152 files changed, 685 insertions, 4228 deletions

diff --git a/lib/models/AdmissionApplication.class.php b/lib/models/AdmissionApplication.php
index 02514ec..7e8c3f5 100644
--- a/lib/models/AdmissionApplication.class.php
+++ b/lib/models/AdmissionApplication.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * AdmissionApplication.class.php
+ * AdmissionApplication.php
  * model class for table admission_seminar_user
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/ArchivedCourse.class.php b/lib/models/ArchivedCourse.php
index 81879af..f3b2de8 100644
--- a/lib/models/ArchivedCourse.class.php
+++ b/lib/models/ArchivedCourse.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * ArchivedCourse.class.php
+ * ArchivedCourse.php
  * model class for table archiv
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/ArchivedCourseMember.class.php b/lib/models/ArchivedCourseMember.php
index 1febd35..e54de91 100644
--- a/lib/models/ArchivedCourseMember.class.php
+++ b/lib/models/ArchivedCourseMember.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * ArchivedCourseMember.class.php
+ * ArchivedCourseMember.php
  * model class for table seminar_user
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/AuthUserMd5.class.php b/lib/models/AuthUserMd5.php
index 48e27f8..d8b7c53 100644
--- a/lib/models/AuthUserMd5.class.php
+++ b/lib/models/AuthUserMd5.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * AuthUserMd5.class.php
+ * AuthUserMd5.php
  * model class for table auth_user_md5
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/AuxLockRule.php b/lib/models/AuxLockRule.php
index abd3327..f5ebfac 100644
--- a/lib/models/AuxLockRule.php
+++ b/lib/models/AuxLockRule.php
@@ -164,7 +164,7 @@ class AuxLockRule extends SimpleORMap
             foreach ($this->datafields as $field => $useless_value_pls_refactor) {
 
                 // if standard get it from the mapping else get it from the datafield
-                if ($mapping[$field]) {
+                if (!empty($mapping[$field])) {
                     $result['head'][$field] = $head_mapping[$field];
                     $new[$field] = htmlReady($mapping[$field]);
                 } else {
diff --git a/lib/models/Banner.class.php b/lib/models/Banner.php
index a418760..a418760 100644
--- a/lib/models/Banner.class.php
+++ b/lib/models/Banner.php
diff --git a/lib/models/BannerRoles.class.php b/lib/models/BannerRoles.php
index d1c2986..a460986 100644
--- a/lib/models/BannerRoles.class.php
+++ b/lib/models/BannerRoles.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * BannerRoles.class.php - model class for the banner roles
+ * BannerRoles.php - model class for the banner roles
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/BlubberThread.php b/lib/models/BlubberThread.php
index 2bc78a9..590a600 100644
--- a/lib/models/BlubberThread.php
+++ b/lib/models/BlubberThread.php
@@ -470,7 +470,7 @@ class BlubberThread extends SimpleORMap implements PrivacyObject
                     if (
                         isset($nav)
                         && $nav->isVisible(true)
-                        && count($module->getTabNavigation($this['context_id'])) > 0
+                        && $module->getTabNavigation($this['context_id'])
                         && $GLOBALS['perm']->have_studip_perm($tool->getVisibilityPermission(), $this['context_id'])
                     ) {
                         $icons[] = $nav;
@@ -1081,7 +1081,7 @@ class BlubberThread extends SimpleORMap implements PrivacyObject
                   FROM user_inst
                   WHERE user_id = ?";
         $institut_ids = DBManager::get()->fetchFirst($query, [$user_id]);
-        $blubberplugin = PluginManager::getInstance()->getPlugin("Blubber");
+        $blubberplugin = PluginManager::getInstance()->getPlugin(Blubber::class);
         if (!$blubberplugin) {
             return [];
         }
diff --git a/lib/models/CaptchaChallenge.php b/lib/models/CaptchaChallenge.php
new file mode 100644
index 0000000..446985d
--- /dev/null
+++ b/lib/models/CaptchaChallenge.php
@@ -0,0 +1,88 @@
+<?php
+final class CaptchaChallenge extends SimpleORMap
+{
+    public const ALGORITHM = 'SHA-256';
+    public const CHALLENGE_EXPIRATION = 5 * 60;
+
+    protected static function configure($config = [])
+    {
+        $config['db_table'] = 'captcha_challenges';
+
+        parent::configure($config);
+    }
+
+    protected static function getKey(): string
+    {
+        $key = Config::get()->CAPTCHA_KEY;
+        if ($key === '') {
+            $key = bin2hex(random_bytes(32));
+            Config::get()->store('CAPTCHA_KEY', $key);
+        }
+        return $key;
+    }
+
+    public static function createChallenge(string $salt, int $number): array
+    {
+        $algorithm = 'sha256';
+        $challenge = hash($algorithm, $salt . $number);
+        $signature = hash_hmac($algorithm, $challenge, self::getKey());
+
+        return [
+            'algorithm' => self::ALGORITHM,
+            'challenge' => $challenge,
+            'salt'      => $salt,
+            'signature' => $signature,
+        ];
+    }
+
+    public static function createNewChallenge(): array
+    {
+        do {
+            $salt = time() . '-' . bin2hex(random_bytes(12));
+            $number = random_int(1e3, 1e5);
+        } while (self::countBySql('salt = ? AND number = ?', [$salt, $number]) > 0);
+
+        return self::createChallenge($salt, $number);
+    }
+
+    public static function decodePayload(string $payload): array|null
+    {
+        return json_decode(base64_decode($payload), true);
+    }
+
+    public static function validatePayload(string $payload): string|bool
+    {
+        $json = self::decodePayload($payload);
+
+        if ($json === null) {
+            return _('Sie haben nicht bestätigt, dass Sie kein Roboter sind');
+        }
+
+        $time = explode('-', $json['salt'])[0];
+        if ($time < time() - self::CHALLENGE_EXPIRATION) {
+            return _('Die Challenge ist abgelaufen');
+        }
+
+        // Replay?
+        if (\CaptchaChallenge::countBySql('salt = ? AND number = ?', [$json['salt'], $json['number']]) > 0) {
+            return _('Nicht schummeln!');
+        }
+
+        $check = self::createChallenge($json['salt'], $json['number']);
+
+        if (
+            $json['algorithm'] !== $check['algorithm']
+            || $json['challenge'] !== $check['challenge']
+            || $json['signature'] !== $check['signature']
+        ) {
+            return _('Sie sind scheinbar ein Roboter...');
+        }
+
+        return true;
+    }
+
+    public static function gc(): void
+    {
+        self::deleteBySQL("mkdate < UNIX_TIMESTAMP() - ?", [self::CHALLENGE_EXPIRATION]);
+    }
+}
diff --git a/lib/models/Clipboard.class.php b/lib/models/Clipboard.php
index cd8fe89..01282cc 100644
--- a/lib/models/Clipboard.class.php
+++ b/lib/models/Clipboard.php
@@ -2,7 +2,7 @@
 
 
 /**
- * Clipboard.class.php - model class for a clipboard (Merkzettel)
+ * Clipboard.php - model class for a clipboard (Merkzettel)
  *
  * The Clipboard class extends the wish list functionality of the clipboard
  * in the old literature management to allow it to be used in other areas of the
diff --git a/lib/models/ClipboardItem.class.php b/lib/models/ClipboardItem.php
index 030388a..a19eeaf 100644
--- a/lib/models/ClipboardItem.class.php
+++ b/lib/models/ClipboardItem.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * ClipboardItem.class.php - model class for clipboard items
+ * ClipboardItem.php - model class for clipboard items
  * (Merkzettel-Einträge)
  *
  * The ClipboardItem class holds single items of a clipboard.
@@ -23,6 +23,8 @@
  * @property int $mkdate database column
  * @property int $chdate database column
  * @property Clipboard $clipboard belongs_to Clipboard
+ *
+ * @property-read string $name
  */
 class ClipboardItem extends SimpleORMap
 {
@@ -36,36 +38,32 @@ class ClipboardItem extends SimpleORMap
             'assoc_func' => 'find'
         ];
 
+        $config['additional_fields']['name'] = [
+            'get' => fn(ClipboardItem $item) => $item->__toString(),
+        ];
+
         parent::configure($config);
     }
 
-
     /**
      * @returns string representation of this clipboard item.
      */
     public function __toString()
     {
-        //Get the class $range_type and the object with ID $range_id,
-        //if $range_type is a StudipItem:
-
-        $use_generic_name = true;
-        $object = null;
-        if (is_subclass_of($this->range_type, 'StudipItem', true)) {
+        // Get the class $range_type and the object with ID $range_id,
+        // if $range_type is a StudipItem:
+        if (is_subclass_of($this->range_type, StudipItem::class)) {
             $range_class_name = $this->range_type;
             $object = $range_class_name::find($this->range_id);
             if ($object) {
-                $use_generic_name = false;
+                return $object->getItemName(false);
             }
         }
 
-        if ($use_generic_name) {
-            //$range_type is not a class name of a StudipItem class
-            //or no object of a StudipItem class could be found:
-            //We cannot determine the name and must therefore use
-            //a generic name:
-            return $this->range_type . '_' . $this->range_id;
-        } else {
-            return $object->getItemName(false);
-        }
+        // $range_type is not a class name of a StudipItem class
+        // or no object of a StudipItem class could be found:
+        // We cannot determine the name and must therefore use
+        // a generic name:
+        return $this->range_type . '_' . $this->range_id;
     }
 }
diff --git a/lib/models/ColourValue.class.php b/lib/models/ColourValue.php
index 6ae05ad..486de45 100644
--- a/lib/models/ColourValue.class.php
+++ b/lib/models/ColourValue.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ColorValue.class.php
+ * ColorValue.php
  * model class for table color_values
  *
  * Objects of this class holds a colour's name (its purpose)
diff --git a/lib/models/ConfigEntry.class.php b/lib/models/ConfigEntry.php
index 5e06da8..dd0efa4 100644
--- a/lib/models/ConfigEntry.class.php
+++ b/lib/models/ConfigEntry.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * ConfigEntry.class.php
+ * ConfigEntry.php
  * model class for table user_config
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/ConsultationBlock.php b/lib/models/ConsultationBlock.php
index e42daaf..cde8f77 100644
--- a/lib/models/ConsultationBlock.php
+++ b/lib/models/ConsultationBlock.php
@@ -25,6 +25,7 @@
  * @property string $note database column
  * @property int $size database column
  * @property int|null $lock_time database column
+ * @property bool $consecutive database column
  * @property int $mkdate database column
  * @property int $chdate database column
  * @property SimpleORMapCollection|ConsultationSlot[] $slots has_many ConsultationSlot
@@ -71,7 +72,7 @@ class ConsultationBlock extends SimpleORMap implements PrivacyObject
             if ($block->range instanceof User) {
                 return $block->range->getFullName() . ' <' . $block->range->email . '>';
             }
-            if ($block->range instanceof Course || $block->range instanceof Institute) {
+            if ($block->range instanceof Course) {
                 return sprintf(_('Veranstaltung: %s'), $block->range->getFullName());
             }
 
@@ -211,6 +212,10 @@ class ConsultationBlock extends SimpleORMap implements PrivacyObject
                 );
             }
 
+            if (!$interval) {
+                break;
+            }
+
             $current = strtotime("+{$interval} weeks", $current);
         }
 
@@ -274,9 +279,9 @@ class ConsultationBlock extends SimpleORMap implements PrivacyObject
             }
 
             $slots[] = ConsultationSlot::build([
-                'block_id'   => $this->id,
-                'start_time' => $now,
-                'end_time'   => strtotime("+{$duration} minutes", $now),
+                'block_id'      => $this->id,
+                'start_time'    => $now,
+                'end_time'      => strtotime("+{$duration} minutes", $now),
             ]);
 
             $now = strtotime("+{$duration} minutes", $now);
diff --git a/lib/models/ConsultationSlot.php b/lib/models/ConsultationSlot.php
index 0da02df..c46e47c 100644
--- a/lib/models/ConsultationSlot.php
+++ b/lib/models/ConsultationSlot.php
@@ -9,6 +9,7 @@
  * @property int $id alias column for slot_id
  * @property int $slot_id database column
  * @property int $block_id database column
+ * @property int $previous_slot_id database column
  * @property int $start_time database column
  * @property int $end_time database column
  * @property string $note database column
@@ -17,6 +18,7 @@
  * @property SimpleORMapCollection|ConsultationBooking[] $bookings has_many ConsultationBooking
  * @property SimpleORMapCollection|ConsultationEvent[] $events has_many ConsultationEvent
  * @property ConsultationBlock $block belongs_to ConsultationBlock
+ * @property ConsultationSlot|null $previous_slot has_one ConsultationSlot
  * @property-read mixed $has_bookings additional field
  * @property-read mixed $is_expired additional field
  */
@@ -45,15 +47,36 @@ class ConsultationSlot extends SimpleORMap
             'assoc_foreign_key' => 'slot_id',
             'on_delete'         => 'delete',
         ];
+        $config['has_one']['previous_slot'] = [
+            'class_name'        => ConsultationSlot::class,
+            'foreign_key'       => 'previous_slot_id',
+        ];
 
         $config['registered_callbacks']['before_create'][] = function (ConsultationSlot $slot) {
             $slot->updateEvents();
         };
+        $config['registered_callbacks']['before_store'][] = function (ConsultationSlot $slot) {
+            $previous = static::findOneBySQL(
+                "block_id = ? AND start_time < ? ORDER BY start_time DESC",
+                [$slot->block_id, $slot->start_time]
+            );
+            $slot->previous_slot_id = $previous?->id;
+        };
         $config['registered_callbacks']['after_delete'][] = function ($slot) {
             $block = $slot->block;
             if ($block && count($block->slots) === 0) {
                 $block->delete();
             }
+
+            // Close gap
+            self::findEachBySQL(
+                function (ConsultationSlot $s) use ($slot) {
+                    $s->previous_slot_id = $slot->previous_slot_id;
+                    $s->store();
+                },
+                'previous_slot_id = ?',
+                [$slot->id]
+            );
         };
 
         $config['additional_fields']['has_bookings']['get'] = function ($slot): bool {
@@ -139,10 +162,6 @@ class ConsultationSlot extends SimpleORMap
 
     /**
      * Returns whether this slot is occupied (by a given user).
-     *
-     * @param  mixed $user_id Id of the user (optional)
-     * @return boolean indicating whether the slot is occupied (by the given
-     *                 user)
      */
     public function isOccupied($user_id = null)
     {
@@ -154,7 +173,6 @@ class ConsultationSlot extends SimpleORMap
     /**
      * Returns whether the slot is locked for bookings.
      *
-     * @return bool
      */
     public function isLocked(): bool
     {
@@ -163,6 +181,20 @@ class ConsultationSlot extends SimpleORMap
     }
 
     /**
+     * Returns whether the slot is bookable for the given user_id
+     */
+    public function isBookable(?string $user_id = null): bool
+    {
+        return !$this->isOccupied($user_id)
+            && !$this->isLocked()
+            && !(
+                $this->block->consecutive
+                && $this->previous_slot
+                && !$this->previous_slot->isOccupied()
+            );
+    }
+
+    /**
      * Creates a Stud.IP calendar event relating to the slot.
      *
      * @param  User $user User object to create the event for
@@ -306,8 +338,7 @@ class ConsultationSlot extends SimpleORMap
         $user = $user ?? User::findCurrent();
 
         return ConsultationBooking::userMayCreateBookingForRange($this->block->range, $user)
-            && !$this->isOccupied()
-            && !$this->isLocked();
+            && $this->isBookable($user->id);
     }
 
 
diff --git a/lib/models/Contact.class.php b/lib/models/Contact.php
index 16bff26..bea5b95 100644
--- a/lib/models/Contact.class.php
+++ b/lib/models/Contact.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * Contact.class.php - model class for table contact
+ * Contact.php - model class for table contact
  *
  * @author      <mlunzena@uos.de>
  * @license GPL 2 or later
diff --git a/lib/models/ContactGroup.class.php b/lib/models/ContactGroup.php
index 0e60d3b..0e60d3b 100644
--- a/lib/models/ContactGroup.class.php
+++ b/lib/models/ContactGroup.php
diff --git a/lib/models/ContactGroupItem.class.php b/lib/models/ContactGroupItem.php
index 0204d0a..0204d0a 100644
--- a/lib/models/ContactGroupItem.class.php
+++ b/lib/models/ContactGroupItem.php
diff --git a/lib/models/ContentTermsOfUse.class.php b/lib/models/ContentTermsOfUse.php
index fb2e592..1982dd6 100644
--- a/lib/models/ContentTermsOfUse.class.php
+++ b/lib/models/ContentTermsOfUse.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * ContentTermsOfUse.class.php
+ * ContentTermsOfUse.php
  * model class for table licenses
  *
  * The ContentTermsOfUse class provides information about the terms under which
diff --git a/lib/models/Course.class.php b/lib/models/Course.php
index 59f9b82..d8bb2f5 100644
--- a/lib/models/Course.class.php
+++ b/lib/models/Course.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Course.class.php
+ * Course.php
  * model class for table seminare
  *
  * This program is free software; you can redistribute it and/or
@@ -306,19 +306,27 @@ class Course extends SimpleORMap implements Range, PrivacyObject, StudipItem, Fe
     /**
      * Returns the associated mvv modules for a given course id.
      *
-     * @param string $course_id
+     * @param string     $course_id
+     * @param array|null $statusses Limit the results by a given module status
      * @return Modul[]
      */
-    public static function getMVVModulesForCourseId(string $course_id): array
+    public static function getMVVModulesForCourseId(string $course_id, ?array $statusses = null): array
     {
         $query = "SELECT mvv_modul.*
                   FROM mvv_lvgruppe_seminar
-                  JOIN `mvv_lvgruppe` on(`mvv_lvgruppe_seminar`.`lvgruppe_id` = `mvv_lvgruppe`.`lvgruppe_id`)
-                  JOIN `mvv_lvgruppe_modulteil` on(`mvv_lvgruppe_seminar`.`lvgruppe_id` = `mvv_lvgruppe_modulteil`.`lvgruppe_id`)
-                  JOIN `mvv_modulteil` on(`mvv_lvgruppe_modulteil`.`modulteil_id` = `mvv_modulteil`.`modulteil_id`)
-                  JOIN `mvv_modul` on(`mvv_modulteil`.`modul_id` = `mvv_modul`.`modul_id`)
+                  JOIN `mvv_lvgruppe` ON (`mvv_lvgruppe_seminar`.`lvgruppe_id` = `mvv_lvgruppe`.`lvgruppe_id`)
+                  JOIN `mvv_lvgruppe_modulteil` ON (`mvv_lvgruppe_seminar`.`lvgruppe_id` = `mvv_lvgruppe_modulteil`.`lvgruppe_id`)
+                  JOIN `mvv_modulteil` ON (`mvv_lvgruppe_modulteil`.`modulteil_id` = `mvv_modulteil`.`modulteil_id`)
+                  JOIN `mvv_modul` ON (`mvv_modulteil`.`modul_id` = `mvv_modul`.`modul_id`)
                   WHERE seminar_id = ?";
-        return DBManager::get()->fetchAll($query, [$course_id], function ($row) {
+        $parameters = [$course_id];
+
+        if ($statusses !== null) {
+            $query .= ' AND `mvv_modul`.`stat` IN (?)';
+            $parameters[] = $statusses;
+        }
+
+        return DBManager::get()->fetchAll($query, $parameters, function ($row) {
             return Modul::buildExisting($row);
         });
     }
diff --git a/lib/models/CourseDate.class.php b/lib/models/CourseDate.php
index ac0c8c3..eadeb0a 100644
--- a/lib/models/CourseDate.class.php
+++ b/lib/models/CourseDate.php
@@ -364,7 +364,7 @@ class CourseDate extends SimpleORMap implements PrivacyObject, Event
         // load room-booking, if any
         $this->room_booking;
 
