Resolve "Sprachauswahl für Originalfassung der Modul(teil)-Deskriptoren", fixes #4261

24 files changed, 450 insertions, 237 deletions

diff --git a/app/controllers/module/download.php b/app/controllers/module/download.php
index be527d5..e5f5be8 100644
--- a/app/controllers/module/download.php
+++ b/app/controllers/module/download.php
@@ -10,14 +10,15 @@ class Module_DownloadController extends MVVController
 
     public function details_action($modul_id, $language = null)
     {
-        $language = Request::get('display_language', $language);
-        ModuleManagementModel::setLanguage($language);
-
         $modul = Modul::find($modul_id);
         if (!$modul) {
             throw new Exception(_('Ungültiges Modul'));
         }
-        $this->getDetails($modul_id, $language);
+        $language = Request::get('display_language', $language) ?? $modul->original_language;
+        I18NString::setDefaultLanguage($modul->original_language);
+        I18NString::setContentLanguage($language);
+
+        $this->getDetails($modul_id);
         $this->download = true;
         $as_pdf = Request::int('pdf');
 
@@ -51,7 +52,7 @@ class Module_DownloadController extends MVVController
         }
     }
 
-    private function getDetails($id, $language = null)
+    private function getDetails($id)
     {
         $modul = Modul::find($id);
         if (!$modul) {
@@ -81,7 +82,7 @@ class Module_DownloadController extends MVVController
         $modulTeilData = [];
 
         foreach ($modul->modulteile as $modulTeil) {
-            $deskriptor = $modulTeil->getDeskriptor($language);
+            $deskriptor = $modulTeil->getDeskriptor();
             $num_bezeichnung = $GLOBALS['MVV_MODULTEIL']['NUM_BEZEICHNUNG']['values'][$modulTeil->num_bezeichnung]['name'] ?? '';
 
             $name_kurz = sprintf('%s %d', $num_bezeichnung, $modulTeil->nummer);
@@ -134,7 +135,7 @@ class Module_DownloadController extends MVVController
         $this->semesterSelector = Semester::GetSemesterSelector(null, $currentSemester->getId(), 'semester_id', false);
         $this->modul = $modul;
         $this->pruefungsEbene = $GLOBALS['MVV_MODUL']['PRUEF_EBENE']['values'][$modul->pruef_ebene]['name'] ?? null;
-        $this->modulDeskriptor = $modul->getDeskriptor($language);
+        $this->modulDeskriptor = $modul->getDeskriptor();
         $this->startSemester = Semester::find($modul->start);
         if ($modul->responsible_institute->institute) {
             $this->instituteName = $modul->responsible_institute->getDisplayName();
diff --git a/app/controllers/module/module.php b/app/controllers/module/module.php
index 10674d0..7ced003 100644
--- a/app/controllers/module/module.php
+++ b/app/controllers/module/module.php
@@ -105,6 +105,20 @@ class Module_ModuleController extends MVVController
         $this->setSidebar();
     }
 
+    public function select_module_language_action()
+    {
+        $this->languages = [];
+        foreach (Config::get()->CONTENT_LANGUAGES as $language_code => $language) {
+            $code = strtok($language_code, '_');
+            $this->languages[] = [
+                'name' => $language['name'],
+                'code' => $language_code,
+                'picture' => "lang_{$code}_text.svg",
+            ];
+        };
+        PageLayout::setTitle(_('Sprache wählen'));
+    }
+
     public function modul_action($modul_id = null, $institut_id = null)
     {
         $own_institutes = MvvPerm::getOwnInstitutes();
@@ -133,13 +147,20 @@ class Module_ModuleController extends MVVController
         if ($this->modul->isNew()) {
             PageLayout::setTitle(_('Neues Modul anlegen'));
             $success_message = ('Das Modul "%s" wurde angelegt.');
-            $this->display_language = $this->modul->getDefaultLanguage();
-            $this->deskriptor = $this->modul->getDeskriptor($this->display_language, true);
+            $language = Request::option('display_language');
+            $content_languages = Config::get()->CONTENT_LANGUAGES;
+            if (!empty($content_languages[$language])) {
+                $this->display_language = $language;
+            } else {
+                $this->display_language = Config::get()->MVV_DEFAULT_LANGUAGE;
+            }
+            $this->modul->original_language = $this->display_language;
+            $this->deskriptor = $this->modul->getDeskriptor();
             $this->reset_search('Modul');
             if (!$modul_id) {
                 PageLayout::postInfo(sprintf(
-                    _('Sie legen ein neues Modul an. Das Modul muss zunächst in der Ausgabesprache <em>%s</em> angelegt werden.'),
-                    $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'][$this->display_language]['name']
+                    _('Sie legen ein neues Modul an. Das Modul wird zunächst in der Ausgabesprache <em>%s</em> angelegt (Originalsprache).'),
+                    Config::get()->CONTENT_LANGUAGES[$this->display_language]['name']
                 ));
             }
             // set default language of instruction
@@ -151,17 +172,17 @@ class Module_ModuleController extends MVVController
         } else {
             $this->display_language = Request::option(
                 'display_language',
-                $this->modul->getDefaultLanguage()
+                $this->modul->original_language
             );
 
-            $this->deskriptor = $this->modul->getDeskriptor($this->display_language, true);
-            $this->translations = $this->deskriptor->getAvailableTranslations();
+            $this->deskriptor = $this->modul->getDeskriptor();
+            $this->translations = $this->deskriptor->getAvailableTranslations($this->modul->original_language);
             if (!in_array($this->display_language, $this->translations)) {
                 PageLayout::setTitle(
                     sprintf(
                         _('Modul: <em>%s</em> in der Ausgabesprache <em>%s</em> neu anlegen.'),
                         $this->modul->getDisplayName(),
-                        $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'][$this->display_language]['name']
+                        Config::get()->CONTENT_LANGUAGE[$this->display_language]['name']
                     )
                 );
             } else {
@@ -173,15 +194,18 @@ class Module_ModuleController extends MVVController
             $success_message = _('Das Modul "%s" wurde geändert.');
             // language selector as sidebar widget
             $template_factory = $this->get_template_factory();
-            $sidebar_template = $template_factory->render('shared/deskriptor_language', [
-                'modul'   => $this->modul,
-                'sprache' => $this->display_language,
-                'link'    => $this->modulURL($this->modul->id, $this->institut_id),
-                'url'     => $this->url]
+            $sidebar_template = $template_factory->render(
+                'shared/deskriptor_language',
+                [
+                    'original_language' => $this->modul->original_language,
+                    'display_language' => $this->display_language,
+                    'descriptor' => $this->modul->deskriptoren,
+                    'link' => $this->modulURL($this->modul->id, $this->institut_id),
+                ]
             );
 
             $widget  = new SidebarWidget();
-            $widget->setTitle(_('Ausgabesprache'));
+            $widget->setTitle(_('Ausgabesprache wählen'));
             $widget->addElement(new WidgetElement($sidebar_template));
             $sidebar->addWidget($widget, 'language');
 
@@ -235,9 +259,11 @@ class Module_ModuleController extends MVVController
                 $sidebar->addWidget($widget, 'variants');
             }
         }
+
         $this->semester = array_reverse(Semester::getAll());
-        $this->def_lang = $this->display_language === $this->modul->getDefaultLanguage();
-        ModuleManagementModel::setContentLanguage($this->display_language);
+        $this->def_lang = $this->display_language === $this->modul->original_language;
+        I18NString::setDefaultLanguage($this->modul->original_language);
+        I18NString::setContentLanguage($this->display_language);
         if (!$this->def_lang) {
             $action_widget = $sidebar->getWidget('actions');
             $action_widget->addLink(
@@ -247,7 +273,6 @@ class Module_ModuleController extends MVVController
             );
         }
 
-        $this->language = $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'][$this->display_language]['content_language'];
         if (Request::isPost()) {
             CSRFProtection::verifyUnsafeRequest();
             $stored = false;
@@ -279,6 +304,13 @@ class Module_ModuleController extends MVVController
                 $this->modul->fassung_typ = Request::option('fassung_typ');
                 $this->modul->version = trim(Request::get('version'));
                 $this->modul->verantwortlich = trim(Request::get('verantwortlich'));
+                // change original language
+                if (
+                    !$this->modul->isNew()
+                    && $this->modul->original_language !== Request::option('original_language')
+                ) {
+                    $this->setOriginalLanguage($this->modul, Request::option('original_language'));
+                }
             }
 
