closes #3352

public/src/modules/translator.js

@@ -125,7 +125,7 @@
 		if (typeof language === 'function') {
 			callback = language;
 			if ('undefined' !== typeof window && config) {
-				language = config.userLang || 'en_GB';
+				language = utils.params().lang || config.userLang || 'en_GB';
 			} else {
 				var meta = require('../../../src/meta');
 				language = meta.config.defaultLang || 'en_GB';

src/controllers/api.js

@@ -64,7 +64,7 @@ apiController.getConfig = function(req, res, next) {
 	config.maximumFileSize = meta.config.maximumFileSize;
 	config['theme:id'] = meta.config['theme:id'];
 	config.defaultLang = meta.config.defaultLang || 'en_GB';
-	config.userLang = config.defaultLang;
+	config.userLang = req.query.lang || config.defaultLang;
 	config.environment = process.env.NODE_ENV;
 	config.loggedIn = !!req.user;
 	config['cache-buster'] = meta.config['cache-buster'] || '';
@@ -89,7 +89,7 @@ apiController.getConfig = function(req, res, next) {
 		config.topicsPerPage = settings.topicsPerPage;
 		config.postsPerPage = settings.postsPerPage;
 		config.notificationSounds = settings.notificationSounds;
-		config.userLang = settings.userLang || config.defaultLang;
+		config.userLang = req.query.lang || settings.userLang || config.defaultLang;
 		config.openOutgoingLinksInNewTab = settings.openOutgoingLinksInNewTab;
 		config.topicPostSort = settings.topicPostSort || config.topicPostSort;
 		config.categoryTopicSort = settings.categoryTopicSort || config.categoryTopicSort;

src/middleware/middleware.js

@@ -347,6 +347,7 @@ middleware.processRender = function(req, res, next) {
 					}
 					str = template + str;
 					var language = res.locals.config ? res.locals.config.userLang || 'en_GB' : 'en_GB';
+					language = req.query.lang || language;
 					translator.translate(str, language, function(translated) {
 						fn(err, translated);
 					});