How to create new sendable versions/commits

[etclub]

I get lost with the doc.
After sendableCommit(state), the client should mark the current state "saved",
so that the next sendableCommit(state) would generate commits based on the saved one, right?

But it is not mentioned in the doc.

[ProTip]

Hi @etclub ,

sendableCommit(state) will keep returning the same commit until the plugin has received confirmation from the authority.

This is covered in the README under Client Receive Commit which handles the broadcast from the last step under Authority Map Commit. The behavior and procedure is very similar to the official prosemirror-collab plugin.

[ProTip]

So, after a user hit a button and sendableCommit(state), no matter what changes afterwords, those changes are not commitable before it receives and applies Authority Map Commit, right?

Correct. Once an "in-flight" commit is created it must be processed by the authority and the confirmation received by the plugin before another commit can be created from local steps.

Further, just like with prosemirror-collab the plugin must receive the commits in order from the authority; it will ignore old and future commit versions. I use code that buffers commits from the authority and then applies them in order until a version gap is reached or the buffer is emptied.

here should it be newCommitJson.version?

Yes, it should be newCommitJson.version.

[etclub]

Well, I did not use prosemirror-collab before. Forgive me if I asked stupid questions.

I have two more questions:

1. In theory, the server has to keep all the commit history to make getDocumentCommitsSince work, in case someone loads a very old version and commits after a very long time, right?

const newCommits = await getDocumentCommitsSince(newCommitJson.version) // TODO: Implement

I don't know how many commit steps for a regular document, so I am not sure if this brings a storage burden for the server.

2. After

const {docJson, commitJson} = applyCommitJSON(version, schema, doc, newCommits, newCommitJson)

a client receives the right commitJson, and rebases to the latest version.
How comes "old and future commit versions"?

[ProTip]

Sorry for the late responses; I'm overseas through the end of this month.

Well, I did not use prosemirror-collab before. Forgive me if I asked stupid questions

No worries; I just reference it as this plugin is built on the bones of prosemirrelor-collab and anticipates familiarity with it.

1.

Yes, but only for as far back as the oldest commit base version you want to accept. It would be unusual in my experience to accept very old commits, and then storage requirements are suprisingly modest for even 60k steps with something like postgres jsonb since it effectively deduplicates keys.

You could downres commits after a week or month(or whatever makes sense) if the storage becomes a major concern in the future.

2.

If the plugin state is on confirmed version 5 it will ignore commits from the authority that are not version 6(expected next version);

prosemirror-collab-commit/src/collab-commit.ts

Line 229 in 33a6e55

if (nextVersion != commit.version) return tr

This is to protect against applying out-of-order commits.

[etclub]

Sorry to interrupt you again.
But I still cannot create new sendable commits.

The client inputs "A" in the editor, and sends sendableCommit(state) to the server, something like:

 {
  version: 0,
  ref: '7x1n5dshnuvr',
  steps: [ { stepType: 'replace', from: 1, to: 1, slice: [Object] } ]
}

The server gets commitJSON (returned from applyCommitJSON), something like:

{
  version: 1,
  ref: '7x1n5dshnuvr',
  steps: [ { stepType: 'replace', from: 1, to: 1, slice: [Object] } ]
}

and take it as a response to the client.

The client deals with the response:

const commitJson = await response.json();
const commit = Commit.FromJSON(state.schema, commitJson)
const tr = receiveCommitTransaction(state, commit)
state = state.apply(tr)                           // I also tried    dispatch(tr)       , but it does not help 

Now no matter what edits the client makes,
calling sendableCommit(state) still generates

{
  version: 0,
  ref: '7x1n5dshnuvr',
  steps: [ { stepType: 'replace', from: 1, to: 1, slice: [Object] } ]
}

which means the first commit is not confirmed, but I cannot see what is wrong.

[etclub]

I solved the problem.
I have to use the current state of the editor.