Use language setting of users when logging in.

src/Controller/RedirectController.php

@@ -0,0 +1,64 @@
+<?php
+/**
+ *
+ * part-db version 0.1
+ * Copyright (C) 2005 Christoph Lechner
+ * http://www.cl-projects.de/
+ *
+ * part-db version 0.2+
+ * Copyright (C) 2009 K. Jacobs and others (see authors.php)
+ * http://code.google.com/p/part-db/
+ *
+ * Part-DB Version 0.4+
+ * Copyright (C) 2016 - 2019 Jan Böhmer
+ * https://github.com/jbtronics
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ *
+ */
+
+namespace App\Controller;
+
+use App\Entity\UserSystem\User;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
+
+class RedirectController extends AbstractController
+{
+    protected $default_locale;
+
+    public function __construct(string $default_locale)
+    {
+        $this->default_locale = $default_locale;
+    }
+
+    public function addLocalePart(Request $request)
+    {
+        //By default we use the global default locale
+        $locale = $this->default_locale;
+
+        //Check if a user has set a preferred language setting:
+        $user = $this->getUser();
+        if ($user instanceof User) {
+           if(!empty($user->getLanguage())) {
+               $locale = $user->getLanguage();
+           }
+        }
+
+        $new_url = str_replace($request->getPathInfo(), '/' . $locale . $request->getPathInfo(), $request->getUri());
+
+        return $this->redirect($new_url);
+    }
+}