Fixes #13

Changes

• Uses qrcode-generator crate.
• Cross-service (local/shuttle) router creation, to avoid updates in two places.
• Moved calendar generation to new file cal.rs to allow reuse between qr generation and normal function.
• Fixed clippy complaining about a match which could have been an if let.

Design

Decisions

• Exports images as PNG for better compatibility (HTML image embedding didn't work with SVG), plus smaller file sizes (<2KB, compared to ~200KB for SVG).
• QR generation is handled by a new endpoint /qr, for continued ease of use with curl etc., plus this allows people to share links to images rather than the image itself if desired.
• QR contains embedded calendar event, rather than a link back to the app to generate the event.
• QR code has medium ECC - not personally sure if this is correct, we could go lower for smaller codes.

UI/UX

QR code is tucked beneath the link to the calendar invite:

QR code directly produces a calendar event on both Android and iOS: Android | iOS -----------|------- |

Hi! I really liked this project and found it inspiring to make a clone in Typescript on Deno Deploy. If you are curious you can see it here - https://kiwical.deno.dev/ Thank you for the inspiration!

Setting duration to "dog" (or any other unparseable value) responds with a 500 error.

I was just noticing this when reading the blog article and thinking about how rust doesn't necessarily protect from logic edge cases :smile:

Use case: as a meeting organizer, i want to quickly create an event on my phone, then share that meeting with my friends though a QR code on my phone

QR code would either be the link to the event or the link to the calendar file

I'm not a designer. Can anyone create a beautiful design for zerocal? 🎨 The entire HTML and CSS is in this file: https://github.com/mre/zerocal/blob/main/static/index.html.

Seems that the browser's local timezone is used (without inspecting code)

I would like a way to set to use my timezone by default, or manually select one from a dropdown list ala google:

Even just manually setting the offset from UTC would be ok too as an MVP.

URLs are truncated for anything including a # MRE:

curl -LG https://zerocal.shuttleapp.rs/ -d title=matrix -d location="https://matrix.to/#/#a-channel:matrix.org"

BEGIN:VCALENDAR
VERSION:2.0
PRODID:ICALENDAR-RS
CALSCALE:GREGORIAN
BEGIN:VEVENT
DTSTAMP:20221010T153700Z
DESCRIPTION:Powered by zerocal.shuttleapp.rs
DTEND:20221010T163700Z
DTSTART:20221010T153700Z
LOCATION:https://matrix.to/
SUMMARY:matrix
UID:0d85aec2-c585-44e5-a80e-c9464e9c5572
END:VEVENT
END:VCALENDAR

Perhaps a # to %23 conversion could fix this? Was needed on twitter for these links as an example to be valid and work a while ago (now patched).

Emoji work fine if downloaded from the gui, but no output on the CLI if used. MRE:

# fails
curl -LG https://zerocal.shuttleapp.rs/ -d title=Valid -d desc=🍺+to+catch+up!
# works
curl -LG https://zerocal.shuttleapp.rs/ -d title=Valid -d desc=beers+to+catch+up!

When a recipient clicks the link, it would be nice if they got a HTML page first. The page could contain links to download as ical, add to Google Calendar etc.