relocate flexi, fixes #4101

Closes #4101

Merge request studip/studip!2977

63 files changed, 729 insertions, 129 deletions

diff --git a/lib/admissionrules/conditionaladmission/ConditionalAdmission.class.php b/lib/admissionrules/conditionaladmission/ConditionalAdmission.class.php
index 63275f0..7fdbc00 100644
--- a/lib/admissionrules/conditionaladmission/ConditionalAdmission.class.php
+++ b/lib/admissionrules/conditionaladmission/ConditionalAdmission.class.php
@@ -207,7 +207,7 @@ class ConditionalAdmission extends AdmissionRule
         // Open generic admission rule template.
         $tpl = $GLOBALS['template_factory']->open('admission/rules/configure');
         $tpl->set_attribute('rule', $this);
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(__DIR__ . '/templates/');
         // Now open specific template for this rule and insert base template.
         $tpl2 = $factory->open('configure');
         $tpl2->set_attribute('rule', $this);
@@ -471,7 +471,7 @@ class ConditionalAdmission extends AdmissionRule
      */
     public function toString()
     {
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(__DIR__ . '/templates/');
         $tpl = $factory->open('info');
         $tpl->set_attribute('rule', $this);
         return $tpl->render();
diff --git a/lib/admissionrules/coursememberadmission/CourseMemberAdmission.class.php b/lib/admissionrules/coursememberadmission/CourseMemberAdmission.class.php
index a502971..a3309e8 100644
--- a/lib/admissionrules/coursememberadmission/CourseMemberAdmission.class.php
+++ b/lib/admissionrules/coursememberadmission/CourseMemberAdmission.class.php
@@ -253,8 +253,8 @@ class CourseMemberAdmission extends AdmissionRule
         return '';
     }
 
-    private function getTemplateFactory(): Flexi_TemplateFactory
+    private function getTemplateFactory(): Flexi\Factory
     {
-        return new Flexi_TemplateFactory(__DIR__ . '/templates/');
+        return new Flexi\Factory(__DIR__ . '/templates/');
     }
 }
diff --git a/lib/admissionrules/limitedadmission/LimitedAdmission.class.php b/lib/admissionrules/limitedadmission/LimitedAdmission.class.php
index b0cb1ca..a193bda 100644
--- a/lib/admissionrules/limitedadmission/LimitedAdmission.class.php
+++ b/lib/admissionrules/limitedadmission/LimitedAdmission.class.php
@@ -126,7 +126,7 @@ class LimitedAdmission extends AdmissionRule
         // Open generic admission rule template.
         $tpl = $GLOBALS['template_factory']->open('admission/rules/configure');
         $tpl->set_attribute('rule', $this);
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         // Now open specific template for this rule and insert base template.
         $tpl2 = $factory->open('configure');
         $tpl2->set_attribute('rule', $this);
@@ -248,7 +248,7 @@ class LimitedAdmission extends AdmissionRule
      * @return String
      */
     public function toString() {
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         $tpl = $factory->open('info');
         $tpl->set_attribute('rule', $this);
         return $tpl->render();
diff --git a/lib/admissionrules/lockedadmission/LockedAdmission.class.php b/lib/admissionrules/lockedadmission/LockedAdmission.class.php
index c313d55..0ca324b 100644
--- a/lib/admissionrules/lockedadmission/LockedAdmission.class.php
+++ b/lib/admissionrules/lockedadmission/LockedAdmission.class.php
@@ -72,7 +72,7 @@ class LockedAdmission extends AdmissionRule
      * @return String
      */
     public function getTemplate() {
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         // Now open specific template for this rule and insert base template. 
         $tpl = $factory->open('configure');
         $tpl->set_attribute('rule', $this);
@@ -125,7 +125,7 @@ class LockedAdmission extends AdmissionRule
      * @return String
      */
     public function toString() {
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         $tpl = $factory->open('info');
         $tpl->set_attribute('rule', $this);
         return $tpl->render();
@@ -133,4 +133,4 @@ class LockedAdmission extends AdmissionRule
 
 } /* end of class LockedAdmission */
 
-?>
\ No newline at end of file
+?>
diff --git a/lib/admissionrules/participantrestrictedadmission/ParticipantRestrictedAdmission.class.php b/lib/admissionrules/participantrestrictedadmission/ParticipantRestrictedAdmission.class.php
index a64b88a..28a910d 100644
--- a/lib/admissionrules/participantrestrictedadmission/ParticipantRestrictedAdmission.class.php
+++ b/lib/admissionrules/participantrestrictedadmission/ParticipantRestrictedAdmission.class.php
@@ -107,7 +107,7 @@ class ParticipantRestrictedAdmission extends AdmissionRule
      */
     public function getTemplate()
     {
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         // Open specific template for this rule and insert base template.
         $tpl = $factory->open('configure');
         $tpl->set_attribute('rule', $this);
@@ -199,7 +199,7 @@ class ParticipantRestrictedAdmission extends AdmissionRule
      */
     public function toString()
     {
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         $tpl = $factory->open('info');
         $tpl->set_attribute('rule', $this);
         return $tpl->render();
diff --git a/lib/admissionrules/passwordadmission/PasswordAdmission.class.php b/lib/admissionrules/passwordadmission/PasswordAdmission.class.php
index 6a99066..0650630 100644
--- a/lib/admissionrules/passwordadmission/PasswordAdmission.class.php
+++ b/lib/admissionrules/passwordadmission/PasswordAdmission.class.php
@@ -80,7 +80,7 @@ class PasswordAdmission extends AdmissionRule
      * @return String A template-based input form.
      */
     public function getInput() {
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         $tpl = $factory->open('input');
         $tpl->set_attribute('rule', $this);
         return $tpl->render();
@@ -111,7 +111,7 @@ class PasswordAdmission extends AdmissionRule
         // Open generic admission rule template.
         $tpl = $GLOBALS['template_factory']->open('admission/rules/configure');
         $tpl->set_attribute('rule', $this);
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         // Now open specific template for this rule and insert base template.
         $tpl2 = $factory->open('configure');
         $tpl2->set_attribute('rule', $this);
@@ -214,7 +214,7 @@ class PasswordAdmission extends AdmissionRule
      * @return String
      */
     public function toString() {
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         $tpl = $factory->open('info');
         $tpl->set_attribute('rule', $this);
         return $tpl->render();
diff --git a/lib/admissionrules/preferentialadmission/PreferentialAdmission.class.php b/lib/admissionrules/preferentialadmission/PreferentialAdmission.class.php
index 6bb6ceb..bee3e19 100644
--- a/lib/admissionrules/preferentialadmission/PreferentialAdmission.class.php
+++ b/lib/admissionrules/preferentialadmission/PreferentialAdmission.class.php
@@ -338,7 +338,7 @@ class PreferentialAdmission extends AdmissionRule
      */
     public function getTemplate()
     {
-        $factory = new Flexi_TemplateFactory(__DIR__.'/templates/');
+        $factory = new Flexi\Factory(__DIR__.'/templates/');
         // Now open specific template for this rule and insert base template.
         $tpl = $factory->open('configure');
         $tpl->set_attribute('rule', $this);
@@ -503,7 +503,7 @@ class PreferentialAdmission extends AdmissionRule
      */
     public function toString()
     {
-        $factory = new Flexi_TemplateFactory(__DIR__.'/templates/');
+        $factory = new Flexi\Factory(__DIR__.'/templates/');
         $tpl = $factory->open('info');
         $tpl->set_attribute('rule', $this);
         return $tpl->render();
diff --git a/lib/admissionrules/termsadmission/TermsAdmission.class.php b/lib/admissionrules/termsadmission/TermsAdmission.class.php
index 112a12e..50c8712 100644
--- a/lib/admissionrules/termsadmission/TermsAdmission.class.php
+++ b/lib/admissionrules/termsadmission/TermsAdmission.class.php
@@ -61,16 +61,16 @@ class TermsAdmission extends AdmissionRule
     /**
      * Shows an input form
      *
-     * @return String A template-based input form.
-     * @throws Flexi_TemplateNotFoundException
+     * @return string A template-based input form.
+     * @throws Flexi\TemplateNotFoundException
      */
     public function getInput()
     {
-        $factory = new Flexi_TemplateFactory(__DIR__ . '/templates');
+        $factory = new Flexi\Factory(__DIR__ . '/templates');
         $template = $factory->open('input');
         $template->rule = $this;
 
-        return MessageBox::info($template->render())->hideClose(true);
+        return (string) MessageBox::info($template->render())->hideClose();
     }
 
     /**
@@ -84,11 +84,11 @@ class TermsAdmission extends AdmissionRule
      * Gets the template that provides a configuration GUI for this rule.
      *
      * @return String
-     * @throws Flexi_TemplateNotFoundException
+     * @throws Flexi\TemplateNotFoundException
      */
     public function getTemplate()
     {
-        $factory = new Flexi_TemplateFactory(__DIR__ . '/templates');
+        $factory = new Flexi\Factory(__DIR__ . '/templates');
         $template = $factory->open('configure');
         $template->rule = $this;
 