             $deskriptor_fields = ['bezeichnung', 'verantwortlich',
@@ -290,10 +322,16 @@ class Module_ModuleController extends MVVController
 
             foreach ($deskriptor_fields as $deskriptor_field) {
                 if ($this->deskriptor->isI18nField($deskriptor_field)) {
-                    $this->deskriptor->$deskriptor_field->setLocalized(
-                        trim(Request::get($deskriptor_field)),
-                        $this->language
-                    );
+                    if ($this->display_language === $this->modul->original_language) {
+                        $this->deskriptor->$deskriptor_field->setOriginal(
+                            trim(Request::get($deskriptor_field))
+                        );
+                    } else {
+                        $this->deskriptor->$deskriptor_field->setLocalized(
+                            trim(Request::get($deskriptor_field)),
+                            $this->display_language
+                        );
+                    }
                 } else {
                     $this->deskriptor->setValue(
                         $deskriptor_field,
@@ -307,7 +345,7 @@ class Module_ModuleController extends MVVController
                 $df = $this->deskriptor->datafields->findOneBy('datafield_id', $df_key);
                 if ($df) {
                     $tdf = $df->getTypedDatafield();
-                    $tdf->setContentLanguage($this->language);
+                    $tdf->setContentLanguage($this->display_language);
                     $tdf->setValueFromSubmit($df_value);
                     $tdf->store();
                 }
@@ -652,29 +690,31 @@ class Module_ModuleController extends MVVController
         if ($this->modulteil->isNew()) {
             PageLayout::setTitle(_('Neuen Modulteil anlegen'));
             $success_message = ('Der Modulteil "%s" wurde angelegt.');
-            $this->display_language = $this->modulteil->getDefaultLanguage();
-            $this->deskriptor = $this->modulteil->getDeskriptor($this->display_language, true);
+            $this->display_language = Request::option(
+                'display_language',
+                $this->modul->original_language
+            );
+            $this->deskriptor = $this->modulteil->getDeskriptor();
             PageLayout::postInfo(sprintf(
                 _('Sie legen einen neuen Modulteil für das Modul <em>%s</em> an. Der Modulteil muss zunächst in der Ausgabesprache <em>%s</em> angelegt werden.'),
                 htmlReady($this->modul->getDisplayName()),
-                htmlReady($GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'][$this->display_language]['name'])
+                htmlReady(Config::get()->MVV_MODUL_DESKRIPTOR['SPRACHE']['values'][$this->display_language]['name'])
             ));
             // set default language of instruction
-            if ($GLOBALS['MVV_MODULTEIL']['SPRACHE']['default']) {
+            if (Config::get()->MVV_MODULTEIL['SPRACHE']['default']) {
                 $this->modulteil->assignLanguagesOfInstruction([
-                    $GLOBALS['MVV_MODULTEIL']['SPRACHE']['default']
+                    Config::get()->MVV_MODULTEIL['SPRACHE']['default']
                 ]);
             }
         } else {
-            $this->display_language = Request::option('display_language', $this->modulteil->getDefaultLanguage());
-            $this->deskriptor = $this->modulteil->getDeskriptor($this->display_language, true);
-            $this->translations = $this->deskriptor->getAvailableTranslations();
-
+            $this->display_language = Request::option('display_language', $this->modul->original_language);
+            $this->deskriptor = $this->modulteil->getDeskriptor();
+            $this->translations = $this->deskriptor->getAvailableTranslations($this->modul->original_language);
             if (!in_array($this->display_language, $this->translations)) {
                 PageLayout::setTitle(sprintf(
                     _('Modulteil: "%s" in der Ausgabesprache "%s" neu anlegen.'),
                     $this->modulteil->getDisplayName(),
-                    $GLOBALS['MVV_MODULTEIL_DESKRIPTOR']['SPRACHE']['values'][$this->display_language]['name']
+                    Config::get()->CONTENT_LANGUAGES[$this->display_language]['name']
                 ));
             } else {
                 PageLayout::setTitle(sprintf(_('Modulteil: %s'), htmlReady($this->modulteil->getDisplayName())));
@@ -688,10 +728,10 @@ class Module_ModuleController extends MVVController
             $widget_element = new WidgetElement(
                 $template_factory->render('shared/deskriptor_language',
                     [
-                        'modul'   => $this->modulteil,
-                        'sprache' => $this->display_language,
-                        'link'    => $this->modulteilURL($this->modulteil->id),
-                        'url'     => $this->url
+                        'descriptor' => $this->modulteil->deskriptoren,
+                        'display_language' => $this->display_language,
+                        'original_language' => $this->modul->original_language,
+                        'link' => $this->modulteilURL($this->modulteil->id),
                     ]
                 )
             );
@@ -699,7 +739,9 @@ class Module_ModuleController extends MVVController
             $sidebar->addWidget($widget, 'languages');
         }
 
-        $this->def_lang = $this->display_language === $this->modulteil->getDefaultLanguage();
+        $this->def_lang = $this->display_language === $this->modul->original_language;
+        I18NString::setDefaultLanguage($this->modul->original_language);
+        I18NString::setContentLanguage($this->display_language);
 
         if (!$this->def_lang) {
             $action_widget = $sidebar->getWidget('actions');
@@ -711,7 +753,6 @@ class Module_ModuleController extends MVVController
             );
         }
 
-        $this->language = $GLOBALS['MVV_MODULTEIL_DESKRIPTOR']['SPRACHE']['values'][$this->display_language]['content_language'];
         if (Request::submitted('store')) {
             CSRFProtection::verifyUnsafeRequest();
             $stored = false;
@@ -748,12 +789,21 @@ class Module_ModuleController extends MVVController
 
             foreach ($deskriptor_fields as $deskriptor_field) {
                 if ($this->deskriptor->isI18nField($deskriptor_field)) {
-                    $this->deskriptor->$deskriptor_field->setLocalized(
-                        trim(Request::get($deskriptor_field)),
-                        $this->language
-                    );
+                    if ($this->display_language === $this->modul->original_language) {
+                        $this->deskriptor->$deskriptor_field->setOriginal(
+                            trim(Request::get($deskriptor_field))
+                        );
+                    } else {
+                        $this->deskriptor->$deskriptor_field->setLocalized(
+                            trim(Request::get($deskriptor_field)),
+                            $this->display_language
+                        );
+                    }
                 } else {
-                    $this->deskriptor->setValue($deskriptor_field, trim(Request::get($deskriptor_field)));
+                    $this->deskriptor->setValue(
+                        $deskriptor_field,
+                        trim(Request::get($deskriptor_field))
+                    );
                 }
             }
 
@@ -762,7 +812,7 @@ class Module_ModuleController extends MVVController
                 $df = $this->deskriptor->datafields->findOneBy('datafield_id', $df_key);
                 if ($df) {
                     $tdf = $df->getTypedDatafield();
-                    $tdf->setContentLanguage($this->language);
+                    $tdf->setContentLanguage($this->display_language);
                     $tdf->setValueFromSubmit($df_value);
                     $tdf->store();
                 }
@@ -795,11 +845,11 @@ class Module_ModuleController extends MVVController
                 return;
             }
         }
-        if ($this->display_language !== $this->modulteil->getDefaultLanguage() && $this->deskriptor->isNew()) {
+        if ($this->display_language !== $this->modul->original_language && $this->deskriptor->isNew()) {
             PageLayout::postInfo(sprintf(
                 _('Neue Beschreibung zum Modulteil "%s" in der Ausgabesprache %s anlegen.'),
                 htmlReady($this->modulteil->getDisplayName()),
-                htmlReady($GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'][$this->display_language]['name'])
+                htmlReady(Config::get()->CONTENT_LANGUAGES[$this->display_language]['name'])
             ));
         }
         $this->cancel_url = $this->detailsURL($this->modulteil->modul_id);
@@ -828,7 +878,7 @@ class Module_ModuleController extends MVVController
         if (is_null($deskriptor)) {
             throw new Trails\Exception(404, _('Unbekannter Deskriptor'));
         }
-        $def_lang = $deskriptor->modulteil->getDefaultLanguage();
+        $def_lang = $deskriptor->modulteil->modul->original_language;
         if ($language === $def_lang) {
             throw new Trails\Exception(403, _('Ein Deskriptor in der Original-Sprache kann nicht gelöscht werden.'));
         }
@@ -1348,9 +1398,9 @@ class Module_ModuleController extends MVVController
         if (MvvPerm::havePermCreate('Modul')) {
             $widget->addLink(
                 _('Neues Modul anlegen'),
-                $this->modulURL(),
+                $this->select_module_languageURL(),
                 Icon::create('add')
-            );
+            )->asDialog('size=600x300');
         }
         $sidebar->addWidget($widget, 'actions');
 
