icalendar.js

Modern module to parse and stringify iCalendar to Javascript.

Features of iCalendar.js:

• Parse an ICalendar object from a BufferArray
• Serialize to RFC 5545 ICS format from an ICalendar object
• Deserialize from RFC 5545 ICS format to an ICalendar object
• Convert from an ICalendar object to JSON
• Convert from JSON to an ICalendar object
• Provides an API to filter components of an ICalendar object

Installing

Using npm:

$ npm add icalendar.js

On Deno

import { ICalendar } from "npm:icalendar.js";

Example

import { ICalendar } from "icalendar.js";

const res = await fetch("https:source/....ics");
const payload = await res.arrayBuffer();
const icalendar = ICalendar.from(payload);

icalendar.filterComponentsByRange(Date.UTC(2023, 2, 10), Date.UTC(2023, 2, 15));

Create a new ICalendar object and write a ICS file.

import { ICalendar, VComponent, PropertyValue } from "icalendar.js";
import * as propertyTypes from "icalendar.js/property_types";

const calendar = ICalendar.create();
const event = new VComponent("VEVENT");

calendar.components.add(event);

event.properties.set(
    "SUMMARY",
    new PropertyValue(new propertyTypes.Text(`text`))
);
event.properties.set(
    "DTSTART",
    new PropertyValue(
        new propertyTypes.Date({
            fullYear: 2023,
            month: 3,
            monthDay: 12,
        })
    )
);
event.properties.set(
    "DTEND",
    new PropertyValue(
        new propertyTypes.Date({
            fullYear: 2023,
            month: 3,
            monthDay: 13,
        })
    )
);

fs.writeFile("myfile.ics", iCalendar.toICS());

Serialize and Deserialize iCalendar Objects to JSON

To serialize an ICalendar object to JSON, you can use the JSON.stringify(icalendar) method. This will convert the ICalendar object into a JSON string, which can be stored or sent over a network.

To deserialize an ICalendar object from a JSON string, you can first use the JSON.parse(payload) method to convert the JSON string into a JavaScript object. Then, you can create a new ICalendar object from the JavaScript object using the static ICalendar.fromJSON(object) method.

This way, iCalendar.js enables bidirectional conversion between ICalendar objects and JSON, which can be useful for storage, transfer, and manipulation of data.

Parse ICS File

Sample Load:

import { ICalendar } from "icalendar.js";

const location = new URL("sample.ics", import.meta.url);
const payload = await readFile(location);
const icalendar = ICalendar.from(payload);
// =>
// ICalendar
//   kind: 'VCALENDAR',
//   properties: Map(9) {
//     'VERSION' => PropertyValue { value: '2.0', parameters: Map(0) {} },
//     'PRODID' => PropertyValue {
//       value: '-//Office Holidays Ltd.//EN',
//       parameters: Map(0) {}
//     },
//     'X-WR-CALNAME' => PropertyValue {
//       value: 'International Holidays',
//       parameters: Map(0) {}
//     },
//     'X-WR-CALDESC' => PropertyValue {
//       value: 'Public Holidays in International. Provided by http://www.officeholidays.com',
//       parameters: Map(0) {}
//     },
//     'REFRESH-INTERVAL' => PropertyValue {
//       value: 'PT48H',
//       parameters: Map(1) { 'VALUE' => 'DURATION' }
//     },
// ...

AST

Kind Allows:

• Module
• PropertyParameter
• PropertyParameterName
• PropertyParameterValue
• AltRepParam
• AltRepParamName
• AltRepParamValue

Sample Parser:

const payload = new TextEncoder().encode(
    "" +
        `DESCRIPTION;ALTREP="http://www.wiz.org":The Fall'98 Wild Wizards\n` +
        ` Conference - - Las Vegas, NV, USA\n`
);
const tokens = Lexer.from(payload);
const ast = AST.from(tokens);
// =>
// {
//   kind: 'Module',
//   span: { start: 0, end: 100 },
//   nodes: [
//     {
//       kind: 'PropertyParameter',
//       span: { start: 0, end: 99 },
//       name: {
//         kind: 'PropertyParameterName',
//         span: { start: 0, end: 11 },
//         value: 'DESCRIPTION'
//       },
//       value: {
//         kind: 'PropertyParameterValue',
//         span: { start: 40, end: 99 },
//         value: "The Fall'98 Wild Wizards Conference - - Las Vegas, NV, USA"
//       },
//       altRepNodes: [
//         {
//           kind: 'AltRepParam',
// ...

Lexer

Token allows:

• colon
• equal
• keyword
• newline
• semicolon
• string
• string_multiline

Sample tokenizer:

import { Lexer } from "icalendar.js/lexer";

const payload = new TextEncoder().encode(
    "" +
        `DESCRIPTION;ALTREP="http://www.wiz.org":The Fall'98 Wild Wizards\n` +
        ` Conference - - Las Vegas, NV, USA\n`
);

const tokens = Lexer.from(payload);
// =>
// [
//   {
//     kind: 'keyword',
//     span: { start: 0, end: 11 },
//     raw: Uint8Array(11) [
//       68, 69, 83, 67, 82,
//       73, 80, 84, 73, 79,
//       78
//     ],
//     value: 'DESCRIPTION'
//   },
//   {
//     kind: 'semicolon',
//     span: { start: 11, end: 12 },
//     raw: Uint8Array(1) [ 59 ]
//   },
//   {
//     kind: 'keyword',
//     span: { start: 12, end: 18 },
//     raw: Uint8Array(6) [ 65, 76, 84, 82, 69, 80 ],
//     value: 'ALTREP'
//   },
// ...

Look this full sample