@@ -158,11 +158,11 @@ class TermsAdmission extends AdmissionRule
      * A textual description of the current rule.
      *
      * @return String
-     * @throws Flexi_TemplateNotFoundException
+     * @throws Flexi\TemplateNotFoundException
      */
     public function toString()
     {
-        $factory = new Flexi_TemplateFactory(__DIR__ . '/templates/');
+        $factory = new Flexi\Factory(__DIR__ . '/templates/');
         $template = $factory->open('info');
         $template->rule = $this;
 
diff --git a/lib/admissionrules/timedadmission/TimedAdmission.class.php b/lib/admissionrules/timedadmission/TimedAdmission.class.php
index 735fdee..e167bd8 100644
--- a/lib/admissionrules/timedadmission/TimedAdmission.class.php
+++ b/lib/admissionrules/timedadmission/TimedAdmission.class.php
@@ -101,7 +101,7 @@ class TimedAdmission extends AdmissionRule
      * @return String
      */
     public function getTemplate() {
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         // Open specific template for this rule and insert base template.
         $tpl = $factory->open('configure');
         $tpl->set_attribute('rule', $this);
@@ -213,7 +213,7 @@ class TimedAdmission extends AdmissionRule
      */
     public function toString()
     {
-        $factory = new Flexi_TemplateFactory(dirname(__FILE__).'/templates/');
+        $factory = new Flexi\Factory(dirname(__FILE__).'/templates/');
         $tpl = $factory->open('info');
         $tpl->set_attribute('rule', $this);
         return $tpl->render();
diff --git a/lib/bootstrap-autoload.php b/lib/bootstrap-autoload.php
index 1f3f6d4..0bbad81 100644
--- a/lib/bootstrap-autoload.php
+++ b/lib/bootstrap-autoload.php
@@ -51,11 +51,18 @@ StudipAutoloader::addAutoloadPath('lib/raumzeit');
 StudipAutoloader::addAutoloadPath('lib/resources');
 StudipAutoloader::addAutoloadPath('lib/activities', 'Studip\\Activity');
 
-StudipAutoloader::addAutoloadPath('lib/extern');
 StudipAutoloader::addAutoloadPath('lib/calendar/lib');
 StudipAutoloader::addAutoloadPath('lib/elearning');
+StudipAutoloader::addAutoloadPath('lib/extern');
 StudipAutoloader::addAutoloadPath('lib/ilias_interface');
 
+// Flexi
+StudipAutoloader::addAutoloadPath('lib/flexi', 'Flexi');
+class_alias(Flexi\PhpTemplate::class, 'Flexi_PhpTemplate');
+class_alias(Flexi\Template::class, 'Flexi_Template');
+class_alias(Flexi\Factory::class, 'Flexi_TemplateFactory');
+class_alias(Flexi\TemplateNotFoundException::class, 'Flexi_TemplateNotFoundException');
+
 // Messy file names
 StudipAutoloader::addClassLookups([
     'email_validation_class' => 'lib/phplib/email_validation.class.php',
diff --git a/lib/bootstrap.php b/lib/bootstrap.php
index 0c66a97..e9c9bb5 100644
--- a/lib/bootstrap.php
+++ b/lib/bootstrap.php
@@ -54,7 +54,7 @@ $ABSOLUTE_URI_STUDIP = "";
 if (isset($_SERVER['SERVER_NAME'])) {
     // work around possible bug in lighttpd
     if (mb_strpos($_SERVER['SERVER_NAME'], ':') !== false) {
-        list($_SERVER['SERVER_NAME'], $_SERVER['SERVER_PORT']) =
+        [$_SERVER['SERVER_NAME'], $_SERVER['SERVER_PORT']] =
             explode(':', $_SERVER['SERVER_NAME']);
     }
 
@@ -125,8 +125,7 @@ Assets::set_assets_url($GLOBALS['ASSETS_URL']);
 Assets::set_assets_path($GLOBALS['ASSETS_PATH']);
 
 // globale template factory anlegen
-require_once 'vendor/flexi/lib/flexi.php';
-$GLOBALS['template_factory'] = new Flexi_TemplateFactory("{$STUDIP_BASE_PATH}/templates");
+$GLOBALS['template_factory'] = new Flexi\Factory("{$STUDIP_BASE_PATH}/templates");
 
 // set default pdo connection
 try {
diff --git a/lib/calendar/CalendarView.class.php b/lib/calendar/CalendarView.class.php
index fc69127..3d89ef1 100644
--- a/lib/calendar/CalendarView.class.php
+++ b/lib/calendar/CalendarView.class.php
@@ -214,7 +214,7 @@ class CalendarView
             'whole_height' => $this->getOverallHeight(),
             'entry_height' => $this->getHeight()
         ];
-        $factory = new Flexi_TemplateFactory(dirname(__file__).'/../../app/views');
+        $factory = new Flexi\Factory(dirname(__file__).'/../../app/views');
         PageLayout::addStyle($factory->render('calendar/schedule/stylesheet', $style_parameters));
 
         $template = $GLOBALS['template_factory']->open("calendar/calendar_view.php");
diff --git a/lib/classes/Fullcalendar.class.php b/lib/classes/Fullcalendar.class.php
index 467b583..db8364a 100644
--- a/lib/classes/Fullcalendar.class.php
+++ b/lib/classes/Fullcalendar.class.php
@@ -64,7 +64,7 @@ class Fullcalendar
 
     public function render()
     {
-        $factory = new \Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/templates');
+        $factory = new \Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/templates');
         $template = $factory->open('studip-fullcalendar.php');
         $real_data_name = sprintf('data-%s', $this->data_name);
         return $template->render(
diff --git a/lib/classes/I18N.php b/lib/classes/I18N.php
index d34ed0b..44252f3 100644
--- a/lib/classes/I18N.php
+++ b/lib/classes/I18N.php
@@ -61,10 +61,10 @@ class I18N
     /**
      * Protected constructor in order to always force a specific input type.
      *
-     * @param string|Flexi_Template $template   Template to use
+     * @param string|Flexi\Template $template   Template to use
      * @param string                $name       Name of the element
      * @param string|I18NString     $value      Value of the element
-     * @param array           $attributes Additional variables for the
+     * @param array                 $attributes Additional variables for the
      *                                          element
      */
     final protected function __construct($template, $name, $value, array $attributes)
diff --git a/lib/classes/QuestionType.interface.php b/lib/classes/QuestionType.interface.php
index ada6005..03019fe 100644
--- a/lib/classes/QuestionType.interface.php
+++ b/lib/classes/QuestionType.interface.php
@@ -60,7 +60,8 @@ interface QuestionType {
      *
      * Try to prefix all your input variables at least with the id of the question,
      * so that they will never conflict with other variables.
-     * @return Flexi_Template
+     *
+     * @return Flexi\Template
      */
     public function getDisplayTemplate();
 
@@ -82,11 +83,13 @@ interface QuestionType {
 
     /**
      * Returns a template with the results of this question.
+     *
      * @param $only_user_ids : array\null array of user_ids that the results should be restricted to.
      *                         this is used to show only a subset of results to the user for
      *                         visible evaluation of the results. If the questionnaire is anonymous
      *                         just do nothing.
-     * @return Flexi_Template
+     *
+     * @return Flexi\Template
      */
     public function getResultTemplate($only_user_ids = null);
 
diff --git a/lib/classes/Seminar.class.php b/lib/classes/Seminar.class.php
index 8aa3d41..a2d69ea 100644
--- a/lib/classes/Seminar.class.php
+++ b/lib/classes/Seminar.class.php
@@ -1735,7 +1735,7 @@ class Seminar
      */
     public function getDatesTemplate($template, $params = [])
     {
-        if (!$template instanceof Flexi_Template && is_string($template)) {
+        if (!$template instanceof Flexi\Template && is_string($template)) {
             $template = $GLOBALS['template_factory']->open($template);
         }
 
diff --git a/lib/classes/Siteinfo.php b/lib/classes/Siteinfo.php
index 0d849ca..4a969ee 100644
--- a/lib/classes/Siteinfo.php
+++ b/lib/classes/Siteinfo.php
@@ -281,7 +281,7 @@ class SiteinfoMarkupEngine {
 
     function __construct() {
         $this->db = DBManager::get();
-        $this->template_factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'].'/app/views/siteinfo/markup/');
+        $this->template_factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'].'/app/views/siteinfo/markup/');
         $this->siteinfoMarkup("/\(:version:\)/", [$this, 'version']);
         $this->siteinfoMarkup("/\(:uniname:\)/", [$this, 'uniName']);
         $this->siteinfoMarkup("/\(:unicontact:\)/", [$this, 'uniContact']);
@@ -659,7 +659,7 @@ function language_filter($input) {
 }
 
 function stripforeignlanguage($language, $text) {
-    list($primary, $sub) = explode('_',$_SESSION['_language']);
+    [$primary, $sub] = explode('_',$_SESSION['_language']);
     if ($language === $primary || $language === $_SESSION['_language']) {
         return str_replace('\"', '"', $text);
     } else {
diff --git a/lib/classes/StudipFileloader.php b/lib/classes/StudipFileloader.php
index 661c062..aab0b31 100644
--- a/lib/classes/StudipFileloader.php
+++ b/lib/classes/StudipFileloader.php
@@ -31,7 +31,7 @@ class StudipFileloader
                 !file_exists($file)
                 && !stream_resolve_include_path($file)
             ) {
-                continue;
+                throw new Exception('Missing file '. $file);
             }
             include $file;
         }
diff --git a/lib/classes/coursewizardsteps/AdvancedBasicDataWizardStep.php b/lib/classes/coursewizardsteps/AdvancedBasicDataWizardStep.php
index 780f837..cd33fd3 100644
--- a/lib/classes/coursewizardsteps/AdvancedBasicDataWizardStep.php
+++ b/lib/classes/coursewizardsteps/AdvancedBasicDataWizardStep.php
@@ -36,7 +36,7 @@ class AdvancedBasicDataWizardStep extends BasicDataWizardStep
         }
 