@@ -1573,4 +1623,40 @@ class Module_ModuleController extends MVVController
                   WHERE `mvv_studiengang`.`abschluss_id` = ?";
         return DBManager::get()->fetchFirst($query, [$abschluss_id]);
     }
+
+    private function setOriginalLanguage(Modul $module, string $original_language): void
+    {
+        $content_language = Config::get()->CONTENT_LANGUAGES[$original_language];
+        if (empty($content_language)) {
+            throw new InvalidArgumentException("Original language $original_language is not defined");
+        }
+        if ($module->deskriptoren) {
+            $current_language = $module->original_language;
+            $module->original_language = $original_language;
+            DBManager::get()->execute("
+                UPDATE `i18n`
+                SET `lang` = ?
+                WHERE `object_id` = ?
+                  AND `table` = 'mvv_modul_deskriptor'
+                  AND `lang` = ?",
+                [
+                    $original_language,
+                    $module->deskriptoren->id,
+                    $current_language
+                ]);
+            $module->modulteile->each(fn($component) => DBManager::get()->execute("
+                    UPDATE `i18n`
+                    SET `lang` = ?
+                    WHERE `object_id` IN (?)
+                      AND `table` = 'mvv_modulteil_deskriptor'
+                      AND `lang` = ?",
+                    [
+                        $original_language,
+                        $module->deskriptoren->id,
+                        $current_language
+                    ]
+                )
+            );
+        }
+    }
 }
diff --git a/app/controllers/search/studiengaenge.php b/app/controllers/search/studiengaenge.php
index e17eb2a..7f6dc5b 100644
--- a/app/controllers/search/studiengaenge.php
+++ b/app/controllers/search/studiengaenge.php
@@ -341,7 +341,7 @@ class Search_StudiengaengeController extends MVVController
             // add links to export Modulhandbücher as PDF
             $widget = new ActionsWidget();
             $widget->setTitle(_('Aktuelle Modulhandbücher'));
-            $avl_lang = array_keys($GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values']);
+            $avl_lang = array_keys(Config::get()->CONTENT_LANGUAGES);
 
             foreach ($avl_lang as $language) {
                 if ($language === $GLOBALS['MVV_LANGUAGES']['default']) {
diff --git a/app/controllers/shared/modul.php b/app/controllers/shared/modul.php
index d1a6ecf..1f1e5ce 100644
--- a/app/controllers/shared/modul.php
+++ b/app/controllers/shared/modul.php
@@ -13,8 +13,6 @@
  * @since       3.5
  */
 
-
-
 class Shared_ModulController extends AuthenticatedController
 {
 
@@ -30,96 +28,89 @@ class Shared_ModulController extends AuthenticatedController
         $display_language = Request::option('display_language', $_SESSION['_language']);
         ModuleManagementModel::setLanguage($display_language);
 
-        $modul = Modul::find($modul_id);
-        if (!$modul->hasPublicStatus()) {
+        $this->modul = Modul::find($modul_id);
+        if (!$this->modul->hasPublicStatus()) {
             throw new AccessDeniedException();
         }
-        if ($modul) {
-            $this->details_id = $modul->getId();
+        if ($this->modul) {
+            $this->details_id = $this->modul->getId();
 
             $type = 1;
-            if (count($modul->modulteile) == 1) {
-                $modulteil = $modul->modulteile->first();
+            if (count($this->modul->modulteile) == 1) {
+                $modulteil = $this->modul->modulteile->first();
                 $type = 3;
                 if (count($modulteil->lvgruppen) > 0) {
                     $type = 2;
                 }
-            } else if (count($modul->modulteile) == 0) {
+            } else if (count($this->modul->modulteile) == 0) {
                 $type = 3;
             }
 
             if (!$semester_id) {
-                $currentSemester = Semester::findDefault();
+                $current_semester = Semester::findDefault();
             } else {
-                $currentSemester = Semester::find($semester_id);
+                $current_semester = Semester::find($semester_id);
             }
 
             $sws = 0;
-            $institut = new Institute($modul->responsible_institute->institut_id);
-            $modulTeileData = [];
-            foreach ($modul->modulteile as $modulTeil) {
-
-                $modulTeilDeskriptor = $modulTeil->getDeskriptor($display_language);
-
-                $sws += (int) $modulTeil->sws;
-
-                $num_bezeichnung = $GLOBALS['MVV_MODULTEIL']['NUM_BEZEICHNUNG']['values'][$modulTeil->num_bezeichnung]['name'] ?? '';
-
-                $name_kurz = sprintf('%s %d', $num_bezeichnung, $modulTeil->nummer);
-
-                $modulTeileData[$modulTeil->getId()] = [
-                    'name' => $modulTeil->getDisplayName(),
+            $institut = new Institute($this->modul->responsible_institute->institut_id);
+            $modulteile_data = [];
+            foreach ($this->modul->modulteile as $modulteil) {
+                $modulteil_deskriptor = $modulteil->getDeskriptor();
+                $sws += (int) $modulteil->sws;
+                $num_bezeichnung = $GLOBALS['MVV_MODULTEIL']['NUM_BEZEICHNUNG']['values'][$modulteil->num_bezeichnung]['name'] ?? '';
+                $name_kurz = sprintf('%s %d', $num_bezeichnung, $modulteil->nummer);
+                $modulteile_data[$modulteil->getId()] = [
+                    'name' => $modulteil->getDisplayName(),
                     'name_kurz' => $name_kurz,
-                    'voraussetzung' => $modulTeilDeskriptor->voraussetzung,
-                    'pruef_leistung' => $modulTeilDeskriptor->pruef_leistung,
-                    'pruef_vorleistung' => $modulTeilDeskriptor->pruef_vorleistung,
-                    'kommentar' => $modulTeilDeskriptor->kommentar,
-                    'kapazitaet' => $modulTeil->kapazitaet,
+                    'voraussetzung' => $modulteil_deskriptor->voraussetzung,
+                    'pruef_leistung' => $modulteil_deskriptor->pruef_leistung,
+                    'pruef_vorleistung' => $modulteil_deskriptor->pruef_vorleistung,
+                    'kommentar' => $modulteil_deskriptor->kommentar,
+                    'kapazitaet' => $modulteil->kapazitaet,
                     'lvGruppen' => []
                 ];
 
-                $lvGruppen = Lvgruppe::findByModulteil($modulTeil->getId());
+                $lvGruppen = Lvgruppe::findByModulteil($modulteil->getId());
                 foreach ($lvGruppen as $lvGruppe) {
-                    $ids = array_column($lvGruppe->getAssignedCoursesBySemester($currentSemester['semester_id'], $GLOBALS['user']->id), 'seminar_id');
+                    $ids = array_column($lvGruppe->getAssignedCoursesBySemester($current_semester['semester_id'], $GLOBALS['user']->id), 'seminar_id');
                     $courses = Course::findMany($ids, 'order by Veranstaltungsnummer, Name');
-                    $modulTeileData[$modulTeil->getId()]['lvGruppen'][$lvGruppe->getId()] = [
+                    $modulteile_data[$modulteil->getId()]['lvGruppen'][$lvGruppe->getId()] = [
                         'courses' => $courses,
                         'alt_texte' => $lvGruppe->alttext
                     ];
                 }
             }
-            $this->modulTeile = $modulTeileData;
-            $this->deskriptor = $modul->getDeskriptor($display_language);
+            $this->modulteile = $modulteile_data;
+            $this->deskriptor = $this->modul->getDeskriptor();
             $this->institut = $institut;
-            $this->semester = $currentSemester;
+            $this->semester = $current_semester;
             $this->sws = $sws;
 
