refactor: Show error on links following in single file mode

src/commands/openDocumentByReference.ts

@@ -12,6 +12,8 @@ import {
  resolveShortRefFolder,
 } from '../utils';
 
+let workspaceErrorShown = false;
+
 const openDocumentByReference = async ({
  reference,
  showOption = vscode.ViewColumn.Active,
@@ -43,6 +45,17 @@ const openDocumentByReference = async ({
  }
 
  await vscode.commands.executeCommand('vscode.open', vscode.Uri.file(filePath), showOption);
+ } else if (!workspaceErrorShown) {
+ workspaceErrorShown = true;
+
+ vscode.window.showErrorMessage(
+ `It seems that you are trying to use Memo in single file mode.
+
+ Memo works best in folder/workspace mode.
+
+ The easiest way to start is to create a new folder and drag it onto the VSCode or use File > Open Folder... from the menu bar.
+ `,
+ );
  }
  }
 };