-        $cache = StudipCacheFactory::getCache();
+        $cache = \Studip\Cache\Factory::getCache();
         $cache->expire('course/undecorated_data/'. $this->range_id);
         return parent::store();
     }
@@ -376,7 +376,7 @@ class CourseDate extends SimpleORMap implements PrivacyObject, Event
      */
     public function delete()
     {
-        $cache = StudipCacheFactory::getCache();
+        $cache = \Studip\Cache\Factory::getCache();
         $cache->expire('course/undecorated_data/'. $this->range_id);
         return parent::delete();
     }
@@ -433,7 +433,7 @@ class CourseDate extends SimpleORMap implements PrivacyObject, Event
             $folders = array_merge($folders, $topic->folders->getArrayCopy());
         }
         foreach ($folders as $folder) {
-            list($files, $typed_folders) = array_values(FileManager::getFolderFilesRecursive($folder->getTypedFolder(), $user_id));
+            [$files, $typed_folders] = array_values(FileManager::getFolderFilesRecursive($folder->getTypedFolder(), $user_id));
             foreach ($files as $file) {
                 $all_files[$file->id] = $file;
             }
@@ -633,7 +633,7 @@ class CourseDate extends SimpleORMap implements PrivacyObject, Event
         );
         $class_names = [];
         if ($membership) {
-            $class_names[] = sprintf('gruppe%u', $membership->status);
+            $class_names[] = 'course-color-' . $membership->gruppe;
         }
         $studip_view_urls = [];
         if ($GLOBALS['perm']->have_studip_perm('user', $this->range_id, $user_id)) {
diff --git a/lib/models/CourseExDate.class.php b/lib/models/CourseExDate.php
index 2d3afea..2d3afea 100644
--- a/lib/models/CourseExDate.class.php
+++ b/lib/models/CourseExDate.php
diff --git a/lib/models/CourseMember.class.php b/lib/models/CourseMember.php
index cd7555f..7c4b335 100644
--- a/lib/models/CourseMember.class.php
+++ b/lib/models/CourseMember.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * CourseMember.class.php
+ * CourseMember.php
  * model class for table seminar_user
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/CourseMemberNotification.php b/lib/models/CourseMemberNotification.php
index e72ba76..5e1b544 100644
--- a/lib/models/CourseMemberNotification.php
+++ b/lib/models/CourseMemberNotification.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * CourseMemberNotification.class.php
+ * CourseMemberNotification.php
  * model class for table seminar_user_notification
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/CourseTopic.class.php b/lib/models/CourseTopic.php
index eb26efa..eb26efa 100644
--- a/lib/models/CourseTopic.class.php
+++ b/lib/models/CourseTopic.php
diff --git a/lib/models/Courseware/BlockTypes/Audio.php b/lib/models/Courseware/BlockTypes/Audio.php
index dd2588a..22dc167 100644
--- a/lib/models/Courseware/BlockTypes/Audio.php
+++ b/lib/models/Courseware/BlockTypes/Audio.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware audio block.
  *
@@ -42,11 +40,10 @@ class Audio extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Audio.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     /**
diff --git a/lib/models/Courseware/BlockTypes/BeforeAfter.php b/lib/models/Courseware/BlockTypes/BeforeAfter.php
index b4f33ca..e174bff 100644
--- a/lib/models/Courseware/BlockTypes/BeforeAfter.php
+++ b/lib/models/Courseware/BlockTypes/BeforeAfter.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware before after block.
  *
@@ -41,11 +39,10 @@ class BeforeAfter extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/BeforeAfter.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     /**
diff --git a/lib/models/Courseware/BlockTypes/BiographyAchievements.php b/lib/models/Courseware/BlockTypes/BiographyAchievements.php
index 3af5d64..2f8aeb7 100644
--- a/lib/models/Courseware/BlockTypes/BiographyAchievements.php
+++ b/lib/models/Courseware/BlockTypes/BiographyAchievements.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware biography achievements block.
  *
@@ -57,11 +55,10 @@ class BiographyAchievements extends BlockType
         parent::setPayload($payload);
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/BiographyAchievements.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/BiographyCareer.php b/lib/models/Courseware/BlockTypes/BiographyCareer.php
index ebd1a85..9425cfe 100644
--- a/lib/models/Courseware/BlockTypes/BiographyCareer.php
+++ b/lib/models/Courseware/BlockTypes/BiographyCareer.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware biography career block.
  *
@@ -48,11 +46,11 @@ class BiographyCareer extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/BiographyCareer.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/BiographyGoals.php b/lib/models/Courseware/BlockTypes/BiographyGoals.php
index dcfb76c..b4f1b64 100644
--- a/lib/models/Courseware/BlockTypes/BiographyGoals.php
+++ b/lib/models/Courseware/BlockTypes/BiographyGoals.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware biography personal goals block.
  *
@@ -53,11 +51,11 @@ class BiographyGoals extends BlockType
         parent::setPayload($payload);
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/BiographyGoals.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/BiographyPersonalInformation.php b/lib/models/Courseware/BlockTypes/BiographyPersonalInformation.php
index 8f3c0c1..bb11f53 100644
--- a/lib/models/Courseware/BlockTypes/BiographyPersonalInformation.php
+++ b/lib/models/Courseware/BlockTypes/BiographyPersonalInformation.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware biography personal information block.
  *
@@ -41,11 +39,11 @@ class BiographyPersonalInformation extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/BiographyPersonalInformation.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/BlockType.php b/lib/models/Courseware/BlockTypes/BlockType.php
index b3d5abf..37e617b 100644
--- a/lib/models/Courseware/BlockTypes/BlockType.php
+++ b/lib/models/Courseware/BlockTypes/BlockType.php
@@ -3,7 +3,6 @@
 namespace Courseware\BlockTypes;
 
 use Courseware\CoursewarePlugin;
-use Opis\JsonSchema\Schema;
 use Opis\JsonSchema\Validator;
 
 /**
@@ -52,9 +51,9 @@ abstract class BlockType
      * Returns the JSON schema which is used to validate the payload of
      * instances of this type of block.
      *
-     * @return Schema the JSON schema to be used
+     * @return string the JSON schema to be used
      */
-    abstract public static function getJsonSchema(): Schema;
+    abstract public static function getJsonSchema(): string;
 
     /**
      * Returns a list of categories to which this type of block is associated.
@@ -192,10 +191,8 @@ abstract class BlockType
      */
     public function validatePayload($payload): bool
     {
-        $schema = static::getJsonSchema();
         $validator = new Validator();
-        $result = $validator->schemaValidation($payload, $schema);
-
+        $result = $validator->validate($payload, static::getJsonSchema());
         return $result->isValid();
     }
 
@@ -441,9 +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/BlockTypes/Canvas.php b/lib/models/Courseware/BlockTypes/Canvas.php
index e7b14e9..cc2196a 100644
--- a/lib/models/Courseware/BlockTypes/Canvas.php
+++ b/lib/models/Courseware/BlockTypes/Canvas.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware canvas block.
  *
@@ -40,11 +38,11 @@ class Canvas extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Canvas.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     /**
diff --git a/lib/models/Courseware/BlockTypes/Chart.php b/lib/models/Courseware/BlockTypes/Chart.php
index 196e90f..147c3c5 100644
--- a/lib/models/Courseware/BlockTypes/Chart.php
+++ b/lib/models/Courseware/BlockTypes/Chart.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware chart block.
  *
@@ -38,11 +36,11 @@ class Chart extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Chart.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Code.php b/lib/models/Courseware/BlockTypes/Code.php
index 5b1454c..d5bd1c5 100644
--- a/lib/models/Courseware/BlockTypes/Code.php
+++ b/lib/models/Courseware/BlockTypes/Code.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware code block.
  *
@@ -37,11 +35,11 @@ class Code extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Code.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Confirm.php b/lib/models/Courseware/BlockTypes/Confirm.php
index bb6738d..2c25316 100644
--- a/lib/models/Courseware/BlockTypes/Confirm.php
+++ b/lib/models/Courseware/BlockTypes/Confirm.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware confirm block.
  *
@@ -36,11 +34,11 @@ class Confirm extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Confirm.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Date.php b/lib/models/Courseware/BlockTypes/Date.php
index 46e77d8..548e648 100644
--- a/lib/models/Courseware/BlockTypes/Date.php
+++ b/lib/models/Courseware/BlockTypes/Date.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware date block.
  *
@@ -37,11 +35,11 @@ class Date extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Date.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/DialogCards.php b/lib/models/Courseware/BlockTypes/DialogCards.php
index 74b843c..875a0b3 100644
--- a/lib/models/Courseware/BlockTypes/DialogCards.php
+++ b/lib/models/Courseware/BlockTypes/DialogCards.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware dialog cards block.
  *
@@ -96,11 +94,11 @@ class DialogCards extends BlockType
         return $payload;
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/DialogCards.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Document.php b/lib/models/Courseware/BlockTypes/Document.php
index db1ba6e..562ec08 100644
--- a/lib/models/Courseware/BlockTypes/Document.php
+++ b/lib/models/Courseware/BlockTypes/Document.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware document block.
  *
@@ -39,11 +37,10 @@ class Document extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Document.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     /**
diff --git a/lib/models/Courseware/BlockTypes/Download.php b/lib/models/Courseware/BlockTypes/Download.php
index d736009..e7bb65c 100644
--- a/lib/models/Courseware/BlockTypes/Download.php
+++ b/lib/models/Courseware/BlockTypes/Download.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware download block.
  *
@@ -72,11 +70,11 @@ class Download extends BlockType
         return $payload;
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Download.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Embed.php b/lib/models/Courseware/BlockTypes/Embed.php
index cb997ee..1b36624 100644
--- a/lib/models/Courseware/BlockTypes/Embed.php
+++ b/lib/models/Courseware/BlockTypes/Embed.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware embed block.
  *
@@ -40,11 +38,10 @@ class Embed extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Embed.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public function getPayload()
diff --git a/lib/models/Courseware/BlockTypes/Error.php b/lib/models/Courseware/BlockTypes/Error.php
index 2e15456..3f290b1 100644
--- a/lib/models/Courseware/BlockTypes/Error.php
+++ b/lib/models/Courseware/BlockTypes/Error.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware error block.
  *
@@ -34,11 +32,11 @@ class Error extends BlockType
         return [];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Error.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Folder.php b/lib/models/Courseware/BlockTypes/Folder.php
index 2eed4b0..9f186df 100644
--- a/lib/models/Courseware/BlockTypes/Folder.php
+++ b/lib/models/Courseware/BlockTypes/Folder.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware folder block.
  *
@@ -55,7 +53,7 @@ class Folder extends BlockType
         if ($folder) {
             $typedFolder = $folder->getTypedFolder();
             $payload['folder-type'] = $typedFolder->folder_type;
-            if ($typedFolder->isReadable($user->id)) {   
+            if ($typedFolder->isReadable($user->id) || $typedFolder->folder_type === 'HomeworkFolder') {   
                 foreach ($typedFolder->getFiles() as $folderFile) {
                     $file['id'] = $folderFile->id;
                     $file['attributes'] = [
@@ -116,11 +114,10 @@ class Folder extends BlockType
         return $payload;
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Folder.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Gallery.php b/lib/models/Courseware/BlockTypes/Gallery.php
index 5f9bb0b..5041573 100644
--- a/lib/models/Courseware/BlockTypes/Gallery.php
+++ b/lib/models/Courseware/BlockTypes/Gallery.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware gallery block.
  *
@@ -133,11 +131,11 @@ class Gallery extends BlockType
         return $payload;
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Gallery.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Headline.php b/lib/models/Courseware/BlockTypes/Headline.php
index 0c82138..616af88 100644
--- a/lib/models/Courseware/BlockTypes/Headline.php
+++ b/lib/models/Courseware/BlockTypes/Headline.php
@@ -2,7 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
 use Opis\JsonSchema\Validator;
 
 /**
@@ -49,11 +48,10 @@ class Headline extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Headline.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     /**
@@ -88,11 +86,8 @@ class Headline extends BlockType
     public function validatePayload($payload): bool
     {
         unset($payload->background_image);
-        $schema = static::getJsonSchema();
-        $validator = new Validator();
-        $result = $validator->schemaValidation($payload, $schema);
 
-        return $result->isValid();
+        return parent::validatePayload($payload);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/IFrame.php b/lib/models/Courseware/BlockTypes/IFrame.php
index 5c914f9..f697e74 100644
--- a/lib/models/Courseware/BlockTypes/IFrame.php
+++ b/lib/models/Courseware/BlockTypes/IFrame.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware iFrame block.
  *
@@ -45,11 +43,10 @@ class IFrame extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/IFrame.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/ImageMap.php b/lib/models/Courseware/BlockTypes/ImageMap.php
index e275c46..d9ad845 100644
--- a/lib/models/Courseware/BlockTypes/ImageMap.php
+++ b/lib/models/Courseware/BlockTypes/ImageMap.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware image map block.
  *
@@ -66,11 +64,11 @@ class ImageMap extends BlockType
         return $payload;
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/ImageMap.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/KeyPoint.php b/lib/models/Courseware/BlockTypes/KeyPoint.php
index 8599704..d1e6c34 100644
--- a/lib/models/Courseware/BlockTypes/KeyPoint.php
+++ b/lib/models/Courseware/BlockTypes/KeyPoint.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware key point block.
  *
@@ -38,11 +36,11 @@ class KeyPoint extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/KeyPoint.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Link.php b/lib/models/Courseware/BlockTypes/Link.php
index ccf9f66..3282e2c 100644
--- a/lib/models/Courseware/BlockTypes/Link.php
+++ b/lib/models/Courseware/BlockTypes/Link.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware link block.
  *
@@ -39,11 +37,10 @@ class Link extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Link.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Lti.php b/lib/models/Courseware/BlockTypes/Lti.php
index 8b527c1..193bfb5 100644
--- a/lib/models/Courseware/BlockTypes/Lti.php
+++ b/lib/models/Courseware/BlockTypes/Lti.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware LTI block.
  *
@@ -44,11 +42,10 @@ class Lti extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Lti.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public function getPayload()
diff --git a/lib/models/Courseware/BlockTypes/TableOfContents.php b/lib/models/Courseware/BlockTypes/TableOfContents.php
index c48b683..f0485b9 100644
--- a/lib/models/Courseware/BlockTypes/TableOfContents.php
+++ b/lib/models/Courseware/BlockTypes/TableOfContents.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware table of contents block.
  *
@@ -37,11 +35,11 @@ class TableOfContents extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/TableOfContents.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Text.php b/lib/models/Courseware/BlockTypes/Text.php
index 441da89..1da7cbe 100644
--- a/lib/models/Courseware/BlockTypes/Text.php
+++ b/lib/models/Courseware/BlockTypes/Text.php
@@ -2,9 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-require_once 'lib/classes/Markup.class.php';
-
 /**
  * This class represents the content of a Courseware text block.
  *
@@ -66,11 +63,10 @@ class Text extends BlockType
         parent::setPayload($payload);
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Text.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     /**
@@ -192,7 +188,7 @@ class Text extends BlockType
 
             }
 
-            return array();
+            return null;
         });
     }
 }
diff --git a/lib/models/Courseware/BlockTypes/Timeline.php b/lib/models/Courseware/BlockTypes/Timeline.php
index 81802ce..5647e92 100644
--- a/lib/models/Courseware/BlockTypes/Timeline.php
+++ b/lib/models/Courseware/BlockTypes/Timeline.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware timeline block.
  *
@@ -45,11 +43,10 @@ class Timeline extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Timeline.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Typewriter.php b/lib/models/Courseware/BlockTypes/Typewriter.php
index 2544dde..b303fb3 100644
--- a/lib/models/Courseware/BlockTypes/Typewriter.php
+++ b/lib/models/Courseware/BlockTypes/Typewriter.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware typewriter block.
  *
@@ -39,11 +37,11 @@ class Typewriter extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Typewriter.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     public static function getCategories(): array
diff --git a/lib/models/Courseware/BlockTypes/Video.php b/lib/models/Courseware/BlockTypes/Video.php
index 431f69b..1ad7064 100644
--- a/lib/models/Courseware/BlockTypes/Video.php
+++ b/lib/models/Courseware/BlockTypes/Video.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\BlockTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware video block.
  *
@@ -42,11 +40,10 @@ class Video extends BlockType
         ];
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/Video.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 
     /**
diff --git a/lib/models/Courseware/ContainerTypes/AccordionContainer.php b/lib/models/Courseware/ContainerTypes/AccordionContainer.php
index 185b6d1..cd00a06 100644
--- a/lib/models/Courseware/ContainerTypes/AccordionContainer.php
+++ b/lib/models/Courseware/ContainerTypes/AccordionContainer.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\ContainerTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware accordion container stored in payload.
  *
@@ -54,10 +52,10 @@ class AccordionContainer extends ContainerType
         $this->setPayload($payload);
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/AccordionContainer.json';
 
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 }
diff --git a/lib/models/Courseware/ContainerTypes/ContainerType.php b/lib/models/Courseware/ContainerTypes/ContainerType.php
index e358c9c..4e816be 100644
--- a/lib/models/Courseware/ContainerTypes/ContainerType.php
+++ b/lib/models/Courseware/ContainerTypes/ContainerType.php
@@ -3,7 +3,6 @@
 namespace Courseware\ContainerTypes;
 
 use Courseware\CoursewarePlugin;
-use Opis\JsonSchema\Schema;
 use Opis\JsonSchema\Validator;
 
 /**
@@ -28,9 +27,9 @@ abstract class ContainerType
      * Returns the JSON schema which is used to validate the payload of
      * instances of this type of container.
      *
-     * @return Schema the JSON schema to be used
+     * @return string the JSON schema to be used
      */
-    abstract public static function getJsonSchema(): Schema;
+    abstract public static function getJsonSchema(): string;
 
     /**
      * Returns a short string describing this type of container.
@@ -150,10 +149,8 @@ abstract class ContainerType
      */
     public function validatePayload($payload): bool
     {
-        $schema = static::getJsonSchema();
         $validator = new Validator();
-        $result = $validator->schemaValidation($payload, $schema);
-
+        $result = $validator->validate($payload, static::getJsonSchema());
         return $result->isValid();
     }
 
@@ -199,7 +196,7 @@ abstract class ContainerType
             foreach ($section['blocks'] as &$block) {
                 $block = $block_map[$block] ?? null;
             }
-            $section['blocks'] = array_filter($section['blocks']);
+            $section['blocks'] = array_values(array_filter($section['blocks']));
         }
 
         return $payload;
@@ -252,9 +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/Courseware/ContainerTypes/ListContainer.php b/lib/models/Courseware/ContainerTypes/ListContainer.php
index b98d8a1..adbf7c3 100644
--- a/lib/models/Courseware/ContainerTypes/ListContainer.php
+++ b/lib/models/Courseware/ContainerTypes/ListContainer.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\ContainerTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware list container stored in payload.
  *
@@ -50,10 +48,9 @@ class ListContainer extends ContainerType
         $this->setPayload($payload);
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/ListContainer.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 }
diff --git a/lib/models/Courseware/ContainerTypes/TabsContainer.php b/lib/models/Courseware/ContainerTypes/TabsContainer.php
index 01f3d45..66a56b8 100644
--- a/lib/models/Courseware/ContainerTypes/TabsContainer.php
+++ b/lib/models/Courseware/ContainerTypes/TabsContainer.php
@@ -2,8 +2,6 @@
 
 namespace Courseware\ContainerTypes;
 
-use Opis\JsonSchema\Schema;
-
 /**
  * This class represents the content of a Courseware tabs container stored in payload.
  *
@@ -54,10 +52,9 @@ class TabsContainer extends ContainerType
         $this->setPayload($payload);
     }
 
-    public static function getJsonSchema(): Schema
+    public static function getJsonSchema(): string
     {
         $schemaFile = __DIR__.'/TabsContainer.json';
-
-        return Schema::fromJsonString(file_get_contents($schemaFile));
+        return file_get_contents($schemaFile);
     }
 }
diff --git a/lib/models/CronjobLog.class.php b/lib/models/CronjobLog.php
index c9e92f7..278a515 100644
--- a/lib/models/CronjobLog.class.php
+++ b/lib/models/CronjobLog.php
@@ -1,7 +1,7 @@
 <?php
 // +---------------------------------------------------------------------------+
 // This file is part of Stud.IP
-// CronjobLog.class.php
+// CronjobLog.php
 //
 // Copyright (C) 2013 Jan-Hendrik Willms <tleilax+studip@gmail.com>
 // +---------------------------------------------------------------------------+
diff --git a/lib/models/CronjobSchedule.class.php b/lib/models/CronjobSchedule.php
index 4304be1..08a18d3 100644
--- a/lib/models/CronjobSchedule.class.php
+++ b/lib/models/CronjobSchedule.php
@@ -1,7 +1,7 @@
 <?php
 // +---------------------------------------------------------------------------+
 // This file is part of Stud.IP
-// CronjobSchedule.class.php
+// CronjobSchedule.php
 //
 // Copyright (C) 2013 Jan-Hendrik Willms <tleilax+studip@gmail.com>
 // +---------------------------------------------------------------------------+
@@ -34,8 +34,6 @@
  * @property string|null $title database column
  * @property string|null $description database column
  * @property string|null $parameters database column
- * @property string $priority database column
- * @property string $type database column
  * @property int|null $minute database column
  * @property int|null $hour database column
  * @property int|null $day database column
@@ -53,10 +51,6 @@
 
 class CronjobSchedule extends SimpleORMap
 {
-    const PRIORITY_LOW    = 'low';
-    const PRIORITY_NORMAL = 'normal';
-    const PRIORITY_HIGH   = 'high';
-
     protected static function configure($config = [])
     {
         $config['db_table'] = 'cronjobs_schedules';
@@ -79,41 +73,6 @@ class CronjobSchedule extends SimpleORMap
     }
 