-            $this->pruef_ebene = $GLOBALS['MVV_MODUL']['PRUEF_EBENE']['values'][$modul->pruef_ebene]['name'] ?? null;
-            $this->modul = $modul;
+            $this->pruef_ebene = $GLOBALS['MVV_MODUL']['PRUEF_EBENE']['values'][$this->modul->pruef_ebene]['name'] ?? null;
             $this->type = $type;
             $this->self_url = $this->url_for('modul/show/' . $modul_id);
             $this->detail_url = $this->url_for('modul/detail/' . $modul_id);
-            $this->teilnahmeVoraussetzung = $modul->getDeskriptor()->voraussetzung;
-            PageLayout::setTitle($modul->getDisplayName() . ' (' . _('Veranstaltungsübersicht') .')');
+            PageLayout::setTitle($this->modul->getDisplayName() . ' (' . _('Veranstaltungsübersicht') .')');
         }
     }
 
     public function description_action($id)
     {
-        $modul = Modul::find($id);
-        $perm = MvvPerm::get($modul);
-        if (!($modul->hasPublicStatus() || $perm->haveObjectPerm(MvvPerm::PERM_READ))) {
+        $this->modul = Modul::find($id);
+        $perm = MvvPerm::get($this->modul);
+        if (!($this->modul->hasPublicStatus() || $perm->haveObjectPerm(MvvPerm::PERM_READ))) {
             throw new AccessDeniedException();
         }
-        $type = 1;
-        if (count($modul->modulteile) == 1) {
-            $modulteil = $modul->modulteile->first();
-            $type = 3;
+        $this->type = 1;
+        if (count($this->modul->modulteile) == 1) {
+            $modulteil = $this->modul->modulteile->first();
+            $this->type = 3;
             if (count($modulteil->lvgruppen) > 0) {
-                $type = 2;
+                $this->type = 2;
             }
-        } else if (count($modul->modulteile) == 0) {
-            $type = 3;
+        } else if (count($this->modul->modulteile) == 0) {
+            $this->type = 3;
         }
 
         if (!Request::get('sem_select')) {
@@ -128,28 +119,27 @@ class Shared_ModulController extends AuthenticatedController
             $currentSemester = Semester::find(Request::get('sem_select'));
         }
 
-        $display_language = Request::get('display_language', $_SESSION['_language']);
-        ModuleManagementModel::setLanguage($display_language);
+        $this->display_language = Request::get('display_language', $this->modul->original_language);
+        ModuleManagementModel::setLanguage($this->display_language);
+        I18NString::setDefaultLanguage($this->modul->original_language);
+        I18NString::setContentLanguage($this->display_language);
 
         $this->semesterSelector = Semester::getSemesterSelector(null, $currentSemester['semester_id'], 'semester_id', false);
-        $this->modul = $modul;
-        $this->pruefungsEbene = isset($GLOBALS['MVV_MODUL']['PRUEF_EBENE']['values'][$modul->pruef_ebene])
-                              ? $GLOBALS['MVV_MODUL']['PRUEF_EBENE']['values'][$modul->pruef_ebene]['name']
+        $this->pruefungsEbene = isset($GLOBALS['MVV_MODUL']['PRUEF_EBENE']['values'][$this->modul->pruef_ebene])
+                              ? $GLOBALS['MVV_MODUL']['PRUEF_EBENE']['values'][$this->modul->pruef_ebene]['name']
                               : null;
-        $this->modulDeskriptor = $modul->getDeskriptor($display_language);
-        $this->startSemester = Semester::findByTimestamp($modul->start);
+        $this->modulDeskriptor = $this->modul->getDeskriptor();
+        $this->startSemester = Semester::findByTimestamp($this->modul->start);
 
-        if (!$modul->responsible_institute) {
+        if (!$this->modul->responsible_institute) {
             $this->instituteName = null;
-        } elseif ($modul->responsible_institute->institute) {
-            $this->instituteName = $modul->responsible_institute->institute->name;
+        } elseif ($this->modul->responsible_institute->institute) {
+            $this->instituteName = $this->modul->responsible_institute->institute->name;
         } else {
             $this->instituteName = _('Unbekannte Einrichtung');
         }
-        $this->type = $type;
         $this->semester = $currentSemester;
-        $this->display_language = $display_language;
-        PageLayout::setTitle($modul->getDisplayName() . ' (' . _('Vollständige Modulbeschreibung') .')');
+        PageLayout::setTitle($this->modul->getDisplayName() . ' (' . _('Vollständige Modulbeschreibung') .')');
     }
 
     public function mail_action($modul_id, $semester_id)
diff --git a/app/views/admin/datafields/edit.php b/app/views/admin/datafields/edit.php
index 46b7aa1..49de452 100644
--- a/app/views/admin/datafields/edit.php
+++ b/app/views/admin/datafields/edit.php
@@ -71,7 +71,7 @@ use Studip\Button, Studip\LinkButton;
 
             <select multiple name="object_class[]" id="object_class" required>
                 <option value="NULL" <? if ($item->object_class === null) echo 'selected'; ?>><?= _('alle (mehrsprachige Eingabe bei Feldtyp textline, textarea, textmarkup)') ?></option>
-            <? foreach ((array) $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'] as $key => $value) : ?>
+            <? foreach (Config::get()->CONTENT_LANGUAGES as $key => $value) : ?>
                 <option value="<?= htmlReady($key) ?>" <? if (mb_strpos($item->object_class, $key) !== false) echo 'selected'; ?>>
                     <?= htmlReady($value['name']) ?>
                 </option>
@@ -82,7 +82,7 @@ use Studip\Button, Studip\LinkButton;
 
