Conditionally load realtime APIs.

package.json

@@ -77,7 +77,7 @@
     "mocha": "~3.5.3",
     "rimraf": "~2.6.2",
     "style-loader": "~0.13.2",
-    "typescript": "~2.4.2",
+    "typescript": "~2.6.2",
     "url-loader": "~0.5.9",
     "webpack": "~2.7.0"
   },

schema/drive.json

@@ -6,6 +6,9 @@
   "properties": {
     "clientId": {
       "type": "string", "title": "Client ID", "default": ""
+    },
+    "realtime": {
+      "type": "boolean", "title": "Realtime", "default": true
     }
   },
   "type": "object"

src/drive/browser.ts

@@ -82,9 +82,7 @@ class GoogleDriveFileBrowser extends Widget {
 
     // Keep references to the createFileBrowser arguments for
     // when we need to construct it.
-    this._registry = registry;
     this._commands = commands;
-    this._manager = manager;
     this._factory = factory;
     this._driveName = driveName;
 
@@ -182,9 +180,7 @@ class GoogleDriveFileBrowser extends Widget {
   private _browser: FileBrowser;
   private _loginScreen: GoogleDriveLogin;
   private _logoutButton: ToolbarButton;
-  private _registry: DocumentRegistry;
   private _commands: CommandRegistry;
-  private _manager: IDocumentManager;
   private _factory: IFileBrowserFactory;
   private _driveName: string;
   private _hasOpenDocuments: () => boolean;

src/drive/contents.ts

@@ -24,7 +24,7 @@ import {
 import * as drive from './drive';
 
 import {
-  makeError
+  makeError, realtimeLoaded
 } from '../gapi';
 
 
@@ -57,18 +57,37 @@ class GoogleDrive implements Contents.IDrive {
     }
   }
 
+  /**
+   * The name of the drive.
+   */
   get name(): 'GDrive' {
     return 'GDrive';
   }
 
+  /**
+   * Getter for the IModelDB factory.
+   */
   get modelDBFactory(): ModelDB.IFactory {
-    return {
-      createNew: (path: string) => {
-        return new GoogleModelDB( {filePath: path} );
+    if (realtimeLoaded) {
+      return {
+        createNew: (path: string) => {
+          return new GoogleModelDB( {filePath: path} );
+        }
+      }
+    } else {
+      return {
+        // If the realtime APIs have not been loaded,
+        // make a new in-memory ModelDB.
+        createNew: (path: string) => {
+          return new ModelDB();
+        }
       }
     }
   }
 
+  /**
+   * Server settings (unused for interfacing with Google Drive).
+   */
   readonly serverSettings: ServerConnection.ISettings;
 
   /**

src/gapi.ts

@@ -59,13 +59,22 @@ const gapiInitialized = new PromiseDelegate<void>();
 export
 let gapiAuthorized = new PromiseDelegate<void>();
 
+/**
+ * A boolean that is set if the deprecated realtime APIs
+ * have been loaded onto the page.
+ */
+export
+let realtimeLoaded = false;
+
 /**
  * Load the gapi scripts onto the page.
  *
+ * @param realtime - whether to load the (deprecated) realtime libraries.
+ *
  * @returns a promise that resolves when the gapi scripts are loaded.
  */
 export
-function loadGapi(): Promise<void> {
+function loadGapi(realtime: boolean): Promise<void> {
   return new Promise<void>( (resolve, reject) => {
     // Get the gapi script from Google.
     const gapiScript = document.createElement('script');
@@ -76,7 +85,11 @@ function loadGapi(): Promise<void> {
     // Load overall API scripts onto the page.
     gapiScript.onload = () => {
       // Load the specific client libraries we need.
-      gapi.load('client:auth2,drive-realtime,drive-share', () => {
+      const libs = realtime ?
+                   'client:auth2,drive-realtime,drive-share' :
+                   'client:auth2';
+      gapi.load(libs, () => {
+        if (realtime) { realtimeLoaded = true };
         gapiLoaded.resolve(void 0);
         resolve(void 0);
       });

src/index.ts

@@ -87,7 +87,17 @@ function activateFileBrowser(app: JupyterLab, palette: ICommandPalette, manager:
   const id = fileBrowserPlugin.id;
 
   // Load the gapi libraries onto the page.
-  loadGapi();
+  settingRegistry.load(id).then(settings => {
+    const realtime = settings.get('realtime').composite as boolean;
+    if (realtime === true) {
+      console.warn('Warning: Google Realtime has been deprecated. ' +
+                   'No new realtime applications may be registered, ' +
+                   'and existing ones will cease to work in December 2018');
+      loadGapi(true);
+    } else {
+      loadGapi(false);
+    }
+  });
 
   // Add the Google Drive backend to the contents manager.
   const drive = new GoogleDrive(app.docRegistry);