Added checkLanguage() function and updated README

luca-vogels · luca-vogels · commit 7b4f1f686cf4 · 2025-04-14T22:00:14.000+02:00
diff --git a/README.md b/README.md
@@ -63,6 +63,28 @@ export default async function loadTranslations(locale: string, translationKeys:
 
 `app/[locale]/layout.tsx`
 ```typescript
+
+export default async function RootLayout({ params, children }: LocaleLayoutProps){
+    const { locale } = await params;
+
+    // if locale is not supported redirect to a supported one
+    const validLocale = await checkLanguage(locale, getDefaultLocale());
+    if(validLocale && locale !== validLocale){
+        redirect('/'+validLocale+'/');
+    }
+
+    // load translations for given translation keys (note this loadTranslations function is defined in translations.ts, see below) 
+    const TEXT = await loadTranslations(locale, [
+        'HelloWorld',
+    ]);
+
+    return <html lang={locale}>
+        <body>
+            {TEXT['HelloWorld']}
+        </body>
+    </html>;
+}
+
 export async function generateStaticParams(context: StaticParamsContext){
   const locales = await getLocales();
   return locales.map((locale) => ({ locale: locale }));
@@ -86,6 +108,19 @@ export default async function Home({ params }: StaticParamsContext) {
 }
 ```
 
+`app/[locale]/translations.ts`
+Server action that also allows client components to load translations.
+```typescript
+'use server';
+import 'server-only';
+
+import { getTranslations } from "lup-language";
+
+export default async function loadTranslations(locale: string, translationKeys: string[]): Promise<{[key: string]: string}> {
+    return await getTranslations(locale, getDefaultLocale(), translationKeys);
+};
+```
+
 Optional if unsupported languages or root should be redirected:  
 `middleware.ts`
 ```typescript
diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "lup-language",
-  "version": "2.1.4",
+  "version": "2.2.1",
   "description": "Node express middleware for detecting requested language",
   "files": [
     "lib/**/*"
diff --git a/src/index.ts b/src/index.ts
@@ -379,6 +379,29 @@ export const getLanguages = async (translationsDir: string = DEFAULTS.TRANSLATIO
   return [...LANGUAGES[translationsDir]];
 };
 
+
+/**
+ * Checks if a given language is supported and returns the supported language code.
+ * If the given language is not supported the default language will be returned.
+ * 
+ * @param lang Language code that should be checked.
+ * @param defaultLang Default language code if given 'lang' is not supported.
+ * @param translationsDir Relative path to directory containing JSON files with translations to lookup supported translations (optional).
+ * @return Promise that resolves to the supported language code or undefined if no language is supported and also no default language is given.
+ */
+export const checkLanguage = async (lang: string | null | undefined, defaultLang?: string, translationsDir: string = DEFAULTS.TRANSLATIONS_DIR): Promise<string | undefined> => {
+  if(!lang) return defaultLang;
+  lang = lang.trim().toLowerCase();
+  const langs = await getLanguages(translationsDir);
+  for(let i=0; i < langs.length; i++){
+    if(langs[i].toLowerCase() === lang){
+      return langs[i];
+    }
+  }
+  return defaultLang;
+}
+
+
 /**
  * Returns a map of all found languages and their native name.
  * Looksup following keys in the translations 'LANGUAGE_NAME_<lang>'.

Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`{`
`2`	`2`	`"name": "lup-language",`
`3`		`- "version": "2.1.4",`
	`3`	`+ "version": "2.2.1",`
`4`	`4`	`"description": "Node express middleware for detecting requested language",`
`5`	`5`	`"files": [`
`6`	`6`	`"lib/*/"`