             <select multiple name="object_class[]" id="object_class" required>
                 <option value="NULL" <? if ($item->object_class === null) echo 'selected'; ?>><?= _('alle (mehrsprachige Eingabe)') ?></option>
-            <? foreach ((array) $GLOBALS['MVV_MODULTEIL_DESKRIPTOR']['SPRACHE']['values'] as $key => $value) : ?>
+            <? foreach (Config::get()->CONTENT_LANGUAGES as $key => $value) : ?>
                 <option value="<?= htmlReady($key) ?>" <? if (mb_strpos($item->object_class, $key) !== false) echo 'selected'; ?>>
                     <?= htmlReady($value['name']) ?>
                 </option>
@@ -90,7 +90,7 @@ use Studip\Button, Studip\LinkButton;
             </select>
         <? elseif ($item->object_type === 'studycourse'): ?>
             <?= _('Typ/Abschnitt') ?>
-            
+
             <select name="object_class" required>
                 <option value="all_settings"<?= mb_strpos($item->object_class, 'all_settings') !== false ? ' selected' : '' ?>><?= _('alle (Abschnitt "Einstellungen")') ?></option>
                 <option value="all_info"<?= mb_strpos($item->object_class, 'all_info') !== false ? ' selected' : '' ?>><?= _('alle (Abschnitt "Inhalte und Informationen")') ?></option>
diff --git a/app/views/admin/datafields/index.php b/app/views/admin/datafields/index.php
index e62b8d6..de4b512 100644
--- a/app/views/admin/datafields/index.php
+++ b/app/views/admin/datafields/index.php
@@ -108,7 +108,7 @@
                 <?=  $val->object_class !== null ? htmlReady($GLOBALS['INST_TYPE'][$val->object_class]['name']) : _('alle')?>
             <? elseif ($key === 'moduldeskriptor' || $key === 'modulteildeskriptor') : ?>
                 <?=  $val->object_class !== null ? htmlReady(implode(', ', array_map(function ($class) {
-                    return $GLOBALS['MVV_MODULTEIL_DESKRIPTOR']['SPRACHE']['values'][$class]['name'];
+                    return Config::get()->CONTENT_LANGUAGES[$class]['name'];
                 }, explode(',', $val->object_class)))) : _('alle')?>
             <? elseif ($key === 'studycourse'): ?>
                 <? $object_classes =
diff --git a/app/views/admin/datafields/new.php b/app/views/admin/datafields/new.php
index e64293f..3b99d2d 100644
--- a/app/views/admin/datafields/new.php
+++ b/app/views/admin/datafields/new.php
@@ -72,13 +72,13 @@ use Studip\Button, Studip\LinkButton;
         <? elseif ($object_typ === 'moduldeskriptor') : ?>
             <select multiple name="object_class[]" required>
                 <option value="NULL" selected><?= _('alle (mehrsprachige Eingabe bei Feldtyp textline, textarea, textmarkup)') ?></option>
-            <? foreach ((array) $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'] as $key => $value) : ?>
+            <? foreach (Config::get()->CONTENT_LANGUAGES as $key => $value) : ?>
                 <option value="<?= htmlReady($key) ?>"><?= htmlReady($value['name']) ?></option>
             <? endforeach; ?>
         <? elseif ($object_typ === 'modulteildeskriptor') : ?>
             <select multiple name="object_class[]" required>
                 <option value="NULL" selected><?= _('alle (mehrsprachige Eingabe bei Feldtyp textline, textarea, textmarkup)') ?></option>
-            <? foreach ((array) $GLOBALS['MVV_MODULTEIL_DESKRIPTOR']['SPRACHE']['values'] as $key => $value) : ?>
+            <? foreach (Config::get()->CONTENT_LANGUAGES as $key => $value) : ?>
                 <option value="<?= htmlReady($key) ?>"><?= htmlReady($value['name']) ?></option>
             <? endforeach; ?>
         <? elseif ($object_typ === 'studycourse') : ?>
diff --git a/app/views/module/module/details.php b/app/views/module/module/details.php
index 4509d52..3666f85 100644
--- a/app/views/module/module/details.php
+++ b/app/views/module/module/details.php
@@ -1,8 +1,19 @@
+<?php
+/**
+ * @var Modul $modul
+ * @var string $modulteil_id
+ * @var string $display_language
+ * @var Module_ModuleController $controller
+ * @var string $institut_id
+ */
+?>
+
 <td colspan="6">
     <table class="default collapsable sortable" id="<?= $modul->id ?>">
         <colgroup>
             <col>
-            <col span="2" style="width: 150px;">
+            <col style="width: 150px;">
+            <col style="width: 70px;">
         </colgroup>
         <? foreach ($modul->modulteile as $modulteil) : ?>
             <? $perm = MvvPerm::get($modulteil) ?>
@@ -20,8 +31,8 @@
                     </td>
                     <td class="dont-hide actions" style="white-space: nowrap; text-align: center;">
                         <? if ($perm->havePermWrite()) : ?>
-                            <? foreach ($modulteil->deskriptoren->getAvailableTranslations() as $language) : ?>
-                                <? $lang = $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'][$language]; ?>
+                            <? foreach ($modulteil->deskriptoren->getAvailableTranslations($modulteil->modul->original_language) as $language) : ?>
+                                <? $lang = Config::get()->CONTENT_LANGUAGES[$language]; ?>
                                 <a href="<?= $controller->action_link('modulteil/' . join('/', [$modulteil->id, $institut_id]), ['display_language' => $language]) ?>">
                                     <?= Assets::img(MVV::getContentLanguageImagePath($language), ['alt' => $lang['name'], 'size' => 24]) ?>
                                 </a>
diff --git a/app/views/module/module/index.php b/app/views/module/module/index.php
index 1028a2d..017d23d 100644
--- a/app/views/module/module/index.php
+++ b/app/views/module/module/index.php
@@ -1,5 +1,21 @@
+<?php
+/**
+ * @var Module_ModuleController $controller
+ * @var int $count
+ * @var int $page
+ */
+?>
+
 <?= $controller->jsUrl() ?>
 <table class="default collapsable">
+    <colgroup>
+        <col>
+        <col>
+        <col>
+        <col>
+        <col style="width: 150px">
+        <col style="width: 70px">
+    </colgroup>
     <caption>
         <?= _('Module')?>
         <span class="actions"><?= sprintf(ngettext('%s Modul', '%s Module', $count), $count) ?></span>
@@ -10,10 +26,10 @@
             <?= $controller->renderSortLink('module/module/', _('Modul'), 'bezeichnung') ?>
             <?= $controller->renderSortLink('module/module/', _('Fassung'), 'fassung_nr', ['style' => 'width: 5%;']) ?>
             <?= $controller->renderSortLink('module/module/', _('Modulteile'), 'count_modulteile', ['style' => 'width: 5%;']) ?>
-            <th style="text-align: right; width: 150px;">
+            <th style="text-align: center;">
                 <?= _('Ausgabesprachen') ?>
             </th>
-            <th style="width: 5%; text-align: right;"><?= _('Aktionen') ?></th>
+            <th style="text-align: right;"><?= _('Aktionen') ?></th>
         </tr>
     </thead>
     <?= $this->render_partial('module/module/module') ?>
diff --git a/app/views/module/module/modul.php b/app/views/module/module/modul.php
index e209a18..8fe49c8 100644
--- a/app/views/module/module/modul.php
+++ b/app/views/module/module/modul.php
@@ -1,9 +1,29 @@
+<?php
+/**
+ * @var Module_ModuleController $controller
+ * @var Modul $modul
+ * @var ModulDeskriptor $deskriptor
+ * @var string $display_language
+ * @var boolean $def_lang
+ * @var QuickSearch $search_modul
+ * @var string $qs_id_module
+ * @var Semester[] $semester
+ * @var QuickSearch $search_responsible
+ * @var string $qs_id_responsible
+ * @var QuickSearch $search_institutes
+ * @var string $qs_id_institutes
+ * @var SimpleORMapCollection $contacts
+ * @var array $translations
+ * @var string $cancel_url
+ */
+?>
+
 <? use Studip\Button, Studip\LinkButton; ?>
 <?= $controller->jsUrl() ?>
 <?
 $perm   = MvvPerm::get($modul);
 $perm_d = MvvPerm::get($deskriptor);
-if ($GLOBALS['MVV_MODUL']['SPRACHE']['default'] != $display_language) {
+if ($GLOBALS['MVV_MODUL']['SPRACHE']['default'] !== $display_language) {
     $perm_d->setVariant($display_language);
 }
 ?>
@@ -144,12 +164,12 @@ if ($GLOBALS['MVV_MODUL']['SPRACHE']['default'] != $display_language) {
                 <?= _('Beschlussdatum:') ?>
                 <? if ($perm->haveFieldPerm('beschlussdatum')) : ?>
                     <input type="text" name="beschlussdatum"
-                           value="<?= ($modul->beschlussdatum ? strftime('%d.%m.%Y', $modul->beschlussdatum) : '') ?>"
+                           value="<?= $modul->beschlussdatum ? date('d.m.Y', $modul->beschlussdatum) : '' ?>"
                            placeholder="<?= _('TT.MM.JJJJ') ?>" class="with-datepicker">
                 <? else : ?>
-                    <?= ($modul->beschlussdatum ? strftime('%d.%m.%Y', $modul->beschlussdatum) : '') ?>
+                    <?= $modul->beschlussdatum ? date('d.m.Y', $modul->beschlussdatum) : '' ?>
                     <input type="hidden" name="beschlussdatum"
-                           value="<?= ($modul->beschlussdatum ? strftime('%d.%m.%Y', $modul->beschlussdatum) : '') ?>">
+                           value="<?= $modul->beschlussdatum ? date('d.m.Y', $modul->beschlussdatum) : '' ?>">
                 <? endif; ?>
             </label>
             <label for="mvv-field-modul-fassung_nr"><?= _('Fassung:') ?>
@@ -196,7 +216,7 @@ if ($GLOBALS['MVV_MODUL']['SPRACHE']['default'] != $display_language) {
             </div>
             <div id="mvv-field-modul-beschlussdatum">
                 <? printf(_('Beschlussdatum: %s'),
-                    $modul->beschlussdatum ? strftime('%d.%m.%Y', $modul->beschlussdatum) : _('nicht angegeben')) ?>
+                    $modul->beschlussdatum ? date('d.m.Y', $modul->beschlussdatum) : _('nicht angegeben')) ?>
             </div>
             <div id="mvv-field-modul-fassung_nr">
                 <?
@@ -444,6 +464,17 @@ if ($GLOBALS['MVV_MODUL']['SPRACHE']['default'] != $display_language) {
         <? endif; ?>
         </label>
 
+        <? if ($def_lang && !$modul->isNew()) : ?>
+            <label id="mvv-field-modul-original_language"><?= _('Originalsprache der Modulbeschreibung') ?>
+                <select name="original_language" id="original_language">
+                <? foreach (Config::get()->CONTENT_LANGUAGES as $language_code => $content_language) : ?>
+                    <option value="<?= htmlReady($language_code) ?>"<?= $modul->original_language === $language_code ? ' selected' : '' ?>>
+                        <?= htmlReady($content_language['name']) ?>
+                    </option>
+                <? endforeach ?>
+                </select>
+            </label>
+        <? endif ?>
     </fieldset>
 
