Intlayer

import { prepareIntlayer } from '@intlayer/chokidar'; import { getConfiguration } from '@intlayer/config'; import { getDictionary as getDictionaryFunction, getIntlayer as getIntlayerFunction, getLocaleFromStorage, getTranslation, localeDetector, } from '@intlayer/core'; import type { Locale, StrictModeLocaleMap } from '@intlayer/types'; import { createNamespace } from 'cls-hooked'; import type { NextFunction, Request, RequestHandler, Response } from 'express'; const configuration = getConfiguration(); const { internationalization } = configuration; /** * Retrieves the locale from storage (cookies, localStorage, sessionStorage). */ const getStorageLocale = (req: Request): Locale | undefined => getLocaleFromStorage({ getCookie: (name: string) => req.cookies?.[name], getHeader: (name: string) => req.headers?.[name] as string | undefined, }); const appNamespace = createNamespace('app'); prepareIntlayer(configuration); export const translateFunction = (_req: Request, res: Response, _next?: NextFunction) => <T extends string>( content: StrictModeLocaleMap<T> | string, locale?: Locale ): T => { const { locale: currentLocale, defaultLocale } = res.locals as { locale: Locale; defaultLocale: Locale; }; const targetLocale = locale ?? currentLocale; if (typeof content === 'undefined') { return '' as unknown as T; } if (typeof content === 'string') { return content as unknown as T; } if ( typeof content?.[ targetLocale as unknown as keyof StrictModeLocaleMap<T> ] === 'undefined' ) { if ( typeof content?.[ defaultLocale as unknown as keyof StrictModeLocaleMap<T> ] === 'undefined' ) { return content as unknown as T; } else { return getTranslation(content, defaultLocale); } } return getTranslation(content, targetLocale); }; /** * Detect locale used by the user and load it into res locale storage * * @returns */ export const intlayer = (): RequestHandler => async (req, res, next) => { // Detect if locale is set by intlayer frontend lib in the headers const localeFromStorage = getStorageLocale(req); // Interpret browser locale const negotiatorHeaders: Record<string, string> = {}; // // Check if req.headers exists and is an object if (req && typeof req.headers === 'object') { // Copy all headers from the request to negotiatorHeaders for (const key in req.headers) { if (typeof req.headers[key] === 'string') { negotiatorHeaders[key] = req.headers[key]; } } } const localeDetected = localeDetector( negotiatorHeaders, internationalization.locales, internationalization.defaultLocale ); res.locals.locale_storage = localeFromStorage; res.locals.locale_detected = localeDetected; res.locals.locale = localeFromStorage ?? localeDetected; res.locals.defaultLocale = internationalization.defaultLocale; const t = translateFunction(req, res, next); const getIntlayer: typeof getIntlayerFunction = ( key, localeArg = localeDetected as Parameters<typeof getIntlayerFunction>[1], ...props ) => getIntlayerFunction(key, localeArg, ...props); const getDictionary: typeof getDictionaryFunction = ( key, localeArg = localeDetected as Parameters<typeof getDictionaryFunction>[1], ...props ) => getDictionaryFunction(key, localeArg, ...props); res.locals.t = t; res.locals.getIntlayer = getIntlayer; res.locals.getDictionary = getDictionary; appNamespace.run(() => { appNamespace.set('t', t); appNamespace.set('getIntlayer', getIntlayer); appNamespace.set('getDictionary', getDictionary); next(); }); }; export const t = <Content = string>( content: StrictModeLocaleMap<Content>, locale?: Locale ): Content => { try { if (typeof appNamespace === 'undefined') { throw new Error( 'Intlayer is not initialized. Add the `app.use(intlayer());` middleware before using this function.' ); } if (typeof appNamespace.get('t') !== 'function') { throw new Error( 'Using the import { t } from "express-intlayer" is not supported in your environment. Use the res.locals.t syntax instead.' ); } return appNamespace.get('t')(content, locale); } catch (error) { if (process.env.NODE_ENV === 'development') { console.error((error as Error).message); } return getTranslation( content, locale ?? internationalization.defaultLocale ); } }; export const getIntlayer: typeof getIntlayerFunction = (...args) => { try { if (typeof appNamespace === 'undefined') { throw new Error( 'Intlayer is not initialized. Add the `app.use(intlayer());` middleware before using this function.' ); } if (typeof appNamespace.get('getIntlayer') !== 'function') { throw new Error( 'Using the import { t } from "express-intlayer" is not supported in your environment. Use the res.locals.t syntax instead.' ); } return appNamespace.get('getIntlayer')(...args); } catch (error) { if (process.env.NODE_ENV === 'development') { console.error((error as Error).message); } return getIntlayerFunction(...args); } }; export const getDictionary: typeof getDictionaryFunction = (...args) => { try { if (typeof appNamespace === 'undefined') { throw new Error( 'Intlayer is not initialized. Add the `app.use(intlayer());` middleware before using this function.' ); } if (typeof appNamespace.get('getDictionary') !== 'function') { throw new Error( 'Using the import { t } from "express-intlayer" is not supported in your environment. Use the res.locals.t syntax instead.' ); } return appNamespace.get('getDictionary')(...args); } catch (error) { if (process.env.NODE_ENV === 'development') { console.error((error as Error).message); } return getDictionaryFunction(...args); } };