are there certain benefits to having individual crdts versus a single one to encapsulate all document changes?
@alidlo
Immutability is a unique feature of Automerge. They create a view on the data and present it to the user. I specifically designed Yjs to be mutable, because manipulations on large lists (e.g. lists of text clusters) are more performant on a mutable data structure. These benchmarks certainly prove my point: https://github.com/dmonad/crdt-benchmarks
Yjs just implements a single list CRDT. A Y.Map is just a mapping from key to a list, where the last item in the list denotes the current value (other values are automatically deleted). I'm pretty sure that Automerge uses two distinct CRDTs (one for list-like objects like Text and Array, and one for key-value stores).
Yjs does history tracking very well (although Automerge's history tracking functionality is currently much easier to use). https://yjs.dev/ shows that you can make snapshots and see an old document state. You can even compute the differences between to states and highlight them by the user who created them. I don't think that you can do that in Automerge. Lots of thought has been put into history tracking (I mostly refer to it as snapshots). But the Yjs shared types don't expose convenient functionality to view past state.
I tried looking at the simple-peer docs on this as they have a way of doing it with their API but i was unable to find the "Peer" object of type simple-peer within WebrtcProvider
hey good afternoon,
this code it is in utils.js to YJS-13
if (typeof persistenceDir === 'string') {
// @ts-ignore
const LevelDbPersistence = require('y-leveldb').LevelDbPersistence
persistence = new LevelDbPersistence(persistenceDir)
}
Is there a level-db for version 13?
or any library to make persistent?
provider.awareness.states.size === 1?) then reset the room and apply the document from this client (doc.getText('roomID').insert(0, content)?). What i cannot seem to figure out is how to clean out the server rooms document. Anyone might have a pointer for that ?
Has anyone used y-prosemirror with document layouts / schemas, for example enforcing a title node at the top by having content: "title block+"?
I'm running into an issue with loading a prosemirror document that has been serialized as a state update. Specifically, with a RangeError: position xx out of range coming from the yjs prosemirror sync plugin. It occurs on line 310 trying to apply fragmentContent to the prosemirrorViewstate.
The issue occurs because, when initializing an editor with an enforced schema, the length of ydoc.getXmlFragment("prosemirror") goes from 0 to 2 for the title and paragraph node, and then 2 to 4 when Y.applyUpdate(ydoc, ystate) is called with ystate loaded from disk.
So the flow is: new Y.Doc(), editor is initialized => the ydoc gets two nodes from that => applyupdate is applied and gives two more nodes from previous session. Ideally, yjs would recognize that these two nodes (title, paragraph) are identical; but im not sure why this doesn't occur. Maybe because its the editor thats creating them not a user?
I think I found the underlying problem; it's within the sync-plugin on line 145. (Link to Github here).
update: () => {
const pluginState = plugin.getState(view.state)
if (pluginState.snapshot == null && pluginState.prevSnapshot == null) {
if (changedInitialContent || view.state.doc.content.size > 2) {
changedInitialContent = true
binding._prosemirrorChanged(view.state.doc)
}
}
},The issue is, when the default schema for an empty document results in a document with content size greater than 2, it will call binding._prosemirrorChanged(view.state.doc)even though changedInitialContent is false. I believe this is because the default prosemirror empty document is just a paragraph, which has size 2. However, a title + a paragraph has size 4.
Are new edits supposed to be appended to the end of the Uint8Array that comes from serializing the ydoc as an update, i.e. the first elements stay the same? Or is that not the case, that new edits can change the existing Uint8 Array anywhere?
I'm printing the Uint8Array after each edit, and I'm noticing most of the elements in the front of the array stay the same. Mostly wondering if the git diff3 algorithm for merge can pick up on this, and auto merge different serialized Uint8Arrays.
Y.encodeStateAsUpdate, yes an update can change other elements. Two document updates Insert(0, "a") • Insert(1, "b")are merged into a single document update Insert(0, "ab"). But what you are trying to do is not impossible. You can simply store all document updates in any order (preferably in the order that they are created). Just listen to the ydoc.on('update', incrementalUpdate => {}) event and get the incremental updates. In order to restore the document state you do Y.applyUpdate(ydoc, update) on all incremental updates. You'd loose a bit of the optimizations of update encoding (e.g. that updates are merged). But that should be fine. However, do not attempt to do diffs on the Uint8Array. That would destroy the integrity of the document update.
I'm using this
bower install --save yjs y-text y-memory y-webrtc y-websockets-client y-array to install but I'm getting this response and none of the options I've chosen have worked:Unable to find a suitable version for yjs, please choose one by typing one of the numbers below:
1) yjs#^9.0.0 || ^10.0.0 || ^11.0.0 || ^12.0.0 which resolved to 12.3.3 and is required by y-memory#8.0.9
2) yjs#>= 12.3.1 < 13.0.0 which resolved to 12.3.3 and is required by y-array#10.1.4
3) yjs#^12.0.0 which resolved to 12.3.3 and is required by y-text#9.5.1
4) yjs#^11.0.0 || ^12.0.0 which resolved to 12.3.3 and is required by y-websockets-client#8.0.16
5) yjs#^13.0.4 which resolved to 13.0.4 and is required by includes
6) yjs#^13.0.4 which resolved to 13.0.4
Hey @markgarbers! I guess that you read the tutorial on y-js.org ? The current documentation is here https://github.com/yjs/yjs and the current website is here https://yjs.dev . The old domain is not owned by me and it still links to the version 12 of Yjs. @istvank is working on linking the old domain to https://github.com/yjs/yjs so we don't have this issue anymore.
You can install compatible versions like this bower install --save yjs@12 y-text y-memory y-webrtc@9 y-websockets-client y-array or use the current version. I propose that you use the current version and start with an example from here https://github.com/yjs/yjs-demos .
@markgarbers There is no abstract connector anymore. You can read up on the simplified update mechanism here https://github.com/yjs/yjs#Document-Updates.
If you also want to implement the Awarenesss protocol, you should have a look at y-protocols, which provides convenient functions to design a communication protocol on your own. https://github.com/yjs/y-protocols
Me again! Thanks for all your help on this... the more I use Yjs the more amazing I find it!
This time my question is regarding the undoManager. I'm editing a doc from 2 browsers and merging updates as they come in... however, the undoManager only undoes the changes made by a particular user (i.e. it doesn't undo changes that came from the remote user). Any thoughts on how to effectively have a unified undo/redo stack?
Hows it going,
I'm wondering how I keep data separate? Currently when I have multiple WebsocketProvider instances in my app, they all receive the same data, even though they have different yDoc instances and shared data field names.
I also specify different rooms, but this doesnt seem to have any effect either. When I look in the source code, roomname that is passed to the provider does not even seem to be used.