     <fieldset class="collapsable collapsed" id="mvv-field-modul-assigned_users">
@@ -657,7 +688,7 @@ if ($GLOBALS['MVV_MODUL']['SPRACHE']['default'] != $display_language) {
                             $entry->datafield_id,
                             $entry->range_id,
                             $entry->sec_range_id,
-                            $language == 'de_DE' ? '' : $language
+                            $display_language === Config::get()->MVV_DEFAULT_LANGUAGE ? '' : $display_language
                         ]); ?>
                 <? else : ?>
                     <? $df = $entry; ?>
@@ -694,6 +725,6 @@ if ($GLOBALS['MVV_MODUL']['SPRACHE']['default'] != $display_language) {
 </form>
 <? if (!$def_lang) : ?>
     <script>
-        jQuery('#modul_form').find('textarea, input[type=text]').after('<div style="padding-top:10px;"><a href="#" title="<?= _('Originalfassung anzeigen') ?>" class="mvv-show-original" data-type="modul"><?= Assets::img(MVV::getContentLanguageImagePath($modul->getDefaultLanguage()), ['alt' => _('Originalfassung'), 'size' => 24]) ?></a></div>');
+        jQuery('#modul_form').find('textarea, input[type=text]').after('<div style="padding-top:10px;"><a href="#" title="<?= _('Originalfassung anzeigen') ?>" class="mvv-show-original" data-type="modul"><?= Assets::img(MVV::getContentLanguageImagePath($modul->original_language), ['alt' => _('Originalfassung'), 'size' => 24]) ?></a></div>');
     </script>
 <? endif; ?>
diff --git a/app/views/module/module/module.php b/app/views/module/module/module.php
index d6cda88..851aabd 100644
--- a/app/views/module/module/module.php
+++ b/app/views/module/module/module.php
@@ -1,3 +1,9 @@
+<?php
+/**
+ * @var Modul[] $module
+ */
+?>
+
 <? foreach ($module as $modul) : ?>
     <? $perm = MvvPerm::get($modul) ?>
     <tbody class="<?= $modul->count_modulteile ? '' : 'empty ' ?><?= $modul_id === $modul->getId() ? 'not-collapsed' : 'collapsed' ?>">
@@ -29,13 +35,13 @@
                     <? endif;?>
                 </td>
             <? else : ?>
-                <td style="white-space:nowrap;">
+                <td style="white-space:nowrap; font-weight: 700; padding-left: 20px;">
                     <? if ($ampel_icon) : ?>
                         <?= $ampel_icon->asImg(['title' => $ampelstatus, 'style' => 'vertical-align: text-top;']) ?>
                     <? endif; ?>
                     <?= htmlReady($modul->code) ?>
                 </td>
-                <td class="dont-hide" style="font-weight: bold;">
+                <td class="dont-hide" style="font-weight: 700;">
                     <?= htmlReady($modul->getDisplayName()) ?>
                 </td>
             <? endif; ?>
@@ -43,11 +49,12 @@
             <td style="text-align: center;" class="dont-hide"><?= $modul->count_modulteile ?></td>
             <td class="dont-hide actions" style="text-align: center;">
                 <? if ($perm->havePermRead()) : ?>
-                    <? $languages = $modul->deskriptoren->getAvailableTranslations(); ?>
+                    <? $languages = $modul->deskriptoren->getAvailableTranslations($modul->original_language); ?>
+                    <? $content_languages = Config::get()->CONTENT_LANGUAGES ?>
                     <? foreach ($languages as $language) : ?>
-                        <? $lang = $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'][$language]; ?>
                         <a href="<?= $controller->action_link('modul/' . $modul->id . '/', ['display_language' => $language]) ?>">
-                            <?= Assets::img(MVV::getContentLanguageImagePath($language), ['alt' => $lang['name'], 'size' => 24]) ?>
+                            <?= Assets::img(MVV::getContentLanguageImagePath($language),
+                                ['alt' => $content_languages[$language]['name'], 'size' => 24]) ?>
                         </a>
                     <? endforeach; ?>
                 <? endif; ?>
diff --git a/app/views/module/module/select_module_language.php b/app/views/module/module/select_module_language.php
new file mode 100644
index 0000000..2e411ab
--- /dev/null
+++ b/app/views/module/module/select_module_language.php
@@ -0,0 +1,26 @@
+<?php
+/**
+ * @var Module_ModuleController $controller
+ * @var array $languages
+ */
+?>
+
+<ul class="content-items" style="padding-top: 10px;">
+    <? foreach ($languages as $language) : ?>
+        <li class="content-item">
+            <a class="content-item-link" href="<?= $controller->modulURL(['display_language' => $language['code']]) ?>">
+                <div class="content-item-img-wrapper">
+                    <?= Assets::img('/images/languages/' . $language['picture'], ['size' => 64]) ?>
+                </div>
+                <div class="content-item-text">
+                    <p class="content-item-title">
+                        <?= htmlReady($language['name']) ?>
+                    </p>
+                    <p class="content-item-description">
+                        <? printf(_('Erstellen Sie ein Modul in der Originalsprache <em>%s</em>.'), $language['name']) ?>
+                    </p>
+                </div>
+            </a>
+        </li>
+    <? endforeach ?>
+</ul>
diff --git a/app/views/shared/deskriptor_language.php b/app/views/shared/deskriptor_language.php
index 44cdb65..dde6120 100644
--- a/app/views/shared/deskriptor_language.php
+++ b/app/views/shared/deskriptor_language.php
@@ -1,11 +1,21 @@
-<? $table = get_class($modul) == 'Modul' ? 'mvv_modul_deskriptor' : 'mvv_modulteil_deskriptor'; ?>
-<? $languages = $modul->deskriptoren->getAvailableTranslations(); ?>
-<? foreach ($GLOBALS[strtoupper($table)]['SPRACHE']['values'] as $lang => $value) : ?>
+<?php
+/**
+ * @var ModulDeskriptor|ModulteilDeskriptor $descriptor
+ * @var string $original_language
+ * @var string $display_language
+ * @var string $link
+ */
+?>
+
+<? $languages = $descriptor->getAvailableTranslations($original_language) ?>
+<? $content_languages = array_merge(array_flip($languages), Config::get()->CONTENT_LANGUAGES) ?>
+<? foreach ($content_languages as $code => $language) : ?>
 <div style="padding-top:10px;">
-    <a href="<?= URLHelper::getLink($link, ['display_language' => $lang]) ?>">
-        <?= Assets::img(MVV::getContentLanguageImagePath($lang), ['alt' => $value['name'], 'size' => 24]) ?>
-        <?= $value['name'] ?> (<?= in_array($lang, $languages) ? 'bearbeiten' : 'neu anlegen' ?>)
-        <?= $lang == $sprache ? Icon::create('accept', 'accept', [])->asImg() : '' ?>
+    <a href="<?= URLHelper::getLink($link, ['display_language' => $code]) ?>">
+        <?= Assets::img(MVV::getContentLanguageImagePath($code), ['alt' => $language['name'], 'size' => 24]) ?>
+        <?= $language['name'] ?> (<?= ($code === $original_language ? 'Originalfassung, ' : '')
+            . (in_array($code, $languages) ? 'bearbeiten' : 'neu anlegen') ?>)
+        <?= $code === $display_language ? Icon::create('accept', Icon::ROLE_ACCEPT) : '' ?>
     </a>
 </div>
-<? endforeach; ?>
+<? endforeach ?>
diff --git a/app/views/shared/modul/description.php b/app/views/shared/modul/description.php
index 59512bd..7acb014 100644
--- a/app/views/shared/modul/description.php
+++ b/app/views/shared/modul/description.php
@@ -1,7 +1,15 @@
+<?php
+/**
+ * @var Modul $modul
+ * @var int $type
+ * @var Shared_ModulController $controller
+ */
+?>
+
 <? if (count($modul->deskriptoren) > 1): ?>
 <div style="width: 100%; text-align: right;">
-    <? foreach ($modul->deskriptoren->getAvailableTranslations() as $language) : ?>
-        <? $lang = $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'][$language]; ?>
+    <? foreach ($modul->deskriptoren->getAvailableTranslations($modul->original_language) as $language) : ?>
+        <? $lang = Config::get()->CONTENT_LANGUAGES[$language]; ?>
         <a data-dialog="size=auto;title='<?= htmlReady($modul->getDisplayName()) ?>'" href="<?= $controller->action_link('description/' . $modul->id . '/', ['display_language' => $language]) ?>">
             <?= Assets::img(MVV::getContentLanguageImagePath($language), ['alt' => $lang['name'], 'size' => 24]) ?>
         </a>
@@ -19,4 +27,4 @@
 <? endif; ?>
 <? if ($type === 3) : ?>
     <?= $this->render_partial('shared/modul/_modul_ohne_lv') ?>
-<? endif; ?>
\ No newline at end of file
+<? endif; ?>
diff --git a/app/views/shared/modul/overview.php b/app/views/shared/modul/overview.php
index 4bfd71e..be91c7a 100644
--- a/app/views/shared/modul/overview.php
+++ b/app/views/shared/modul/overview.php
@@ -1,3 +1,15 @@
+<?php
+/**
+ * @var Modul $modul
+ * @var Institute $institut
+ * @var ModulDeskriptor $deskriptor
+ * @var array $modulteile
+ * @var Semester $semester
+ * @var string $pruef_ebene
+ * @var int $type
+ */
+?>
+
 <table class="default mvv-modul-details nohover">
     <tr>
         <th class="mvv-modul-details-head" style="width: 30%"><?= htmlReady($modul->code) ?></th>
@@ -34,10 +46,10 @@
     <tr>
         <td colspan="4" style="padding: 0;">
             <table class="default nohover">
-                <? if (mb_strlen($teilnahmeVoraussetzung) > 0): ?>
+                <? if (mb_strlen($deskriptor->voraussetzung) > 0): ?>
                     <tr>
                         <td style="width: 20%; font-weight: bold;"><?= _('Teilnahmevoraussetzungen') ?></td>
-                        <td ><?= formatReady($teilnahmeVoraussetzung) ?></td>
+                        <td ><?= formatReady($deskriptor->voraussetzung) ?></td>
                     </tr>
                 <? endif; ?>
                 <? if (mb_strlen($deskriptor->kommentar)) : ?>
@@ -104,7 +116,7 @@
                 <th><?= _('Prüfungsleistung') ?></th>
             <? endif; ?>
         </tr>
-        <? foreach ($modulTeile as $modul_teil): ?>
+        <? foreach ($modulteile as $modul_teil): ?>
             <tr>
                 <? if ($type === 1): ?>
                 <td>
diff --git a/config/mvv_config.php b/config/mvv_config.php
index dae7c5d..79ee915 100644
--- a/config/mvv_config.php
+++ b/config/mvv_config.php
@@ -114,17 +114,6 @@ $GLOBALS['MVV_MODUL']['INSTITUT_GRUPPEN'] = [
     ]
 ];
 