         // Load template from step template directory.
-        $factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'].'/app/views/course/wizard/steps');
+        $factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'].'/app/views/course/wizard/steps');
         $template = $factory->open('advancedbasicdata/index');
 
         $template = $this->setupTemplateAttributes($template, $values, $stepnumber, $temp_id);
diff --git a/lib/classes/coursewizardsteps/BasicDataWizardStep.php b/lib/classes/coursewizardsteps/BasicDataWizardStep.php
index 6a1438f..d47c4f3 100644
--- a/lib/classes/coursewizardsteps/BasicDataWizardStep.php
+++ b/lib/classes/coursewizardsteps/BasicDataWizardStep.php
@@ -28,7 +28,7 @@ class BasicDataWizardStep implements CourseWizardStep
     public function getStepTemplate($values, $stepnumber, $temp_id)
     {
         // Load template from step template directory.
-        $factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views/course/wizard/steps');
+        $factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views/course/wizard/steps');
         if (!empty($values[__CLASS__]['studygroup'])) {
             $tpl = $factory->open('basicdata/index_studygroup');
             $values[__CLASS__]['lecturers'][$GLOBALS['user']->id] = 1;
diff --git a/lib/classes/coursewizardsteps/LVGroupsWizardStep.php b/lib/classes/coursewizardsteps/LVGroupsWizardStep.php
index f343730..e79e1bd 100644
--- a/lib/classes/coursewizardsteps/LVGroupsWizardStep.php
+++ b/lib/classes/coursewizardsteps/LVGroupsWizardStep.php
@@ -39,7 +39,7 @@ class LVGroupsWizardStep implements CourseWizardStep
         $values = $values[__CLASS__] ?? [];
 
         // Load template from step template directory.
-        $factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views/course/wizard/steps');
+        $factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views/course/wizard/steps');
         $tpl = $factory->open('lvgroups/index');
         $tpl->set_attribute('values', $values);
 
@@ -226,7 +226,7 @@ class LVGroupsWizardStep implements CourseWizardStep
                 continue;
             }
 
-            $factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views');
+            $factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views');
             $html = $factory->render('course/wizard/steps/lvgroups/lvgroup_searchentry', compact('area'));
             $data = [
                 'id' => $area->id,
@@ -288,7 +288,7 @@ class LVGroupsWizardStep implements CourseWizardStep
             'Studiengang']);
         $pathes = ModuleManagementModelTreeItem::getPathes($trails);
 
-        $factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views');
+        $factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views');
         $html = $factory->render('course/lvgselector/entry_trails',
                 compact('area', 'pathes'));
 
@@ -308,7 +308,7 @@ class LVGroupsWizardStep implements CourseWizardStep
         $mvvid = explode('-', $id);
         $area = Lvgruppe::find($mvvid[0]);
 
-        $factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views');
+        $factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views');
         $html = $factory->render('course/wizard/steps/lvgroups/lvgroup_entry', ['area' => $area, 'locked' => false, 'course_id' => '']);
 
         $data = [
diff --git a/lib/classes/coursewizardsteps/StudyAreasWizardStep.php b/lib/classes/coursewizardsteps/StudyAreasWizardStep.php
index 29de617..eac7e37 100644
--- a/lib/classes/coursewizardsteps/StudyAreasWizardStep.php
+++ b/lib/classes/coursewizardsteps/StudyAreasWizardStep.php
@@ -30,7 +30,7 @@ class StudyAreasWizardStep implements CourseWizardStep
         // We only need our own stored values here.
         $values = $values[get_class($this)] ?? [];
         // Load template from step template directory.
-        $factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'].'/app/views/course/wizard/steps');
+        $factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'].'/app/views/course/wizard/steps');
         $tpl = $factory->open('studyareas/index');
         if (!empty($values['studyareas'])) {
             $tree = $this->buildPartialSemTree(StudipStudyArea::backwards(StudipStudyArea::findMany($values['studyareas'])));
diff --git a/lib/classes/forms/Form.php b/lib/classes/forms/Form.php
index 8977a37..36a2e7d 100644
--- a/lib/classes/forms/Form.php
+++ b/lib/classes/forms/Form.php
@@ -492,7 +492,7 @@ class Form extends Part
     /**
      * Renders the whole form as a string.
      * @return string
-     * @throws \Flexi_TemplateNotFoundException
+     * @throws \Flexi\TemplateNotFoundException
      */
     public function render()
     {
diff --git a/lib/classes/librarysearch/LibraryDocument.class.php b/lib/classes/librarysearch/LibraryDocument.class.php
index 4c90e0b4..46e11b2 100644
--- a/lib/classes/librarysearch/LibraryDocument.class.php
+++ b/lib/classes/librarysearch/LibraryDocument.class.php
@@ -14,7 +14,6 @@
  * @since       4.6
  */
 
-
 /**
  * This class represents a document from a library.
  */
@@ -386,12 +385,12 @@ class LibraryDocument
 
 
     /**
-     * @returns Flexi_Template A template containing information about the
+     * @returns Flexi\Template A template containing information about the
      *     the document.
      */
     public function getInfoTemplate($format = 'short')
     {
-        $factory = new Flexi_TemplateFactory(
+        $factory = new Flexi\Factory(
             $GLOBALS['STUDIP_BASE_PATH'] . '/templates/library/'
         );
         $template = $factory->open('library_document_info');
diff --git a/lib/classes/sidebar/TemplateWidget.php b/lib/classes/sidebar/TemplateWidget.php
index c937c3b..2ca2d70 100644
--- a/lib/classes/sidebar/TemplateWidget.php
+++ b/lib/classes/sidebar/TemplateWidget.php
@@ -15,10 +15,10 @@ class TemplateWidget extends SidebarWidget
      * Constructor of the widget.
      *
      * @param String         $title     Title of the widget
-     * @param Flexi_Template $template  Template for the widget
+     * @param Flexi\Template $template  Template for the widget
      * @param array          $variables Associated variables for the template
      */
-    public function __construct($title, Flexi_Template $template, array $variables = [])
+    public function __construct($title, Flexi\Template $template, array $variables = [])
     {
         parent::__construct();
 
diff --git a/lib/filesystem/CourseDateFolder.php b/lib/filesystem/CourseDateFolder.php
index 2ab0435..7c91c87 100644
--- a/lib/filesystem/CourseDateFolder.php
+++ b/lib/filesystem/CourseDateFolder.php
@@ -92,7 +92,7 @@ class CourseDateFolder extends PermissionEnabledFolder implements FolderType
     /**
      * This method returns the special part for the edit template
      *
-     * @return Flexi_Template  edit template
+     * @return Flexi\Template  edit template
      */
     public function getEditTemplate()
     {
@@ -126,7 +126,7 @@ class CourseDateFolder extends PermissionEnabledFolder implements FolderType
     /**
      * Returns the description template
      *
-     * @return Flexi_Template description template
+     * @return Flexi\Template description template
      */
     public function getDescriptionTemplate()
     {
diff --git a/lib/filesystem/CoursePublicFolder.php b/lib/filesystem/CoursePublicFolder.php
index 463fe19..6fa722d 100644
--- a/lib/filesystem/CoursePublicFolder.php
+++ b/lib/filesystem/CoursePublicFolder.php
@@ -112,7 +112,7 @@ class CoursePublicFolder extends StandardFolder
     /**
      * Returns the edit template for this folder type.
      *
-     * @return Flexi_Template
+     * @return Flexi\Template
      */
     public function getEditTemplate()
     {
diff --git a/lib/filesystem/FileType.php b/lib/filesystem/FileType.php
index 5a53896..3dcd32f 100644
--- a/lib/filesystem/FileType.php
+++ b/lib/filesystem/FileType.php
@@ -177,10 +177,12 @@ interface FileType
     public function convertToStandardFile();
 
     /**
-     * Returns the content for that additional column, if it exists. You can return null a string
-     * or a Flexi_Template as the content.
+     * Returns the content for that additional column, if it exists. You can
+     * return null, a string or a Flexi\Template as the content.
+     *
      * @param string $column_index
-     * @return null|string|Flexi_Template
+     *
+     * @return null|string|Flexi\Template
      */
     public function getContentForAdditionalColumn($column_index);
 
