Monthly.js

import { useState, useEffect, useRef } from "react";
import { useHistory } from "react-router-dom";
import CalendarBtn from "../Buttons/CalendarBtn.js";
import DatePickerModal from "../Modal/DatePickerModal.js";
import moment from 'moment';
import FullCalendar from '@fullcalendar/react';
import dayGridPlugin from '@fullcalendar/daygrid';
import interactionPlugin from "@fullcalendar/interaction";
import bootstrapPlugin from '@fullcalendar/bootstrap';
import '@fortawesome/fontawesome-free/css/all.css';

const Monthly = () => {
    const [initialDate, setInitialDate] = useState(moment().format('YYYY-MM-DD'))
    const [changeDate, setChangeDate] = useState(moment().format('YYYY-MM-DD'))
    const [show, setShow] = useState(false)
    const calenIconRef = useRef(null)
    const calendarRef = useRef(null)
    let calendar = null
    const history = useHistory();

    useEffect(() => {
        if (calendarRef && calendarRef.current) {
            calendar = calendarRef.current.getApi()
        }
    })

    useEffect(() => {
        if (calenIconRef && calenIconRef.current) {
            calenIconRef.current.addEventListener('click', () => {
                calendar.today()
                let date = moment(calendar.getDate()).format('YYYY-MM-DD')
                setChangeDate(date)
            })
        }
        return () => {
            if (calenIconRef && calenIconRef.current) {
                calenIconRef.current.removeEventListener('click', () => {
                    calendar.today()
                    let date = moment(calendar.getDate()).format('YYYY-MM-DD')
                    setChangeDate(date)
                })
            }
        }
    }, [calenIconRef.current])

    useEffect(() => {
        calendar.gotoDate(changeDate)
    }, [changeDate])

    return (
        <>
            <div ref={calenIconRef} className="position-absolute" style={{ top: "9px", right: "8px" }}>
                <CalendarBtn date={moment(initialDate).format('DD')} />
            </div>
            <FullCalendar
                ref={calendarRef}
                plugins={[dayGridPlugin, interactionPlugin, bootstrapPlugin]}
                initialView="dayGridMonth"
                initialDate={initialDate}
                headerToolbar={{
                    start: 'prev',
                    center: 'myCustomButton',
                    end: 'next'
                }}
                dayHeaderContent={(date) => {
                    const weekList = ["일", "월", "화", "수", "목", "금", "토"]
                    return weekList[date.dow]
                }}
                validRange={{
                    start: moment(initialDate).subtract(3, 'years').format('YYYY-MM[-01]'),
                    end: moment(initialDate).add(3, 'years').add(1, 'months').format('YYYY-MM[-01]')
                }}
                customButtons={{
                    myCustomButton: {
                        text: moment(changeDate).format('YYYY.MM'),
                        click: () => {
                            setShow(true)
                            return <button className="btn btn-primary" type="button" data-bs-toggle="offcanvas" data-bs-target="#datePicker" aria-controls="datePicker" />
                        }
                    },
                    prev: {
                        icon: "fa-chevron-left",
                        click: () => {
                            calendar.prev()
                            let date = moment(calendar.getDate()).format('YYYY-MM-DD')
                            setChangeDate(date)
                        }
                    },
                    next: {
                        icon: "fa-chevron-right",
                        click: () => {
                            calendar.next()
                            let date = moment(calendar.getDate()).format('YYYY-MM-DD')
                            setChangeDate(date)
                        }
                    }
                }}
                dateClick={({ dateStr }) => history.push(`/schedule/${dateStr}`)}
                timeZone="local"
                themeSystem='bootstrap'
                eventLimit="true"
                height='75vh'
            />
            <DatePickerModal initialDate={initialDate} changeDate={changeDate} setChangeDate={setChangeDate} show={show} setShow={setShow} />
        </>
    )
}

export default Monthly