useInterval #react #hook

useInterval.tsx

/**
 * This is an implementation of javascript's imperative setInterval API
 * combined with React hooks' declarative approach.
 *
 * It is actually a replica of Dan Abramov's implementation described here:
 * https://overreacted.io/making-setinterval-declarative-with-react-hooks/
 */

import { useEffect, useRef } from "react";

export function useInterval(callback: any, delay: number | null) {
  const savedCallback = useRef<any | null>(null);

  // Remember the latest callback.
  useEffect(() => {
    savedCallback.current = callback;
  }, [callback]);

  // Set up the interval.
  useEffect(() => {
    function tick() {
      savedCallback.current();
    }

    if (delay !== null) {
      const id = setInterval(tick, delay);
      return () => clearInterval(id);
    }

    return;
  }, [delay]);
}