@@ -194,14 +196,14 @@ interface FileType
 
 
     /**
-     * Generates a Flexi_Template containing additional information that are
+     * Generates a Flexi\Template containing additional information that are
      * displayes in the information dialog of a file.
      *
      * @param bool $include_downloadable_infos Whether to include information
      *     like file previews that can be downloaded (true) or to not
      *     include them (false). Defaults to false.
      *
-     * @returns Flexi_Template|null Either a Flexi_Template containing
+     * @returns Flexi\Template|null Either a Flexi\Template containing
      *     additional information or null if no such information shall be
      *     displayed in the information dialog.
      */
diff --git a/lib/filesystem/FolderType.php b/lib/filesystem/FolderType.php
index 94d8667..69dae30 100644
--- a/lib/filesystem/FolderType.php
+++ b/lib/filesystem/FolderType.php
@@ -119,7 +119,7 @@ interface FolderType
     /**
      * returns description of the folder
      *
-     * @return Flexi_Template | string
+     * @return Flexi\Template | string
      */
     public function getDescriptionTemplate();
 
@@ -144,7 +144,7 @@ interface FolderType
     /**
      * returns template form, must not contain opening and closing <form> tags
      *
-     * @return Flexi_Template | string
+     * @return Flexi\Template | string
      */
     public function getEditTemplate();
 
@@ -243,10 +243,12 @@ interface FolderType
     public function getAdditionalColumns();
 
     /**
-     * Returns the content for that additional column, if it exists. You can return null a string
-     * or a Flexi_Template as the content.
+     * Returns the content for that additional column, if it exists. You can
+     * return null, a string or a Flexi\Template as the content.
+     *
      * @param string $column_index
-     * @return null|string|Flexi_Template
+     *
+     * @return null|string|Flexi\Template
      */
     public function getContentForAdditionalColumn($column_index);
 
diff --git a/lib/filesystem/HiddenFolder.php b/lib/filesystem/HiddenFolder.php
index b29f5fb..4daee0b 100644
--- a/lib/filesystem/HiddenFolder.php
+++ b/lib/filesystem/HiddenFolder.php
@@ -78,7 +78,7 @@ class HiddenFolder extends PermissionEnabledFolder
     /**
      * Returns the edit template for this folder type.
      *
-     * @return Flexi_Template
+     * @return Flexi\Template
      */
     public function getEditTemplate()
     {
diff --git a/lib/filesystem/InboxOutboxFolder.php b/lib/filesystem/InboxOutboxFolder.php
index 9386be4..6a8f2fd 100644
--- a/lib/filesystem/InboxOutboxFolder.php
+++ b/lib/filesystem/InboxOutboxFolder.php
@@ -269,10 +269,12 @@ class InboxOutboxFolder implements FolderType
     }
 
     /**
-     * Returns the content for that additional column, if it exists. You can return null a string
-     * or a Flexi_Template as the content.
+     * Returns the content for that additional column, if it exists. You can
+     * return null, a string or a Flexi\Template as the content.
+     *
      * @param string $column_index
-     * @return null|string|Flexi_Template
+     *
+     * @return null|string|Flexi\Template
      */
     public function getContentForAdditionalColumn($column_index)
     {
diff --git a/lib/filesystem/PublicFolder.php b/lib/filesystem/PublicFolder.php
index 6b06ac9..2dc4847 100644
--- a/lib/filesystem/PublicFolder.php
+++ b/lib/filesystem/PublicFolder.php
@@ -160,7 +160,7 @@ class PublicFolder extends StandardFolder
     /**
      * Returns the edit template for this folder type.
      *
-     * @return Flexi_Template
+     * @return Flexi\Template
      */
     public function getEditTemplate()
     {
diff --git a/lib/filesystem/RootFolder.php b/lib/filesystem/RootFolder.php
index 0727770..9771c32 100644
--- a/lib/filesystem/RootFolder.php
+++ b/lib/filesystem/RootFolder.php
@@ -86,7 +86,7 @@ class RootFolder extends StandardFolder
     }
 
     /**
-     * @return Flexi_Template
+     * @return Flexi\Template
      */
     public function getEditTemplate()
     {
diff --git a/lib/filesystem/StandardFile.php b/lib/filesystem/StandardFile.php
index 9d2d35c..4eb3140 100644
--- a/lib/filesystem/StandardFile.php
+++ b/lib/filesystem/StandardFile.php
@@ -460,9 +460,11 @@ class StandardFile implements FileType, ArrayAccess, StandardFileInterface
 
     /**
      * Returns the content for that additional column, if it exists. You can return null a string
-     * or a Flexi_Template as the content.
+     * or a Flexi\Template as the content.
+     *
      * @param string $column_index
-     * @return null|string|Flexi_Template
+     *
+     * @return null|string|Flexi\Template
      */
     public function getContentForAdditionalColumn($column_index)
     {
@@ -497,7 +499,7 @@ class StandardFile implements FileType, ArrayAccess, StandardFileInterface
             return null;
         }
 
-        $factory = new Flexi_TemplateFactory(
+        $factory = new Flexi\Factory(
             $GLOBALS['STUDIP_BASE_PATH'] . '/templates/filesystem/file_types/'
         );
         $template = $factory->open('standard_file_info');
diff --git a/lib/filesystem/StandardFolder.php b/lib/filesystem/StandardFolder.php
index a34ca4a..bbbb1fc 100644
--- a/lib/filesystem/StandardFolder.php
+++ b/lib/filesystem/StandardFolder.php
@@ -186,7 +186,7 @@ class StandardFolder implements FolderType
     }
 
     /**
-     * @return string|Flexi_Template
+     * @return string|Flexi\Template
      */
     public function getDescriptionTemplate()
     {
@@ -194,7 +194,7 @@ class StandardFolder implements FolderType
     }
 
     /**
-     * @return string|Flexi_Template
+     * @return string|Flexi\Template
      */
     public function getEditTemplate()
     {
@@ -509,9 +509,11 @@ class StandardFolder implements FolderType
 