     /**
-     * Returns a mapped version of the priorities (key = priority value,
-     * value = localized priority label).
-     *
-     * @return Array The mapped priorities
-     */
-    public static function getPriorities()
-    {
-        $mapping = [];
-        $mapping[self::PRIORITY_LOW]    = _('niedrig');
-        $mapping[self::PRIORITY_NORMAL] = _('normal');
-        $mapping[self::PRIORITY_HIGH]   = _('hoch');
-
-        return $mapping;
-    }
-
-    /**
-     * Maps a priority value to it's localized label.
-     *
-     * @param  String $priority Priority value
-     * @return String The localized label
-     * @throws RuntimeException when an unknown priority value is passed
-     */
-    public static function describePriority($priority)
-    {
-        $priority = $priority ?? 'normal';
-
-        $mapping = self::getPriorities();
-        if (!isset($mapping[$priority])) {
-            throw new RuntimeException('Access to unknown priority "' . $priority . '"');
-        }
-
-        return $mapping[$priority];
-    }
-
-    /**
      * replaces title with task name if title is empty.
      *
      * @return string the title or the task name
@@ -171,10 +130,12 @@ class CronjobSchedule extends SimpleORMap
      *
      * @return CronjobSchedule Returns itself to allow chaining
      */
-    public function activate()
+    public function activate(bool $run_immediately = false)
     {
-        $this->active         = 1;
-        $this->next_execution = $this->calculateNextExecution();
+        $next_execution = $run_immediately ? strtotime('-1 minute') : $this->calculateNextExecution();
+
+        $this->active = true;
+        $this->next_execution = $next_execution;
         $this->store();
 
         return $this;
@@ -187,7 +148,7 @@ class CronjobSchedule extends SimpleORMap
      */
     public function deactivate()
     {
-        $this->active = 0;
+        $this->active = false;
         $this->store();
 
         return $this;
@@ -221,9 +182,6 @@ class CronjobSchedule extends SimpleORMap
 
         $result = $this->task->engage($this->last_result, $this->parameters);
 
-        if ($this->type === 'once') {
-            $this->active = 0;
-        }
         $this->last_result = $result;
         $this->store();
 
@@ -245,16 +203,12 @@ class CronjobSchedule extends SimpleORMap
     /**
      * Calculates the next execution for this schedule.
      *
-     * For schedules of type 'once' the check solely tests whether the
-     * timestamp has already passed and will return false in that case.
-     * Otherwise the defined timestamp will be returned.
-     *
-     * For schedules of type 'periodic' the next execution
-     * is calculated by increasing the current timestamp and testing
-     * whether all conditions match. This is not the best method to test
-     * and should be optimized sooner or later.
+     * The next execution is calculated by increasing the current timestamp
+     * and testing whether all conditions match. This is not the best method
+     * to test and should be optimized sooner or later.
      *
      * @param mixed $now Defines the temporal fix point
+     *
      * @return int Timestamp of calculated next execution
      * @throws RuntimeException When calculation takes too long (you should
      *                          check the conditions for validity in that case)
@@ -263,12 +217,6 @@ class CronjobSchedule extends SimpleORMap
     {
         $now = $now ?: time();
 
-        if ($this->type === 'once') {
-            return $now <= $this->next_execution
-                ? $this->next_execution
-                : false;
-        }
-
         $result  = $now;
         $result -= $result % 60;
 
diff --git a/lib/models/CronjobTask.class.php b/lib/models/CronjobTask.php
index f235951..1304bc1 100644
--- a/lib/models/CronjobTask.class.php
+++ b/lib/models/CronjobTask.php
@@ -1,7 +1,7 @@
 <?php
 // +---------------------------------------------------------------------------+
 // This file is part of Stud.IP
-// CronjobSchedule.class.php
+// CronjobSchedule.php
 //
 // Copyright (C) 2013 Jan-Hendrik Willms <tleilax+studip@gmail.com>
 // +---------------------------------------------------------------------------+
@@ -160,72 +160,70 @@ class CronjobTask extends SimpleORMap
 // Convenience methods to ease the usage
 
     /**
-     * Schedules this task for a single execution at the provided time.
-     *
-     * @param int    $timestamp  When the task should be executed
-     * @param String $priority   Priority of the execution (low, normal, high),
-     *                           defaults to normal
-     * @param Array  $parameters Optional parameters passed to the task
-     * @return CronjobSchedule The generated schedule object.
-     */
-    public function scheduleOnce($timestamp, $priority = CronjobSchedule::PRIORITY_NORMAL,
-                                 $parameters = [])
-    {
-        return CronjobScheduler::getInstance()->scheduleOnce(
-            $this->id,
-            $timestamp,
-            $priority,
-            $parameters
-        );
-    }
-
-    /**
      * Schedules this task for periodic execution with the provided schedule.
      *
-     * @param mixed  $minute      Minute part of the schedule:
+     * @param int|null  $minute      Minute part of the schedule:
      *                            - null for "every minute" a.k.a. "don't care"
      *                            - x < 0 for "every x minutes"
      *                            - x >= 0 for "only at minute x"
-     * @param mixed  $hour        Hour part of the schedule:
+     * @param int|null  $hour        Hour part of the schedule:
      *                            - null for "every hour" a.k.a. "don't care"
      *                            - x < 0 for "every x hours"
      *                            - x >= 0 for "only at hour x"
-     * @param mixed  $day         Day part of the schedule:
+     * @param int|null  $day         Day part of the schedule:
      *                            - null for "every day" a.k.a. "don't care"
      *                            - x < 0 for "every x days"
      *                            - x > 0 for "only at day x"
-     * @param mixed  $month       Month part of the schedule:
+     * @param int|null  $month       Month part of the schedule:
      *                            - null for "every month" a.k.a. "don't care"
      *                            - x < 0 for "every x months"
      *                            - x > 0 for "only at month x"
-     * @param mixed  $day_of_week Day of week part of the schedule:
+     * @param int|null  $day_of_week Day of week part of the schedule:
      *                            - null for "every day" a.k.a. "don't care"
      *                            - 1 >= x >= 7 for "exactly at day of week x"
      *                              (x starts with monday at 1 and ends with
      *                               sunday at 7)
-     * @param String $priority   Priority of the execution (low, normal, high),
-     *                           defaults to normal
-     * @param Array  $parameters Optional parameters passed to the task
+     * @param array  $parameters Optional parameters passed to the task
      * @return CronjobSchedule The generated schedule object.
      */
-    public function schedulePeriodic($minute = null, $hour = null,
-                                     $day = null, $month = null, $day_of_week = null,
-                                     $priority = CronjobSchedule::PRIORITY_NORMAL,
-                                     $parameters = [])
-    {
-        return CronjobScheduler::getInstance()->schedulePeriodic(
+    public function schedule(
+        ?int $minute = null,
+        ?int $hour = null,
+        ?int $day = null,
+        ?int $month = null,
+        ?int $day_of_week = null,
+        array $parameters = []
+    ): CronjobSchedule {
+        return CronjobScheduler::getInstance()->schedule(
             $this->id,
             $minute,
             $hour,
             $day,
             $month,
             $day_of_week,
-            $priority,
             $parameters
         );
     }
 
     /**
+     * An alias for schedule for backwards compatibility.
+     *
+     * @see CronjobTask::schedule()
+     * @return CronjobSchedule
+     */
+    public function schedulePeriodic(
+        $minute = null,
+        $hour = null,
+        $day = null,
+        $month = null,
+        $day_of_week = null,
+        $priority = '',
+        $parameters = []
+    ) {
+        return $this->schedule($minute, $hour, $day, $month, $day_of_week, $parameters);
+    }
+
+    /**
      * Extracts the default parameter values from the associated task.
      *
      * @return array
diff --git a/lib/models/DataField.class.php b/lib/models/DataField.php
index 2d745a9..8a0bdb6 100644
--- a/lib/models/DataField.class.php
+++ b/lib/models/DataField.php
@@ -256,11 +256,8 @@ class DataField extends SimpleORMap implements PrivacyObject
      * Specialized count method that returns the number of concrete entries.
      *
      * @return int number of entries
-     *
-     * @todo Add int return type when Stud.IP requires PHP8 minimal
      */
-    #[ReturnTypeWillChange]
-    public function count()
+    public function count(): int
     {
         return DatafieldEntryModel::countBySQL('datafield_id = ?', [$this->id]);
     }
diff --git a/lib/models/DatafieldEntryModel.class.php b/lib/models/DatafieldEntryModel.php
index 33503e3..33503e3 100644
--- a/lib/models/DatafieldEntryModel.class.php
+++ b/lib/models/DatafieldEntryModel.php
diff --git a/lib/models/DatafieldEntryModelI18N.class.php b/lib/models/DatafieldEntryModelI18N.php
index aa93a63..aa93a63 100644
--- a/lib/models/DatafieldEntryModelI18N.class.php
+++ b/lib/models/DatafieldEntryModelI18N.php
diff --git a/lib/models/Degree.class.php b/lib/models/Degree.php
index 6fef834..9c908d3 100644
--- a/lib/models/Degree.class.php
+++ b/lib/models/Degree.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Degree.class.php
+ * Degree.php
  * model class for table studiengang
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/Deputy.php b/lib/models/Deputy.php
index e2917e7..c74c741 100644
--- a/lib/models/Deputy.php
+++ b/lib/models/Deputy.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Deputy.class.php
+ * Deputy.php
  * model class for table deputies
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/FileRef.php b/lib/models/FileRef.php
index c70d171..6bffbf3 100644
--- a/lib/models/FileRef.php
+++ b/lib/models/FileRef.php
@@ -86,9 +86,10 @@ class FileRef extends SimpleORMap implements PrivacyObject, FeedbackRange
     public function cbLogDeleteFileRef()
     {
         StudipLog::log('FILE_DELETE',
-            $this->id,
+            User::findCurrent()->id,
             null,
             sprintf(
+                'Kommentar: %s',
                 $this->name
             )
         );
diff --git a/lib/models/Folder.php b/lib/models/Folder.php
index b2e8886..7b66621 100644
--- a/lib/models/Folder.php
+++ b/lib/models/Folder.php
@@ -97,9 +97,10 @@ class Folder extends SimpleORMap implements FeedbackRange
     protected function cbLogDeleteFolder()
     {
         StudipLog::log('FOLDER_DELETE',
-            $this->id,
+            User::findCurrent()->id,
             null,
             sprintf(
+                'Kommentar: %s',
                 $this->name
             )
         );
diff --git a/lib/models/Freetext.php b/lib/models/Freetext.php
index 52182de..f241b5a 100644
--- a/lib/models/Freetext.php
+++ b/lib/models/Freetext.php
@@ -1,6 +1,6 @@
 <?php
 
-require_once 'lib/classes/QuestionType.interface.php';
+require_once 'lib/classes/QuestionType.php';
 
 /**
  * @license GPL2 or any later version
@@ -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/Grading/Instance.php b/lib/models/Grading/Instance.php
index 14ab25a..7f362d3 100644
--- a/lib/models/Grading/Instance.php
+++ b/lib/models/Grading/Instance.php
@@ -66,4 +66,22 @@ class Instance extends \SimpleORMap
 
         return self::findBySql('definition_id IN (?) AND user_id = ?', [$definitionIds, $user->id]);
     }
+
+    /**
+     * setter for the rawgrade column. The database type is decimal(6,5) UNSIGNED, therefore
+     * the setter mimics the database behaviour to get valid results from ::isFieldDirty()
+     *
+     * @param mixed $grade
+     * @return string
+     */
+    public function setRawgrade($grade = 0): string
+    {
+        if ($grade < 0) {
+            $grade = 0;
+        }
+        if ($grade >= 10) {
+            $grade = 9.99999;
+        }
+        return $this->content['rawgrade'] = number_format($grade, 5, '.', '');
+    }
 }
diff --git a/lib/models/HelpContent.class.php b/lib/models/HelpContent.php
index f1e61b1..e9a6f47 100644
--- a/lib/models/HelpContent.class.php
+++ b/lib/models/HelpContent.php
@@ -21,7 +21,7 @@
 //require_once 'lib/object.inc.php';
 
 /**
- * HelpContent.class.php - model class for Stud.IP help content
+ * HelpContent.php - model class for Stud.IP help content
  *
  * @author   Arne Schröder <schroeder@data-quest>
  * @access   public
diff --git a/lib/models/HelpTour.class.php b/lib/models/HelpTour.php
index 68bd830..978e203 100644
--- a/lib/models/HelpTour.class.php
+++ b/lib/models/HelpTour.php
@@ -21,7 +21,7 @@
 require_once 'lib/object.inc.php';
 
 /**
- * HelpTour.class.php - model class for Stud.IP tours
+ * HelpTour.php - model class for Stud.IP tours
  *
  *
  *
diff --git a/lib/models/HelpTourAudience.class.php b/lib/models/HelpTourAudience.php
index 6255a46..f341196 100644
--- a/lib/models/HelpTourAudience.class.php
+++ b/lib/models/HelpTourAudience.php
@@ -19,7 +19,7 @@
 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 // +---------------------------------------------------------------------------+
 /**
- * HelpTourSteps.class.php - model class for tour audiences
+ * HelpTourSteps.php - model class for tour audiences
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/HelpTourSettings.class.php b/lib/models/HelpTourSettings.php
index f24c86b..1cac957 100644
--- a/lib/models/HelpTourSettings.class.php
+++ b/lib/models/HelpTourSettings.php
@@ -19,7 +19,7 @@
 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 // +---------------------------------------------------------------------------+
 /**
- * HelpTourSteps.class.php - model class for tour steps
+ * HelpTourSteps.php - model class for tour steps
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/HelpTourStep.class.php b/lib/models/HelpTourStep.php
index 6f31326..3bd5ad8 100644
--- a/lib/models/HelpTourStep.class.php
+++ b/lib/models/HelpTourStep.php
@@ -19,7 +19,7 @@
 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 // +---------------------------------------------------------------------------+
 /**
- * HelpTourSteps.class.php - model class for tour steps
+ * HelpTourSteps.php - model class for tour steps
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -104,4 +104,3 @@ class HelpTourStep extends SimpleORMap
         return true;
     }
 }
-
diff --git a/lib/models/HelpTourUser.class.php b/lib/models/HelpTourUser.php
index aa2869d..4992225 100644
--- a/lib/models/HelpTourUser.class.php
+++ b/lib/models/HelpTourUser.php
@@ -19,7 +19,7 @@
 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 // +---------------------------------------------------------------------------+
 /**
- * HelpTourUser.class.php - model class for tour user visits
+ * HelpTourUser.php - model class for tour user visits
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/Institute.class.php b/lib/models/Institute.php
index 47cf271..df344ff 100644
--- a/lib/models/Institute.class.php
+++ b/lib/models/Institute.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Institute.class.php - model class for table Institute
+ * Institute.php - model class for table Institute
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/InstituteMember.class.php b/lib/models/InstituteMember.php
index ec1c026..ec1c026 100644
--- a/lib/models/InstituteMember.class.php
+++ b/lib/models/InstituteMember.php
diff --git a/lib/models/InstitutePlanColumn.class.php b/lib/models/InstitutePlanColumn.php
index b5ec876..b5ec876 100644
--- a/lib/models/InstitutePlanColumn.class.php
+++ b/lib/models/InstitutePlanColumn.php
diff --git a/lib/models/Kategorie.class.php b/lib/models/Kategorie.php
index a43629f..a43629f 100644
--- a/lib/models/Kategorie.class.php
+++ b/lib/models/Kategorie.php
diff --git a/lib/models/LikertScale.php b/lib/models/LikertScale.php
index 8ac7823..3a055f3 100644
--- a/lib/models/LikertScale.php
+++ b/lib/models/LikertScale.php
@@ -1,6 +1,4 @@
 <?php
-require_once 'lib/classes/QuestionType.interface.php';
-
 /**
  * @license GPL2 or any later version
  *
@@ -53,7 +51,7 @@ 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 $template;
@@ -73,7 +71,7 @@ class LikertScale extends QuestionnaireQuestion implements QuestionType
     public function getUserIdsOfFilteredAnswer($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 +91,7 @@ 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/LockRule.class.php b/lib/models/LockRule.php
index a3ef271..83dec60 100644
--- a/lib/models/LockRule.class.php
+++ b/lib/models/LockRule.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * LockRule.class.php
+ * LockRule.php
  * model class for table lock_rule
  * this class represents one record of the lock_rules table
  * the column attributes is converted to an ArrayObject and vice-versa,
diff --git a/lib/models/LoginBackground.class.php b/lib/models/LoginBackground.php
index 3ede275..530ae42 100644
--- a/lib/models/LoginBackground.class.php
+++ b/lib/models/LoginBackground.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * LoginBackground.class.php
+ * LoginBackground.php
  * model class for table loginbackgrounds
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/LoginFaq.class.php b/lib/models/LoginFaq.php
index d6cad40..4c049ac 100644
--- a/lib/models/LoginFaq.class.php
+++ b/lib/models/LoginFaq.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * LoginFaq.class.php
+ * LoginFaq.php
  * model class for table login_faq
  *
  *
diff --git a/lib/models/Lvgruppe.php b/lib/models/Lvgruppe.php
index 138d28e..05f3b59 100644
--- a/lib/models/Lvgruppe.php
+++ b/lib/models/Lvgruppe.php
@@ -232,7 +232,7 @@ class Lvgruppe extends ModuleManagementModelTreeItem
      *
      * @param string $term The search term.
      * @param array|string $filter An array with filter options or a where part.
-     * @return object A SimpleORMapCollection of LV-Gruppen.
+     * @return SimpleORMapCollection A SimpleORMapCollection of LV-Gruppen.
      */
     public static function findBySearchTerm($term, $filter = null)
     {
@@ -271,7 +271,7 @@ class Lvgruppe extends ModuleManagementModelTreeItem
      * Retrieves all LV-Gruppen related to the Modulteil with given id.
      *
      * @param string $modulteil_id The id of a Modulteil.
-     * @return object A SimpleORMapCollection of LV-Gruppen.
+     * @return SimpleORMapCollection A SimpleORMapCollection of LV-Gruppen.
      */
     public static function findByModulteil($modulteil_id)
     {
@@ -286,7 +286,7 @@ class Lvgruppe extends ModuleManagementModelTreeItem
      * Retrieves all LV-Gruppen related to the course with given id.
      *
      * @param string $seminar_id The id of a course.
-     * @return object A SimpleORMapCollection of LV-Gruppen.
+     * @return SimpleORMapCollection A SimpleORMapCollection of LV-Gruppen.
      */
     public static function findBySeminar($seminar_id)
     {
@@ -339,7 +339,7 @@ class Lvgruppe extends ModuleManagementModelTreeItem
     /**
      * Assigns the given course to the given LvGruppen.
      *
-     * @param array Array of ids
+     * @param string $seminar_id Array of ids
      * @return int The number of assigned LvGruppen.
      */
     public static function setLvgruppen($seminar_id, $lvgruppen_ids)
@@ -347,9 +347,13 @@ class Lvgruppe extends ModuleManagementModelTreeItem
         $old = Lvgruppe::findBySeminar($seminar_id);
         $removed = array_diff($old->pluck('id'), $lvgruppen_ids);
         $added = array_diff($lvgruppen_ids, $old->pluck('id'));
+
+        $count_removed = 0;
         foreach ($removed as $one) {
             $count_removed += $old->findOneBy('id', $one)->removeSeminar($seminar_id);
         }
+
+        $count_added = 0;
         foreach ($added as $one) {
             $count_added += Lvgruppe::get($one)->addSeminar($seminar_id);
         }
diff --git a/lib/models/MailQueueEntry.class.php b/lib/models/MailQueueEntry.php
index bc956e7..d0f9685 100644
--- a/lib/models/MailQueueEntry.class.php
+++ b/lib/models/MailQueueEntry.php
@@ -104,7 +104,7 @@ class MailQueueEntry extends SimpleORMap
 
             $status_messages[] = $status_message;
         }, "tries = 0 " .
-           "OR (last_try > (UNIX_TIMESTAMP() - 60 * 60) AND tries < 25) ORDER BY mkdate".
+           "OR (last_try > (UNIX_TIMESTAMP() - 60 * 60) AND tries < 25) ORDER BY tries, mkdate".
            ($limit > 0 ? " LIMIT ". (int) $limit : "")
         );
 
diff --git a/lib/models/Message.class.php b/lib/models/Message.php
index 46493d6..fb6b78e 100644
--- a/lib/models/Message.class.php
+++ b/lib/models/Message.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Message.class.php
+ * Message.php
  * model class for table message
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/MessageUser.class.php b/lib/models/MessageUser.php
index 0ae6dd5..1715de1 100644
--- a/lib/models/MessageUser.class.php
+++ b/lib/models/MessageUser.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * MessageUser.class.php
+ * MessageUser.php
  * model class for table message_user
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/MvvOverlappingConflict.class.php b/lib/models/MvvOverlappingConflict.php
index 6ac8e29..54b367f 100644
--- a/lib/models/MvvOverlappingConflict.class.php
+++ b/lib/models/MvvOverlappingConflict.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * MvvOverlappingConflict.class.php - model class for table mvv_ovl_conflicts
+ * MvvOverlappingConflict.php - model class for table mvv_ovl_conflicts
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/MvvOverlappingExclude.php b/lib/models/MvvOverlappingExclude.php
index d199e30..6cde414 100644
--- a/lib/models/MvvOverlappingExclude.php
+++ b/lib/models/MvvOverlappingExclude.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * MvvOverlappingExclude.class.php - model class for table mvv_ovl_excludes
+ * MvvOverlappingExclude.php - model class for table mvv_ovl_excludes
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -46,4 +46,3 @@ class MvvOverlappingExclude extends SimpleORMap
     }
 
