ICS Calendar Export Plugin

Published by Jordan October 20, 2023
Last changed 7 months ago
views
name	ICS Calendar Export
description	Export the scheduled tasks in a specific task domain to an ICS file that can be imported in various calendar apps and services.
{
  async appOption(app) {
    const taskDomains = await app.getTaskDomains();
 
    const taskDomainUUID = await app.prompt("Select a task domain", {
      inputs: [
        {
          options: taskDomains.map(taskDomain => ({
            label: taskDomain.name,
            value: taskDomain.uuid,
          })),
          type: "select",
        }
      ]
    });
    if (!taskDomainUUID) return;
 
    const now = Math.floor(Date.now() / 1000);
 
    const lines = [
      "BEGIN:VCALENDAR",
      "VERSION:2.0",
      "PRODID:-//Amplenote//CalDAV Client//EN",
    ];
 
    for await (const task of app.getTaskDomainTasks(taskDomainUUID)) {
      if (!task.startAt) continue;
 
      lines.push("BEGIN:VEVENT");
      lines.push(`DTSTART:${ this._formatDateTime(new Date(task.startAt * 1000)) }`);
 
      const endAt = task.endAt || (task.startAt + 15 * 60);
      lines.push(`DTEND:${ this._formatDateTime(new Date(endAt * 1000)) }`);
 
      if (task.repeat) {
        const [ _dtstart, rrule ] = task.repeat.split("\n");
        if (rrule.startsWith("RRULE:")) lines.push(rrule);
      }
 
      lines.push(`UID:${ task.uuid }`);
 
      // All these are attempts to get external calendars to update the instance if the user re-imports an
      // updated ics, however as of 10/2023 this is still not sufficient to get Apple Calendar to update an
      // event.
      lines.push("METHOD:REQUEST");
      lines.push(`SEQUENCE:${ now }`);
      lines.push("ORGANIZER:Amplenote");
 
      lines.push(`SUMMARY:${ this._escapeICalValue(task.content) }`);
      lines.push(`URL;VALUE=URI:${ this._escapeICalValue("https://www.amplenote.com/notes/" + task.noteUUID) }`);
      lines.push("END:VEVENT");
    }
 
    lines.push("END:VCALENDAR");
 
    const ical = this._foldICalLines(lines);
 
    const file = new Blob([ ical ], { type: "text/calendar" });
    await app.saveFile(file, "tasks.ics");
  },
 
  // --------------------------------------------------------------------------
  // Based on https://github.com/sebbo2002/ical-generator/blob/develop/src/tools.ts#L117
  _escapeICalValue(value) {
    return value.replace(/[\\;,]/g, match => `\\${ match }`).replace(/(?:\r\n|\r|\n)/g, '\\n');
  },
 
  // --------------------------------------------------------------------------
  // From https://github.com/sebbo2002/ical-generator/blob/develop/src/tools.ts#L126
  _foldICalLines(lines) {
    return lines.map(function(line) {
      let result = '';
      let c = 0;
      for (let i = 0; i < line.length; i++) {
        let ch = line.charAt(i);
 
        // surrogate pair, see https://mathiasbynens.be/notes/javascript-encoding#surrogate-pairs
        if (ch >= '\ud800' && ch <= '\udbff') {
          ch += line.charAt(++i);
        }
 
        // TextEncoder is available in browsers and node.js >= 11.0.0
        const charsize = new TextEncoder().encode(ch).length;
        c += charsize;
        if (c > 74) {
          result += '\r\n ';
          c = charsize;
        }
 
        result += ch;
      }
      return result;
    }).join('\r\n');
  },
 
  // --------------------------------------------------------------------------
  _formatDateTime(date) {
    const year = date.getUTCFullYear();
    const month = this._pad(date.getUTCMonth() + 1);
    const day = this._pad(date.getUTCDate());
    const hour = this._pad(date.getUTCHours());
    const minute = this._pad(date.getUTCMinutes());
    const second = this._pad(date.getUTCSeconds());
    return `${ year }${ month }${ day }T${ hour }${ minute }${ second }Z`;
  },
 
  // --------------------------------------------------------------------------
  _pad(i) {
    return i < 10 ? `0${i}` : `${i}`;
  },
} 