alt Hacker NewsAre there any major libraries for OT? I've been looking into this recently for a project at work, and OT would be completely sufficient for our use case, and does look simpler overall, but from what I could tell, we'd need to write a lot of stuff ourselves. The only vaguely active-looking project in JS at least seems to be DocNode (https://www.docukit.dev/docnode), and that looks very cool but also very early days.
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Author of DocNode here. Yes, it’s still early days. But it’s a very robust library that I don’t expect will go through many breaking changes. It has been developed privately for over 2 years and has 100% test coverage. Additionally, each test uses a wrapper to validate things like operation reversibility, consistency across different replicas, etc.
DocSync, which is the sync engine mainly designed with DocNode in mind, I would say is a bit less mature.
I’d love it if you could take a look and see if there’s anything that doesn’t convince you. I’ll be happy to answer any questions.
Author here. I think it depends what you're doing! OT is a true distributed systems algorithm and to my knowledge there are no projects that implement true, distributed OT with strong support for modern rich text editor SDKs like ProseMirror. ShareJS, for example, is abandoned, and predates most modern editors.
If you are using a centralized server and ProseMirror, there are several OT and pseudo-OT implementations. Most popularly, there is prosemirror-collab[4], which is basically "OT without the stuff you don't need with an authoritative source for documents." Practically speaking that means "OT without T", but because it does not transform the ops to be order-independent, it has an extra step on conflict where the user has to rebase changes and re-submit. This is can cause minor edit starvation of less-connected clients. prosemirror-collab-commit[5] fixes this by performing the rebasing on the server... so it's still "OT without the T", but also with an authoritative conflict resolution pseudo-T at the end. I personally recommend prosemirror-collab-commit, it's what we use, and it's extremely fast and predictable.
If you just want something pedogocically helpful, the blessed upstream collaborative editing solution for CodeMirror is OT. See author's blog post[1], the @codemirror/collab package[2], and the live demo[3]. In general this implementation is quite good and worth reading if you are interested in this kind of thing. ShareJS and OTTypes are both very readable and very good, although we found them very challenging to adopt in a real-world ProseMirror-based editor.
[1]: https://marijnhaverbeke.nl/blog/collaborative-editing-cm.htm...
[2]: https://codemirror.net/docs/ref/#collab
[3]: https://codemirror.net/examples/collab/
[4]: https://github.com/ProseMirror/prosemirror-collab
[5]: https://github.com/stepwisehq/prosemirror-collab-commit