This script exports greytHR holidays in iCal format, Used for syncing holidays to calendars - Apple, Google, Outlook, etc.

greytHR-export-holiday-to-ical-sync.js

/* 
    Author: Rudra Roy
    Description: 
    This script exports greytHR holidays in iCal format. 
    Used for syncing holidays to calendars - Apple, Google, Outlook, etc.
 */

// Constants for customizing holiday Reason
const prefix = 'Holiday: '
const optPostFix = ' (Optional)'

// Constants for greytHR holiday calendar - Needs update if greytHR changes their UI
const GHRConst = {
    month: '.month-container',
    title: '.month-title',
    holiday: '.month-holiday-list-item',
    optIdentifier: 'Apply'
}

// Function to format date in iCal format
function formatDateForICal(date) {
    const year = date.getFullYear();
    const month = String(date.getMonth() + 1).padStart(2, '0');
    const day = String(date.getDate()).padStart(2, '0');
    return `${year}${month}${day}`;
}

// Function to generate iCal content
function generateICalContent(holidays) {
    let c = 'BEGIN:VCALENDAR\n';
    c += 'VERSION:2.0\n';
    c += 'PRODID:-//Greythr//Holiday Calendar//EN\n';
    holidays.forEach(holiday => {
        let icalDate = formatDateForICal(holiday.date)
        c += 'BEGIN:VEVENT\n';
        c += `UID:${icalDate}@greythr.com\n`;
        c += `DTSTAMP:${icalDate}\n`;
        c += `DTSTART;VALUE=DATE:${icalDate}\nDTEND;VALUE=DATE:${icalDate};\n`
        c += `SUMMARY:${holiday.reason}\n`;
        c += `DESCRIPTION:${holiday.reason}\n`;
        c += 'END:VEVENT\n';
    });
    c += 'END:VCALENDAR\n';
    return c;
}

// Function to download iCal file
function downloadICalFile(content, filename) {
    const blob = new Blob([content], { type: 'text/calendar' });
    const link = document.createElement('a');
    link.href = window.URL.createObjectURL(blob);
    link.setAttribute('download', filename);
    link.click();
}

// Function to parse greythr holiday calendar
function parseGreythrHolidays(reasonPrefix = prefix){
    let year_holidays = []
    let monthDivs = document.querySelectorAll(GHRConst.month)
    monthDivs.forEach(month => {
        let monthYear = month.querySelector(GHRConst.title).textContent
        let holidays = month.querySelectorAll(GHRConst.holiday)
        holidays.forEach(holiday => {
            let details = holiday.textContent
            let splitDetails = details.trim().split(/\s+/)
            let day = splitDetails[0]
            let optional = false
            if(splitDetails[splitDetails.length-1] === GHRConst.optIdentifier){
                optional = true
                splitDetails = splitDetails.slice(0, splitDetails.length-1)
            }
            let reason = reasonPrefix + splitDetails.slice(2).join(' ')
            if(optional) reason += optPostFix
            const date = new Date(day + " " + monthYear)
            year_holidays.push({date,reason})
        })
    })
    return year_holidays
}

// Driver to download greythr holidays iCal
const holidays = parseGreythrHolidays(prefix)
const ical = generateICalContent(holidays);
downloadICalFile(ical, 'greytHRHolidays.ics');