 }
-
diff --git a/lib/models/MvvOverlappingSelection.class.php b/lib/models/MvvOverlappingSelection.php
index 9d159e2..b3fcc15 100644
--- a/lib/models/MvvOverlappingSelection.class.php
+++ b/lib/models/MvvOverlappingSelection.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * MvvOverlappingSelection.class.php - model class for table mvv_ovl_selections
+ * MvvOverlappingSelection.php - model class for table mvv_ovl_selections
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/NewsRange.class.php b/lib/models/NewsRange.php
index 7785214..675478f 100644
--- a/lib/models/NewsRange.class.php
+++ b/lib/models/NewsRange.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * NewsRange.class.php - model class for table Institute
+ * NewsRange.php - model class for table Institute
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/NewsRoles.class.php b/lib/models/NewsRoles.php
index 56da6ec..28a4064 100644
--- a/lib/models/NewsRoles.class.php
+++ b/lib/models/NewsRoles.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * NewsRoles.class.php - model class for the news roles
+ * NewsRoles.php - model class for the news roles
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/OERHostOERSI.php b/lib/models/OERHostOERSI.php
index 52e50d3..5e539bf 100644
--- a/lib/models/OERHostOERSI.php
+++ b/lib/models/OERHostOERSI.php
@@ -76,7 +76,7 @@ class OERHostOERSI extends OERHost
                     $material['difficulty_end'] = 12;
                     $material['uri'] = $material_data['_source']['id'];
                     $material['source_url'] = $material_data['_source']['id'];
-                    $material['content_type'] = $material_data['_source']['encoding'][0]['encodingFormat'] ?: '';
+                    $material['content_type'] = $material_data['_source']['encoding'][0]['encodingFormat'] ?? '';
                     $material['license_identifier'] = $this->getLicenseID($material_data['_source']['license']['id']) ?: '';
                     if (!$material['category']) {
                         $material['category'] = $material->autoDetectCategory();
@@ -86,18 +86,23 @@ class OERHostOERSI extends OERHost
                         'front_image_url' => $material_data['_source']['image'] ?? null,
                         'download' => $material_data['_source']['encoding'][0]['contentUrl'] ?: '',
                         'id' => $material_data['_id'],
-                        'organization' => $material_data['_source']['sourceOrganization'][0]['name'] ?: $material_data['_source']['publisher'][0]['name']
+                        'organization' => $material_data['_source']['sourceOrganization'][0]['name'] ?? $material_data['_source']['publisher'][0]['name'] ?? '',
                     ];
                     $material->store();
 
                     //set users:
                     $userdata = [];
-                    foreach ((array) $material_data['_source']['creator'] as $creator) {
-                        $userdata[] = [
-                            'user_id' => md5($creator['name']),
-                            'name' => $creator['name'],
-                            'host_url' => $this['url']
-                        ];
+                    if (
+                        isset($material_data['_source']['creator'])
+                        && is_array($material_data['_source']['creator'])
+                    ) {
+                        foreach ($material_data['_source']['creator'] as $creator) {
+                            $userdata[] = [
+                                'user_id' => md5($creator['name']),
+                                'name' => $creator['name'],
+                                'host_url' => $this['url']
+                            ];
+                        }
                     }
                     $material->setUsers($userdata);
 
diff --git a/lib/models/OERMaterial.php b/lib/models/OERMaterial.php
index 94559ef..604f845 100644
--- a/lib/models/OERMaterial.php
+++ b/lib/models/OERMaterial.php
@@ -164,7 +164,7 @@ class OERMaterial extends SimpleORMap
     public static function fetchRemoteSearch($text, $tag = false)
     {
         $cache_name = "oer_remote_searched_for_".md5($text)."_".($tag ? 1 : 0);
-        $already_searched = (bool) StudipCacheFactory::getCache()->read($cache_name);
+        $already_searched = (bool) \Studip\Cache\Factory::getCache()->read($cache_name);
         if (!$already_searched) {
             $hosts = OERHost::findBySQL("index_server = '1' AND allowed_as_index_server = '1' ORDER BY RAND()");
             foreach ($hosts as $host) {
@@ -172,7 +172,7 @@ class OERMaterial extends SimpleORMap
                     $host->fetchRemoteSearch($text, $tag);
                 }
             }
-            StudipCacheFactory::getCache()->read($cache_name, "1", 60);
+            \Studip\Cache\Factory::getCache()->write($cache_name, "1", 60);
         }
     }
 
@@ -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()) {
@@ -703,7 +703,7 @@ class OERMaterial extends SimpleORMap
         $message = sprintf(
             _('%1$s hat soeben neues Material auf dem OER Campus zur verfügung gestellt. Viel Spaß! <br> %2$s'),
             $user_name,
-            URLHelper::getURL("dispatch.php/oer/market/details/".$this->getId())
+            URLHelper::getURL("dispatch.php/oer/market/details/".$this->getId(), [], true)
         );
         URLHelper::setBaseURL($oldbase);
         $messsaging->insert_message(
diff --git a/lib/models/OpenGraphURL.class.php b/lib/models/OpenGraphURL.php
index 29e5718..29e5718 100644
--- a/lib/models/OpenGraphURL.class.php
+++ b/lib/models/OpenGraphURL.php
diff --git a/lib/models/OpenGraphURLCollection.class.php b/lib/models/OpenGraphURLCollection.php
index f575945..f575945 100644
--- a/lib/models/OpenGraphURLCollection.class.php
+++ b/lib/models/OpenGraphURLCollection.php
diff --git a/lib/models/PersonalNotifications.class.php b/lib/models/PersonalNotifications.php
index 721038c..12d9c1b 100644
--- a/lib/models/PersonalNotifications.class.php
+++ b/lib/models/PersonalNotifications.php
@@ -262,7 +262,7 @@ class PersonalNotifications extends SimpleORMap
      */
     protected static function getCache($user_id)
     {
-        $cache  = StudipCacheFactory::getCache();
+        $cache  = \Studip\Cache\Factory::getCache();
         $hash   = self::getCacheHash($user_id);
         $cached = $cache->read($hash);
 
@@ -281,7 +281,7 @@ class PersonalNotifications extends SimpleORMap
      */
     protected static function setCache($user_id, $items)
     {
-        $cache = StudipCacheFactory::getCache();
+        $cache = \Studip\Cache\Factory::getCache();
         $hash  = self::getCacheHash($user_id);
         $cache->write($hash, serialize($items), self::CACHE_DURATION);
     }
@@ -293,7 +293,7 @@ class PersonalNotifications extends SimpleORMap
      */
     protected static function expireCache($user_id)
     {
-        $cache = StudipCacheFactory::getCache();
+        $cache = \Studip\Cache\Factory::getCache();
         $hash  = self::getCacheHash($user_id);
         $cache->expire($hash);
     }
diff --git a/lib/models/Questionnaire.php b/lib/models/Questionnaire.php
index f29a2de..777182d 100644
--- a/lib/models/Questionnaire.php
+++ b/lib/models/Questionnaire.php
@@ -129,7 +129,7 @@ class Questionnaire extends SimpleORMap implements PrivacyObject
                 return true;
             } else {
                 //now look through all plugin if this assignment is related to plugin contents:
-                foreach (PluginManager::getInstance()->getPlugins("QuestionnaireAssignmentPlugin") as $plugin) {
+                foreach (PluginManager::getInstance()->getPlugins(QuestionnaireAssignmentPlugin::class) as $plugin) {
                     if ($plugin->isQuestionnaireViewable($assignment)) {
                         return true;
                     }
@@ -172,7 +172,7 @@ class Questionnaire extends SimpleORMap implements PrivacyObject
                     return true;
                 } else {
                     //now look through all plugin if this assignment is related to plugin contents:
-                    foreach (PluginManager::getInstance()->getPlugins("QuestionnaireAssignmentPlugin") as $plugin) {
+                    foreach (PluginManager::getInstance()->getPlugins(QuestionnaireAssignmentPlugin::class) as $plugin) {
                         if ($plugin->isQuestionnaireEditable($assignment)) {
                             return true;
                         }
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..20e134a 100644
--- a/lib/models/RangeScale.php
+++ b/lib/models/RangeScale.php
@@ -1,6 +1,4 @@
 <?php
-require_once 'lib/classes/QuestionType.interface.php';
-
 /**
  * @license GPL2 or any later version
  *
@@ -20,7 +18,7 @@ class RangeScale extends QuestionnaireQuestion implements QuestionType
 {
     public static function getIcon(bool $active = false) : Icon
     {
-        return Icon::create(static::getIconShape(), $active ? 'clickable' : 'info');
+        return Icon::create(static::getIconShape(), $active ? Icon::ROLE_CLICKABLE : Icon::ROLE_INFO);
     }
 
     /**
@@ -53,7 +51,7 @@ 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;
@@ -64,7 +62,11 @@ class RangeScale extends QuestionnaireQuestion implements QuestionType
         $answer = $this->getMyAnswer();
 
         $answers = Request::getArray('answers');
-        $userAnswer = (array) $answers[$this->getId()]['answerdata']['answers'];
+        if (!empty($answers[$this->getId()])) {
+            $userAnswer = (array)$answers[$this->getId()]['answerdata']['answers'];
+        } else {
+            $userAnswer = [];
+        }
         $answer->setData(['answerdata' => ['answers' => $userAnswer ] ]);
         return $answer;
     }
@@ -72,7 +74,7 @@ class RangeScale extends QuestionnaireQuestion implements QuestionType
     public function getUserIdsOfFilteredAnswer($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 +94,7 @@ 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/Semester.class.php b/lib/models/Semester.php
index 4eefa3b..ef3246b 100644
--- a/lib/models/Semester.class.php
+++ b/lib/models/Semester.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * Semester.class.php
+ * Semester.php
  * model class for table semester_data
  *
  * This program is free software; you can redistribute it and/or
@@ -181,7 +181,7 @@ class Semester extends SimpleORMap
         if (!is_array(self::$semester_cache) || $force_reload) {
             self::$semester_cache = [];
             if (!$force_reload) {
-                $cache = StudipCacheFactory::getCache();
+                $cache = \Studip\Cache\Factory::getCache();
                 $semester_data_array = unserialize($cache->read('DB_SEMESTER_DATA'));
                 if ($semester_data_array) {
                     foreach ($semester_data_array as $semester_data) {
@@ -202,7 +202,7 @@ class Semester extends SimpleORMap
                     }
                     $semester_data[] = $semester->toRawArray();
                 }
-                $cache = StudipCacheFactory::getCache();
+                $cache = \Studip\Cache\Factory::getCache();
                 $cache->write('DB_SEMESTER_DATA', serialize($semester_data));
             }
         }
@@ -471,7 +471,7 @@ class Semester extends SimpleORMap
      */
     public function refreshCache()
     {
-        StudipCacheFactory::getCache()->expire('DB_SEMESTER_DATA');
+        \Studip\Cache\Factory::getCache()->expire('DB_SEMESTER_DATA');
     }
 
     /*
diff --git a/lib/models/SemesterCourse.class.php b/lib/models/SemesterCourse.php
index 04590e3..79e5230 100644
--- a/lib/models/SemesterCourse.class.php
+++ b/lib/models/SemesterCourse.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * SemesterCourse.class.php
+ * SemesterCourse.php
  * Contains the SemesterCourse model.
  *
  * This class represents entries in the mapping table
diff --git a/lib/models/SemesterHoliday.class.php b/lib/models/SemesterHoliday.php
index 90f9ecd..265f8e1 100644
--- a/lib/models/SemesterHoliday.class.php
+++ b/lib/models/SemesterHoliday.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * SemesterHoliday.class.php
+ * SemesterHoliday.php
  * model class for table semester_holiday
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/SeminarCycleDate.class.php b/lib/models/SeminarCycleDate.php
index f384426..b8431a3 100644
--- a/lib/models/SeminarCycleDate.class.php
+++ b/lib/models/SeminarCycleDate.php
@@ -6,7 +6,7 @@ require_once 'lib/dates.inc.php';
 
