Merge pull request #6399 from ian-r-rose/connection-lost-token

Connection lost token

packages/application-extension/src/index.tsx

@@ -2,6 +2,8 @@
 // Distributed under the terms of the Modified BSD License.
 
 import {
+  ConnectionLost,
+  IConnectionLost,
   ILabShell,
   ILabStatus,
   ILayoutRestorer,
@@ -73,10 +75,11 @@ namespace CommandIDs {
  */
 const main: JupyterFrontEndPlugin<void> = {
   id: '@jupyterlab/application-extension:main',
-  requires: [ICommandPalette, IRouter, IWindowResolver],
+  requires: [ICommandPalette, IConnectionLost, IRouter, IWindowResolver],
   activate: (
     app: JupyterFrontEnd,
     palette: ICommandPalette,
+    connectionLost: IConnectionLost,
     router: IRouter,
     resolver: IWindowResolver
   ) => {
@@ -108,6 +111,10 @@ const main: JupyterFrontEndPlugin<void> = {
       app.commands.notifyCommandChanged();
     });
 
+    // If the connection to the server is lost, handle it with the
+    // connection lost token.
+    app.serviceManager.connectionFailure.connect(connectionLost);
+
     const builder = app.serviceManager.builder;
     const build = () => {
       return builder
@@ -741,6 +748,19 @@ const paths: JupyterFrontEndPlugin<JupyterFrontEnd.IPaths> = {
   provides: JupyterFrontEnd.IPaths
 };
 
+/**
+ * The default JupyterLab connection lost provider. This may be overridden
+ * to provide custom behavior when a connection to the server is lost.
+ */
+const connectionlost: JupyterFrontEndPlugin<IConnectionLost> = {
+  id: '@jupyterlab/apputils-extension:connectionlost',
+  activate: (app: JupyterFrontEnd): IConnectionLost => {
+    return ConnectionLost;
+  },
+  autoStart: true,
+  provides: IConnectionLost
+};
+
 /**
  * Export the plugins as default.
  */
@@ -755,7 +775,8 @@ const plugins: JupyterFrontEndPlugin<any>[] = [
   shell,
   status,
   info,
-  paths
+  paths,
+  connectionlost
 ];
 
 export default plugins;

packages/application/src/connectionlost.ts

@@ -0,0 +1,41 @@
+// Copyright (c) Jupyter Development Team.
+// Distributed under the terms of the Modified BSD License.
+
+import { showErrorMessage } from '@jupyterlab/apputils';
+
+import { ServerConnection, ServiceManager } from '@jupyterlab/services';
+
+import { IConnectionLost } from './tokens';
+
+/**
+ * A default connection lost handler, which brings up an error dialog.
+ */
+export const ConnectionLost: IConnectionLost = async function(
+  manager: ServiceManager.IManager,
+  err: ServerConnection.NetworkError
+): Promise<void> {
+  if (Private.showingError) {
+    return;
+  }
+  Private.showingError = true;
+
+  const title = 'Server Connection Error';
+  const networkMsg =
+    'A connection to the Jupyter server could not be established.\n' +
+    'JupyterLab will continue trying to reconnect.\n' +
+    'Check your network connection or Jupyter server configuration.\n';
+
+  return showErrorMessage(title, { message: networkMsg }).then(() => {
+    Private.showingError = false;
+  });
+};
+
+/**
+ * A namespace for module private functionality.
+ */
+namespace Private {
+  /**
+   * Whether the connection lost error is currently being shown.
+   */
+  export let showingError = false;
+}

packages/application/src/index.ts

@@ -4,6 +4,8 @@
 // Local CSS must be loaded prior to loading other libs.
 import '../style/index.css';
 
+export { ConnectionLost } from './connectionlost';
+
 export { JupyterFrontEnd, JupyterFrontEndPlugin } from './frontend';
 
 export { JupyterLab } from './lab';
@@ -12,8 +14,10 @@ export { ILayoutRestorer, LayoutRestorer } from './layoutrestorer';
 
 export { IMimeDocumentTracker } from './mimerenderers';
 
