ICS Watcher

A Rust library that watches ICS calendar files. You give ICS Watcher a URL pointing to an .ics calendar file and it will poll for changes at regular intervals. When changes are detected, your callback functions get called with details about what changed.

Examples

• Log all events: pass log_events as one of the callbacks
• TUM to Google Calendar Proxy: pass tum_google_sync as one of the callbacks
  • This is already implemented in main.rs which means, you can create a .env with your TUM_URL and GOOGLE_CALENDAR_ID, put your Google Calendar API client secret in .secrets/client_secret.json and start syncing :)
  • Unlike https://github.com/TUM-Dev/CalendarProxy/, events in this implementation can be modified (which is the main reason for creating this crate)
• TUM to Apple Calendar Proxy: pass tum_apple_sync as one of the callbacks
  • Behaves just like the Google sync, but talks CalDAV to iCloud instead
  • Also implemented in main.rs: add APPLE_ID, APPLE_APP_PASSWORD and APPLE_CALENDAR_NAME (the name of the calendar as shown in the Apple Calendar app) to your .env and start syncing
    • APPLE_APP_PASSWORD has to be an app-specific password, your regular Apple ID password won't be accepted
    • If you'd rather skip the calendar discovery, set APPLE_CALENDAR_URL to the CalDAV collection instead of APPLE_CALENDAR_NAME
    • Not sure how your calendar is named? list_icloud_calendars returns all of them
  • Want your exams in a color of their own? Apple Calendar only colors whole calendars, not single events - set APPLE_EXAM_CALENDAR_NAME (or APPLE_EXAM_CALENDAR_URL) and exams (events with "Prüfung" in their title) go into that calendar instead
    • ics-watcher sort-exams moves the exams that are in the main calendar already - it only shows what it would move, until you run it with --apply
    • Events stay in whichever calendar they are, so you can still move them around by hand
  • GOOGLE_CALENDAR_ID and the Apple variables are independent - configure one of them or both to sync to both calendars at once
  • AppleCalendar::connect_to works with any other CalDAV server (Fastmail, Nextcloud, Radicale, …) as well

Moving from Google Calendar to Apple Calendar

Has the Google sync been running for a while? ics-watcher migrate copies that calendar over to the Apple Calendar, so that the Apple sync can take over:

• Events created by the Google sync keep their uid, so the Apple sync picks up right where the Google sync left off
• Whatever you changed in Google Calendar comes along (notes, a seat number in the location, reminders, colors), and events you deleted there stay deleted
• Events you added to the calendar yourself are copied as well, recurring ones included
• Nothing is deleted, neither in Google nor in the Apple Calendar, and events that are in the Apple Calendar already are skipped

Configure both calendars in the .env, stop the watcher and run the migration in the watcher's folder (it needs .secrets and .backups):

1. ics-watcher migrate shows what would happen without writing anything - --dump <folder> additionally saves every event as an .ics file to look at
2. ics-watcher migrate --apply writes to the Apple Calendar
3. With an exam calendar, ics-watcher sort-exams --apply moves the exams over into it
4. Remove GOOGLE_CALENDAR_ID from the .env and start the watcher again

TODO's

• TUM Sync
  • Refactor TUM Sync creation and deletion of events
  • Introduce reminders for exams
• Fix the examples in the docs (they work, they just don't pass the docs tests because they're async)

License

Licensed under either of:

• Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

The TUM Google / Apple Sync can also function as a summary shortener using the replacements.json. Due to licensing restrictions, I do not distribute it myself, but you can find a good replacements.json here: https://github.com/TUM-Dev/CalendarProxy.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.