     /**
      * Returns the content for that additional column, if it exists. You can return null a string
-     * or a Flexi_Template as the content.
+     * or a Flexi\Template as the content.
+     *
      * @param string $column_index
-     * @return null|string|Flexi_Template
+     *
+     * @return null|string|Flexi\Template
      */
     public function getContentForAdditionalColumn($column_index)
     {
diff --git a/lib/filesystem/TimedFolder.php b/lib/filesystem/TimedFolder.php
index 442c084..d5f933b 100644
--- a/lib/filesystem/TimedFolder.php
+++ b/lib/filesystem/TimedFolder.php
@@ -132,7 +132,7 @@ class TimedFolder extends PermissionEnabledFolder
     /**
      * Returns the description template for a instance of a TimedFolder type.
      *
-     * @return Flexi_Template A description template for a instance of the type TimedFolder
+     * @return Flexi\Template A description template for a instance of the type TimedFolder
      */
     public function getDescriptionTemplate()
     {
@@ -155,7 +155,7 @@ class TimedFolder extends PermissionEnabledFolder
     /**
      * Returns the edit template for this folder type.
      *
-     * @return Flexi_Template
+     * @return Flexi\Template
      */
     public function getEditTemplate()
     {
diff --git a/lib/flexi/Factory.php b/lib/flexi/Factory.php
new file mode 100644
index 0000000..b6c30fd
--- /dev/null
+++ b/lib/flexi/Factory.php
@@ -0,0 +1,243 @@
+<?php
+/**
+ * Using this factory you can create new Template objects.
+ *
+ * @copyright 2008 Marcus Lunzenauer <mlunzena@uos.de>
+ * @author Marcus Lunzenauer <mlunzena@uos.de>
+ * @license MIT
+ */
+
+namespace Flexi;
+
+class Factory
+{
+    /**
+     * mapping of file extensions to supported template classes
+     */
+    protected array $handlers = [
+        'php' => [PhpTemplate::class, []],
+    ];
+
+    /**
+     * Constructor of TemplateFactory.
+     *
+     * @param string $path the template include path
+     */
+    public function __construct(protected string $path)
+    {
+        $this->set_path($path);
+    }
+
+    /**
+     * Sets a new include path for the factory and returns the old one.
+     *
+     * @param string $path the new path
+     *
+     * @return string the old path
+     */
+    public function set_path(string $path): string
+    {
+        $old_path = $this->get_path();
+
+        if (!str_ends_with($path, '/')) {
+            $path .= '/';
+        }
+
+        $this->path = $path;
+
+        return $old_path;
+    }
+
+    /**
+     * Returns the include path of the factory
+     *
+     * @return string the current include path
+     */
+    public function get_path(): string
+    {
+        return $this->path;
+    }
+
+    /**
+     * Open a template of the given name using the factory method pattern.
+     * If a string was given, the path of the factory is searched for a matching
+     * template.
+     * If this string starts with a slash or with /\w+:\/\//, the string is
+     * interpreted as an absolute path. Otherwise the path of the factory will be
+     * prepended.
+     * After that the factory searches for a file extension in this string. If
+     * there is none, the directory where the template is supposed to live is
+     * searched for a file starting with the template string and a supported
+     * file extension.
+     * At last the factory instantiates a template object of the matching template
+     * class.
+     *
+     * Examples:
+     *
+     *   $factory->open('/path/to/template')
+     *     does not prepend the factory's path but searches for "template.*" in
+     *     "/path/to"
+     *
+     *   $factory->open('template')
+     *     prepends the factory's path and searches there for "template.*"
+     *
+     *  $factory->open('template.php')
+     *     prepends the factory's path but does not search and instantiates a
+     *     PHPTemplate instead
+     *
+     * This method returns it's parameter, if it is not a string. This
+     * functionality is useful for helper methods like #render_partial
+     *
+     * @param Template|string $template A name of a template.
+     * @return Template the factored object
+     * @throws TemplateNotFoundException if the template could not be found
+     */
+    public function open(Template|string $template): Template
+    {
+        # if it is not a string, this method behaves like identity
+        if ($template instanceof Template) {
+            return $template;
+        }
+
+        # get file
+        $file = $this->get_template_file($template);
+
+        # retrieve handler
+        [$class, $options] = $this->get_template_handler($file);
+
+        return new $class($file, $this, $options);
+    }
+
+    /**
+     * This method returns the absolute filename of the template
+     *
+     * @param string $template0 a template string
+     *
+     * @return string     an absolute filename
+     *
+     * @throws TemplateNotFoundException  if the template could not be found
+     */
+    public function get_template_file(string $template0): string
+    {
+        $template = $this->get_absolute_path($template0);
+        $extension = $this->get_extension($template);
+
+        # extension defined, is there a matching template class?
+        if ($extension !== null) {
+            if (file_exists($template)) {
+                return $template;
+            }
+        } # no extension defined, find it
+        else {
+            $file = $this->find_template($template);
+            if ($file !== null) {
+                return $file;
+            }
+        }
+
+        # falling through to throw exception
+        throw new TemplateNotFoundException(sprintf(
+            'Missing template "%s" in "%s".',
+            $template0,
+            $this->path
+        ));
+    }
+
+    /**
+     * Matches an extension to a template handler.
+     *
+     * @param string $template the template
+     *
+     * @return array|null an array containing the class name and an array of
+     *                    options of the matched extension;
+     *                    or NULL if the extension did not match
+     */
+    public function get_template_handler(string $template): ?array
+    {
+        $extension = $this->get_extension($template);
+        return $this->handlers[$extension] ?? null;
+    }
+
+    /**
+     * Registers a handler for templates with a matching extension.
+     *
+     * @param string $extension the extension of the templates to handle
+     * @param class-string<Template> $class the name of the already loaded class
+     * @param array $options optional; an array of options which is used
+     *                       when constructing a new instance
+     */
+    public function add_handler(
+        string $extension,
+        string $class,
+        array $options = []
+    ): void {
+        $this->handlers[$extension] = [$class, $options];
+    }
+
+    /**
+     * Returns the absolute path to the template. If the given argument starts
+     * with a slash or with a protocoll, this method just returns its arguments.
+     *
+     * @param string $template an incomplete template name
+     *
+     * @return string an absolute path to the incomplete template name
+     */
+    public function get_absolute_path(string $template): string
+    {
+        return preg_match('#^(/|\w+://)#', $template)
+            ? $template
+            : $this->get_path() . $template;
+    }
+
+
+    /**
+     * Find template given w/o extension.
+     *
+     * @param string $template the template's filename w/o extension
+     * @return string|null null if there no such file could be found, a string
+     *                     containing the complete file name otherwise
+     */
+    public function find_template(string $template): ?string
+    {
+        foreach ($this->handlers as $ext => $handler) {
+            $file = "$template.$ext";
+            if (file_exists($file)) {
+                return $file;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Returns the file extension if there is one.
+     *
+     * @param string $file an possibly incomplete template file name
+     * @return string|null a string containing the file extension if there is one,
+     *                     NULL otherwise
+     */
+    public function get_extension(string $file): ?string
+    {
+        return pathinfo($file, PATHINFO_EXTENSION) ?: null;
+    }
+
+    /**
+     * Class method to parse, render and return the presentation of a
+     * template.
+     *
+     * @param Template|string $template   A name of a template or a template
+     * @param array           $attributes An associative array of attributes and their
+     *                                    associated values.
+     * @param string|null     $layout     A name of a layout template.
+     *
+     * @return string A string representing the rendered presentation.
+     *
+     * @throws TemplateNotFoundException
+     */
+    public function render(
+        Template|string $template,
+        array $attributes = [],
+        ?string $layout = null
+    ): string {
+        return $this->open($template)->render($attributes, $layout);
+    }
+}
diff --git a/lib/flexi/PhpTemplate.php b/lib/flexi/PhpTemplate.php
new file mode 100644
index 0000000..8110b50
--- /dev/null
+++ b/lib/flexi/PhpTemplate.php
@@ -0,0 +1,111 @@
+<?php
+/**
+ * A template engine that uses PHP to render templates.
+ *
+ * @copyright 2008 Marcus Lunzenauer <mlunzena@uos.de>
+ * @author Marcus Lunzenauer <mlunzena@uos.de>
+ * @license MIT
+ */
+
+namespace Flexi;
+
+class PhpTemplate extends Template
+{
+    /**
+     * Parse, render and return the presentation.
+     *
+     * @return string A string representing the rendered presentation.
+     * @throws TemplateNotFoundException
+     */
+    public function _render(): string
+    {
+        extract($this->get_attributes());
+
+        # include template, parse it and get output
+        try {
+            ob_start();
+            require $this->template;
+            $content_for_layout = ob_get_contents();
+        } catch (\Error $e) {
+            throw new TemplateNotFoundException(previous: $e);
+        } finally {
+            ob_end_clean();
+        }
+
+        # include layout, parse it and get output
+        if (isset($this->layout)) {
+            $defined = get_defined_vars();
+            unset($defined['this']);
+            $content_for_layout = $this->layout->render($defined);
+        }
+
+        return $content_for_layout;
+    }
+
+    /**
+     * Parse, render and return the presentation of a partial template.
+     *
+     * @param Template|string $partial A partial name or template
+     * @param array $attributes An optional associative array of attributes
+     *                          and their associated values.
+     * @return string A string representing the rendered presentation.
+     * @throws TemplateNotFoundException
+     */
+    public function render_partial(Template|string $partial, array $attributes = []): string
+    {
+        return $this->factory->render($partial, $attributes + $this->attributes);
+    }
+
+    /**
+     * Renders a partial template with every member of a collection. This member
+     * can be accessed by a template variable with the same name as the name of
+     * the partial template.
+     *
+     * Example:
+     *
+     *   # template entry.php contains:
+     *   <li><?= $entry ?></li>
+     *
+     *
+     *   $entries = ['lorem', 'ipsum'];
+     *   $template->render_partial_collection('entry', $entries);
+     *
+     *   # results in:
+     *   <li>lorem</li>
+     *   <li>ipsum</li>
+     *
+     * If you want to use specific content between the rendered partials, you
+     * may define a spacer partial that will be used for that. The spacer will
+     * be rendered with the given attributes.
+     *
+     * @param string $partial A name of a partial template.
+     * @param array $collection The collection to be rendered.
+     * @param Template|string|null $spacer Optional a name of a partial template
+     *                                     used as spacer.
+     * @param array $attributes An optional associative array of attributes
+     *                          and their associated values.
+     *
+     * @return string A string representing the rendered presentation.
+     * @throws TemplateNotFoundException
+     */
+    public function render_partial_collection(
+        string $partial,
+        array $collection,
+        Template|string|null $spacer = null,
+        array $attributes = []
+    ): string {
+        $template = $this->factory->open($partial);
+        $template->set_attributes($this->attributes);
+        $template->set_attributes($attributes);
+
+        $collected = [];
+        $iterator_name = pathinfo($partial, PATHINFO_FILENAME);
+        foreach ($collection as $element) {
+            $collected[] = $template->render([$iterator_name => $element]);
+        }
+
+        $spacer = isset($spacer) ? $this->render_partial($spacer, $attributes) : '';
+
+        return implode($spacer, $collected);
+    }
+}
diff --git a/lib/flexi/Template.php b/lib/flexi/Template.php
new file mode 100644
index 0000000..de2547e
--- /dev/null
+++ b/lib/flexi/Template.php
@@ -0,0 +1,208 @@
+<?php
+/**
+ * Abstract template class representing the presentation layer of an action.
+ *  Output can be customized by supplying attributes, which a template can
+ *  manipulate and display.
+ *
+ * @copyright 2008 Marcus Lunzenauer <mlunzena@uos.de>
+ * @author Marcus Lunzenauer <mlunzena@uos.de>
+ * @license MIT
+ */
+
+namespace Flexi;
+
+abstract class Template
+{
+    /**
+     * Parse, render and return the presentation.
+     *
+     * @return string A string representing the rendered presentation.
+     */
+    abstract public function _render(): string;
+
+    protected array $attributes = [];
+    protected Template|null $layout = null;
+
+    /**
+     * Constructor
+     *
+     * @param string  $template the path of the template.
+     * @param Factory $factory  the factory creating this template
+     * @param array   $options  optional array of options
+     */
+    public function __construct(
+        protected string $template,
+        protected Factory $factory,
+        protected array $options = []
+    ) {
+    }
+
+    /**
+     * __set() is a magic method run when writing data to inaccessible members.
+     * In this class it is used to set attributes for the template in a
+     * comfortable way.
+     *
+     * @param string $name  the name of the member field
+     * @param mixed  $value the value for the member field
+     *
+     * @see http://php.net/__set
+     */
+    public function __set(string $name, mixed $value): void
+    {
+        $this->set_attribute($name, $value);
+    }
+
+    /**
+     * __get() is a magic method utilized for reading data from inaccessible
+     * members.
+     * In this class it is used to get attributes for the template in a
+     * comfortable way.
+     *
+     * @param string $name the name of the member field
+     *
+     * @return mixed the value for the member field
+     * @see http://php.net/__get
+     */
+    public function __get(string $name): mixed
+    {
+        return $this->get_attribute($name);
+    }
+
+    /**
+     * __isset() is a magic method triggered by calling isset() or empty() on
+     * inaccessible members.
+     * In this class it is used to check for attributes for the template in a
+     * comfortable way.
+     *
+     * @param string $name the name of the member field
+     *
+     * @return bool TRUE if that attribute exists, FALSE otherwise
+     * @see http://php.net/__isset
+     */
+    public function __isset(string $name): bool
+    {
+        return isset($this->attributes[$name]);
+    }
+
+    /**
+     * __unset() is a magic method invoked when unset() is used on inaccessible
+     * members.
+     * In this class it is used to check for attributes for the template in a
+     * comfortable way.
+     *
+     * @param string $name the name of the member field
+     *
+     * @see http://php.net/__set
+     */
+    public function __unset(string $name): void
+    {
+        $this->clear_attribute($name);
+    }
+
+    /**
+     * Parse, render and return the presentation.
+     *
+     * @param array $attributes An optional associative array of attributes and
+     *                          their associated values.
+     * @param string|Template|null $layout A name of a layout template.
+     *
+     * @return string A string representing the rendered presentation.
+     * @throws TemplateNotFoundException
+     */
+    public function render(array $attributes = [], string|Template $layout = null): string
+    {
+        if (isset($layout)) {
+            $this->set_layout($layout);
+        }
+
+        # merge attributes
+        $this->set_attributes($attributes);
+
+        return $this->_render();
+    }
+
+    /**
+     * Returns the value of an attribute.
+     *
+     * @param string $name An attribute name.
+     * @return mixed  An attribute value.
+     */
+    public function get_attribute(string $name)
+    {
+        return $this->attributes[$name] ?? null;
+    }
+
+    /**
+     * Set an array of attributes.
+     *
+     * @return array An associative array of attributes and their associated
+     *               values.
+     */
+    public function get_attributes(): array
+    {
+        return $this->attributes;
+    }
+
+    /**
+     * Set an attribute.
+     *
+     * @param string $name  An attribute name.
+     * @param mixed  $value An attribute value.
+     */
+    public function set_attribute(string $name, mixed $value): void
+    {
+        $this->attributes[$name] = $value;
+    }
+
+    /**
+     * Set an array of attributes.
+     *
+     * @param array $attributes An associative array of attributes and their
+     *                          associated values.
+     */
+    public function set_attributes(array $attributes): void
+    {
+        $this->attributes = $attributes + $this->attributes;
+    }
+
+
+    /**
+     * Clear all attributes associated with this template.
+     */
+    public function clear_attributes(): void
+    {
+        $this->attributes = [];
+    }
+
+    /**
+     * Clear an attribute associated with this template.
+     *
+     * @param string $name The name of the attribute to be cleared.
+     */
+    public function clear_attribute(string $name): void
+    {
+        unset($this->attributes[$name]);
+    }
+
+    /**
+     * Set the template's layout.
+     *
+     * @param Template|string|null $layout A name of a layout template or a
+     *                                     layout template.
+     * @throws TemplateNotFoundException
+     */
+    public function set_layout(Template|string|null $layout): void
+    {
+        $this->layout = $this->factory->open($layout);
+    }
+
+    /**
+     * Returns the template's layout.
+     *
+     * @return Template|null
+     */
+    public function get_layout(): ?Template
+    {
+        return $this->layout;
+    }
+}
diff --git a/lib/flexi/TemplateNotFoundException.php b/lib/flexi/TemplateNotFoundException.php
new file mode 100644
index 0000000..dbef2c6
--- /dev/null
+++ b/lib/flexi/TemplateNotFoundException.php
@@ -0,0 +1,12 @@
+<?php
+/**
+ * @copyright 2009 Marcus Lunzenauer <mlunzena@uos.de>
+ * @author Marcus Lunzenauer <mlunzena@uos.de>
+ * @license MIT
+ */
+
+namespace Flexi;
+
+class TemplateNotFoundException extends \Exception
+{
+}
diff --git a/lib/models/Courseware/BlockTypes/BlockType.php b/lib/models/Courseware/BlockTypes/BlockType.php
index b87a219..37e617b 100644
--- a/lib/models/Courseware/BlockTypes/BlockType.php
+++ b/lib/models/Courseware/BlockTypes/BlockType.php
@@ -438,9 +438,9 @@ abstract class BlockType
      * It turns the classname into snakecase in order to find the
      * template file in templates/courseware/block_types.
      *
-     * @return mixed the \Flexi_Template instance if exists, otherwise null.
+     * @return \Flexi\Template|null the \Flexi\Template instance if exists, otherwise null.
      */
-    public function getPdfHtmlTemplate(): ?\Flexi_Template
+    public function getPdfHtmlTemplate(): ?\Flexi\Template
     {
         $template = null;
         try {
diff --git a/lib/models/Courseware/ContainerTypes/ContainerType.php b/lib/models/Courseware/ContainerTypes/ContainerType.php
index baddaab..4e816be 100644
--- a/lib/models/Courseware/ContainerTypes/ContainerType.php
+++ b/lib/models/Courseware/ContainerTypes/ContainerType.php
@@ -249,9 +249,9 @@ abstract class ContainerType
      * It turns the classname into snakecase in order to find the
      * template file in templates/courseware/container_types.
      *
-     * @return mixed the \Flexi_Template instance if exists, otherwise null.
+     * @return \Flexi\Template|null the \Flexi\Template instance if exists, otherwise null.
      */
-    public function getPdfHtmlTemplate(): ?\Flexi_Template
+    public function getPdfHtmlTemplate(): ?\Flexi\Template
     {
         $template = null;
         try {
diff --git a/lib/models/Freetext.php b/lib/models/Freetext.php
index 52182de..66b93c5 100644
--- a/lib/models/Freetext.php
+++ b/lib/models/Freetext.php
@@ -65,12 +65,13 @@ class Freetext extends QuestionnaireQuestion implements QuestionType
 
