i18n

v3/src/i18n.ts

@@ -0,0 +1,92 @@
+import { DEFAULT_LOCALE_SETTING, LOCALES_SETTING } from "./locales";
+import { getRelativeLocaleUrl } from "astro:i18n";
+
+
+/**
+ * User-defined locales list
+ * @constant @readonly
+ */
+export const LOCALES = LOCALES_SETTING as Record<string, LocaleConfig>;
+type LocaleConfig = {
+  readonly label: string;
+  readonly lang?: string;
+  readonly dir?: "ltr" | "rtl";
+};
+
+
+/**
+ * Type for the language code
+ * @example
+ * "en" | "ja" | ...
+ */
+export type Lang = keyof typeof LOCALES;
+
+
+/**
+ * Default locale code
+ * @constant @readonly
+*/
+export const DEFAULT_LOCALE = DEFAULT_LOCALE_SETTING as Lang;
+
+
+/**
+ * Type for the multilingual object
+ * @example
+ * { en: "Hello", ja: "こんにちは", ... }
+ */
+export type Multilingual = { [key in Lang]?: string };
+
+
+/**
+ * Helper to get the translation function
+ * @param - The current language
+ * @returns - The translation function
+ */
+export function useTranslations(lang: Lang) {
+  return function t(multilingual: Multilingual | string): string {
+    if (typeof multilingual === "string") {
+      return multilingual;
+    } else {
+      return multilingual[lang] || multilingual[DEFAULT_LOCALE] || "";
+    }
+  };
+}
+
+
+/**
+ * Helper to get corresponding path list for all locales
+ * @param url - The current URL object
+ * @returns - The list of locale paths
+ */
+export function getLocalePaths(url: URL): LocalePath[] {
+  const path = url.pathname.replace(/^\/([a-zA-Z-]+)(?=\/|$)/, (match, p1) => {
+    return LOCALES[p1] ? '' : match;
+  });
+  return Object.keys(LOCALES).map((lang) => {
+    return {
+      lang: lang as Lang,
+      path: getRelativeLocaleUrl(lang, path)
+    };
+  });
+}
+type LocalePath = {
+  lang: Lang;
+  path: string;
+};
+
+
+/**
+ * Helper to get locale parms for Astro's `getStaticPaths` function
+ * @returns - The list of locale params
+ * @see https://docs.astro.build/en/guides/routing/#dynamic-routes
+ */
+export const localeParams = Object.keys(LOCALES).map((lang) => ({
+  params: { lang },
+}));
+
+export const getLocalPath = (lang: Lang, path: string) => {
+  if (!lang || lang === DEFAULT_LOCALE) {
+    return path + '?lang=en';
+  }
+  return lang + path;
+}