 
 /**
- * SeminarCycleDate.class.php
+ * SeminarCycleDate.php
  * model class for table seminar_cycle_dates
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/SimpleCollection.class.php b/lib/models/SimpleCollection.class.php
deleted file mode 100644
index 4d77682..0000000
--- a/lib/models/SimpleCollection.class.php
+++ /dev/null
@@ -1,788 +0,0 @@
-<?php
-if (!defined('SORT_NATURAL')) {
-    define('SORT_NATURAL', 6);
-}
-if (!defined('SORT_FLAG_CASE')) {
-    define('SORT_FLAG_CASE', 8);
-}
-
-/**
- * SimpleCollection.class.php
- * collection of assoc arrays with convenience
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * @author      André Noack <noack@data-quest.de>
- * @copyright   2013 Stud.IP Core-Group
- * @license     http://www.gnu.org/licenses/gpl-2.0.html GPL version 2
- * @category    Stud.IP
- *
- * @template T
- */
-class SimpleCollection extends StudipArrayObject
-{
-    /**
-     * callable to initialize collection
-     *
-     * @var ?callable(): array<T>
-     */
-    protected $finder;
-
-    /**
-     * number of records after last init
-     *
-     * @var int
-     */
-    protected $last_count;
-
-    /**
-     * collection with deleted records
-     * @var static
-     */
-    protected $deleted;
-
-    /**
-     * creates a collection from an array of arrays
-     * all arrays should contain same keys, but is not enforced
-     *
-     * @param array<T> $data array containing assoc arrays
-     * @return SimpleCollection<T>
-     */
-    public static function createFromArray(array $data)
-    {
-        return new self($data);
-    }
-
-    /**
-     * converts arrays or objects to ArrayObject objects
-     * if ArrayAccess interface is not available
-     *
-     * @param mixed $a
-     * @return StudipArrayObject|ArrayAccess
-     */
-    public static function arrayToArrayObject($a)
-    {
-        if ($a instanceof StudipArrayObject) {
-            $a->setFlags(StudipArrayObject::ARRAY_AS_PROPS);
-            return $a;
-        }
-
-        if ($a instanceof ArrayObject) {
-            return new StudipArrayObject($a->getArrayCopy(), StudipArrayObject::ARRAY_AS_PROPS);
-        }
-
-        if ($a instanceof ArrayAccess) {
-            return $a;
-        }
-
-        return new StudipArrayObject((array) $a, StudipArrayObject::ARRAY_AS_PROPS);
-    }
-
-    /**
-     * returns closure to compare a value against given arguments
-     * using given operator
-     *
-     * @param string|callable(mixed, mixed|array): bool  $operator
-     * @param mixed|array $args
-     * @throws InvalidArgumentException
-     * @return callable(mixed): bool comparison function
-     */
-    public static function getCompFunc($operator, $args)
-    {
-        if (is_callable($operator)) {
-            $comp_func = function ($a) use ($args, $operator) {
-                return $operator($a, $args);
-            };
-        } else {
-            if (!is_array($args)) {
-                $args = [$args];
-            }
-            switch ($operator) {
-                case '==':
-                    $comp_func = function ($a) use ($args) {
-                        return in_array($a, $args);
-                    };
-                break;
-                case '===':
-                    $comp_func = function ($a) use ($args) {
-                        return in_array($a, $args, true);
-                    };
-                break;
-                case '!=':
-                case '<>':
-                    $comp_func = function ($a) use ($args) {
-                        return !in_array($a, $args);
-                    };
-                break;
-                case '!==':
-                    $comp_func = function ($a) use ($args) {
-                        return !in_array($a, $args, true);
-                    };
-                break;
-                case '<':
-                case '>':
-                case '<=':
-                case '>=':
-                    $op_func = function ($a, $b) use ($operator) {
-                        if ($operator === '<') {
-                            return $a < $b;
-                        } elseif ($operator === '<=') {
-                            return $a <= $b;
-                        } elseif ($operator === '>=') {
-                            return $a >= $b;
-                        } elseif ($operator === '>') {
-                            return $a > $b;
-                        }
-                    };
-                    $comp_func = function ($a) use ($op_func, $args) {
-                        return $op_func($a, $args[0]);
-                    };
-                break;
-                case '><':
-                    $comp_func = function ($a) use ($args) {
-                        return $a > $args[0] && $a < $args[1];
-                    };
-                break;
-                case '>=<=':
-                    $comp_func = function ($a) use ($args) {
-                        return $a >= $args[0] && $a <= $args[1];
-                    };
-                    break;
-                case '%=':
-                    $comp_func = function ($a) use ($args) {
-                        $a = mb_strtolower(static::translitLatin1($a));
-                        $args = array_map([static::class, 'translitLatin1'], $args);
-                        $args = array_map('mb_strtolower', $args);
-                        return in_array($a, $args);
-                    };
-                break;
-                case '*=':
-                    $comp_func = function ($a) use ($args) {
-                        foreach ($args as $arg) {
-                            if (mb_strpos($a, $arg) !== false) {
-                                return true;
-                            }
-                        }
-                        return false;
-                    };
-                break;
-                case '^=':
-                    $comp_func = function ($a) use ($args) {
-                        foreach ($args as $arg) {
-                            if (mb_strpos($a, $arg) === 0) {
-                                return true;
-                            }
-                        }
-                        return false;
-                    };
-                break;
-                case '$=':
-                    $comp_func = function ($a) use ($args) {
-                        foreach ($args as $arg) {
-                            $found = mb_strrpos($a, $arg);
-                            if ($found !== false && ($found + mb_strlen($arg)) === mb_strlen($a)) {
-                                return true;
-                            }
-                        }
-                        return false;
-                    };
-                break;
-                case '~=':
-                    $comp_func = function ($a) use ($args) {
-                        foreach ($args as $arg) {
-                            if (preg_match($arg, $a) === 1) {
-                                return true;
-                            }
-                        }
-                        return false;
-                    };
-                    break;
-                default:
-                    throw new InvalidArgumentException('unknown operator: ' . $operator);
-             }
-         }
-         return $comp_func;
-    }
-
-    /**
-     * transliterates latin1 string to ascii
-     *
-     * @param string $text
-     * @return string
-     */
-    public static function translitLatin1($text)
-    {
-        if (!preg_match('/[\200-\377]/', $text)) {
-            return $text;
-        }
-        $text = str_replace(['ä','Ä','ö','Ö','ü','Ü','ß'], ['a','A','o','O','u','U','s'], $text);
-        $text = str_replace(['À','Á','Â','Ã','Å','Æ'], 'A' , $text);
-        $text = str_replace(['à','á','â','ã','å','æ'], 'a' , $text);
-        $text = str_replace(['È','É','Ê','Ë'], 'E' , $text);
-        $text = str_replace(['è','é','ê','ë'], 'e' , $text);
-        $text = str_replace(['Ì','Í','Î','Ï'], 'I' , $text);
-        $text = str_replace(['ì','í','î','ï'], 'i' , $text);
-        $text = str_replace(['Ò','Ó','Õ','Ô','Ø'], 'O' , $text);
-        $text = str_replace(['ò','ó','ô','õ','ø'], 'o' , $text);
-        $text = str_replace(['Ù','Ú','Û'], 'U' , $text);
-        $text = str_replace(['ù','ú','û'], 'u' , $text);
-        $text = str_replace(['Ç','ç','Ð','Ñ','Ý','ñ','ý','ÿ'], ['C','c','D','N','Y','n','y','y'] , $text);
-        return $text;
-    }
-
-    /**
-     * Constructor
-     *
-     * @param array<T>|callable(): array<T> $data array or closure to fill collection
-     */
-    public function __construct($data = [])
-    {
-        parent::__construct();
-        $this->finder = is_callable($data) ? $data : null;
-        $this->deleted = clone $this;
-        if (is_callable($data)) {
-            $this->refresh();
-        } else {
-            $this->exchangeArray($data);
-        }
-    }
-
-    /**
-     * @param array $input
-     * @return array
-     */
-    public function exchangeArray($input)
-    {
-        return parent::exchangeArray(array_map(
-            [static::class, 'arrayToArrayObject'],
-            $input
-        ));
-    }
-
-    /**
-     * converts the object and all elements to plain arrays
-     *
-     * @return array
-     */
-    public function toArray()
-    {
-        $args = func_get_args();
-        return $this->map(function ($a) use ($args) {
-            if (method_exists($a, 'toArray')) {
-                return call_user_func_array([$a, 'toArray'], $args);
-            }
-            if (method_exists($a, 'getArrayCopy')) {
-                return $a->getArrayCopy();
-            }
-            return (array) $a;
-        }
-        );
-    }
-
-    /**
-     *
-     * @see ArrayObject::append()
-     */
-    public function append($newval)
-    {
-        parent::append(static::arrayToArrayObject($newval));
-    }
-
-    /**
-     * Sets the value at the specified index
-     * ensures the value has ArrayAccess
-     *
-     * @param mixed $index
-     * @param mixed $newval
-     *
-     * @see ArrayObject::offsetSet()
-     * @return void
-     *
-     * @todo Add void return type when Stud.IP requires PHP8 minimal
-     */
-    #[ReturnTypeWillChange]
-    public function offsetSet($index, $newval)
-    {
-        if (is_numeric($index)) {
-            $index = (int) $index;
-        }
-        parent::offsetSet($index, static::arrayToArrayObject($newval));
-    }
-
-    /**
-     * Unsets the value at the specified index
-     * value is moved to internal deleted collection
-     *
-     * @see ArrayObject::offsetUnset()
-     * @throws InvalidArgumentException
-     *
-     * @todo Add void return type when Stud.IP requires PHP8 minimal
-     */
-    #[ReturnTypeWillChange]
-    public function offsetUnset($index)
-    {
-        if ($this->offsetExists($index)) {
-            $this->deleted[] = $this->offsetGet($index);
-        }
-        parent::offsetUnset($index);
-    }
-
-    /**
-     * sets the finder function
-     *
-     * @param callable(): array<T> $finder
-     * @return void
-     */
-    public function setFinder(callable $finder)
-    {
-        $this->finder = $finder;
-    }
-
-    /**
-     * get deleted records collection
-     * @return SimpleCollection<T>
-     */
-    public function getDeleted()
-    {
-        return $this->deleted;
-    }
-
-    /**
-     * reloads the elements of the collection
-     * by calling the finder function
-     *
-     * @return ?int of records after refresh
-     */
-    public function refresh()
-    {
-        if (is_callable($this->finder)) {
-            $data = call_user_func($this->finder);
-            $this->exchangeArray($data);
-            $this->deleted->exchangeArray([]);
-            return $this->last_count = $this->count();
-        }
-    }
-
-    /**
-     * returns a new collection containing all elements
-     * where given columns value matches given value(s) using passed operator
-     * pass array for multiple values
-     *
-     * operators:
-     * == equal, like php
-     * === identical, like php
-     * !=,<> not equal, like php
-     * !== not identical, like php
-     * <,>,<=,>= less,greater,less or equal,greater or equal
-     * >< between without borders, needs two arguments
-     * >=<= between including borders, needs two arguments
-     * %= like string, transliterate to ascii,case insensitive
-     * *= contains string
-     * ^= begins with string
-     * $= ends with string
-     * ~= regex
-     *
-     * @param string $key the column name
-     * @param mixed $values value to search for
-     * @param string|callable $op operator to find
-     * @return SimpleCollection<T> with found records
-     */
-    public function findBy($key, $values, $op = '==')
-    {
-        $comp_func = self::getCompFunc($op, $values);
-        return $this->filter(function ($record) use ($comp_func, $key) {
-            return $comp_func($record[$key]);
-        });
-    }
-
-    /**
-     * returns the first element
-     * where given column has given value(s)
-     * pass array for multiple values
-     *
-     * @param string $key the column name
-     * @param mixed $values value to search for,
-     * @param string|callable $op operator to find
-     * @return ?T found record
-     */
-    public function findOneBy($key, $values, $op = '==')
-    {
-        $comp_func = self::getCompFunc($op, $values);
-        return $this->filter(function ($record) use ($comp_func, $key) {
-            return $comp_func($record[$key]);
-        }, 1)->first();
-    }
-
-    /**
-     * apply given callback to all elements of
-     * collection
-     *
-     * @param callable(T): int $func the function to call
-     * @return int|false addition of return values
-     */
-    public function each(callable $func)
-    {
-        $result = false;
-        foreach ($this->storage as $record) {
-            $result += call_user_func($func, $record);
-        }
-        return $result;
-    }
-
-    /**
-     * apply given callback to all elements of
-     * collection and give back array of return values
-     *
-     * @param callable(T, mixed): mixed $func the function to call
-     * @return array<mixed>
-     */
-    public function map(callable $func)
-    {
-        $results = [];
-        foreach ($this->storage as $key => $value) {
-            $results[$key] = call_user_func($func, $value, $key);
-        }
-        return $results;
-    }
-
-    /**
-     * filter elements
-     * if given callback returns true
-     *
-     * @param ?callable(T, mixed): bool $func the function to call
-     * @param ?integer $limit limit number of found records
-     * @return SimpleCollection<T> containing filtered elements
-     */
-    public function filter(callable $func = null, $limit = null)
-    {
-        $results = [];
-        $found = 0;
-        foreach ($this->storage as $key => $value) {
-            if (call_user_func($func, $value, $key)) {
-                $results[$key] = $value;
-                if ($limit && (++$found == $limit)) {
-                    break;
-                }
-            }
-        }
-        return self::createFromArray($results);
-    }
-
-    /**
-     * Returns whether any element of the collection returns true for the
-     * given callback.
-     *
-     * @param  callable(T, mixed): bool $func the function to call
-     * @return bool
-     */
-    public function any(callable $func)
-    {
-        foreach ($this->storage as $key => $value) {
-            if (call_user_func($func, $value, $key)) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    /**
-     * Returns whether every element of the collection returns true for the
-     * given callback.
-     *
-     * @param  callable(T, mixed): bool $func the function to call
-     * @return bool
-     */
-    public function every(callable $func)
-    {
-        foreach ($this->storage as $key => $value) {
-            if (!call_user_func($func, $value, $key)) {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    /**
-     * extract array of columns values
-     * pass array or space-delimited string for multiple columns
-     *
-     * @param string|array $columns the column(s) to extract
-     * @return array of extracted values
-     */
-    public function pluck($columns)
-    {
-        if (!is_array($columns)) {
-            $columns = words($columns);
-        }
-        $func = function ($r) use ($columns) {
-            $result = [];
-            foreach ($columns as $c) {
-                $result[] = $r[$c];
-            }
-            return $result;
-        };
-        $result = $this->map($func);
-        return count($columns) === 1 ? array_map('current', $result) : $result;
-    }
-
-    /**
-     * returns the collection as grouped array
-     * first param is the column to group by, it becomes the key in
-     * the resulting array, default is pk. Limit returned fields with second param
-     * The grouped entries can optoionally go through the given
-     * callback. If no callback is provided, only the first grouped
-     * entry is returned, suitable for grouping by unique column
-     *
-     * @param string $group_by the column to group by, pk if ommitted
-     * @param string|array|null $only_these_fields limit returned fields
-     * @param ?callable $group_func closure to aggregate grouped entries
-     * @return array assoc array
-     */
-    public function toGroupedArray($group_by = 'id', $only_these_fields = null, callable $group_func = null)
-    {
-        $result = [];
-        if (is_string($only_these_fields)) {
-            $only_these_fields = words($only_these_fields);
-        }
-        foreach ($this->toArray() as $record) {
-            $key = $record[$group_by];
-            $ret = [];
-            if (is_array($only_these_fields)) {
-                $result[$key][] = array_intersect_key($record, array_flip($only_these_fields));
-            } else {
-                $result[$key][] = $record;
-            }
-        }
-        if ($group_func === null) {
-            $group_func = 'current';
-        }
-        return array_map($group_func, $result);
-    }
-
-    /**
-     * get the first element
-     *
-     * @return ?T first element or null
-     */
-    public function first()
-    {
-        $keys = array_keys($this->storage);
-        $first_offset = reset($keys);
-        return $this->offsetGet($first_offset ?: 0);
-    }
-
-    /**
-     * get the last element
-     *
-     * @return ?T last element or null
-     */
-    public function last()
-    {
-        $keys = array_keys($this->storage);
-        $last_offset = end($keys);
-        return $this->offsetGet($last_offset ?: 0);
-    }
-
-     /**
-     * get the the value from given key from first element
-     *
-     * @param string $key
-     * @return mixed
-     */
-    public function val($key)
-    {
-        $first = $this->first();
-        return $first[$key] ?? null;
-    }
-
-    /**
-     * mark element(s) for deletion
-     * where given column has given value(s)
-     * element(s) are moved to
-     * internal deleted collection
-     * pass array for multiple values
-     *
-     * operators:
-     * == equal, like php
-     * === identical, like php
-     * !=,<> not equal, like php
-     * !== not identical, like php
-     * <,>,<=,>= less,greater,less or equal,greater or equal
-     * >< between without borders, needs two arguments
-     * >=<= between including borders, needs two arguments
-     * %= like string, transliterate to ascii,case insensitive
-     * *= contains string
-     * ^= begins with string
-     * $= ends with string
-     * ~= regex
-     *
-     * @param string $key
-     * @param mixed $values
-     * @param string|callable(mixed, mixed|array): bool $op operator to find elements
-     * @return int|false number of unsetted elements
-     */
-    public function unsetBy($key, $values, $op = '==')
-    {
-        $ret = false;
-        $comp_func = self::getCompFunc($op, $values);
-        foreach ($this->storage as $k => $record) {
-            if ($comp_func($record[$key])) {
-                $this->offsetunset($k);
-                $ret += 1;
-            }
-        }
-        return $ret;
-    }
-
-    /**
-     * sorts the collection by columns of contained elements and returns it
-     *
-     * works like sql order by:
-     * first param is a string containing combinations of column names
-     * and sort direction, separated by comma e.g.
-     *  'name asc, nummer desc '
-     *  sorts first by name ascending and then by nummer descending
-     *  second param denotes the sort type (using PHP sort constants):
-     *  SORT_LOCALE_STRING:
-     *  compare items as strings, transliterate latin1 to ascii, case insensitiv, natural order for numbers
-     *  SORT_NUMERIC:
-     *  compare items as integers
-     *  SORT_STRING:
-     *  compare items as strings
-     *  SORT_NATURAL:
-     *  compare items as strings using "natural ordering"
-     *  SORT_FLAG_CASE:
-     *  can be combined (bitwise OR) with SORT_STRING or SORT_NATURAL to sort strings case-insensitively
-     *
-     * @param string $order columns to order by
-     * @param integer $sort_flags
-     * @return $this the sorted collection
-     */
-    public function orderBy($order, $sort_flags = SORT_LOCALE_STRING)
-    {
-        //('name asc, nummer desc ')
-        $sort_locale = false;
-        switch ($sort_flags) {
-        case SORT_NATURAL:
-            $sort_func = 'strnatcmp';
-            break;
-        case SORT_NATURAL | SORT_FLAG_CASE:
-            $sort_func = 'strnatcasecmp';
-            break;
-        case SORT_STRING | SORT_FLAG_CASE:
-            $sort_func = 'strcasecmp';
-            break;
-        case SORT_STRING:
-            $sort_func = 'strcmp';
-            break;
-        case SORT_NUMERIC:
-            $sort_func = function ($a, $b) {
-                return (int) $a - (int) $b;
-            };
-            break;
-        case SORT_LOCALE_STRING:
-        default:
-            $sort_func = 'strnatcasecmp';
-            $sort_locale = true;
-        }
-
-        $sorter = [];
-        foreach (explode(',', $order) as $one) {
-            $sorter[] = array_values(array_filter(array_map('trim', explode(' ', $one))));
-        }
-
-        $func = function ($d1, $d2) use ($sorter, $sort_func, $sort_locale) {
-            do {
-                $current_sorter = current($sorter);
-                $field = $current_sorter[0];
-                $dir = $current_sorter[1] ?? '';
-                if (!$sort_locale) {
-                    $value1 = $d1[$field];
-                    $value2 = $d2[$field];
-                } else {
-                    $value1 = static::translitLatin1(mb_substr($d1[$field], 0, 100));
-                    $value2 = static::translitLatin1(mb_substr($d2[$field], 0, 100));
-                }
-                $ret = $sort_func($value1, $value2);
-                if (strtolower($dir) == 'desc') $ret = $ret * -1;
-            } while ($ret === 0 && next($sorter));
-
-            return $ret;
-        };
-        if (count($sorter)) {
-            $this->uasort($func);
-        }
-        return $this;
-    }
-
-    /**
-     * returns a new collection contaning a sequence of original collection
-     * mimics the sql limit constrain:
-     * used with one parameter, the first x elements are extracted
-     * used with two parameters, the first parameter denotes the offset, the second the
-     * number of elements
-     *
-     * @param integer $arg1
-     * @param ?integer $arg2
-     * @return SimpleCollection<T>
-     */
-    public function limit($arg1, $arg2 = null)
-    {
-        if (is_null($arg2)) {
-            if ($arg1 > 0) {
-                $row_count = $arg1;
-                $offset = 0;
-            } else {
-                $row_count = abs($arg1);
-                $offset = $arg1;
-            }
-        } else {
-            $offset = $arg1;
-            $row_count = $arg2;
-        }
-        return self::createFromArray(array_slice($this->storage, $offset, $row_count, true));
-    }
-
-     /**
-     * calls the given method on all elements
-     * of the collection
-     * @param literal-string $method methodname to call
-     * @param array $params parameters for methodcall
-     * @return array of all return values
-     */
-    public function sendMessage($method, $params = []) {
-        $results = [];
-        foreach ($this->storage as $record) {
-            $results[] = call_user_func_array([$record, $method], $params);
-        }
-        return $results;
-    }
-
-    /**
-     * magic version of sendMessage
-     * calls undefineds methods on all elements of the collection
-     * But beware of the dark side...
-     *
-     * @param literal-string $method methodname to call
-     * @param array $params parameters for methodcall
-     * @return array of all return values
-     */
-    public function __call($method, $params)
-    {
-        return $this->sendMessage($method, $params);
-    }
-
-    /**
-     * merge in another collection, elements are appended
-     *
-     * @param SimpleCollection<T> $a_collection
-     * @return void
-     */
-    public function merge(SimpleCollection $a_collection)
-    {
-        $this->storage = array_merge($this->storage, $a_collection->getArrayCopy());
-    }
-}
diff --git a/lib/models/SimpleORMap.class.php b/lib/models/SimpleORMap.class.php
deleted file mode 100644
index 4a0caa3..0000000
--- a/lib/models/SimpleORMap.class.php
+++ /dev/null
@@ -1,2501 +0,0 @@
-<?php
-/**
- * SimpleORMap.class.php
- * simple object-relational mapping
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * @author      André Noack <noack@data-quest.de>
- * @copyright   2010 Stud.IP Core-Group
- * @license     http://www.gnu.org/licenses/gpl-2.0.html GPL version 2
- * @category    Stud.IP
-*/
-
-class SimpleORMap implements ArrayAccess, Countable, IteratorAggregate
-{
-    /**
-     * Defines `_` as character used when joining composite primary keys.
-     */
-    const ID_SEPARATOR = '_';
-
-    /**
-     * table row data
-     * @var array $content
-     */
-    protected $content = [];
-
-    /**
-     * table row data
-     * @var array $content_db
-     */
-    protected $content_db = [];
-
-    /**
-     * new state of entry
-     * @var boolean $is_new
-     */
-    protected $is_new = true;
-
-    /**
-     * deleted state of entry
-     * @var boolean $is_deleted
-     */
-    protected $is_deleted = false;
-
-     /**
-     * db table metadata
-     * @var ?array $schemes;
-     */
-    public static $schemes = null;
-
-    /**
-     * configuration data for subclasses
-     * @see self::configure()
-     * @var array $config;
-     */
-    protected static $config = [];
-
-    /**
-     * stores instantiated related objects
-     * @var array $relations
-     */
-    protected $relations = [];
-
-    /**
-     * assoc array for storing values for additional fields
-     *
-     * @var array $additional_data
-     */
-    protected $additional_data = [];
-
-    /**
-     * reserved indentifiers, fields with those names must not have an explicit getXXX() method
