useDebounce, useDebouncedCallback & useThrottledCallback

React libraries for debouncing without tears!

• Small size < 1 Kb
• Compatible with underscore / lodash impl — learn once, use everywhere
• Server-rendering friendly!

Features

• classic debounced callback
• value debouncing
• cancel, maxWait and memoization

Install

1yarn add use-debounce
2# or
3npm i use-debounce --save

Copy paste guidance:

use-debounce

Simple usage: https://codesandbox.io/s/kx75xzyrq7

Debounce HTTP request: https://codesandbox.io/s/rr40wnropq

Debounce HTTP request with leading param: https://codesandbox.io/s/cache-example-with-areas-and-leading-param-119r3i

use-debounce callback

Simple usage: https://codesandbox.io/s/x0jvqrwyq

Combining with native event listeners: https://codesandbox.io/s/32yqlyo815

Cancelling, maxWait and memoization: https://codesandbox.io/s/4wvmp1xlw4

HTTP requests: https://codesandbox.io/s/use-debounce-callback-http-y1h3m6

Changelog

https://github.com/xnimorz/use-debounce/blob/master/CHANGELOG.md

Simple values debouncing

According to https://twitter.com/dan_abramov/status/1060729512227467264 WebArchive link: https://web.archive.org/web/20210828073432/https://twitter.com/dan_abramov/status/1060729512227467264

1import React, { useState } from 'react';
2import { useDebounce } from 'use-debounce';
3
4export default function Input() {
5  const [text, setText] = useState('Hello');
6  const [value] = useDebounce(text, 1000);
7
8  return (
9    <div>
10      <input
11        defaultValue={'Hello'}
12        onChange={(e) => {
13          setText(e.target.value);
14        }}
15      />
16      <p>Actual value: {text}</p>
17      <p>Debounce value: {value}</p>
18    </div>
19  );
20}

This hook compares prev and next value using shallow equal. It means, setting an object {} will trigger debounce timer. If you have to compare objects (https://github.com/xnimorz/use-debounce/issues/27#issuecomment-496828063), you can use useDebouncedCallback, that is explained below:

Debounced callbacks

Besides useDebounce for values you can debounce callbacks, that is the more commonly understood kind of debouncing. Example with Input (and react callbacks): https://codesandbox.io/s/x0jvqrwyq

1import { useDebouncedCallback } from 'use-debounce';
2
3function Input({ defaultValue }) {
4  const [value, setValue] = useState(defaultValue);
5  // Debounce callback
6  const debounced = useDebouncedCallback(
7    // function
8    (value) => {
9      setValue(value);
10    },
11    // delay in ms
12    1000
13  );
14
15  // you should use `e => debounced(e.target.value)` as react works with synthetic events
16  return (
17    <div>
18      <input
19        defaultValue={defaultValue}
20        onChange={(e) => debounced(e.target.value)}
21      />
22      <p>Debounced value: {value}</p>
23    </div>
24  );
25}

Example with Scroll (and native event listeners): https://codesandbox.io/s/32yqlyo815

1function ScrolledComponent() {
2  // just a counter to show, that there are no any unnessesary updates
3  const updatedCount = useRef(0);
4  updatedCount.current++;
5
6  const [position, setPosition] = useState(window.pageYOffset);
7
8  // Debounce callback
9  const debounced = useDebouncedCallback(
10    // function
11    () => {
12      setPosition(window.pageYOffset);
13    },
14    // delay in ms
15    800
16  );
17
18  useEffect(() => {
19    const unsubscribe = subscribe(window, 'scroll', debounced);
20    return () => {
21      unsubscribe();
22    };
23  }, []);
24
25  return (
26    <div style={{ height: 10000 }}>
27      <div style={{ position: 'fixed', top: 0, left: 0 }}>
28        <p>Debounced top position: {position}</p>
29        <p>Component rerendered {updatedCount.current} times</p>
30      </div>
31    </div>
32  );
33}

Returned value from debounced()

Subsequent calls to the debounced function debounced return the result of the last func invocation. Note, that if there are no previous invocations it's mean you will get undefined. You should check it in your code properly.

Example:

1it('Subsequent calls to the debounced function `debounced` return the result of the last func invocation.', () => {
2  const callback = jest.fn(() => 42);
3
4  let callbackCache;
5  function Component() {
6    const debounced = useDebouncedCallback(callback, 1000);
7    callbackCache = debounced;
8    return null;
9  }
10  Enzyme.mount(<Component />);
11
12  const result = callbackCache();
13  expect(callback.mock.calls.length).toBe(0);
14  expect(result).toBeUndefined();
15
16  act(() => {
17    jest.runAllTimers();
18  });
19  expect(callback.mock.calls.length).toBe(1);
20  const subsequentResult = callbackCache();
21
22  expect(callback.mock.calls.length).toBe(1);
23  expect(subsequentResult).toBe(42);
24});

Advanced usage

Cancel, maxWait and memoization

1. Both useDebounce and useDebouncedCallback works with maxWait option. This params describes the maximum time func is allowed to be delayed before it's invoked.
2. You can cancel debounce cycle, by calling cancel callback