-// Moduldeskriptor Ausgabesprache
-$GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE'] = [
-    'values'            => [
-        'DE'                => ['visible' => 1, 'name' => _('Originalfassung'), 'content_language' => 'de_DE'],
-        'EN'                => ['visible' => 1, 'name' => _('Englisch'), 'content_language' => 'en_GB']
-    //    'de_DE'                => array('visible' => 1, 'name' => _('Originalfassung')),
-    //    'en_GB'                => array('visible' => 1, 'name' => _('Englisch'))
-    ],
-    'default'           => 'DE'
-];
-
 // Modulteile
 $GLOBALS['MVV_MODULTEIL']['NUM_BEZEICHNUNG'] = [
     'values'            => [
@@ -201,9 +190,6 @@ $GLOBALS['MVV_MODULTEIL']['LERNLEHRFORM'] = [
     'default'           => ''
 ];
 
-// Modulteildeskriptor
-$GLOBALS['MVV_MODULTEIL_DESKRIPTOR']['SPRACHE'] = $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE'];
-
 // Maximale Anzahl Fachsemester
 $GLOBALS['MVV_MODULTEIL_FACHSEMESTER'] = 10;
 
@@ -230,16 +216,6 @@ $GLOBALS['MVV_STGTEILVERSION']['STATUS'] = $GLOBALS['MVV_MODUL']['STATUS'];
 
 $GLOBALS['MVV_STGTEIL']['STATUS'] = $GLOBALS['MVV_MODUL']['STATUS'];
 
-$GLOBALS['MVV_LANGUAGES'] = [
-    'values'            => [
-        'DE'                => ['visible' => 1, 'name' => _('Deutsch'),
-                                'locale' => 'de_DE'],
-        'EN'                => ['visible' => 1, 'name' => _('Englisch'),
-                                'locale' => 'en_GB']
-    ],
-    'default'           => 'DE'
-];
-
 $GLOBALS['MVV_STUDIENGANG']['FASSUNG_TYP'] = $GLOBALS['MVV_STGTEILVERSION']['FASSUNG_TYP'];
 
 $GLOBALS['MVV_STUDIENGANG']['STUDYCOURSE_TYPE'] = [
diff --git a/db/migrations/6.0.36_step_4261.php b/db/migrations/6.0.36_step_4261.php
new file mode 100644
index 0000000..0e5fe39
--- /dev/null
+++ b/db/migrations/6.0.36_step_4261.php
@@ -0,0 +1,50 @@
+<?php
+
+final class Step4261 extends Migration
+{
+    public function description()
+    {
+        return 'Add field to module table to store original language.';
+    }
+
+    protected function up()
+    {
+        $db = DBManager::get();
+
+        // retrieve default language from config
+        $config_language = $db->fetchColumn(
+            "SELECT `value` FROM `config` WHERE `field` = 'DEFAULT_LANGUAGE'"
+        );
+        $default_language = $config_language ?? array_keys($GLOBALS['CONTENT_LANGUAGES'])[0] ?? 'de_DE';
+        $db->execute(
+            'ALTER TABLE `mvv_modul`
+            ADD `original_language` VARCHAR(10) NOT NULL DEFAULT ? COLLATE latin1_bin AFTER `verantwortlich`',
+            [$default_language]
+        );
+
+        $query = "INSERT INTO `config` (`field`, `value`, `type`, `range`, `section`, `mkdate`, `chdate`, `description`)
+                  VALUES ('MVV_DEFAULT_LANGUAGE', ?, 'string', 'global', 'mvv', UNIX_TIMESTAMP(), UNIX_TIMESTAMP(), ?)";
+        $db->execute($query,
+            [
+                $default_language,
+                'Code der Inhalts-Sprache, die als Original-Sprache der Deskriptoren für Module und Modulteile vorausgewählt ist.',
+            ]
+        );
+    }
+
+    protected function down()
+    {
+        $db = DBManager::get();
+
+        $db->exec(
+            "ALTER TABLE `mvv_modul`
+            DROP COLUMN `original_language`"
+        );
+
+        $query = "DELETE `config`, `config_values`
+                  FROM `config`
+                  LEFT JOIN `config_values` USING (`field`)
+                  WHERE `field` = 'MVV_DEFAULT_LANGUAGE'";
+        $db->exec($query);
+    }
+}
diff --git a/lib/classes/MVV.php b/lib/classes/MVV.php
index b4d9edf..83568a9 100644
--- a/lib/classes/MVV.php
+++ b/lib/classes/MVV.php
@@ -834,7 +834,7 @@ class MVV implements Loggable {
     }
 
     /**
-     * Returns imagepath for given language, used by MVV
+     * Returns image path for given language, used by MVV
      * First tries $GLOBALS['CONTENT_LANGUAGES'], if not defined returns hardcoded path
      *
      * @param string $language e.g. 'DE'
@@ -842,8 +842,8 @@ class MVV implements Loggable {
      */
     public static function getContentLanguageImagePath($language): string
     {
-        $content_language = $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'][$language]['content_language'];
-        return 'languages/' . ($GLOBALS['CONTENT_LANGUAGES'][$content_language]['picture'] ?? 'lang_' . mb_strtolower($language) . '.gif');
+        $code = strtok($language, '_');
+        return 'languages/' . ($GLOBALS['CONTENT_LANGUAGES'][$language]['picture'] ?? 'lang_' . mb_strtolower($code) . '.gif');
     }
 
 }
diff --git a/lib/models/Lvgruppe.php b/lib/models/Lvgruppe.php
index 5e9eb7b..6f82215 100644
--- a/lib/models/Lvgruppe.php
+++ b/lib/models/Lvgruppe.php
@@ -583,9 +583,7 @@ class Lvgruppe extends ModuleManagementModelTreeItem
         $modul = Modul::find($modul_id);
         if ($modul) {
             $name = $modul->responsible_institute->institute->getShortName();
-            $short_name_modul = $modul->getDeskriptor(
-                    $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['default'])
-                    ->bezeichnung_kurz;
+            $short_name_modul = $modul->getDeskriptor()->bezeichnung_kurz;
             $name .= $short_name_modul ? ' ' . $short_name_modul : '';
         }
          *
@@ -594,7 +592,6 @@ class Lvgruppe extends ModuleManagementModelTreeItem
         $modulteil = Modulteil::findCached($modulteil_id);
         if ($modulteil) {
             $name = $modulteil->getDeskriptor()->bezeichnung;
-            //$name = $name_modulteil ? ' ' . $name_modulteil : '';
         }
         return $name;
     }
diff --git a/lib/models/Modul.php b/lib/models/Modul.php
index 31f4bbe..70ffad6 100644
--- a/lib/models/Modul.php
+++ b/lib/models/Modul.php
@@ -36,6 +36,7 @@
  * @property string|null $stat database column
  * @property string|null $kommentar_status database column
  * @property string|null $verantwortlich database column
+ * @property string $original_language database column
  * @property string $author_id database column
  * @property string $editor_id database column
  * @property int $mkdate database column
@@ -383,14 +384,12 @@ class Modul extends ModuleManagementModelTreeItem
      * previously set by ApplicationSimpleORMap::setLanguage() or the one
      * defined as default in mvv_config.php.
      */
-    private function setDefaultLanguage()
+    private function setDefaultLanguage(): void
     {
-        if (isset($GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values']
-                [ModuleManagementModel::getLanguage()])) {
-            $this->default_language = ModuleManagementModel::getLanguage();
+        if ($this->isNew()) {
+            $this->default_language = Config::get()->MVV_DESCRIPTOR_DEFAULT_LANGUAGE;
         } else {
-            $this->default_language =
-                    $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['default'];
+            $this->default_language = $this->original_language;
         }
     }
 