-     * @var array $reserved_slots
-     */
-    protected static $reserved_slots = ['value','newid','iterator','tablemetadata', 'relationvalue','wherequery','relationoptions','data','new','id'];
-
-    /**
-     * indicator for batch operations in findEachBySQL
-     *
-     * @var bool $performs_batch_operation
-     */
-    protected static $performs_batch_operation = false;
-
-    /**
-     * name of db table
-     * @return string
-     */
-    protected static function db_table()
-    {
-        return static::config('db_table');
-    }
-
-    /**
-     * table columns
-     * @return array
-     */
-    protected static function db_fields()
-    {
-        return static::config('db_fields');
-    }
-
-    /**
-     * primary key columns
-     * @return array
-     */
-    protected static function pk()
-    {
-        return static::config('pk');
-    }
-
-    /**
-     * default values for columns
-     * @return array
-     */
-    protected static function default_values()
-    {
-        return static::config('default_values');
-    }
-
-    /**
-     * list of columns to deserialize
-     * @return array key is name of column, value is name of ArrayObject class
-     */
-    protected static function serialized_fields()
-    {
-        return static::config('serialized_fields');
-    }
-
-    /**
-     * aliases for columns
-     * alias => column
-     * @return array
-     */
-    protected static function alias_fields()
-    {
-        return static::config('alias_fields');
-    }
-
-    /**
-     * multi-language fields
-     * name => boolean
-     * @return array
-     */
-    protected static function i18n_fields()
-    {
-        return static::config('i18n_fields');
-    }
-
-    /**
-     * additional computed fields
-     * name => callable
-     * @return array
-     */
-    protected static function additional_fields()
-    {
-        return static::config('additional_fields');
-    }
-
-    /**
-     * 1:n relation
-     * @return array
-     */
-    protected static function has_many()
-    {
-        return static::config('has_many');
-    }
-
-    /**
-     * 1:1 relation
-     * @return array
-     */
-    protected static function has_one()
-    {
-        return static::config('has_one');
-    }
-
-    /**
-     * n:1 relations
-     * @return array
-     */
-    protected static function belongs_to()
-    {
-        return static::config('belongs_to');
-    }
-
-    /**
-     * n:m relations
-     * @return array
-     */
-    protected static function has_and_belongs_to_many()
-    {
-        return static::config('has_and_belongs_to_many');
-    }
-
-    /**
-     * callbacks
-     * @return array<string, array<string|Closure>>
-     */
-    protected static function registered_callbacks()
-    {
-        return static::config('registered_callbacks');
-    }
-
-    /**
-     * contains an array of all used identifiers for fields
-     * (db columns + aliased columns + additional columns + relations)
-     * @return array
-     */
-    protected static function known_slots()
-    {
-        return static::config('known_slots');
-    }
-
-    /**
-     * assoc array used to map SORM callback to NotificationCenter
-     * keys are SORM callbacks, values notifications
-     * eg. 'after_create' => 'FooDidCreate'
-     *
-     * @return array
-     */
-    protected static function notification_map()
-    {
-        return static::config('notification_map');
-    }
-
-    /**
-     * assoc array for mapping get/set Methods
-     *
-     * @return array
-     */
-    protected static function getter_setter_map()
-    {
-        return static::config('getter_setter_map');
-    }
-
-    //////////////////////////////////////////////////
-
-    /**
-     * set configuration data from subclass
-     *
-     * @param ?array $config configuration data
-     * @return void
-     */
-    protected static function configure($config = [])
-    {
-        $class = get_called_class();
-
-        if (empty($config['db_table'])) {
-            $config['db_table'] = strtolower($class);
-        }
-
-        if (!isset($config['db_fields'])) {
-            if (static::tableScheme($config['db_table'])) {
-                $config['db_fields'] = self::$schemes[$config['db_table']]['db_fields'];
-                $config['pk'] = self::$schemes[$config['db_table']]['pk'];
-            }
-        }
-
-        if (isset($config['pk'])
-            && !isset($config['db_fields']['id'])
-            && !isset($config['alias_fields']['id'])
-            && !isset($config['additional_fields']['id'])
-        ) {
-            if (count($config['pk']) === 1) {
-                $config['alias_fields']['id'] = $config['pk'][0];
-            } else {
-                $config['additional_fields']['id'] = ['get' => '_getId',
-                                                           'set' => '_setId'];
-            }
-        }
-        if (isset($config['additional_fields'])) {
-            foreach ($config['additional_fields'] as $a_field => $a_config) {
-                if (is_array($a_config) && !(isset($a_config['get']) || isset($a_config['set']))) {
-                    $relation = $a_config[0] ?? '';
-                    $relation_field = $a_config[1] ?? '';
-                    if (!$relation) {
-                        list($relation, $relation_field) = explode('_', $a_field);
-                    }
-                    if (!$relation_field || !$relation) {
-                        throw new UnexpectedValueException('no relation found for autoget/set additional field: ' . $a_field);
-                    }
-                    $config['additional_fields'][$a_field] = ['get'            => '_getAdditionalValueFromRelation',
-                                                                   'set'            => '_setAdditionalValue',
-                                                                   'relation'       => $relation,
-                                                                   'relation_field' => $relation_field];
-                }
-            }
-        }
-        if (isset($config['serialized_fields'])) {
-            foreach ($config['serialized_fields'] as $a_field => $object_type) {
-                if (!(is_subclass_of($object_type, 'StudipArrayObject'))) {
-                    throw new UnexpectedValueException(sprintf('serialized field %s must use subclass of StudipArrayObject', $a_field));
-                }
-            }
-        }
-
-        foreach (['default_values', 'serialized_fields', 'alias_fields', 'i18n_fields', 'additional_fields'] as $fields) {
-            if (!isset($config[$fields])) {
-                $config[$fields] = [];
-            }
-        }
-
-        foreach (['has_many', 'belongs_to', 'has_one', 'has_and_belongs_to_many'] as $type) {
-            if (isset($config[$type]) && is_array($config[$type])) {
-                foreach (array_keys($config[$type]) as $one) {
-                    $config['relations'][$one] = null;
-                }
-            } else {
-                $config[$type] = [];
-            }
-        }
-
-        $callbacks = ['before_create',
-                      'before_update',
-                      'before_store',
-                      'before_delete',
-                      'before_initialize',
-                      'after_create',
-                      'after_update',
-                      'after_store',
-                      'after_delete',
-                      'after_initialize'];
-
-        foreach ($callbacks as $callback) {
-            if (!isset($config['registered_callbacks'][$callback])) {
-                $config['registered_callbacks'][$callback] = [];
-            }
-        }
-
-        $auto_notification_map['after_create'] = $class . 'DidCreate';
-        $auto_notification_map['after_store'] = $class . 'DidStore';
-        $auto_notification_map['after_delete'] = $class . 'DidDelete';
-        $auto_notification_map['after_update'] = $class . 'DidUpdate';
-        $auto_notification_map['before_create'] = $class . 'WillCreate';
-        $auto_notification_map['before_store'] = $class . 'WillStore';
-        $auto_notification_map['before_delete'] = $class . 'WillDelete';
-        $auto_notification_map['before_update'] = $class . 'WillUpdate';
-
-        foreach ($auto_notification_map as $cb => $notification) {
-            if (isset($config['notification_map'][$cb])) {
-                if (strpos($config['notification_map'][$cb], $notification) !== false) {
-                    $config['notification_map'][$cb] .= ' ' . $notification;
-                }
-            } else {
-                $config['notification_map'][$cb] = $notification;
-            }
-        }
-
-        if (is_array($config['notification_map'])) {
-            foreach (array_keys($config['notification_map']) as $cb) {
-                $config['registered_callbacks'][$cb][] = 'cbNotificationMapper';
-            }
-        }
-
-        if (!I18N::isEnabled() || empty($config['i18n_fields'])) {
-            $config['i18n_fields'] = [];
-        } elseif (is_string($config['i18n_fields'])) {
-            $i18n_fields = words($config['i18n_fields']);
-            $config['i18n_fields'] = array_combine(
-                $i18n_fields,
-                array_fill(0, count($i18n_fields), true)
-            );
-        } elseif (array_is_list($config['i18n_fields'])) {
-            $config['i18n_fields'] = array_combine(
-                $config['i18n_fields'],
-                array_fill(0, count($config['i18n_fields']), true)
-            );
-        }
-
-        array_unshift($config['registered_callbacks']['after_initialize'], 'cbAfterInitialize');
-
-        $config['known_slots'] = array_merge(
-            array_keys($config['db_fields']),
-            array_keys($config['alias_fields'] ?? []),
-            array_keys($config['additional_fields'] ?? []),
-            array_keys($config['relations'] ?? [])
-        );
-
-        foreach (array_map('strtolower', get_class_methods($class)) as $method) {
-            if (in_array(substr($method, 0, 3), ['get', 'set'])) {
-                $verb = substr($method, 0, 3);
-                $name = substr($method, 3);
-                if (in_array($name, $config['known_slots']) && !in_array($name, static::$reserved_slots) && !isset($config['additional_fields'][$name][$verb])) {
-                    $config['getter_setter_map'][$name][$verb] = $method;
-                }
-            }
-        }
-        self::$config[$class] = $config;
-    }
-
-    /**
-     * fetch config data for the called class
-     *
-     * @param string $key config key
-     * @return mixed value of config key (null if not set)
-     */
-    protected static function config($key)
-    {
-        if (!array_key_exists(static::class, self::$config)) {
-            static::configure();
-        }
-
-        return self::$config[static::class][$key] ?? null;
-    }
-
-    /**
-     * fetch table metadata from db or from local cache
-     *
-     * @param string $db_table
-     * @return bool true if metadata could be fetched
-     */
-    public static function tableScheme($db_table)
-    {
-        if (self::$schemes === null) {
-            $cache = StudipCacheFactory::getCache();
-            self::$schemes = unserialize($cache->read('DB_TABLE_SCHEMES'));
-        }
-        if (!isset(self::$schemes[$db_table])) {
-            $db = DBManager::get()->query("SHOW COLUMNS FROM $db_table");
-            while($rs = $db->fetch(PDO::FETCH_ASSOC)){
-                $db_fields[strtolower($rs['Field'])] = [
-                    'name' => $rs['Field'],
-                    'null' => $rs['Null'],
-                    'default' => $rs['Default'],
-                    'type' => $rs['Type'],
-                    'extra' => $rs['Extra']
-                ];
-                if ($rs['Key'] == 'PRI'){
-                    $pk[] = strtolower($rs['Field']);
-                }
-            }
-            self::$schemes[$db_table]['db_fields'] = $db_fields;
-            self::$schemes[$db_table]['pk'] = $pk;
-            $cache = StudipCacheFactory::getCache();
-            $cache->write('DB_TABLE_SCHEMES', serialize(self::$schemes));
-        }
-        return isset(self::$schemes[$db_table]);
-    }
-
-    /**
-     * force reload of cached table metadata
-     * @return void
-     */
-    public static function expireTableScheme()
-    {
-        StudipCacheFactory::getCache()->expire('DB_TABLE_SCHEMES');
-        self::$schemes = null;
-        self::$config = [];
-    }
-
-    /**
-     * Returns new instance for given key when found in the database, else null.
-     *
-     * @param string $id primary key
-     * @return static|null
-     */
-    public static function find($id)
-    {
-        $class = get_called_class();
-        $ref = new ReflectionClass($class);
-        /** @var static $record */
-        $record = $ref->newInstanceArgs(func_get_args());
-        if (!$record->isNew()) {
-            return $record;
-        } else {
-            return null;
-        }
-    }
-
-    /**
-     * Returns true if given key exists in the database.
-     *
-     * @param string|array $id primary key
-     * @return boolean
-     */
-    public static function exists($id)
-    {
-        $ret = false;
-        $db_table = static::db_table();
-        $class = get_called_class();
-        $record = new $class();
-        call_user_func_array([$record, 'setId'], func_get_args());
-        $where_query = $record->getWhereQuery();
-        if ($where_query) {
-            $query = "SELECT 1 FROM `$db_table` WHERE "
-                    . join(" AND ", $where_query);
-            $ret = (bool)DBManager::get()->query($query)->fetchColumn();
-        }
-        return $ret;
-    }
-
-    /**
-     * returns number of records
-     *
-     * @param ?string $sql sql clause to use on the right side of WHERE
-     * @param ?array $params params for query
-     * @return int
-     */
-    public static function countBySql($sql = '1', $params = [])
-    {
-        $db_table = static::db_table();
-        $db = DBManager::get();
-        $has_join = stripos($sql, 'JOIN ');
-        if ($has_join === false || $has_join > 10) {
-            $sql = 'WHERE ' . $sql;
-        }
-        $sql = "SELECT count(*) FROM `" .  $db_table . "` " . $sql;
-        $st = $db->prepare($sql);
-        $st->execute($params);
-        return (int)$st->fetchColumn();
-    }
-
-    /**
-     * creates new record with given data in db
-     * returns the new object or null
-     * @param array $data assoc array of record
-     * @return ?static
-     */
-    public static function create($data)
-    {
-        $class = get_called_class();
-        $record = new $class();
-        $record->setData($data, false);
-        if ($record->store()) {
-            return $record;
-        } else {
-            return null;
-        }
-    }
-
-    /**
-     * build object with given data
-     *
-     * @param array $data assoc array of record
-     * @param ?bool $is_new set object to new state
-     * @return static
-     */
-    public static function build($data, $is_new = true)
-    {
-        $class = get_called_class();
-        /** @var static $record */
-        $record = new $class();
-        $record->setData($data, !$is_new);
-        $record->setNew($is_new);
-        return $record;
-    }
-
-    /**
-     * build object with given data and mark it as existing
-     *
-     * @param array $data assoc array of record
-     * @return static
-     */
-    public static function buildExisting($data)
-    {
-        return static::build($data, false);
-    }
-
-    /**
-     * generate SimpleORMap object structure from assoc array
-     * if given array contains data of related objects in sub-arrays
-     * they are also generated. Existing records are updated, new records are created
-     * (but changes are not yet stored)
-     *
-     * @param array $data
-     * @return static
-     */
-    public static function import($data)
-    {
-        $class = get_called_class();
-        $record_data = [];
-        $relation_data = [];
-        foreach ($data as $key => $value) {
-            if (is_array($value)) {
-                $relation_data[$key] = $value;
-            } else {
-                $record_data[$key] = $value;
-            }
-        }
-        $record = static::toObject($record_data);
-        if (!$record instanceof $class) {
-            $record = new $class();
-            $record->setData($record_data, true);
-        } else {
-            $record->setData($record_data);
-        }
-        if (is_array($relation_data)) {
-            foreach ($relation_data as $relation => $data) {
-                $options = $record->getRelationOptions($relation);
-                if ($options['type'] == 'has_one') {
-                    $record->{$relation} = call_user_func([$options['class_name'], 'import'], $data);
-                }
-                if ($options['type'] == 'has_many' || $options['type'] == 'has_and_belongs_to_many') {
-                    foreach ($data as $one) {
-                        $current = call_user_func([$options['class_name'], 'import'], $one);
-                        if ($options['type'] == 'has_many') {
-                            $foreign_key_value = call_user_func($options['assoc_func_params_func'], $record);
-                            call_user_func($options['assoc_foreign_key_setter'], $current, $foreign_key_value);
-                        }
-                        if ($current->id !== null) {
-                            $existing = $record->{$relation}->find($current->id);
-                            if ($existing) {
-                                $existing->setData($current);
-                            } else {
-                                $record->{$relation}->append($current);
-                            }
-                        } else {
-                            $record->{$relation}->append($current);
-                        }
-                    }
-                }
-            }
-        }
-        return $record;
-    }
-
-    /**
-     * returns array of instances of given class filtered by given sql
-     * @param string $sql sql clause to use on the right side of WHERE
-     * @param ?array $params parameters for query
-     * @return static[] array of "self" objects
-     */
-    public static function findBySQL($sql, $params = [])
-    {
-        $db_table = static::db_table();
-
-        $has_join = stripos($sql, 'JOIN ');
-        if ($has_join === false || $has_join > 10) {
-            $sql = 'WHERE ' . $sql;
-        }
-        $sql = "SELECT `" . $db_table . "`.* FROM `" . $db_table . "` " . $sql;
-        $stmt = DBManager::get()->prepare($sql);
-        $stmt->execute($params);
-
-        $record = static::build([], false);
-
-        $ret = [];
-        do  {
-            $clone = clone $record;
-            $clone->setNew(false);
-            $stmt->setFetchMode(PDO::FETCH_INTO, $clone);
-
-            if ($clone = $stmt->fetch()) {
-                $clone->applyCallbacks('after_initialize');
-                $ret[] = $clone;
-            }
-        } while ($clone);
-        return $ret;
-    }
-
-    /**
-     * returns one instance of given class filtered by given sql
-     * only first row of query is used
-     * @param string $where sql clause to use on the right side of WHERE
-     * @param ?array $params parameters for query
-     * @return ?static
-     */
-    public static function findOneBySQL($where, $params = [])
-    {
-        if (stripos($where, 'LIMIT') === false) {
-            $where .= " LIMIT 1";
-        }
-        $found = static::findBySQL($where, $params);
-        return isset($found[0]) ? $found[0] : null;
-    }
-
-    /**
-     * find related records for a n:m relation (has_many_and_belongs_to_many)
-     * using a combination table holding the keys
-     *
-     * @param string $foreign_key_value value of foreign key to find related records
-     * @param array $options relation options from other side of relation
-     * @return static[] array of "self" objects
-     */
-    public static function findThru($foreign_key_value, $options)
-    {
-        $thru_table = $options['thru_table'];
-        $thru_key = $options['thru_key'];
-        $thru_assoc_key = $options['thru_assoc_key'];
-        $assoc_foreign_key = $options['assoc_foreign_key'];
-
-        $db_table = static::db_table();
-
-        $sql = "SELECT `$db_table`.* FROM `$thru_table`
-        INNER JOIN `$db_table` ON `$thru_table`.`$thru_assoc_key` = `$db_table`.`$assoc_foreign_key`
-        WHERE `$thru_table`.`$thru_key` = ? " . ($options['order_by'] ?? '');
-        $st = DBManager::get()->prepare($sql);
-        $st->execute([$foreign_key_value]);
-
-        $record = static::build([], false);
-
-        $ret = [];
-        do {
-            $clone = clone $record;
-            $clone->setNew(false);
-            $st->setFetchMode(PDO::FETCH_INTO, $clone);
-
-            if ($clone = $st->fetch()) {
-                $clone->applyCallbacks('after_initialize');
-                $ret[] = $clone;
-            }
-        } while ($clone);
-        return $ret;
-    }
-
-    /**
-     * passes objects for given sql through given callback
-     *
-     * @param callable $callable callback which gets the current record as param
-     * @param string $sql where clause of sql
-     * @param ?array $params sql statement parameters
-     * @return integer number of found records
-     */
-    public static function findEachBySQL($callable, $sql, $params = [])
-    {
-        $has_join = stripos($sql, 'JOIN ');
-        if ($has_join === false || $has_join > 10) {
-            $sql = "WHERE {$sql}";
-        }
-
-        $db_table = static::db_table();
-        $st = DBManager::get()->prepare("SELECT `{$db_table}`.* FROM `{$db_table}` {$sql}");
-        $st->execute($params);
-
-        // Indicate that we are performing a batch operation
-        static::$performs_batch_operation = true;
-
-        $record = static::build([], false);
-
-        $ret = 0;
-        do {
-            $clone = clone $record;
-            $clone->setNew(false);
-            $st->setFetchMode(PDO::FETCH_INTO, $clone);
-
-            if ($clone = $st->fetch()) {
-                $clone->applyCallbacks('after_initialize');
-                $callable($clone, $ret++);
-            }
-        } while ($clone);
-
-        // Reset batch operation indicator
-        static::$performs_batch_operation = false;
-
-        return $ret;
-    }
-
-    /**
-     * returns array of instances of given class for by given pks
-     * @param ?array $pks array of primary keys
-     * @param ?string $order order by clause
-     * @param ?array $order_params
-     * @return static[]
-     */
-    public static function findMany($pks = [], $order = '', $order_params = [])
-    {
-        $db_table = static::db_table();
-        $pk = static::pk();
-        $db = DBManager::get();
-        if (count($pk) > 1) {
-            throw new Exception('not implemented yet');
-        }
-        $where = "`$db_table`.`{$pk[0]}` IN ("  . $db->quote($pks) . ") ";
-        return static::findBySQL($where . $order, $order_params);
-    }
-
-    /**
-     * passes objects for by given pks through given callback
-     *
-     * @param callable $callable callback which gets the current record as param
-     * @param ?array $pks array of primary keys of called class
-     * @param ?string $order order by sql
-     * @param ?array $order_params
-     * @return integer number of found records
-     */
-    public static function findEachMany($callable, $pks = [], $order = '', $order_params = [])
-    {
-        $db_table = static::db_table();
-        $pk = static::pk();
-        $db = DBManager::get();
-        if (count($pk) > 1) {
-            throw new Exception('not implemented yet');
-        }
-        $where = "`$db_table`.`{$pk[0]}` IN ("  . $db->quote($pks) . ") ";
-        return static::findEachBySQL($callable, $where . $order, $order_params);
-    }
-
-    /**
-     * passes objects for given sql through given callback
-     * and returns an array of callback return values
-     *
-     * @param callable $callable callback which gets the current record as param
-     * @param string $where where clause of sql
-     * @param array $params sql statement parameters
-     * @return array return values of callback
-     */
-    public static function findAndMapBySQL($callable, $where, $params = [])
-    {
-        $ret = [];
-        $calleach = function($m) use (&$ret, $callable) {
-            $ret[] = $callable($m);
-        };
-        static::findEachBySQL($calleach, $where, $params);
-        return $ret;
-    }
-
-    /**
-     * passes objects for by given pks through given callback
-     * and returns an array of callback return values
-     *
-     * @param callable $callable callback which gets the current record as param
-     * @param ?array $pks array of primary keys of called class
-     * @param ?string $order order by sql
-     * @param ?array $order_params
-     * @return array return values of callback
-     */
-    public static function findAndMapMany($callable, $pks = [], $order = '', $order_params = [])
-    {
-        $ret = [];
-        $calleach = function($m) use (&$ret, $callable) {
-            $ret[] = $callable($m);
-        };
-        $db_table = static::db_table();
-        $pk = static::pk();
-        $db = DBManager::get();
-        if (count($pk) > 1) {
-            throw new Exception('not implemented yet');
-        }
-        $where = "`$db_table`.`{$pk[0]}` IN ("  . $db->quote($pks) . ") ";
-        static::findEachBySQL($calleach, $where . $order, $order_params);
-        return $ret;
-    }
-
-    /**
-     * deletes objects specified by sql clause
-     * @param string $where sql clause to use on the right side of WHERE
-     * @param ?array $params parameters for query
-     * @return integer number of deleted records
-     */
-    public static function deleteBySQL($where, $params = [])
-    {
-        $killeach = function($record) {$record->delete();};
-        return static::findEachBySQL($killeach, $where, $params);
-    }
-
-    /**
-     * returns object of given class for given id or null
-     * the param could be a string, an assoc array containing primary key field
-     * or an already matching object. In all these cases an object is returned
-     *
-     * @param string|static|array $id_or_object id as string, object or assoc array
-     * @return static
-     */
-    public static function toObject($id_or_object)
-    {
-        $class = get_called_class();
-        if ($id_or_object instanceof $class) {
-            return $id_or_object;
-        }
-        if (is_array($id_or_object)) {
-            $pk = static::pk();
-            $key_values = [];
-            foreach ($pk as $key) {
-                if (array_key_exists($key, $id_or_object)) {
-                    $key_values[] = $id_or_object[$key];
-                }
-            }
-            if (count($pk) === count($key_values)) {
-                if (count($pk) === 1) {
-                    $id = $key_values[0];