     /**
      * Returns the template of this question to answer the question.
-     * @return Flexi_Template
-     * @throws Flexi_TemplateNotFoundException if there is no template.
+     *
+     * @return Flexi\Template
+     * @throws Flexi\TemplateNotFoundException if there is no template.
      */
     public function getDisplayTemplate()
     {
-        $factory = new Flexi_TemplateFactory(realpath(__DIR__ . '/../../app/views'));
+        $factory = new Flexi\Factory(realpath(__DIR__ . '/../../app/views'));
         $template = $factory->open('questionnaire/question_types/freetext/freetext_answer.php');
         $template->vote = $this;
         return $template;
@@ -97,9 +98,11 @@ class Freetext extends QuestionnaireQuestion implements QuestionType
 
     /**
      * Returns the template with the answers of the question so far.
+     *
      * @param null $only_user_ids : array of user_ids
-     * @return Flexi_Template
-     * @throws Flexi_TemplateNotFoundException if there is no template.
+     *
+     * @return Flexi\Template
+     * @throws Flexi\TemplateNotFoundException if there is no template.
      */
     public function getResultTemplate($only_user_ids = null)
     {
@@ -111,7 +114,7 @@ class Freetext extends QuestionnaireQuestion implements QuestionType
                 }
             }
         }
-        $factory = new Flexi_TemplateFactory(realpath(__DIR__ . '/../../app/views'));
+        $factory = new Flexi\Factory(realpath(__DIR__ . '/../../app/views'));
         $template = $factory->open('questionnaire/question_types/freetext/freetext_evaluation.php');
         $template->vote = $this;
         $template->set_attribute('answers', $answers);
diff --git a/lib/models/LikertScale.php b/lib/models/LikertScale.php
index 8ac7823..833d794 100644
--- a/lib/models/LikertScale.php
+++ b/lib/models/LikertScale.php
@@ -53,7 +53,7 @@ class LikertScale extends QuestionnaireQuestion implements QuestionType
 
     public function getDisplayTemplate()
     {
-        $factory = new Flexi_TemplateFactory(realpath(__DIR__.'/../../app/views'));
+        $factory = new Flexi\Factory(realpath(__DIR__.'/../../app/views'));
         $template = $factory->open('questionnaire/question_types/likert/likert_answer');
         $template->set_attribute('vote', $this);
         return $template;
@@ -73,7 +73,7 @@ class LikertScale extends QuestionnaireQuestion implements QuestionType
     public function getUserIdsOfFilteredAnswer($answer_option)
     {
         $user_ids = [];
-        list($statement_key, $options_key) = explode('_', $answer_option);
+        [$statement_key, $options_key] = explode('_', $answer_option);
         foreach ($this->answers as $answer) {
             $answerData = $answer['answerdata']->getArrayCopy();
             if ($answerData['answers'][$statement_key] == $options_key) {
@@ -93,7 +93,7 @@ class LikertScale extends QuestionnaireQuestion implements QuestionType
                 }
             }
         }
-        $factory = new Flexi_TemplateFactory(realpath(__DIR__.'/../../app/views'));
+        $factory = new Flexi\Factory(realpath(__DIR__.'/../../app/views'));
         $template = $factory->open('questionnaire/question_types/likert/likert_evaluation');
         $template->set_attribute('vote', $this);
         $template->set_attribute('answers', $answers);
diff --git a/lib/models/OERMaterial.php b/lib/models/OERMaterial.php
index 8411d14..604f845 100644
--- a/lib/models/OERMaterial.php
+++ b/lib/models/OERMaterial.php
@@ -198,7 +198,7 @@ class OERMaterial extends SimpleORMap
             return $output;
         }
 
