frontend-app-api: register appLanguageApi and translationApi

Signed-off-by: Vincenzo Scamporlino <vincenzos@spotify.com>

packages/frontend-app-api/src/wiring/createApp.tsx

@@ -57,9 +57,14 @@ import {
   ApiFactoryRegistry,
   ApiProvider,
   ApiResolver,
-  AppThemeSelector,
 } from '@backstage/core-app-api';
 
+import {
+  AppLanguageSelector,
+  AppThemeSelector,
+  I18nextTranslationApi,
+} from '@backstage/core-app-api/alpha';
+
 // TODO: Get rid of all of these
 // eslint-disable-next-line @backstage/no-relative-monorepo-imports
 import { AppThemeProvider } from '../../../core-app-api/src/app/AppThemeProvider';
@@ -86,6 +91,10 @@ import { SidebarItem } from '@backstage/core-components';
 import { DarkTheme, LightTheme } from '../extensions/themes';
 import { extractRouteInfoFromInstanceTree } from '../routing/extractRouteInfoFromInstanceTree';
 import { getOrCreateGlobalSingleton } from '@backstage/version-bridge';
+import {
+  appLanguageApiRef,
+  translationApiRef,
+} from '@backstage/core-plugin-api/alpha';
 
 /** @public */
 export interface ExtensionTreeNode {
@@ -474,6 +483,21 @@ function createApiHolder(
     factory: () => configApi,
   });
 
+  factoryRegistry.register('static', {
+    api: appLanguageApiRef,
+    deps: {},
+    factory: () => AppLanguageSelector.createWithStorage(),
+  });
+
+  factoryRegistry.register('default', {
+    api: translationApiRef,
+    deps: { languageApi: appLanguageApiRef },
+    factory: ({ languageApi }) =>
+      I18nextTranslationApi.create({
+        languageApi,
+      }),
+  });
+
   // TODO: ship these as default extensions instead
   for (const factory of defaultApis as AnyApiFactory[]) {
     if (!factoryRegistry.register('app', factory)) {