Allow undoing changes when connecting, add handler for deleting fork

jupyter_collaboration/app.py

@@ -8,7 +8,7 @@
 from pycrdt_websocket.ystore import BaseYStore
 from traitlets import Bool, Float, Type
 
-from .handlers import DocForkHandler, DocMergeHandler, DocSessionHandler, YDocWebSocketHandler
+from .handlers import DocForkHandler, DocDeleteHandler, DocMergeHandler, DocSessionHandler, YDocWebSocketHandler
 from .loaders import FileLoaderMapping
 from .stores import SQLiteYStore
 from .utils import AWARENESS_EVENTS_SCHEMA_PATH, EVENTS_SCHEMA_PATH
@@ -123,6 +123,13 @@ def initialize_handlers(self):
                         "ywebsocket_server": self.ywebsocket_server,
                     }
                 ),
+                (
+                    r"/api/collaboration/delete_room",
+                    DocDeleteHandler,
+                    {
+                        "ywebsocket_server": self.ywebsocket_server,
+                    }
+                ),
             ]
         )
 

jupyter_collaboration/handlers.py

@@ -471,13 +471,53 @@ async def put(self):
         if idx in root_state:
             del root_state[idx]
         else:
+            self.set_status(404)
             raise RuntimeError(f"Could not find root document fork with ID: {fork_roomid}")
         fork_room = await self._websocket_server.get_room(fork_roomid)
         fork_ydoc = fork_room.ydoc
-        update = fork_ydoc.get_update()
-        root_ydoc.apply_update(update)
+        fork_update = fork_ydoc.get_update()
+        root_ydoc.apply_update(fork_update)
         root_room.fork_ydocs.remove(fork_ydoc)
         fork_state = fork_ydoc.get("state", type=Map)
         fork_state["merge"] = fork_roomid
         #self._websocket_server.delete_room(name=fork_roomid)
         self.set_status(200)
+
+
+class DocDeleteHandler(APIHandler):
+    """
+    Jupyter Server's handler to delete a document.
+    """
+
+    auth_resource = "contents"
+
+    def initialize(
+        self,
+        ywebsocket_server: JupyterWebsocketServer,
+    ) -> None:
+        self._websocket_server = ywebsocket_server
+
+    @web.authenticated
+    @authorized
+    async def delete(self):
+        """
+        Deletes a forked document.
+        """
+        model = self.get_json_body()
+        fork_roomid = model["fork_roomid"]
+        root_room = await self._websocket_server.get_room(model["root_roomid"])
+        root_ydoc = root_room.ydoc
+        idx = f"fork_{fork_roomid}"
+        root_state = root_ydoc.get("state", type=Map)
+        if idx in root_state:
+            del root_state[idx]
+        else:
+            self.set_status(404)
+            raise RuntimeError(f"Could not find root document fork with ID: {fork_roomid}")
+        fork_room = await self._websocket_server.get_room(fork_roomid)
+        fork_ydoc = fork_room.ydoc
+        root_room.fork_ydocs.remove(fork_ydoc)
+        fork_state = fork_ydoc.get("state", type=Map)
+        fork_state["delete"] = fork_roomid
+        #self._websocket_server.delete_room(name=fork_roomid)
+        self.set_status(200)

packages/collaboration-extension/src/collaboration.ts

@@ -28,7 +28,7 @@ import {
   EditorExtensionRegistry,
   IEditorExtensionRegistry
 } from '@jupyterlab/codemirror';
-import { requestDocMerge, WebSocketAwarenessProvider } from '@jupyter/docprovider';
+import { requestDocDelete, requestDocMerge, WebSocketAwarenessProvider } from '@jupyter/docprovider';
 import {
   SidePanel,
   usersIcon,
@@ -310,6 +310,7 @@ export class EditingModeExtension implements DocumentRegistry.IWidgetExtension<N
     reviewCommands.addCommand('discard', {
       label: 'Discard',
       execute: () => {
+        requestDocDelete(sharedModel.currentRoomId, sharedModel.rootRoomId);
       }
     });
 
