initial commit

packages/backend/src/Connection.ts

@@ -0,0 +1,147 @@
+import io from 'socket.io'
+import { ValueJSON } from 'slate'
+import * as Automerge from 'automerge'
+import throttle from 'lodash/throttle'
+
+import { toSync, toJS } from '@slate-collaborative/bridge'
+
+import { getClients, defaultValue, defaultOptions } from './utils'
+import { ConnectionOptions } from './model'
+
+class Connection {
+  private io: any
+  private docSet: any
+  private connections: { [key: string]: Automerge.Connection<any> }
+  private options: ConnectionOptions
+
+  constructor(options: ConnectionOptions = defaultOptions) {
+    this.io = io(options.port, options.connectOpts)
+    this.docSet = new Automerge.DocSet()
+    this.connections = {}
+    this.options = options
+
+    this.configure()
+  }
+
+  private configure = () =>
+    this.io
+      .of(this.nspMiddleware)
+      .use(this.authMiddleware)
+      .on('connect', this.onConnect)
+
+  private appendDoc = (path: string, value: ValueJSON) => {
+    const sync = toSync(value)
+
+    const doc = Automerge.from(sync)
+
+    this.docSet.setDoc(path, doc)
+  }
+
+  private saveDoc = throttle(pathname => {
+    if (this.options.onDocumentSave) {
+      const doc = this.docSet.getDoc(pathname)
+
+      this.options.onDocumentSave(pathname, toJS(doc))
+    }
+  }, (this.options && this.options.saveTreshold) || 2000)
+
+  private nspMiddleware = async (path, query, next) => {
+    const { onDocumentLoad } = this.options
+
+    if (!this.docSet.getDoc(path)) {
+      const valueJson = onDocumentLoad
+        ? await onDocumentLoad(path)
+        : this.options.defaultValue || defaultValue
+
+      if (!valueJson) return next(null, false)
+
+      this.appendDoc(path, valueJson)
+    }
+
+    return next(null, true)
+  }
+
+  private authMiddleware = async (socket, next) => {
+    const { query } = socket.handshake
+    const { onAuthRequest } = this.options
+
+    if (onAuthRequest) {
+      const permit = await onAuthRequest(query, socket)
+
+      if (!permit)
+        return next(new Error(`Authentification error: ${socket.id}`))
+    }
+
+    return next()
+  }
+
+  private onConnect = socket => {
+    const { id, conn } = socket
+    const { name } = socket.nsp
+
+    const doc = this.docSet.getDoc(name)
+
+    const data = Automerge.save(doc)
+
+    this.connections[id] = new Automerge.Connection(this.docSet, data => {
+      socket.emit('operation', { id: conn.id, ...data })
+    })
+
+    socket.join(id, () => {
+      this.connections[id].open()
+
+      socket.emit('document', data)
+    })
+
+    socket.on('operation', this.onOperation(id, name))
+
+    socket.on('disconnect', this.onDisconnect(id, socket))
+  }
+
+  private onOperation = (id, name) => data => {
+    try {
+      this.connections[id].receiveMsg(data)
+
+      this.saveDoc(name)
+    } catch (e) {
+      console.log(e)
+    }
+  }
+
+  private onDisconnect = (id, socket) => () => {
+    this.connections[id].close()
+    delete this.connections[id]
+
+    socket.leave(id)
+
+    this.garbageNsp()
+  }
+
+  garbageNsp = () => {
+    Object.keys(this.io.nsps)
+      .filter(n => n !== '/')
+      .forEach(nsp => {
+        getClients(this.io, nsp).then((clientsList: any[]) => {
+          if (!clientsList.length) this.removeDoc(nsp)
+        })
+      })
+  }
+
+  removeDoc = async nsp => {
+    const doc = this.docSet.getDoc(nsp)
+
+    if (this.options.onDocumentSave) {
+      await this.options.onDocumentSave(nsp, toJS(doc))
+    }
+
+    this.docSet.removeDoc(nsp)
+
+    delete this.io.nsps[nsp]
+  }
+
+  destroy = async () => {
+    this.io.close()
+  }
+}
+
+export default Connection

packages/backend/src/index.ts

@@ -0,0 +1,3 @@
+import Connection from './Connection'
+
+module.exports = Connection

packages/backend/src/model.ts

@@ -0,0 +1,17 @@
+import { ValueJSON } from 'slate'
+
+export interface ConnectionOptions {
+  port: number
+  connectOpts?: SocketIO.ServerOptions
+  defaultValue?: ValueJSON
+  saveTreshold?: number
+  onAuthRequest?: (
+    query: Object,
+    socket?: SocketIO.Socket
+  ) => Promise<boolean> | boolean
+  onDocumentLoad?: (
+    pathname: string,
+    query?: Object
+  ) => ValueJSON | null | false | undefined
+  onDocumentSave?: (pathname: string, json: ValueJSON) => Promise<void> | void
+}

packages/backend/src/utils/defaultValue.ts

@@ -0,0 +1,21 @@
+import { ValueJSON } from 'slate'
+
+const json: ValueJSON = {
+  document: {
+    nodes: [
+      {
+        object: 'block',
+        type: 'paragraph',
+        nodes: [
+          {
+            object: 'text',
+            marks: [],
+            text: ''
+          }
+        ]
+      }
+    ]
+  }
+}
+
+export default json

packages/backend/src/utils/index.ts

@@ -0,0 +1,13 @@
+import defaultValue from './defaultValue'
+
+export const getClients = (io, nsp) =>
+  new Promise((r, j) => {
+    io.of(nsp).clients((e, c) => (e ? j(e) : r(c)))
+  })
+
+export const defaultOptions = {
+  port: 9000,
+  saveTreshold: 2000
+}
+
+export { defaultValue }