-        $tf = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH']."/app/views");
+        $tf = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH']."/app/views");
         if ($material->hasValidPreviewUrl() || $material->isPDF()) {
             $template = $tf->open("oer/embed/url");
         } elseif ($material->isVideo()) {
diff --git a/lib/models/QuestionnaireInfo.php b/lib/models/QuestionnaireInfo.php
index fc6efc7..2bcf25d 100644
--- a/lib/models/QuestionnaireInfo.php
+++ b/lib/models/QuestionnaireInfo.php
@@ -50,7 +50,7 @@ class QuestionnaireInfo extends QuestionnaireQuestion implements QuestionType
 
     public function getDisplayTemplate()
     {
-        $factory = new Flexi_TemplateFactory(realpath(__DIR__.'/../../app/views'));
+        $factory = new Flexi\Factory(realpath(__DIR__.'/../../app/views'));
         $template = $factory->open('questionnaire/question_types/info/info');
         $template->set_attribute('vote', $this);
         return $template;
@@ -68,7 +68,7 @@ class QuestionnaireInfo extends QuestionnaireQuestion implements QuestionType
 
     public function getResultTemplate($only_user_ids = null)
     {
-        $factory = new Flexi_TemplateFactory(realpath(__DIR__.'/../../app/views'));
+        $factory = new Flexi\Factory(realpath(__DIR__.'/../../app/views'));
         $template = $factory->open('questionnaire/question_types/info/info');
         $template->set_attribute('vote', $this);
         return $template;
diff --git a/lib/models/RangeScale.php b/lib/models/RangeScale.php
index 78bc65b..44b946b 100644
--- a/lib/models/RangeScale.php
+++ b/lib/models/RangeScale.php
@@ -53,7 +53,7 @@ class RangeScale extends QuestionnaireQuestion implements QuestionType
 
     public function getDisplayTemplate()
     {
-        $factory = new Flexi_TemplateFactory(realpath(__DIR__.'/../../app/views'));
+        $factory = new Flexi\Factory(realpath(__DIR__.'/../../app/views'));
         $template = $factory->open('questionnaire/question_types/rangescale/rangescale_answer');
         $template->set_attribute('vote', $this);
         return $template;
@@ -72,7 +72,7 @@ class RangeScale extends QuestionnaireQuestion implements QuestionType
     public function getUserIdsOfFilteredAnswer($answer_option)
     {
         $user_ids = [];
-        list($statement_key, $options_key) = explode('_', $answer_option);
+        [$statement_key, $options_key] = explode('_', $answer_option);
         foreach ($this->answers as $answer) {
             $answerData = $answer['answerdata']->getArrayCopy();
             if ($answerData['answers'][$statement_key] == $options_key) {
@@ -92,7 +92,7 @@ class RangeScale extends QuestionnaireQuestion implements QuestionType
                 }
             }
         }
-        $factory = new Flexi_TemplateFactory(realpath(__DIR__.'/../../app/views'));
+        $factory = new Flexi\Factory(realpath(__DIR__.'/../../app/views'));
         $template = $factory->open('questionnaire/question_types/rangescale/rangescale_evaluation');
         $template->set_attribute('vote', $this);
         $template->set_attribute('answers', $answers);
diff --git a/lib/models/Vote.php b/lib/models/Vote.php
index 0520401..ede0cea 100644
--- a/lib/models/Vote.php
+++ b/lib/models/Vote.php
@@ -53,7 +53,7 @@ class Vote extends QuestionnaireQuestion implements QuestionType
 
     public function getDisplayTemplate()
     {
-        $factory = new Flexi_TemplateFactory(realpath(__DIR__.'/../../app/views'));
+        $factory = new Flexi\Factory(realpath(__DIR__.'/../../app/views'));
         $template = $factory->open('questionnaire/question_types/vote/vote_answer');
         $template->set_attribute('vote', $this);
         return $template;
@@ -100,7 +100,7 @@ class Vote extends QuestionnaireQuestion implements QuestionType
                 }
             }
         }
-        $factory = new Flexi_TemplateFactory(realpath(__DIR__.'/../../app/views'));
+        $factory = new Flexi\Factory(realpath(__DIR__.'/../../app/views'));
         $template = $factory->open('questionnaire/question_types/vote/vote_evaluation');
         $template->set_attribute('vote', $this);
         $template->set_attribute('answers', $answers);
diff --git a/lib/models/calendar/CalendarDate.class.php b/lib/models/calendar/CalendarDate.class.php
index 7026ece..d901cf1 100644
--- a/lib/models/calendar/CalendarDate.class.php
+++ b/lib/models/calendar/CalendarDate.class.php
@@ -114,7 +114,7 @@ class CalendarDate extends SimpleORMap implements PrivacyObject
 
     public function cbSendDateModificationMail()
     {
-        $template_factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/locale/');
+        $template_factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/locale/');
 
         foreach ($this->calendars as $calendar) {
             if ($calendar->range_id === $this->editor_id) {
diff --git a/lib/models/calendar/CalendarDateAssignment.class.php b/lib/models/calendar/CalendarDateAssignment.class.php
index bd99dd3..e0bf467 100644
--- a/lib/models/calendar/CalendarDateAssignment.class.php
+++ b/lib/models/calendar/CalendarDateAssignment.class.php
@@ -79,7 +79,7 @@ class CalendarDateAssignment extends SimpleORMap implements Event
             return;
         }
 
-        $template_factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/locale/');
+        $template_factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/locale/');
 
         setTempLanguage($this->range_id);
         $lang_path = getUserLanguagePath($this->range_id);
@@ -112,7 +112,7 @@ class CalendarDateAssignment extends SimpleORMap implements Event
             return;
         }
 
-        $template_factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/locale/');
+        $template_factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/locale/');
 
         setTempLanguage($this->range_id);
         $lang_path = getUserLanguagePath($this->range_id);
@@ -160,7 +160,7 @@ class CalendarDateAssignment extends SimpleORMap implements Event
             return;
         }
 
-        $template_factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/locale/');
+        $template_factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/locale/');
 
         setTempLanguage($this->range_id);
         $lang_path = getUserLanguagePath($this->range_id);
diff --git a/lib/models/resources/ResourceBooking.class.php b/lib/models/resources/ResourceBooking.class.php
index f55b3b3..fadf92f 100644
--- a/lib/models/resources/ResourceBooking.class.php
+++ b/lib/models/resources/ResourceBooking.class.php
@@ -876,7 +876,7 @@ class ResourceBooking extends SimpleORMap implements PrivacyObject, Studip\Calen
 
         $deleted_c = 0;
 
-        $template_factory = new Flexi_TemplateFactory(
+        $template_factory = new Flexi\Factory(
             $GLOBALS['STUDIP_BASE_PATH'] . '/locale/'
         );
 
@@ -1917,7 +1917,7 @@ class ResourceBooking extends SimpleORMap implements PrivacyObject, Studip\Calen
             return;
         }
 
-        $template_factory = new Flexi_TemplateFactory(
+        $template_factory = new Flexi\Factory(
             $GLOBALS['STUDIP_BASE_PATH'] . '/locale/'
         );
         setTempLanguage($booking_user->id);
diff --git a/lib/models/resources/ResourcePropertyDefinition.class.php b/lib/models/resources/ResourcePropertyDefinition.class.php
index 82d29c9..450ec00 100644
--- a/lib/models/resources/ResourcePropertyDefinition.class.php
+++ b/lib/models/resources/ResourcePropertyDefinition.class.php
@@ -221,7 +221,7 @@ class ResourcePropertyDefinition extends SimpleORMap
                 );
             }
         } elseif ($type === 'position') {
-            $factory = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH']);
+            $factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH']);
             $template = $factory->open('templates/resources/position_attribute_form_part.php');
             $template->set_attribute(
                 'input_name',
diff --git a/lib/models/resources/ResourceRequest.class.php b/lib/models/resources/ResourceRequest.class.php
index 6b22b44..9cad900 100644
--- a/lib/models/resources/ResourceRequest.class.php
+++ b/lib/models/resources/ResourceRequest.class.php
@@ -1963,7 +1963,7 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
             return;
         }
 