-                } else {
-                    $id = $key_values;
-                }
-            } else {
-                $id = null;
-            }
-        } else {
-            $id = $id_or_object;
-        }
-        return call_user_func([$class, 'find'], $id);
-    }
-
-    /**
-     * interceptor for static findByColumn / findEachByColumn / countByColumn /
-     * deleteByColumn magic
-     * @param string $name
-     * @param array $arguments
-     * @throws BadMethodCallException
-     * @return int|static|static[]
-     */
-    public static function __callStatic($name, $arguments)
-    {
-        $db_table = static::db_table();
-        $alias_fields = static::alias_fields();
-        $db_fields = static::db_fields();
-        $name = strtolower($name);
-        $class = get_called_class();
-        $order = '';
-        $param_arr = [];
-        $where = '';
-        $where_param = is_array($arguments[0]) ? $arguments[0] : [$arguments[0]];
-        $prefix = strstr($name, 'by', true);
-        $field = substr($name, strlen($prefix) + 2);
-        switch ($prefix) {
-            case 'findone':
-                $order = $arguments[1] ?? '';
-                $param_arr[0] =& $where;
-                $param_arr[1] = [$where_param];
-                $method = 'findonebysql';
-                break;
-            case 'find':
-            case 'findmany':
-                $order = $arguments[1] ?? '';
-                $param_arr[0] =& $where;
-                $param_arr[1] = [$where_param];
-                $method = 'findbysql';
-                break;
-            case 'findeach':
-            case 'findeachmany':
-                $order = $arguments[2] ?? '';
-                $param_arr[0] = $arguments[0];
-                $param_arr[1] =& $where;
-                $param_arr[2] = [$arguments[1]];
-                $method = 'findeachbysql';
-                break;
-            case 'count':
-            case 'delete':
-                $param_arr[0] =& $where;
-                $param_arr[1] = [$where_param];
-                $method = "{$prefix}bysql";
-                break;
-            default:
-                throw new BadMethodCallException("Method $class::$name not found");
-        }
-        if (isset($alias_fields[$field])) {
-            $field = $alias_fields[$field];
-        }
-        if (isset($db_fields[$field])) {
-            $where = "`$db_table`.`$field` IN(?) " . $order;
-            return call_user_func_array([$class, $method], $param_arr);
-        }
-        throw new BadMethodCallException("Method $class::$name not found");
-    }
-
-    /**
-     * constructor, give primary key of record as param to fetch
-     * corresponding record from db if available, if not preset primary key
-     * with given value. Give null to create new record
-     *
-     * @param null|int|string|array $id primary key of table
-     */
-    function __construct($id = null)
-    {
-        foreach(['has_many', 'belongs_to', 'has_one', 'has_and_belongs_to_many'] as $type) {
-            foreach (array_keys($this->$type()) as $one) {
-                $this->relations[$one] = null;
-            }
-        }
-
-        if ($id) {
-            $this->setId($id);
-        }
-        $this->restore();
-    }
-
-    /**
-     * returns internal used id value (multiple keys concatenated with _)
-     * @param mixed $field unused parameter
-     * @return ?string
-     */
-    protected function _getId($field)
-    {
-        return is_null($this->getId())
-             ? null
-             : implode(self::ID_SEPARATOR, $this->getId());
-    }
-
-    /**
-     * sets internal used id value (multiple keys concatenated with _)
-     * @param string $field Field to set (unused since it's always the id)
-     * @param string $value Value for id field
-     * @return bool
-     */
-    protected function _setId($field, $value)
-    {
-        return $this->setId(explode(self::ID_SEPARATOR, $value));
-    }
-
-    /**
-     * retrieves an additional field value from relation
-     *
-     * @param string $field
-     * @return mixed
-     */
-    protected function _getAdditionalValueFromRelation($field)
-    {
-        list($relation, $relation_field) = [$this->additional_fields()[$field]['relation'],
-                                                $this->additional_fields()[$field]['relation_field']];
-        if (!array_key_exists($field, $this->additional_data)) {
-            $this->_setAdditionalValue($field, $this->getRelationValue($relation, $relation_field));
-        }
-        return $this->additional_data[$field];
-    }
-
-    /**
-     * sets additional value in field imported from relation
-     *
-     * @param string $field
-     * @param mixed $value
-     * @return mixed
-     */
-    protected function _setAdditionalValueFromRelation($field, $value)
-    {
-        list($relation, $relation_field) = [$this->additional_fields()[$field]['relation'],
-                $this->additional_fields()[$field]['relation_field']];
-        $this->$relation->$field = $value;
-        unset($this->additional_data[$field]);
-        return $this->_getAdditionalValueFromRelation($field);
-    }
-
-    /**
-     * @param string $field
-     * @return mixed
-     */
-    protected function _getAdditionalValue($field)
-    {
-        return $this->additional_data[$field];
-    }
-
-    /**
-     * @param string $field
-     * @param mixed $value
-     * @return mixed
-     */
-    protected function _setAdditionalValue($field, $value)
-    {
-        return $this->additional_data[$field] = $value;
-    }
-
-    /**
-     * clean up references after cloning
-     * @return void
-     */
-    function __clone()
-    {
-        $this->setNew(true);
-        //all references link still to old object => reset all aliases
-        foreach ($this->alias_fields() as $alias => $field) {
-            if (isset($this->db_fields()[$field])) {
-                $content_value = $this->content[$field];
-                $content_db_value = $this->content_db[$field];
-                unset($this->content[$alias]);
-                unset($this->content_db[$alias]);
-                unset($this->content[$field]);
-                unset($this->content_db[$field]);
-                if (is_object($content_value)) {
-                    $this->content[$field] = clone $content_value;
-                } else {
-                    $this->content[$field] = $content_value;
-                }
-                if (is_object($content_db_value)) {
-                    $this->content_db[$field] = clone $content_db_value;
-                } else {
-                    $this->content_db[$field] = $content_db_value;
-                }
-            }
-        }
-        foreach ($this->alias_fields() as $alias => $field) {
-            if (isset($this->db_fields()[$field])) {
-                $this->content[$alias] =& $this->content[$field];
-                $this->content_db[$alias] =& $this->content_db[$field];
-            }
-        }
-        //unset all relations for now
-        //TODO: maybe a deep copy of all belonging objects is more appropriate
-        foreach(['has_many', 'belongs_to', 'has_one', 'has_and_belongs_to_many'] as $type) {
-            foreach (array_keys($this->$type()) as $one) {
-                $this->relations[$one] = null;
-            }
-        }
-        //begun the clone war has... hmpf
-    }
-
-    /**
-     * try to determine all needed options for a relationship from
-     * configured options
-     *
-     * @param string $type
-     * @param string $name
-     * @param array $options
-     * @throws Exception if options for thru_table could not be determined
-     * @return array
-     */
-    protected function parseRelationOptions($type, $name, $options)
-    {
-        if (empty($options['class_name'])) {
-            throw new Exception('Option class_name not set for relation ' . $name);
-        }
-        if (empty($options['assoc_foreign_key'])) {
-            if ($type === 'has_many' || $type === 'has_one') {
-                $options['assoc_foreign_key'] = $this->pk()[0];
-            } else if ($type === 'belongs_to') {
-                $options['assoc_foreign_key'] = 'id';
-            }
-        }
-        if ($type === 'has_and_belongs_to_many') {
-            $thru_table = $options['thru_table'];
-            if (empty($options['thru_key'])) {
-                $options['thru_key'] = $this->pk()[0];
-            }
-            if (empty($options['thru_assoc_key']) || empty($options['assoc_foreign_key'])) {
-                $class = $options['class_name'];
-                $record = new $class();
-                $meta = $record->getTableMetadata();
-                if (empty($options['thru_assoc_key'])) {
-                    $options['thru_assoc_key'] = $meta['pk'][0];
-                }
-                if (empty($options['assoc_foreign_key'])) {
-                    $options['assoc_foreign_key']= $meta['pk'][0];
-                }
-            }
-            static::tableScheme($thru_table);
-            if (is_array(self::$schemes[$thru_table])) {
-                $thru_key_ok = isset(self::$schemes[$thru_table]['db_fields'][$options['thru_key']]);
-                $thru_assoc_key_ok = isset(self::$schemes[$thru_table]['db_fields'][$options['thru_assoc_key']]);
-            }
-            if (!$thru_assoc_key_ok || !$thru_key_ok) {
-                throw new Exception("Could not determine keys for relation " . $name . " through table " . $thru_table);
-            }
-            if ($options['assoc_foreign_key'] instanceof Closure) {
-                throw new Exception("For relation " . $name . " assoc_foreign_key must be a name of a column");
-            }
-        }
-        if (empty($options['assoc_func'])) {
-            if ($type !== 'has_and_belongs_to_many') {
-                $options['assoc_func'] = $options['assoc_foreign_key'] === 'id' ? 'find' : 'findBy' . $options['assoc_foreign_key'];
-            } else {
-                $options['assoc_func'] = 'findThru';
-            }
-        }
-        if (empty($options['foreign_key'])) {
-            $options['foreign_key'] = 'id';
-        }
-        if (isset($options['foreign_key']) && $options['foreign_key'] instanceof Closure) {
-            $options['assoc_func_params_func'] = function($record) use ($name, $options) { return call_user_func($options['foreign_key'], $record, $name, $options);};
-        } else {
-            $options['assoc_func_params_func'] = function($record) use ($name, $options) { return $options['foreign_key'] === 'id' ? $record->getId() : $record->getValue($options['foreign_key']);};
-        }
-        if (isset($options['assoc_foreign_key']) && $options['assoc_foreign_key'] instanceof Closure) {
-            if ($type === 'belongs_to') {
-                $options['assoc_foreign_key_getter'] = function($record, $that) use ($name, $options) { return call_user_func($options['assoc_foreign_key'], $record, $name, $options, $that);};
-            } else {
-                $options['assoc_foreign_key_setter'] = function($record, $params) use ($name, $options) { return call_user_func($options['assoc_foreign_key'], $record, $params, $name, $options);};
-            }
-        } elseif (!empty($options['assoc_foreign_key'])) {
-            if ($type === 'belongs_to') {
-                $options['assoc_foreign_key_getter'] = function($record, $that) use ($name, $options) { return $record->getValue($options['assoc_foreign_key']);};
-            } else {
-                $options['assoc_foreign_key_setter'] = function($record, $value) use ($name, $options) { return $record->setValue($options['assoc_foreign_key'], $value);};
-            }
-        } else {
-            throw new Exception("Could not determine assoc_foreign_key for relation " . $name);
-        }
-        return $options;
-    }
-
-    /**
-     * returns array with option for given relation
-     * available options:
-     * 'type':                   relation type, on of 'has_many', 'belongs_to', 'has_one', 'has_and_belongs_to_many'
-     * 'class_name':             name of class for related records
-     * 'foreign_key':            name of column with foreign key
-     *                           or callback to retrieve foreign key value
-     * 'assoc_foreign_key':      name of foreign key column in related class
-     * 'assoc_func':             name of static method to call on related class to find related records
-     * 'assoc_func_params_func': callback to retrieve params for assoc_func
-     * 'thru_table':             name of relation table for n:m relation
-     * 'thru_key':               name of column holding foreign key in relation table
-     * 'thru_assoc_key':         name of column holding foreign key from related class in relation table
-     * 'on_delete':              contains simply 'delete' to indicate that related records should be deleted
-     *                           or callback to invoke before record gets deleted
-     * 'on_store':               contains simply 'store' to indicate that related records should be stored
-     *                           or callback to invoke after record gets stored
-     *
-     * @param string $relation name of relation
-     * @return array assoc array containing options
-     */
-    function getRelationOptions($relation)
-    {
-        $options = [];
-        foreach(['has_many', 'belongs_to', 'has_one', 'has_and_belongs_to_many'] as $type) {
-            if (isset($this->$type()[$relation])) {
-                $options = self::$config[get_class($this)][$type][$relation];
-                if (!isset($options['type'])) {
-                    $options = $this->parseRelationOptions($type, $relation, $options, $this->db_table());
-                    $options['type'] = $type;
-                    self::$config[get_class($this)][$type][$relation] = $options;
-                }
-                break;
-            }
-        }
-        return $options;
-    }
-
-    /**
-     * returns table and columns metadata
-     *
-     * @return array assoc array with columns, primary keys and name of table
-     */
-    function getTableMetadata()
-    {
-        return ['fields' => $this->db_fields(),
-                     'pk' => $this->pk(),
-                     'table' => $this->db_table(),
-                     'additional_fields' => $this->additional_fields(),
-                     'alias_fields' => $this->alias_fields(),
-                     'relations' => array_keys($this->relations)];
-    }
-
-    /**
-     * returns true, if table has an auto_increment column
-     *
-     * @return boolean
-     */
-    function hasAutoIncrementColumn()
-    {
-        return $this->db_fields()[$this->pk()[0]]['extra'] == 'auto_increment';
-    }
-
-    /**
-     * set primary key for entry, combined keys must be passed as array
-     * @param int|string|array $id primary key
-     * @throws InvalidArgumentException if given key is not complete
-     * @return boolean
-     */
-    public function setId($id)
-    {
-        if (!is_array($id)){
-            $id = [$id];
-        }
-        if (count($this->pk()) != count($id)){
-            throw new InvalidArgumentException("Invalid ID, Primary Key {$this->db_table()} is " .join(",",$this->pk()));
-        } else {
-            foreach ($this->pk() as $count => $key){
-                $this->content[$key] = $id[$count];
-            }
-            return true;
-        }
-    }
-
-    /**
-     * returns primary key, multiple keys as array
-     * @return null|string|array current primary key, null if not set
-     */
-    function getId()
-    {
-        if (count($this->pk()) == 1) {
-            return $this->content[$this->pk()[0]] ?? null;
-        } else {
-            $id = [];
-            foreach ($this->pk() as $key) {
-                if (array_key_exists($key, $this->content)) {
-                    $id[] = $this->content[$key];
-                }
-            }
-            return (count($this->pk()) == count($id) ? $id : null);
-        }
-    }
-
-    /**
-     * create new unique pk as md5 hash
-     * if pk consists of multiple columns, false is returned
-     * @return boolean|string
-     */
-    function getNewId()
-    {
-        $id = false;
-        if (count($this->pk()) == 1) {
-            do {
-                $id = md5(uniqid($this->db_table(), 1));
-                $db = DBManager::get()->query("SELECT `{$this->pk()[0]}` FROM `{$this->db_table()}` "
-                . "WHERE `{$this->pk()[0]}` = '$id'");
-            } while($db->fetch());
-        }
-        return $id;
-    }
-
-    /**
-     * returns data of table row as assoc array
-     * pass array of fieldnames or ws separated string to limit
-     * fields
-     *
-     * @param null|array|string $only_these_fields limit returned fields
-     * @return array
-     */
-    function toArray($only_these_fields = null)
-    {
-        $ret = [];
-        if (is_string($only_these_fields)) {
-            $only_these_fields = words($only_these_fields);
-        }
-        $fields = array_diff($this->known_slots(), array_keys($this->relations));
-        if (is_array($only_these_fields)) {
-            $only_these_fields = array_filter(array_map(function($s) {
-                return is_string($s) ? strtolower($s) : null;
-            }, $only_these_fields));
-            $fields = array_intersect($only_these_fields, $fields);
-        }
-        foreach ($fields as $field) {
-            $ret[$field] = $this->getValue($field);
-            if ($ret[$field] instanceof StudipArrayObject) {
-                $ret[$field] = $ret[$field]->getArrayCopy();
-            }
-        }
-        return $ret;
-    }
-
-    /**
-     * Returns data of table row as assoc array with raw contents like
-     * they are in the database.
-     * Pass array of fieldnames or ws separated string to limit
-     * fields.
-     *
-     * @param null|array|string $only_these_fields
-     * @return array
-     */
-    function toRawArray($only_these_fields = null)
-    {
-        $ret = [];
-        if (is_string($only_these_fields)) {
-            $only_these_fields = words($only_these_fields);
-        }
-        $fields = array_keys($this->db_fields());
-        if (is_array($only_these_fields)) {
-            $only_these_fields = array_filter(array_map(function ($s) {
-                return is_string($s) ? strtolower($s) : null;
-            }, $only_these_fields));
-            $fields = array_intersect($only_these_fields, $fields);
-        }
-        foreach ($fields as $field) {
-            if ($this->content[$field] instanceof I18NString) {
-                $ret[$field] = $this->content[$field]->original();
-            } elseif ($this->content[$field] === null) {
-                $ret[$field] = null;
-            } else {
-                $ret[$field] = (string)$this->content[$field];
-            }
-        }
-        return $ret;
-    }
-
-    /**
-     * returns data of table row as assoc array
-     * including related records with a 'has*' relationship
-     * recurses one level without param
-     *
-     * $only_these_fields limits output for relationships in this way:
-     * $only_these_fields = array('field_1',
-     *                            'field_2',
-     *                            'relation1',
-     *                            'relation2' => array('rel2_f1',
-     *                                                 'rel2_f2',
-     *                                                 'rel2_rel11' => array(
-     *                                                           rel2_rel1_f1)
-     *                                                )
-     *                           )
-     * Here all fields of relation1 will be returned.
-     *
-     * @param null|array|string $only_these_fields limit returned fields
-     * @return array
-     */
-    function toArrayRecursive($only_these_fields = null)
-    {
-        if (is_string($only_these_fields)) {
-            $only_these_fields = words($only_these_fields);
-        }
-        if (is_null($only_these_fields)) {
-            $only_these_fields = $this->known_slots();
-        }
-        $ret = $this->toArray($only_these_fields);
-        $relations = [];
-        if (is_array($only_these_fields)) {
-            foreach ($only_these_fields as $key => $value) {
-                if (!is_array($value) &&
-                    array_key_exists(strtolower($value), $this->relations)
-                ) {
-                    $relations[strtolower($value)] = 0; //not null|array|string to stop recursion
-                }
-                if (array_key_exists(strtolower($key), $this->relations)) {
-                    $relations[strtolower($key)] = $value;
-                }
-            }
-        }
-        if (count($relations)) {
-            foreach ($relations as $relation_name => $relation_only_these_fields) {
-                $options = $this->getRelationOptions($relation_name);
-                if ($options['type'] === 'has_one' ||
-                        $options['type'] === 'belongs_to') {
-                    $ret[$relation_name] =
-                            $this->{$relation_name}->
-                                            toArrayRecursive($relation_only_these_fields);
-                }
-                if ($options['type'] === 'has_many' ||
-                    $options['type'] === 'has_and_belongs_to_many') {
-                    $ret[$relation_name] =
-                            $this->{$relation_name}->
-                                            sendMessage('toArrayRecursive',
-                                            [$relation_only_these_fields]);
-                }
-            }
-        }
-        return $ret;
-    }
-
-    /**
-     * returns value of a column
-     *
-     * @throws InvalidArgumentException if column could not be found
-     * @throws BadMethodCallException if getter for additional field could not be found
-     * @param string $field
-     * @return null|string|SimpleORMapCollection
-     */
-    public function getValue($field)
-    {
-        $field = strtolower($field);
-
-        // No value defined, throw exception
-        if (!in_array($field, $this->known_slots())) {
-            throw new InvalidArgumentException(static::class . '::'.$field . ' not found.');
-        }
-
-        // Get value by getter
-        if (isset($this->getter_setter_map()[$field]['get'])) {
-            return call_user_func([$this, $this->getter_setter_map()[$field]['get']]);
-        }
-
-        // Get value from content
-        if (array_key_exists($field, $this->content)) {
-            return $this->content[$field];
-        }
-
-        // Get value from relation
-        if (array_key_exists($field, $this->relations)) {
-            $this->initRelation($field);
-            return $this->relations[$field];
-        }
-
-        // Get value from additional_field
-        if (isset($this->additional_fields()[$field]['get'])) {
-            // Getter is defined as a closure
-            if ($this->additional_fields()[$field]['get'] instanceof Closure) {
-                return call_user_func_array($this->additional_fields()[$field]['get'], [$this, $field]);
-            }
-
-            // Getter is defined as a method of this object
-            return call_user_func([$this, $this->additional_fields()[$field]['get']], $field);
-        }
-
-        // No value found, throw exception
-        throw new RuntimeException('No value could be found for ' . static::class . '::' . $field);
-    }
-
-    /**
-     * gets a value from a related object
-     * only possible, if the relation has cardinality 1
-     * e.g. 'has_one' or 'belongs_to'
-     *
-     * @param string $relation name of relation
-     * @param string $field name of column
-     * @throws InvalidArgumentException if no relation with given name is found
-     * @return mixed the value from the related object
-     */
-    function getRelationValue($relation, $field)
-    {
-        $field = strtolower($field);
-        $options = $this->getRelationOptions($relation);
-        if ($options['type'] === 'has_one' || $options['type'] === 'belongs_to') {
-            return $this->{$relation}->{$field} ?? null;
-        } else {
-            throw new InvalidArgumentException('Relation ' . $relation . ' not found or not applicable.');
-        }
-    }
-
-    /**
-     * returns default value for column
-     *
-     * @param string $field name of column
-     * @return mixed the default value
-     */
-     function getDefaultValue($field)
-     {
-         $default_value = null;
-         if (!isset($this->default_values()[$field])) {
-             if (!in_array($field, $this->pk())) {
-                 $meta = $this->db_fields()[$field];
-                 if (isset($meta['default'])) {
-                     $default_value = $meta['default'];
-                 } elseif ($meta['null'] == 'NO') {
-                     if (strpos($meta['type'], 'text') !== false || strpos($meta['type'], 'char') !== false) {
-                         $default_value = '';
-                     }
-                     if (strpos($meta['type'], 'int') !== false) {
-                         $default_value = '0';
-                     }
-                 }
-             }
-         } else {
-             $default_value = $this->default_values()[$field];
-         }
-         return $default_value;
-     }
-
-    /**
-     * sets value of a column
-     *
-     * @throws InvalidArgumentException if column could not be found
-     * @throws BadMethodCallException if setter for additional field could not be found
-     * @param string $field
-     * @param mixed $value
-     * @return string
-     */
-     function setValue($field, $value)
-     {
-         $field = strtolower($field);
-         $ret = false;
-         if (in_array($field, $this->known_slots())) {
-             if (isset($this->getter_setter_map()[$field]['set'])) {
-                 return call_user_func([$this, $this->getter_setter_map()[$field]['set']], $value);
-             }
-             if (array_key_exists($field, $this->content)) {
-                 if (array_key_exists($field, $this->serialized_fields())) {
-                     $ret = $this->setSerializedValue($field, $value);
-                 } elseif ($this->isI18nField($field)) {
-                         $ret = $this->setI18nValue($field, $value);
-                 } else {
-                     $ret = ($this->content[$field] = $value);
-                 }
-             } elseif (isset($this->additional_fields()[$field]['set'])) {
-                 if ($this->additional_fields()[$field]['set'] instanceof Closure) {
-                     return call_user_func_array($this->additional_fields()[$field]['set'], [$this, $field, $value]);
-                 } else {
-                     return call_user_func([$this, $this->additional_fields()[$field]['set']], $field, $value);
-                 }
-             } elseif (array_key_exists($field, $this->relations)) {
-                 $options = $this->getRelationOptions($field);
-                 if ($options['type'] === 'has_one' || $options['type'] === 'belongs_to') {