@@ -322,7 +323,7 @@ export class EditingModeExtension implements DocumentRegistry.IWidgetExtension<N
       if (changes.stateChange) {
         changes.stateChange.forEach(value => {
           const forkPrefix = 'fork_';
-          if (value.name === 'merge') {
+          if (value.name === 'merge' || value.name === 'delete') {
             // FIXME: a client who is not connected to the fork should not see this update
             if (sharedModel.currentRoomId === value.newValue) {
               editingMenu.title.label = 'Editing';
@@ -331,7 +332,8 @@ export class EditingModeExtension implements DocumentRegistry.IWidgetExtension<N
               delete suggestions[value.newValue];
               suggestionMenu.removeItem(item);
               reviewMenu.clearItems();
-              sharedModel.provider.connect(sharedModel.rootRoomId);
+              const merge = value.name === 'merge';
+              sharedModel.provider.connect(sharedModel.rootRoomId, merge);
               open_dialog('Editing', this._trans);
             }
           }

packages/docprovider/src/requests.ts

@@ -13,6 +13,7 @@ import { ServerConnection, Contents } from '@jupyterlab/services';
 const DOC_SESSION_URL = 'api/collaboration/session';
 const DOC_FORK_URL = 'api/collaboration/fork_room';
 const DOC_MERGE_URL = 'api/collaboration/merge_room';
+const DOC_DELETE_URL = 'api/collaboration/delete_room';
 
 /**
  * Document session model
@@ -150,3 +151,42 @@ export async function requestDocMerge(
 
   return data;
 }
+
+
+export async function requestDocDelete(
+  forkRoomid: string,
+  rootRoomid: string,
+): Promise<any> {
+  const settings = ServerConnection.makeSettings();
+  const url = URLExt.join(
+    settings.baseUrl,
+    DOC_DELETE_URL,
+  );
+  const body = {
+    method: 'DELETE',
+    body: JSON.stringify({ fork_roomid: forkRoomid, root_roomid: rootRoomid })
+  };
+
+  let response: Response;
+  try {
+    response = await ServerConnection.makeRequest(url, body, settings);
+  } catch (error) {
+    throw new ServerConnection.NetworkError(error as Error);
+  }
+
+  let data: any = await response.text();
+
+  if (data.length > 0) {
+    try {
+      data = JSON.parse(data);
+    } catch (error) {
+      console.log('Not a JSON response body.', response);
+    }
+  }
+
+  if (!response.ok) {
+    throw new ServerConnection.ResponseError(response, data.message || data);
+  }
+
+  return data;
+}

packages/docprovider/src/yprovider.ts

@@ -96,9 +96,25 @@ export class WebSocketProvider implements IDocumentProvider {
     return forkId;
   }
 
-  connect(roomId: string) {
+  connect(roomId: string, merge?: boolean) {
     this._sharedModel.currentRoomId = roomId;
     this._yWebsocketProvider?.disconnect();
+    if (roomId === this._sharedModel.rootRoomId) {
+      // connecting to the root
+      // don't bring our changes there if not merging
+      if (merge !== true) {
+        while (this._sharedModel.undoManager.canUndo()) {
+          this._sharedModel.undoManager.undo();
+        }
+      }
+      this._sharedModel.undoManager.clear();
+    }
+    else {
+      // connecting to a fork
+      // keep track of changes so that we can undo them when connecting back to root
+      this._sharedModel.undoManager.clear();
+    }
+
     this._yWebsocketProvider = new YWebsocketProvider(
       this._serverUrl,
       roomId,

yarn.lock

@@ -2156,7 +2156,7 @@ __metadata:
 
 "@jupyter/ydoc@file:.yalc/@jupyter/ydoc::locator=%40jupyter%2Freal-time-collaboration%40workspace%3A.":
   version: 2.0.1
-  resolution: "@jupyter/ydoc@file:.yalc/@jupyter/ydoc#.yalc/@jupyter/ydoc::hash=e50509&locator=%40jupyter%2Freal-time-collaboration%40workspace%3A."
+  resolution: "@jupyter/ydoc@file:.yalc/@jupyter/ydoc#.yalc/@jupyter/ydoc::hash=045bce&locator=%40jupyter%2Freal-time-collaboration%40workspace%3A."
   dependencies:
     "@jupyterlab/application": ^4.0.0
     "@jupyterlab/nbformat": ^3.0.0 || ^4.0.0-alpha.21 || ^4.0.0
@@ -2165,7 +2165,7 @@ __metadata:
     "@lumino/signaling": ^1.10.0 || ^2.0.0
     y-protocols: ^1.0.5
     yjs: ^13.5.40
-  checksum: c54e335aebc1f0b28241fe0031d5f47513a7a90621b5cca10e6aec3a965adea96390bd8e2c51191e448a9c276ca284ff563eb4870844233798e79a03560b1648
+  checksum: aed2b93d1f9d447e7ad1be8699dc3a31968f4cfd4772a1ed1330308eb08ba8d14973df24bae4e49bd93f416f646b84edb44c567487403e7d0bdb665e6ca0e29f
   languageName: node
   linkType: hard