Bring Real Time Collaboration to ActionText

rubyonrails-talk
1

Hi,

So it’s almost 2021 and there still nothing magic out of the box to add Real Time Collaboration to a Rails stack.

But as far as i know, we almost have everything to make it happen:

  • ActionCable for websockets client/server communication.
  • ActionText based on top of trix.js is using a document model,
  • OT algorithm or CRDT algorithm to solve collaboration conflicts. (Probably need to create new trix.js api’s to access operations)
  • Using a jsonb column instead storing the rendered html, we could store the solved document model for all nodes and broadcast it and restore the client document.
  • Adding multi cursor support + tooltip (to display who is editing name) to trix.js
  • ActiveStorage would be compatible since it’s just modifying the document model.

Am i missing anything ?

Does the rails team has any plan on implementing something of that nature ? That would make the world a better place and enabled collaboration for everyone.

Regards

Useful links:

GitHub - ball-hayden/ot.rb: A Ruby port of the Operational Transformation library ot.js

GitHub - Operational-Transformation/ot.js

GitHub - automerge/automerge: A JSON-like data structure (a CRDT) that can be modified concurrently by different users, and merged again automatically.

GitHub - benaubin/rails-collab: Collaborative Editing on Rails (using ProseMirror)

8 Likes
3

I’ve been following this space pretty closely for the last few years, and I have a few suggestions for anybody else that is interested:

Some general resources on realtime collaboration:

1 Like
4

I think you’ll find this thread interesting

It doesn’t have anything specific about real time collaboration but it does touch on the subject of actiontext in the long run

5

This would be an absolutely amazing addition to Rails, making building 2020+ era collaborative apps in rails a no-brainer.

I think the things needed for a true real time app are almost all there now, with the only missing pieces being CRDT/OT for text:

  • Presence (already handled, with additional PR available here that will make it more robust: https://github.com/rails/rails/pull/50039 )
  • Realtime updates of fields (handled with Turbo streams / action cable)
  • Realtime collaboration on text fields (not handled yet)

From my limited research it seems like there are two competing solutions for the latter:

  • OT (Operational Transform). This is well known, battle tested, centralized tech. It might be the best option for a rails default. It’s less performant than CRDT, and requires being online, but so does rails.
  • CRDT. This is maturing, but still kind of experimental - with Y.js leading the open source charge here as far as I can tell. It allows offline first apps and can be super performant. But: It’s also complicated, and might have some weird side effects when a client comes online a month later and does some changes that no longer make sense.

For CRDT there are bindings to the TipTap editor with Y.js, and it’s possible to set something up with a seperate node server running HocusPocus and Redis, and communicating with Rails - but as far as I can tell there are no stable, mature, ruby based implementations of either available open source. Anyone know of something?

6

Just found this ActionText integration for Tiptap in another thread here: Configurable ActionText - #12 by ParamagicDev

7

:wave: that’s me. It does support realtime collaboration, I just haven’t documented it.

There’s a few ways to do it. The most “stable” way is using HocusPocus as your Y.js server. There’s a more bleeding edge approach using Yrb-ActionCable https://github.com/y-crdt/yrb-actioncable# happy to help if anyone gets stuck.

8

So, with yrb-actioncable we don’t need hocuspocus at all, and ActionCable can be the backend?

9

Yes. Although I don’t know the stability of the ActionCable YRB gem. It’s still largely experimental as far as I know. But in small local tests it seems to work.

10

What happens if it fails? Will anyone get data loss, or will it just revert to a non collaborative editor?