Support workspace images in markdown cells (#11086)

For #10893

Author: DonJayamanne

news/2 Fixes/11040.md

@@ -0,0 +1 @@
+Ensure images in workspace folder are supported within markdown cells in a `Notebook`.

src/client/common/application/types.ts

@@ -1094,6 +1094,11 @@ export interface IWebPanelOptions {
     listener: IWebPanelMessageListener;
     title: string;
     rootPath: string;
+    /**
+     * Additional paths apart from cwd and rootPath, that webview would allow loading resources/files from.
+     * E.g. required for webview to serve images from worksapces when nb is in a nested folder.
+     */
+    additionalPaths?: string[];
     scripts: string[];
     startHttpServer: boolean;
     cwd: string;

src/client/common/application/webPanels/webPanelProvider.ts

@@ -30,6 +30,9 @@ export class WebPanelProvider implements IWebPanelProvider {
         // Allow loading resources from the `<extension folder>/tmp` folder when in webiviews.
         // Used by widgets to place files that are not otherwise accessible.
         const additionalRootPaths = [Uri.file(path.join(this.context.extensionPath, 'tmp'))];
+        if (Array.isArray(options.additionalPaths)) {
+            additionalRootPaths.push(...options.additionalPaths.map((item) => Uri.file(item)));
+        }
         return new WebPanel(
             this.fs,
             this.disposableRegistry,

src/client/datascience/webViewHost.ts

@@ -256,6 +256,8 @@ export abstract class WebViewHost<IMapping> implements IDisposable {
 
             traceWarning(`startHttpServer=${startHttpServer}, will not be used. Temporarily turned off`);
 
+            const workspaceFolder = this.workspaceService.getWorkspaceFolder(Uri.file(cwd))?.uri;
+
             // Use this script to create our web view panel. It should contain all of the necessary
             // script to communicate with this class.
             this.webPanel = await this.provider.create({
@@ -267,7 +269,8 @@ export abstract class WebViewHost<IMapping> implements IDisposable {
                 settings,
                 startHttpServer: false,
                 cwd,
-                webViewPanel
+                webViewPanel,
+                additionalPaths: workspaceFolder ? [workspaceFolder.fsPath] : []
             });
 
             traceInfo('Web view created.');