callbacks/useIdleCallback.html
[all-hooks]: https://ericlambrecht.github.io/react-timing-hooks/list-of-all-hooks/