@@ -405,18 +404,13 @@ class Modul extends ModuleManagementModelTreeItem
     }
 
     /**
-     * Returns the Deskriptor in the given language. A Modul has always a
-     * Deskriptor in the default language. If the given language is unknown, the
-     * method returns the deskriptor in the default language.
+     * Returns the descriptor. If this component has no descriptor already
+     * a new one is created and returned.
      *
-     * @param string $language The id of the language
-     * @param bool If true returns always a new descriptor
-     * @return object The Deskriptor.
+     * @return ModulDeskriptor The descriptor.
      */
-    public function getDeskriptor($language = null, $force_new = false) {
-        if (!isset($GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['values'][$language])) {
-            $language = $this->default_language;
-        }
+    public function getDeskriptor()
+    {
         if (!$this->deskriptoren) {
             // the module is new and has no descriptor
             // return a new descriptor in the default language
@@ -481,7 +475,7 @@ class Modul extends ModuleManagementModelTreeItem
     /**
      * Assignes languages of instruction to this part-module.
      *
-     * @param type $languages An array of language keys defined in mvv_config.php.
+     * @param array $languages An array of language keys defined in mvv_config.php.
      */
     public function assignLanguagesOfInstruction($languages)
     {
diff --git a/lib/models/ModulDeskriptor.php b/lib/models/ModulDeskriptor.php
index 5a3d071..9f48fc2 100644
--- a/lib/models/ModulDeskriptor.php
+++ b/lib/models/ModulDeskriptor.php
@@ -140,12 +140,13 @@ class ModulDeskriptor extends ModuleManagementModel
      * @see ModuleManagementModel::getVariant()
      * @return string The language identifier.
      */
-    public function getVariant()
+    public function getVariant(): string
     {
-        if (self::getLanguage() == $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['default']) {
+        if (self::getLanguage() === Config::get()->MVV_DESCRIPTOR_DEFAULT_LANGUAGE) {
             return '';
         }
-        return self::getLanguage();
+        $splitted_code = explode('_', self::getLanguage());
+        return mb_strtoupper($splitted_code[0] ?? '');
     }
 
     /**
@@ -156,7 +157,6 @@ class ModulDeskriptor extends ModuleManagementModel
      */
     public function deleteTranslation($language)
     {
-        $locale = $GLOBALS['MVV_LANGUAGES']['values'][$language]['locale'];
-        return I18NString::removeAllTranslations($this->id, 'mvv_modul_deskriptor', $locale);
+        return I18NString::removeAllTranslations($this->id, 'mvv_modul_deskriptor', $language);
     }
 }
diff --git a/lib/models/ModuleManagementModel.php b/lib/models/ModuleManagementModel.php
index 3bd5eb7..88b264f 100644
--- a/lib/models/ModuleManagementModel.php
+++ b/lib/models/ModuleManagementModel.php
@@ -725,25 +725,26 @@ abstract class ModuleManagementModel extends SimpleORMap implements ModuleManage
      */
     public static function setContentLanguage($language)
     {
-        if (!is_array($GLOBALS['MVV_LANGUAGES']['values'][$language])) {
+        if (!is_array(Config::get()->CONTENT_LAGUAGES[$language])) {
             throw new InvalidArgumentException();
         }
-        $locale = $GLOBALS['MVV_LANGUAGES']['values'][$language]['locale'];
-        I18NString::setContentLanguage($locale);
+        I18NString::setContentLanguage($language);
         self::$language = $language;
     }
 
-    public function getAvailableTranslations()
+    public function getAvailableTranslations(string $original_language): array
     {
-        $translations[] = $GLOBALS['MVV_LANGUAGES']['default'];
+        $translations = [];
         $stmt = DBManager::get()->prepare('SELECT DISTINCT `lang` '
                 . 'FROM i18n '
                 . 'WHERE `object_id` = ? AND `table` = ?');
         $stmt->execute([$this->id, $this->db_table()]);
-        foreach ($stmt->fetchAll() as $locale) {
-            $language = mb_strtoupper(mb_strstr($locale['lang'], '_', true));
-            if (is_array($GLOBALS['MVV_LANGUAGES']['values'][$language])) {
-                $translations[] = $language;
+        $languages = array_merge([$original_language],
+            $stmt->fetchAll(PDO::FETCH_COLUMN));
+        $content_languages = Config::get()->CONTENT_LANGUAGES;
+        foreach ($languages as $code) {
+            if (is_array($content_languages[$code])) {
+                $translations[] = $code;
             }
         }
         return $translations;
diff --git a/lib/models/Modulteil.php b/lib/models/Modulteil.php
index 3b8f146..cc992af 100644
--- a/lib/models/Modulteil.php
+++ b/lib/models/Modulteil.php
@@ -114,7 +114,11 @@ class Modulteil extends ModuleManagementModelTreeItem
     {
         parent::__construct($id);
         $this->object_real_name = _('Modulteil');
-        $this->default_language = $GLOBALS['MVV_MODUL_DESKRIPTOR']['SPRACHE']['default'];
+        if ($this->modul) {
+            $this->default_language = $this->modul->original_language;
+        } else {
+            $this->default_language = Config::get()->MVV_DESCRIPTOR_DEFAULT_LANGUAGE;
+        }
     }
 
     /**
@@ -165,7 +169,7 @@ class Modulteil extends ModuleManagementModelTreeItem
 
     public function getDisplayName()
     {
-        $deskriptor = $this->getDeskriptor(self::getLanguage());
+        $deskriptor = $this->getDeskriptor();
         $template = Config::get()->MVV_TEMPLATE_NAME_MODULTEIL;
         if (trim($template)) {
             $placeholders = [
@@ -210,19 +214,12 @@ class Modulteil extends ModuleManagementModelTreeItem
     }
 
     /**
-     * Returns the Deskriptor in the given language. A Modul has always a
-     * Deskriptor in the default language. If the given language is unknown, the
-     * method returns the deskriptor in the default language.
+     * Returns the descriptor. If this component has no descriptor already
+     * a new one is created and returned.
      *
-     * @param string $language The id of the language
-     * @param bool If true returns always a new descriptor
-     * @return object The Deskriptor.
+     * @return ModulteilDeskriptor The descriptor.
      */
-    public function getDeskriptor($language = null, $force_new = false) {
-        if (!isset($GLOBALS['MVV_MODULTEIL_DESKRIPTOR']['SPRACHE']['values'][$language])) {
-            $language = $this->default_language;
-        }
-
+    public function getDeskriptor() {
         if (!$this->deskriptoren) {
             // the module is new and has no descriptor
             // return a new descriptor in the default language
diff --git a/lib/models/ModulteilDeskriptor.php b/lib/models/ModulteilDeskriptor.php
index aa6ddf7..ebe5026 100644
--- a/lib/models/ModulteilDeskriptor.php
+++ b/lib/models/ModulteilDeskriptor.php
@@ -114,12 +114,13 @@ class ModulteilDeskriptor extends ModuleManagementModel
      * @see ModuleManagementModel::getVariant()
      * @return string The language identifier.
      */
-    public function getVariant()
+    public function getVariant(): string
     {
-        if (self::getLanguage() == $GLOBALS['MVV_MODULTEIL_DESKRIPTOR']['SPRACHE']['default']) {
+        if (self::getLanguage() === Config::get()->MVV_DESCRIPTOR_DEFAULT_LANGUAGE) {
             return '';
         }
-        return self::getLanguage();
+        $splitted_code = explode('_', self::getLanguage());
+        return mb_strtoupper($splitted_code[0] ?? '');
     }
 
     /**
@@ -130,7 +131,6 @@ class ModulteilDeskriptor extends ModuleManagementModel
      */
     public function deleteTranslation($language)
     {
-        $locale = $GLOBALS['MVV_LANGUAGES']['values'][$language]['locale'];
-        return I18NString::removeAllTranslations($this->id, 'mvv_modulteil_deskriptor', $locale);
+        return I18NString::removeAllTranslations($this->id, 'mvv_modulteil_deskriptor', $language);
     }
 }