fix: middleware i18n localization.

server/src/api/middleware/I18nAuthenticatedMiddlware.ts

@@ -0,0 +1,30 @@
+import { Container } from 'typedi';
+import { Request, Response, NextFunction } from 'express';
+import i18n from 'i18n';
+
+/**
+ * I18n from organization settings.
+ */
+export default (req: Request, res: Response, next: NextFunction) => {
+  const Logger = Container.get('logger');
+  const { settings } = req;
+
+  if (!req.user) {
+    throw new Error('Should load this middleware after `JWTAuth`.');
+  }
+  if (!req.settings) {
+    throw new Error('Should load this middleware after `SettingsMiddleware`.');
+  }
+  // Get the organization language from settings.
+  const language = settings.get({
+    group: 'organization', key: 'language',
+  });
+  if (language) {
+    i18n.setLocale(req, language);
+  }
+  Logger.info('[i18n_authenticated_middleware] set locale language to i18n.', {
+    language,
+    user: req.user,
+  });
+  next();
+};

server/src/api/middleware/I18nMiddleware.ts

@@ -1,16 +1,23 @@
 import { Container } from 'typedi';
 import { Request, Response, NextFunction } from 'express';
+import { lowerCase } from 'lodash';
 import i18n from 'i18n';
 
+/**
+ * Set the language from request `accept-language` header
+*  or default application language.
+ */
 export default (req: Request, res: Response, next: NextFunction) => {
   const Logger = Container.get('logger');
-  let language = req.headers['accept-language'] || 'en';
 
-  if (req.user && req.user.language) {
-    language = req.user.language;
-  }
-  Logger.info('[i18n_middleware] set locale language to i18n.', { language, user: req.user });
+  // Parses the accepted language from request object.
+  const language = lowerCase(req.headers['accept-language']) || 'en';
+
+  Logger.info('[i18n_middleware] set locale language to i18n.', {
+    language,
+    user: req.user,
+  });
   i18n.setLocale(req, language);
 
   next();
-};
+};