-export { IRouter, Router } from './router';
+export { Router } from './router';
 
 export { ILabShell, LabShell } from './shell';
 
 export { ILabStatus } from './status';
+
+export * from './tokens';

packages/application/src/router.ts

@@ -7,158 +7,13 @@ import { URLExt } from '@jupyterlab/coreutils';
 
 import { CommandRegistry } from '@phosphor/commands';
 
-import {
-  PromiseDelegate,
-  ReadonlyJSONObject,
-  Token
-} from '@phosphor/coreutils';
+import { PromiseDelegate, Token } from '@phosphor/coreutils';
 
 import { DisposableDelegate, IDisposable } from '@phosphor/disposable';
 
 import { ISignal, Signal } from '@phosphor/signaling';
 
-/* tslint:disable */
-/**
- * The URL Router token.
- */
-export const IRouter = new Token<IRouter>('@jupyterlab/application:IRouter');
-/* tslint:enable */
-
-/**
- * A static class that routes URLs within the application.
- */
-export interface IRouter {
-  /**
-   * The base URL for the router.
-   */
-  readonly base: string;
-
-  /**
-   * The command registry used by the router.
-   */
-  readonly commands: CommandRegistry;
-
-  /**
-   * The parsed current URL of the application.
-   */
-  readonly current: IRouter.ILocation;
-
-  /**
-   * A signal emitted when the router routes a route.
-   */
-  readonly routed: ISignal<IRouter, IRouter.ILocation>;
-
-  /**
-   * If a matching rule's command resolves with the `stop` token during routing,
-   * no further matches will execute.
-   */
-  readonly stop: Token<void>;
-
-  /**
-   * Navigate to a new path within the application.
-   *
-   * @param path - The new path or empty string if redirecting to root.
-   *
-   * @param options - The navigation options.
-   */
-  navigate(path: string, options?: IRouter.INavOptions): void;
-
-  /**
-   * Register a rule that maps a path pattern to a command.
-   *
-   * @param options - The route registration options.
-   *
-   * @returns A disposable that removes the registered rule from the router.
-   */
-  register(options: IRouter.IRegisterOptions): IDisposable;
-
-  /**
-   * Cause a hard reload of the document.
-   */
-  reload(): void;
-
-  /**
-   * Route a specific path to an action.
-   *
-   * @param url - The URL string that will be routed.
-   *
-   * #### Notes
-   * If a pattern is matched, its command will be invoked with arguments that
-   * match the `IRouter.ILocation` interface.
-   */
-  route(url: string): void;
-}
-
-/**
- * A namespace for the `IRouter` specification.
- */
-export namespace IRouter {
-  /**
-   * The parsed location currently being routed.
-   */
-  export interface ILocation extends ReadonlyJSONObject {
-    /**
-     * The location hash.
-     */
-    hash: string;
-
-    /**
-     * The path that matched a routing pattern.
-     */
-    path: string;
-
-    /**
-     * The request being routed with the router `base` omitted.
-     *
-     * #### Notes
-     * This field includes the query string and hash, if they exist.
-     */
-    request: string;
-
-    /**
-     * The search element, including leading question mark (`'?'`), if any,
-     * of the path.
-     */
-    search: string;
-  }
-
-  /**
-   * The options passed into a navigation request.
-   */
-  export interface INavOptions {
-    /**
-     * Whether the navigation should be hard URL change instead of an HTML
-     * history API change.
-     */
-    hard?: boolean;
-
-    /**
-     * Whether the navigation should be added to the browser's history.
-     */
-    silent?: boolean;
-  }
-
-  /**
-   * The specification for registering a route with the router.
-   */
-  export interface IRegisterOptions {
-    /**
-     * The command string that will be invoked upon matching.
-     */
-    command: string;
-
-    /**
-     * The regular expression that will be matched against URLs.
-     */
-    pattern: RegExp;
-
-    /**
-     * The rank order of the registered rule. A lower rank denotes a higher
-     * priority. The default rank is `100`.
-     */
-    rank?: number;
-  }
-}
+import { IRouter } from './tokens';
 
 /**
  * A static class that routes URLs within the application.