set directory

frontend/libs/components/settings-modal/src/lib/MiscSettingsPane.tsx

@@ -1,7 +1,7 @@
 import { useEffect, useState } from "react";
 import { Button } from "@storyteller/ui-button";
 import { Input } from "@storyteller/ui-input";
-import { AppPreferencesPayload, GetAppPreferences, CustomDirectory } from "@storyteller/tauri-api";
+import { AppPreferencesPayload, CustomDirectory, GetAppPreferences } from "@storyteller/tauri-api";
 import { PreferenceName, UpdateAppPreferences } from "libs/tauri-api/src/lib/settings/UpdateAppPreference";
 import { open } from '@tauri-apps/plugin-dialog';
 
@@ -57,9 +57,14 @@ export const MiscSettingsPane = (args: MiscSettingsPaneProps) => {
     });
 
     if (directory === null) {
-      return;
+      return; // User dismissed the dialog choice
     }
 
+    // Serialize for backend
+    directory = JSON.stringify({
+      custom: directory,
+    } as CustomDirectory);
+
     await UpdateAppPreferences({
       preference: PreferenceName.PreferredDownloadDirectory, 
       value: directory,

frontend/libs/tauri-api/src/lib/settings/GetAppPreferences.ts

@@ -6,14 +6,19 @@ export interface GetAppPreferencesResult {
 
 export interface AppPreferencesPayload {
   // Preferred download directory
-  preferred_download_directory: string | CustomDirectory,
+  preferred_download_directory: SystemDirectory | CustomDirectory,
 
   // Play sounds on events.
   play_sounds: boolean,
 }
 
+export interface SystemDirectory {
+  // If the directory is a system directory.
+  system: string,
+}
+
 export interface CustomDirectory {
-  // If the directory is custom.
+  // If the directory is a custom user directory.
   custom: string,
 }