Files F100867417

useInterval.js
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Created: Mon, Feb 3, 10:45

useInterval.js
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	import { useEffect } from 'react';
	import useCommittedRef from './useCommittedRef';
	/**
	* Creates a `setInterval` that is properly cleaned up when a component unmounted
	*
	* ```tsx
	* function Timer() {
	* const [timer, setTimer] = useState(0)
	* useInterval(() => setTimer(i => i + 1), 1000)
	*
	* return <span>{timer} seconds past</span>
	* }
	* ```
	*
	* @param fn an function run on each interval
	* @param ms The milliseconds duration of the interval
	*/

	function useInterval(fn, ms, paused, runImmediately) {
	if (paused === void 0) {
	paused = false;
	}

	if (runImmediately === void 0) {
	runImmediately = false;
	}

	var handle;
	var fnRef = useCommittedRef(fn); // this ref is necessary b/c useEffect will sometimes miss a paused toggle
	// orphaning a setTimeout chain in the aether, so relying on it's refresh logic is not reliable.

	var pausedRef = useCommittedRef(paused);

	var tick = function tick() {
	if (pausedRef.current) return;
	fnRef.current();
	schedule(); // eslint-disable-line no-use-before-define
	};

	var schedule = function schedule() {
	clearTimeout(handle);
	handle = setTimeout(tick, ms);
	};

	useEffect(function () {
	if (runImmediately) {
	tick();
	} else {
	schedule();
	}

	return function () {
	return clearTimeout(handle);
	};
	}, [paused, runImmediately]);
	}

	export default useInterval;

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