@barelyreaper/background-timer/dist/use-background-timer.js

Simple react hook to run a timer in the background

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.useBackgroundTimer = void 0;
const react_1 = require("react");
const useBackgroundTimer = (timeInMilliseconds, options = {}) => {
    const [timer, setTimer] = react_1.useState();
    const [endTime, setEndTime] = react_1.useState();
    const timerRef = react_1.useRef();
    react_1.useEffect(() => {
        if (!endTime && timeInMilliseconds > 0) {
            setEndTime(_getEndTime());
            setTimer(timeInMilliseconds);
        }
    }, [timeInMilliseconds]);
    react_1.useEffect(() => {
        function tick() {
            const now = new Date().getTime();
            const diff = endTime - now;
            if (diff <= 0) {
                clearInterval(timerRef.current);
                options?.onTimerEnd && options.onTimerEnd();
                setTimer(0);
            }
            else {
                setTimer(diff);
            }
        }
        if (timer > 0) {
            timerRef.current = setInterval(tick, 1000);
            return () => clearInterval(timerRef.current);
        }
        return () => { };
    }, [timer]);
    function reset() {
        clearInterval(timerRef.current);
        setEndTime(_getEndTime());
        setTimer(timeInMilliseconds);
    }
    function _getEndTime() {
        return new Date().setTime(new Date().getTime() + timeInMilliseconds);
    }
    return { timer, reset };
};
exports.useBackgroundTimer = useBackgroundTimer;