y-codemirror

CodeMirror Binding for Yjs - Demo

This binding binds a Y.Text to a CodeMirror editor.

Features

• Sync CodeMirror editor
• Shared Cursors
• Shared Undo / Redo (each client has its own undo-/redo-history)
• Successfully recovers when concurrents edit result in an invalid document schema

Example

import * as Y from 'yjs'
import { CodemirrorBinding } from 'y-codemirror'
import { WebrtcProvider } from 'y-webrtc'
import CodeMirror from 'codemirror'

const ydoc = new Y.Doc()
const provider = new WebrtcProvider('codemirror-demo-room', ydoc)
const yText = ydoc.getText('codemirror')
const yUndoManager = new Y.UndoManager(yText)

const editor = CodeMirror(editorDiv, {
  mode: 'javascript',
  lineNumbers: true
})

const binding = new CodemirrorBinding(yText, editor, provider.awareness, { yUndoManager })

Also look here for a working example.

API

const binding = new CodemirrorBinding(yText: Y.Text, editor: CodeMirror.Editor, [ awareness: y-protocols.Awareness|null, [ { yUndoManager: Y.UndoManager } ]])

Binds a Y.Text type to the CodeMirror document that is currently in use. You can swapDoc the CodeMirror document while a binding is active. Make sure to destroy a binding when it is no longer needed.

When Y.UndoManager is defined, y-codemirror will use a custom collaborative undo manager instead of CodeMirror's UndoManager. The collaboration-aware Y.UndoManager tracks only local changes by default and doesn't track changes from remote users. You should undo/redo changes using yUndoManager.undo() / yUndoManager.redo() instead of using CodeMirror's history manager. See the extensive documentation on Y.UndoManager for documentation on how to filter specific changes.

The shared cursors depend on the Awareness instance that is exported by most providers. The Awareness protocol handles non-permanent data like the number of users, their user names, their cursor location, and their colors. You can change the name and color of the user like this:

example.binding.awareness.setLocalStateField('user', { color: '#008833', name: 'My real name' })

In order to render cursor information you need to embed custom CSS for the user icon. This is a template that you can use for styling cursor information.

.remote-caret {
  position: absolute;
  border-left: black;
  border-left-style: solid;
  border-left-width: 2px;
  height: 1em;
}
.remote-caret > div {
  position: relative;
  top: -1.05em;
  font-size: 13px;
  background-color: rgb(250, 129, 0);
  font-family: serif;
  font-style: normal;
  font-weight: normal;
  line-height: normal;
  user-select: none;
  color: white;
  padding-left: 2px;
  padding-right: 2px;
  z-index: 3;
}

License

The MIT License © Kevin Jahns