The full example you can see here https://codesandbox.io/s/4wvmp1xlw4

1import React, { useState } from 'react';
2import ReactDOM from 'react-dom';
3import { useDebouncedCallback } from 'use-debounce';
4
5function Input({ defaultValue }) {
6  const [value, setValue] = useState(defaultValue);
7  const debounced = useDebouncedCallback(
8    (value) => {
9      setValue(value);
10    },
11    500,
12    // The maximum time func is allowed to be delayed before it's invoked:
13    { maxWait: 2000 }
14  );
15
16  // you should use `e => debounced(e.target.value)` as react works with synthetic events
17  return (
18    <div>
19      <input
20        defaultValue={defaultValue}
21        onChange={(e) => debounced(e.target.value)}
22      />
23      <p>Debounced value: {value}</p>
24      <button onClick={debounced.cancel}>Cancel Debounce cycle</button>
25    </div>
26  );
27}
28
29const rootElement = document.getElementById('root');
30ReactDOM.render(<Input defaultValue="Hello world" />, rootElement);

The same API is available for useDebounce calls:

1const [value, {cancel, isPending, flush}] = useDebounce(valueToDebounce);
2...
3cancel() // cancels pending debounce request
4isPending() // returns if there is a pending debouncing request
5flush() // immediately flushes pending request

Flush method

useDebouncedCallback has flush method. It allows to call the callback manually if it hasn't fired yet. This method is handy to use when the user takes an action that would cause the component to unmount, but you need to execute the callback.

1import React, { useState } from 'react';
2import { useDebouncedCallback } from 'use-debounce';
3
4function InputWhichFetchesSomeData({ defaultValue, asyncFetchData }) {
5  const debounced = useDebouncedCallback(
6    (value) => {
7      asyncFetchData;
8    },
9    500,
10    { maxWait: 2000 }
11  );
12
13  // When the component goes to be unmounted, we will fetch data if the input has changed.
14  useEffect(
15    () => () => {
16      debounced.flush();
17    },
18    [debounced]
19  );
20
21  return (
22    <input
23      defaultValue={defaultValue}
24      onChange={(e) => debounced(e.target.value)}
25    />
26  );
27}

isPending method

isPending method shows whether component has pending callbacks. Works for both useDebounce and useDebouncedCallback:

1import React, { useCallback } from 'react';
2
3function Component({ text }) {
4  const debounced = useDebouncedCallback(
5    useCallback(() => {}, []),
6    500
7  );
8
9  expect(debounced.isPending()).toBeFalsy();
10  debounced();
11  expect(debounced.isPending()).toBeTruthy();
12  debounced.flush();
13  expect(debounced.isPending()).toBeFalsy();
14
15  return <span>{text}</span>;
16}

leading/trailing calls

Both useDebounce and useDebouncedCallback work with the leading and trailing options. leading param will execute the function once immediately when called. Subsequent calls will be debounced until the timeout expires. trailing option controls whenever to call the callback after timeout again.

For more information on how leading debounce calls work see: https://lodash.com/docs/#debounce

1import React, { useState } from 'react';
2import { useDebounce } from 'use-debounce';
3
4export default function Input() {
5  const [text, setText] = useState('Hello');
6  const [value] = useDebounce(text, 1000, { leading: true });
7
8  // value is updated immediately when text changes the first time,
9  // but all subsequent changes are debounced.
10  return (
11    <div>
12      <input
13        defaultValue={'Hello'}
14        onChange={(e) => {
15          setText(e.target.value);
16        }}
17      />
18      <p>Actual value: {text}</p>
19      <p>Debounce value: {value}</p>
20    </div>
21  );
22}

Options:

You can provide additional options as a third argument to both useDebounce and useDebouncedCallback:

option	default	Description	Example
maxWait	-	Describes the maximum time func is allowed to be delayed before it's invoked	https://github.com/xnimorz/use-debounce#cancel-maxwait-and-memoization
leading	-	This param will execute the function once immediately when called. Subsequent calls will be debounced until the timeout expires.	https://github.com/xnimorz/use-debounce#leading-calls
trailing	true	This param executes the function after timeout.	https://github.com/xnimorz/use-debounce#leading-calls
equalityFn	(prev, next) => prev === next	[useDebounce ONLY] Comparator function which shows if timeout should be started

useThrottledCallback

You are able to use throttled callback with this library also (starting 5.2.0 version). For this purpose use:

import useThrottledCallback from 'use-debounce/useThrottledCallback';

or

import { useThrottledCallback } from 'use-debounce';

Several examples:

1. Avoid excessively updating the position while scrolling.

   1const scrollHandler = useThrottledCallback(updatePosition, 100);
   2window.addEventListener('scroll', scrollHandler);

2. Invoke renewToken when the click event is fired, but not more than once every 5 minutes.

   1const throttled = useThrottledCallback(renewToken, 300000, { 'trailing': false })
   2<button onClick={throttled}>click</button>

All the params for useThrottledCallback are the same as for useDebouncedCallback except maxWait option. As it's not needed for throttle callbacks.

Special thanks:

@tryggvigy — for managing lots of new features of the library like trailing and leading params, throttle callback, etc;

@omgovich — for reducing bundle size.