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useStateWithCallback React Hook

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Custom hook to include a callback function for useState which was previously available for setState in class components. Read more about it here.

Installation

npm install use-state-with-callback

Usage

useStateWithCallback:

import * as React from 'react'; import useStateWithCallback from 'use-state-with-callback'; // Note: cannot be used on the server-side (e.g. Next.js) // import { useStateWithCallbackInstant } from 'use-state-with-callback'; const App = () => { const [count, setCount] = useStateWithCallback(0, currentCount => { console.log('render, then callback.'); console.log('otherwise use useStateWithCallbackInstant()'); if (currentCount > 1) { console.log('Threshold of over 1 reached.'); } else { console.log('No threshold reached.'); } }); // const [count, setCount] = useStateWithCallbackInstant(0, currentCount => { // console.log('render with instant callback.'); // if (currentCount > 1) { // console.log('Threshold of over 1 reached.'); // } else { // console.log('No threshold reached.'); // } // }); const handleClick = () => { setCount(count + 1); }; return ( <div> {count} <button type="button" onClick={handleClick}> Increase </button> </div> ); }; export default App;

useStateWithCallbackLazy:

import * as React from 'react'; import { useStateWithCallbackLazy } from 'use-state-with-callback'; const App = () => { const [count, setCount] = useStateWithCallbackLazy(0); const handleClick = () => { setCount(count + 1, (currentCount) => { if (currentCount > 1) { console.log('Threshold of over 1 reached.'); } else { console.log('No threshold reached.'); } }); }; return ( <div> <p>{count}</p> <button type="button" onClick={handleClick}> Increase </button> </div> ); }; export default App;

Pitfalls

  • When a state update is called with the current value and optimized away, the callback is never called.
  • useStateWithCallbackLazy calls the callback with the scope that existed before update, while this.setState callback can access the updated this.state and get something() computed values. This can't be fixed, but it's a problem for people who expect a drop-in replacement.
  • When useStateWithCallbackLazy state is updated several times with batching (e.g. in an event handler), only the last update calls the callback.

Contribute

  • git clone git@github.com:the-road-to-learn-react/use-state-with-callback.git
  • cd use-state-with-callback
  • npm install
  • npm run test

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Custom hook to include a callback function for useState.

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