-        $factory = new Flexi_TemplateFactory(
+        $factory = new Flexi\Factory(
             $GLOBALS['STUDIP_BASE_PATH'] . '/locale/'
         );
 
@@ -2020,7 +2020,7 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
      */
     public function sendCloseRequestMailToRequester($bookings = [])
     {
-        $factory = new Flexi_TemplateFactory(
+        $factory = new Flexi\Factory(
             $GLOBALS['STUDIP_BASE_PATH'] . '/locale/'
         );
 
@@ -2110,7 +2110,7 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
             );
 
             if ($lecturers) {
-                $factory = new Flexi_TemplateFactory(
+                $factory = new Flexi\Factory(
                     $GLOBALS['STUDIP_BASE_PATH'] . '/locale/'
                 );
 
@@ -2199,7 +2199,7 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
         }
 
         //Load the mail template:
-        $factory        = new Flexi_TemplateFactory(
+        $factory = new Flexi\Factory(
             $GLOBALS['STUDIP_BASE_PATH'] . '/locale/'
         );
         $user_lang_path = getUserLanguagePath($user->id);
diff --git a/lib/modules/ScheduleWidget.php b/lib/modules/ScheduleWidget.php
index 5adc801..c4ab769 100644
--- a/lib/modules/ScheduleWidget.php
+++ b/lib/modules/ScheduleWidget.php
@@ -35,7 +35,7 @@ class ScheduleWidget extends CorePlugin implements PortalPlugin
     /**
      * Return the template for the widget.
      *
-     * @return Flexi_PhpTemplate The template containing the widget contents
+     * @return Flexi\PhpTemplate The template containing the widget contents
      */
     public function getPortalTemplate()
     {
diff --git a/lib/modules/StudipModule.class.php b/lib/modules/StudipModule.class.php
index 6cbcaf9..c281d29 100644
--- a/lib/modules/StudipModule.class.php
+++ b/lib/modules/StudipModule.class.php
@@ -54,7 +54,7 @@ interface StudipModule
     public function getMetadata();
 
     /**
-     * Return a template (an instance of the Flexi_Template class)
+     * Return a template (an instance of the Flexi\Template class)
      * to be rendered on the course summary page. Return NULL to
      * render nothing for this plugin.
      *
@@ -66,7 +66,7 @@ interface StudipModule
      *  admin_url    admin link for this plugin (if any)
      *  admin_title  title for admin link (default: Administration)
      *
-     * @return object   template object to render or NULL
+     * @return Flexi\Template|null template object to render or NULL
      */
     public function getInfoTemplate($course_id);
 }
diff --git a/lib/plugins/core/AdminCourseContents.class.php b/lib/plugins/core/AdminCourseContents.class.php
index 065cc9e..0e07b58 100644
--- a/lib/plugins/core/AdminCourseContents.class.php
+++ b/lib/plugins/core/AdminCourseContents.class.php
@@ -15,9 +15,11 @@ interface AdminCourseContents
 
     /**
      * Returns the value of the additional column for the course-overview table in the admin-area.
+     *
      * @param Course $course : A Course-object of the given ... course
      * @param string $index : the index that comes from adminAvailableContents to identify the column.
-     * @return Flexi_Template | String : Either one will do, but string is preferred, because it can exported as CSV-file more easily.
+     *
+     * @return Flexi\Template | String : Either one will do, but string is preferred, because it can exported as CSV-file more easily.
      */
     public function adminAreaGetCourseContent($course, $index);
 }
diff --git a/lib/plugins/core/DetailspagePlugin.class.php b/lib/plugins/core/DetailspagePlugin.class.php
index 15eda09..36e6efa 100644
--- a/lib/plugins/core/DetailspagePlugin.class.php
+++ b/lib/plugins/core/DetailspagePlugin.class.php
@@ -12,7 +12,7 @@
 interface DetailspagePlugin
 {
     /**
-     * Return a template (an instance of the Flexi_Template class)
+     * Return a template (an instance of the Flexi\Template class)
      * to be rendered on the details page. Return NULL to
      * render nothing for this plugin or this course.
      *
@@ -21,7 +21,7 @@ interface DetailspagePlugin
      *
      *  title        title to display, defaults to plugin name
      *
-     * @return object   template object to render or NULL
+     * @return Flexi\Template|null template object to render or NULL
      */
     public function getDetailspageTemplate($course);
 }
diff --git a/lib/plugins/core/ExternPagePlugin.php b/lib/plugins/core/ExternPagePlugin.php
index 5b40775..d12efc5 100644
--- a/lib/plugins/core/ExternPagePlugin.php
+++ b/lib/plugins/core/ExternPagePlugin.php
@@ -42,10 +42,10 @@ interface ExternPagePlugin
     public function getExternPage(ExternPageConfig $config): ExternPage;
 
     /**
-     * Returns a Flexi_Template or a path to the template file. This template contains the form
+     * Returns a Flexi\Template or a path to the template file. This template contains the form
      * to configure the external page.
      *
-     * @return string|Flexi_Template
+     * @return string|Flexi\Template
      */
     public function getConfigurationFormTemplate();
 
diff --git a/lib/plugins/core/FilesystemPlugin.class.php b/lib/plugins/core/FilesystemPlugin.class.php
index 6d4c46c..31b4b5b 100644
--- a/lib/plugins/core/FilesystemPlugin.class.php
+++ b/lib/plugins/core/FilesystemPlugin.class.php
@@ -34,11 +34,12 @@ interface FilesystemPlugin
 
     /**
      * This method is used to get a folder-object for this plugin.
-     * Not recommended but still possible is to return a Flexi_Template for the folder, if you want to
+     * Not recommended but still possible is to return a Flexi\Template for the folder, if you want to
      * take care of the frontend of displaying the folder as well.
      *
      * @param null $folder_id : folder_id of folder to get or null if you want the top-folder
-     * @return FolderType|Flexi_Template
+     *
+     * @return FolderType|Flexi\Template
      */
     public function getFolder($folder_id = null);
 
diff --git a/lib/plugins/core/HomepagePlugin.class.php b/lib/plugins/core/HomepagePlugin.class.php
index 74d0204..37efb54 100644
--- a/lib/plugins/core/HomepagePlugin.class.php
+++ b/lib/plugins/core/HomepagePlugin.class.php
@@ -15,7 +15,7 @@
 interface HomepagePlugin
 {
     /**
-     * Return a template (an instance of the Flexi_Template class)
+     * Return a template (an instance of the Flexi\Template class)
      * to be rendered on the given user's home page. Return NULL to
      * render nothing for this plugin.
      *
@@ -27,7 +27,7 @@ interface HomepagePlugin
      *  admin_url    admin link for this plugin (if any)
      *  admin_title  title for admin link (default: Administration)
      *
-     * @return object   template object to render or NULL
+     * @return Flexi\Template|null template object to render or NULL
      */
     function getHomepageTemplate($user_id);
 }
diff --git a/lib/plugins/core/PortalPlugin.class.php b/lib/plugins/core/PortalPlugin.class.php
index dce5774..cb5aca4 100644
--- a/lib/plugins/core/PortalPlugin.class.php
+++ b/lib/plugins/core/PortalPlugin.class.php
@@ -15,7 +15,7 @@
 interface PortalPlugin
 {
     /**
-     * Return a template (an instance of the Flexi_Template class)
+     * Return a template (an instance of the Flexi\Template class)
      * to be rendered on the start or portal page. Return NULL to
      * render nothing for this plugin.
      *
@@ -27,7 +27,7 @@ interface PortalPlugin
      *  admin_url    admin link for this plugin (if any)
      *  admin_title  title for admin link (default: Administration)
      *
-     * @return ?Flexi_Template template object to render or NULL
+     * @return ?Flexi\Template template object to render or NULL
      */
     function getPortalTemplate();
 }
diff --git a/lib/plugins/core/QuestionnaireAssignmentPlugin.class.php b/lib/plugins/core/QuestionnaireAssignmentPlugin.class.php
index 6892f8a..cadaf52 100644
--- a/lib/plugins/core/QuestionnaireAssignmentPlugin.class.php
+++ b/lib/plugins/core/QuestionnaireAssignmentPlugin.class.php
@@ -39,8 +39,10 @@ interface QuestionnaireAssignmentPlugin
      * This template will get displayed when someone at tools -> questionnaires
      * wants to edit the contexts of the questionnaire. Maybe you don't want to provide a
      * template here, so return null or just a readonly html-snippet.
+     *
      * @param Questionnaire $questionnaire
-     * @return null|Flexi_Template
+     *
+     * @return null|Flexi\Template
      */
     public function getQuestionnaireAssignmentEditTemplate(Questionnaire $questionnaire);
 
diff --git a/lib/raumzeit/SingleDate.class.php b/lib/raumzeit/SingleDate.class.php
index 1a58695..3268935 100644
--- a/lib/raumzeit/SingleDate.class.php
+++ b/lib/raumzeit/SingleDate.class.php
@@ -861,7 +861,7 @@ class SingleDate
      */
     function getDatesTemplate($template)
     {
-        if (!$template instanceof Flexi_Template && is_string($template)) {
+        if (!$template instanceof Flexi\Template && is_string($template)) {
             $template = $GLOBALS['template_factory']->open($template);
         }