-                     if (is_a($value, $options['class_name'])) {
-                         $this->relations[$field] = $value;
-                         if ($options['type'] == 'has_one') {
-                             $foreign_key_value = call_user_func($options['assoc_func_params_func'], $this);
-                             call_user_func($options['assoc_foreign_key_setter'], $value, $foreign_key_value);
-                         } else {
-                             $assoc_foreign_key_value = call_user_func($options['assoc_foreign_key_getter'], $value, $this);
-                             if ($assoc_foreign_key_value === null) {
-                                 throw new InvalidArgumentException(sprintf('trying to set belongs_to object of type: %s, but assoc_foreign_key: %s is null', get_class($value), $options['assoc_foreign_key']));
-                             }
-                             $this->setValue($options['foreign_key'], $assoc_foreign_key_value);
-                         }
-                     } else {
-                         throw new InvalidArgumentException(sprintf('relation %s expects object of type: %s', $field, $options['class_name']));
-                     }
-                 }
-                 if ($options['type'] == 'has_many' || $options['type'] == 'has_and_belongs_to_many') {
-                     if (is_array($value) || $value instanceof Traversable) {
-                         $new_ids = [];
-                         $old_ids = $this->{$field}->pluck('id');
-                         foreach ($value as $current) {
-                             if (!is_a($current, $options['class_name'])) {
-                                 throw new InvalidArgumentException(sprintf('relation %s expects object of type: %s', $field, $options['class_name']));
-                             }
-                             if ($options['type'] == 'has_many') {
-                                 $foreign_key_value = call_user_func($options['assoc_func_params_func'], $this);
-                                 call_user_func($options['assoc_foreign_key_setter'], $current, $foreign_key_value);
-                             }
-                             if ($current->id !== null) {
-                                 $new_ids[] = $current->id;
-                                 $existing = $this->{$field}->find($current->id);
-                                 if ($existing) {
-                                     $existing->setData($current);
-                                 } else {
-                                     $this->{$field}->append($current);
-                                 }
-                             } else {
-                                 $this->{$field}->append($current);
-                             }
-                         }
-                         foreach (array_diff($old_ids, $new_ids) as $to_delete) {
-                             $this->{$field}->unsetByPK($to_delete);
-                         }
-                     } else {
-                         throw new InvalidArgumentException(sprintf('relation %s expects collection or array of objects of type: %s', $field, $options['class_name']));
-                     }
-                 }
-             }
-         } else {
-             throw new InvalidArgumentException(get_class($this) . '::'. $field . ' not found.');
-         }
-         return $ret;
-     }
-
-    /**
-     * magic method for dynamic properties
-     *
-     * @throws InvalidArgumentException if column could not be found
-     * @throws BadMethodCallException if getter for additional field could not be found
-     * @param string $field the column or additional field
-     * @return null|string|SimpleORMapCollection
-     */
-    function __get($field)
-    {
-        return $this->getValue($field);
-    }
-    /**
-     * magic method for dynamic properties
-     *
-     * @throws InvalidArgumentException if column could not be found
-     * @throws BadMethodCallException if setter for additional field could not be found
-     * @param string $field
-     * @param string $value
-     * @return string
-     */
-    function __set($field, $value)
-    {
-        return $this->setValue($field, $value);
-    }
-    /**
-     * magic method for dynamic properties
-     *
-     * @param string $field
-     * @return bool
-     */
-    function __isset($field)
-    {
-        $field = strtolower($field);
-        if (in_array($field, $this->known_slots())) {
-            $value = $this->getValue($field);
-            return $value instanceOf SimpleORMapCollection ? (bool)count($value) : !is_null($value);
-        } else {
-            return false;
-        }
-    }
-    /**
-     * ArrayAccess: Check whether the given offset exists.
-     *
-     * @param string $offset
-     * @return bool
-     *
-     * @todo Add bool return type when Stud.IP requires PHP8 minimal
-     */
-    #[ReturnTypeWillChange]
-    public function offsetExists($offset)
-    {
-        return $this->__isset($offset);
-    }
-
-    /**
-     * ArrayAccess: Get the value at the given offset.
-     *
-     * @throws InvalidArgumentException if column could not be found
-     * @throws BadMethodCallException if getter for additional field could not be found
-     * @param string $offset the column or additional field
-     * @return null|string|SimpleORMapCollection
-     *
-     * @todo Add mixed return type when Stud.IP requires PHP8 minimal
-     */
-    #[ReturnTypeWillChange]
-    public function offsetGet($offset)
-    {
-        return $this->getValue($offset);
-    }
-
-    /**
-     * ArrayAccess: Set the value at the given offset.
-     *
-     * @throws InvalidArgumentException if column could not be found
-     * @throws BadMethodCallException if setter for additional field could not be found
-     * @param string $offset
-     * @param mixed $value
-     * @return void
-     *
-     * @todo Add void return type when Stud.IP requires PHP8 minimal
-     */
-    #[ReturnTypeWillChange]
-    public function offsetSet($offset, $value)
-    {
-        $this->setValue($offset, $value);
-    }
-    /**
-     * ArrayAccess: unset the value at the given offset (not applicable)
-     *
-     * @param string $offset
-     * @return void
-     *
-     * @todo Add void return type when Stud.IP requires PHP8 minimal
-     */
-    #[ReturnTypeWillChange]
-    public function offsetUnset($offset)
-    {
-
-    }
-    /**
-     * IteratorAggregate
-     *
-     * @return ArrayIterator
-     *
-     * @todo Add Traversable return type when Stud.IP requires PHP8 minimal
-     */
-    #[ReturnTypeWillChange]
-    public function getIterator()
-    {
-        return new ArrayIterator($this->toArray());
-    }
-    /**
-     * Countable
-     *
-     * @return int
-     *
-     * @todo Add int return type when Stud.IP requires PHP8 minimal
-     */
-    #[ReturnTypeWillChange]
-    public function count()
-    {
-        return count($this->known_slots()) - count($this->relations);
-    }
-
-    /**
-     * check if given column exists in table
-     * @param string $field
-     * @return boolean
-     */
-    function isField($field)
-    {
-        $field = strtolower($field);
-        return isset($this->db_fields()[$field]);
-    }
-
-    /**
-     * check if given relation exists in this class
-     * @param string $field
-     * @return boolean
-     */
-    function isRelation($field)
-    {
-        $field = strtolower($field);
-        return array_key_exists($field, $this->relations);
-    }
-
-    /**
-     * check if given column is additional
-     * @param string $field
-     * @return boolean
-     */
-    function isAdditionalField($field)
-    {
-        $field = strtolower($field);
-        return isset($this->additional_fields()[$field]);
-    }
-
-    /**
-     * check if given column is an alias
-     * @param string $field
-     * @return boolean
-     */
-    function isAliasField($field)
-    {
-        $field = strtolower($field);
-        return isset($this->alias_fields()[$field]);
-    }
-
-    /**
-     * check if given column is a multi-language field
-     * @param string $field
-     * @return boolean
-     */
-    function isI18nField($field)
-    {
-        $field = strtolower($field);
-        return isset($this->i18n_fields()[$field]);
-    }
-
-    /**
-     * set multiple column values
-     * if second param is set, existing data in object will be
-     * discarded and dirty state is cleared,
-     * else new data overrides old data
-     *
-     * @param ?iterable $data assoc array
-     * @param ?boolean $reset existing data in object will be discarded
-     * @return int|bool number of columns changed
-     */
-    function setData($data, $reset = false)
-    {
-        $count = 0;
-        if ($reset) {
-            if ($this->applyCallbacks('before_initialize') === false) {
-                return false;
-            }
-            $this->initializeContent();
-        }
-        if (is_iterable($data)) {
-            foreach($data as $key => $value) {
-                $key = strtolower($key);
-                if (isset($this->db_fields()[$key])
-                    || isset($this->alias_fields()[$key])
-                    || isset($this->additional_fields()[$key]['set'])
-                ) {
-                    $this->setValue($key, $value);
-                    ++$count;
-                }
-            }
-        }
-        if ($reset) {
-            $this->applyCallbacks('after_initialize');
-        }
-        return $count;
-    }
-
-    /**
-     * check if object exists in database
-     * @return boolean
-     */
-    function isNew()
-    {
-        return $this->is_new;
-    }
-
-    /**
-     * check if object was deleted
-     *
-     * @return boolean
-     */
-    function isDeleted()
-    {
-        return $this->is_deleted;
-    }
-
-    /**
-     * set object to new state
-     * @param boolean $is_new
-     * @return boolean
-     */
-    function setNew($is_new)
-    {
-        return $this->is_new = $is_new;
-    }
-
-    /**
-     * returns sql clause with current table and pk
-     * @throws UnexpectedValueException if the primary key is incomplete
-     * @return boolean|array<string>
-     */
-    function getWhereQuery()
-    {
-        $where_query = null;
-        $pk_not_set = [];
-        foreach ($this->pk() as $key) {
-            $pk = $this->content_db[$key] ?? $this->content[$key] ?? null;
-            if (isset($pk)) {
-                $where_query[] = "`{$this->db_table()}`.`{$key}` = "  . DBManager::get()->quote($pk);
-            } else {
-                $pk_not_set[] = $key;
-            }
-        }
-        if (!$where_query || count($pk_not_set)){
-            if ($this->isNew()) {
-                return false;
-            } else {
-                throw new UnexpectedValueException(sprintf("primary key incomplete: %s must not be null", join(',',$pk_not_set)));
-            }
-        }
-        return $where_query;
-    }
-
-    /**
-     * restore entry from database
-     * @return boolean
-     */
-    function restore()
-    {
-        $where_query = $this->getWhereQuery();
-        $id = $this->getId();
-        if ($where_query) {
-            if ($this->applyCallbacks('before_initialize') === false) {
-                return false;
-            }
-            $this->initializeContent();
-            $query = "SELECT * FROM `{$this->db_table()}` WHERE "
-                    . join(" AND ", $where_query);
-            $st = DBManager::get()->prepare($query);
-            $st->execute();
-            $st->setFetchMode(PDO::FETCH_INTO , $this);
-            if ($st->fetch()) {
-                $this->setNew(false);
-                $this->applyCallbacks('after_initialize');
-                return true;
-            }
-        }
-        $this->setData([], true);
-        $this->setNew(true);
-        if (isset($id)) {
-            $this->setId($id);
-        }
-        return false;
-    }
-
-    /**
-     * store entry in database
-     *
-     * @throws UnexpectedValueException if there are forbidden NULL values
-     * @return number|boolean
-     */
-    function store()
-    {
-        // Set id or prepare setting of id
-        if ($this->isNew() && $this->getId() === null) {
-            // Explicitly set id to 0 if auto increment pk is null
-            if ($this->hasAutoIncrementColumn()) {
-                $this->setId(0);
-            } else {
-                $this->setId($this->getNewId());
-            }
-        }
-
-        if ($this->applyCallbacks('before_store') === false) {
-            return false;
-        }
-
-        $ret = 0;
-
-        if (!$this->isDeleted() && ($this->isDirty() || $this->isNew())) {
-            $callback = $this->isNew() ? 'before_create' : 'before_update';
-            if ($this->applyCallbacks($callback) === false) {
-                return false;
-            }
-
-            // Collect i18n contents
-            $i18ncontent = [];
-            foreach (array_keys($this->i18n_fields()) as $field) {
-                if ($this->content[$field] instanceof I18NString) {
-                    $i18ncontent[$field] = $this->content[$field];
-                    $this->content[$field] = $this->content[$field]->original();
-                    $this->content_db[$field] = $this->content_db[$field]->original();
-                }
-            }
-
-            // Create sql data assignment chunks
-            foreach ($this->db_fields() as $field => $meta) {
-                $value = $this->content[$field];
-                if ($field == 'chdate' && !$this->isFieldDirty($field) && $this->isDirty()) {
-                    $value = time();
-                }
-                if ($field == 'mkdate') {
-                    if ($this->isNew()) {
-                        if (!$this->isFieldDirty($field)) {
-                            $value = time();
-                        }
-                    } else {
-                        continue;
-                    }
-                }
-                if ($value === null && $meta['null'] == 'NO') {
-                    throw new UnexpectedValueException($this->db_table() . '.' . $field . ' must not be null.');
-                }
-                if (is_float($value)) {
-                    $value = str_replace(',', '.', $value);
-                }
-                $this->content[$field] = $value;
-                $query_part[] = "`$field` = " . DBManager::get()->quote($value) . " ";
-            }
-
-            // Create store query
-            if (!$this->isNew()) {
-                $where_query = $this->getWhereQuery();
-                $query = "UPDATE `{$this->db_table()}` SET "
-                    . implode(',', $query_part);
-                $query .= " WHERE " . join(" AND ", $where_query);
-            } else {
-                $query = "INSERT INTO `{$this->db_table()}` SET "
-                    . implode(',', $query_part);
-            }
-            $ret = DBManager::get()->exec($query);
-
-            // Retrieve generated id from database if pk is an auto increment
-            // column
-            if ($this->isNew()) {
-                if ($this->hasAutoIncrementColumn() && !$this->getId()) {
-                    $this->setId(DBManager::get()->lastInsertId());
-                }
-            }
-
-            // Store i18n contents
-            foreach ($i18ncontent as $field => $one) {
-                $meta = [
-                    'object_id' => $this->getId(),
-                    'table'     => $this->db_table(),
-                    'field'     => $field
-                ];
-                $one->setMetadata($meta);
-                $one->storeTranslations();
-                if (!$this->content[$field] instanceof I18NString) {
-                    $this->content[$field] = $one;
-                    $this->content_db[$field] = clone $one;
-                }
-            }
-
-            // Apply callbacks
-            $this->applyCallbacks($this->isNew() ? 'after_create' : 'after_update');
-        }
-        $rel_ret = $this->storeRelations();
-
-        $this->applyCallbacks('after_store');
-
-        if ($ret || $rel_ret) {
-            $this->restore();
-        }
-        return $ret + $rel_ret;
-    }
-
-    /**
-     * sends a store message to all initialized related objects
-     * if a relation has a callback for 'on_store' configured, the callback
-     * is instead invoked
-     *
-     * @param null|array|string $only_these
-     * @return int|false number addition of all return values, false if none was called
-     */
-    protected function storeRelations($only_these = null)
-    {
-        $ret = false;
-        if (is_string($only_these)) {
-            $only_these = words($only_these);
-        }
-        $relations = array_keys($this->relations);
-        if (is_array($only_these)) {
-            $only_these = array_filter(array_map(function ($s) {
-                return is_string($s) ? strtolower($s) : null;
-            }, $only_these));
-            $relations = array_intersect($only_these, $relations);
-        }
-        foreach ($relations as $relation) {
-            $options = $this->getRelationOptions($relation);
-            if (isset($options['on_store']) &&
-            ($options['type'] === 'has_one' ||
-            $options['type'] === 'has_many' ||
-            $options['type'] === 'has_and_belongs_to_many')) {
-                if ($options['on_store'] instanceof Closure) {
-                    $ret += call_user_func($options['on_store'], $this, $relation);
-                } elseif (isset($this->relations[$relation])) {
-                    $foreign_key_value = call_user_func($options['assoc_func_params_func'], $this);
-                    if ($options['type'] === 'has_one') {
-                        call_user_func($options['assoc_foreign_key_setter'], $this->{$relation}, $foreign_key_value);
-                        $ret = call_user_func([$this->{$relation}, 'store']);
-                    } elseif ($options['type'] === 'has_many') {
-                        foreach ($this->{$relation} as $r) {
-                            call_user_func($options['assoc_foreign_key_setter'], $r, $foreign_key_value);
-                        }
-                        $ret += array_sum(call_user_func([$this->{$relation}, 'sendMessage'], 'store'));
-                        $ret += array_sum(call_user_func([$this->{$relation}->getDeleted(), 'sendMessage'], 'delete'));
-                    } else {
-                        call_user_func([$this->{$relation}, 'sendMessage'], 'store');
-                        $to_delete = array_filter($this->{$relation}->getDeleted()->pluck($options['assoc_foreign_key']));
-                        $to_insert = array_filter($this->{$relation}->pluck($options['assoc_foreign_key']));
-                        $sql = "DELETE FROM `" . $options['thru_table'] ."` WHERE `" . $options['thru_key'] ."` = ? AND `" . $options['thru_assoc_key'] . "` = ?";
-                        $st = DBManager::get()->prepare($sql);
-                        foreach ($to_delete as $one_value) {
-                            $st->execute([$foreign_key_value, $one_value]);
-                            $ret += $st->rowCount();
-                        }
-                        $sql = "INSERT IGNORE INTO `" . $options['thru_table'] ."` SET `" . $options['thru_key'] ."` = ?, `" . $options['thru_assoc_key'] . "` = ?";
-                        $st = DBManager::get()->prepare($sql);
-                        foreach ($to_insert as $one_value) {
-                            $st->execute([$foreign_key_value, $one_value]);
-                            $ret += $st->rowCount();
-                        }
-                    }
-                }
-            }
-        }
-        return $ret;
-    }
-
-    /**
-     * set chdate column to current timestamp
-     * @return boolean
-     */
-    function triggerChdate()
-    {
-        if ($this->db_fields()['chdate']) {
-            $this->content['chdate'] = time();
-            if ($where_query = $this->getWhereQuery()) {
-                DBManager::get()->exec("UPDATE `{$this->db_table()}` SET chdate={$this->content['chdate']}
-                            WHERE ". join(" AND ", $where_query));
-                return true;
-            }
-        }
-
-        return false;
-    }
-
-    /**
-     * delete entry from database
-     * the object is cleared, but is not(!) turned to new state
-     * @return bool|int number of deleted rows
-     */
-    function delete()
-    {
-        $ret = false;
-        if (!$this->isDeleted() && !$this->isNew()) {
-            if ($this->applyCallbacks('before_delete') === false) {
-                return false;
-            }
-            $ret = $this->deleteRelations();
-            $where_query = $this->getWhereQuery();
-            if ($where_query) {
-                $query = "DELETE FROM `{$this->db_table()}` WHERE "
-                        . join(" AND ", $where_query);
-                $ret += DBManager::get()->exec($query);
-            }
-            $this->is_deleted = true;
-            $this->applyCallbacks('after_delete');
-
-            // Remove i18n translations
-            if (I18N::isEnabled()) {
-                foreach (array_keys($this->i18n_fields()) as $field) {
-                    if ($this->content[$field] instanceof I18NString) {
-                        $this->content[$field]->removeTranslations();
-                    }
-                }
-            }
-        }
-        $this->setData([], true);
-        return $ret;
-    }
-
-    /**
-     * sends a delete message to all related objects
-     * if a relation has a callback for 'on_delete' configured, the callback
-     * is invoked instead
-     *
-     * @return bool|int addition of all return values, false if none was called
-     */
-    protected function deleteRelations()
-    {
-        $ret = false;
-        foreach (array_keys($this->relations) as $relation) {
-            $options = $this->getRelationOptions($relation);
-            if (isset($options['on_delete']) &&
-                ($options['type'] === 'has_one' ||
-                $options['type'] === 'has_many' ||
-                $options['type'] === 'has_and_belongs_to_many')) {
-                if ($options['on_delete'] instanceof Closure) {
-                    $ret += call_user_func($options['on_delete'], $this, $relation);
-                } else {
-                    if ($options['type'] === 'has_one' || $options['type'] === 'has_many') {
-                        $this->initRelation($relation);
-                        if (isset($this->relations[$relation])) {
-                            if ($options['type'] === 'has_one') {
-                                $ret += call_user_func([$this->{$relation}, 'delete']);
-                            } elseif ($options['type'] === 'has_many') {
-                                $ret += array_sum(call_user_func([$this->{$relation}, 'sendMessage'], 'delete'));
-                            }
-                        }
-                    } else {
-                        $foreign_key_value = call_user_func($options['assoc_func_params_func'], $this);
-                        $sql = "DELETE FROM `" . $options['thru_table'] ."` WHERE `" . $options['thru_key'] ."` = ?";
-                        $st = DBManager::get()->prepare($sql);
-                        $st->execute([$foreign_key_value]);
-                        $ret += $st->rowCount();
-                    }
-                }
-                $this->relations[$relation] = null;
-            }
-        }
-        return $ret;
-    }
-
-    /**
-     * init internal content arrays with nulls or defaults
-     *
-     * @throws UnexpectedValueException if there is an unmatched alias
-     * @return void
-     */
-    protected function initializeContent()
-    {
-        $this->content = [];
-        foreach (array_keys($this->db_fields()) as $field) {
-            $this->content[$field] = null;
-            $this->content_db[$field] = null;
-            $this->setValue($field, $this->getDefaultValue($field));
-        }
-        foreach ($this->alias_fields() as $alias => $field) {
-            if (isset($this->db_fields()[$field])) {
-                $this->content[$alias] =& $this->content[$field];
-                $this->content_db[$alias] =& $this->content_db[$field];
-            } else {
-                throw new UnexpectedValueException(sprintf('Column %s not found for alias %s', $field, $alias));
-            }
-        }
-        foreach (array_keys($this->relations) as $one) {
-            $this->relations[$one] = null;
-        }
-        $this->additional_data = [];
-    }
-
-    /**
-     * checks if at least one field was modified since last restore
-     *
-     * @return boolean
-     */
-    public function isDirty()
-    {
-        foreach (array_keys($this->db_fields()) as $field) {
-            if ($this->isFieldDirty($field)) {
-                return true;
-            }
-        }
-        return false;
-    }
-
-    /**
-     * checks if given field was modified since last restore
-     *
-     * @param string $field
-     * @return boolean
-     */
-    public function isFieldDirty($field)
-    {
-        $field = strtolower($field);
-        if ($this->content[$field] === null || $this->content_db[$field] === null) {
-            return $this->content[$field] !== $this->content_db[$field];
-        } else if ($this->content[$field] instanceof I18NString || $this->content_db[$field] instanceof I18NString) {
-            return $this->content[$field] != $this->content_db[$field];
-        } else {
-            return (string)$this->content[$field] !== (string)$this->content_db[$field];
-        }
-    }
-
-    /**
-     * reverts value of given field to last restored value
-     *
-     * @param string $field
-     * @return mixed the restored value
-     */
-    public function revertValue($field)
-    {
-        $field = strtolower($field);
-        return ($this->content[$field] = $this->content_db[$field]);
-    }
-
-    /**
-     * returns unmodified value of given field
-     *
-     * @param string $field
-     * @throws InvalidArgumentException
-     * @return mixed
-     */
-    public function getPristineValue($field)
-    {
-        $field = strtolower($field);
-        if (array_key_exists($field, $this->content_db)) {
-            return $this->content_db[$field];
-        } else {
-            throw new InvalidArgumentException(get_class($this) . '::'. $field . ' not found.');
-        }
-    }
-
-    /**
-     * intitalize a relationship and get related record(s)
-     *
-     * @param string $relation name of relation
-     * @throws InvalidArgumentException if the relation does not exists
-     * @return void
-     */
-    public function initRelation($relation)
-    {
-        if (!array_key_exists($relation, $this->relations)) {
-            throw new InvalidArgumentException('Unknown relation: ' . $relation);
-        }
-        if ($this->relations[$relation] === null) {
-            $options = $this->getRelationOptions($relation);
-            $to_call = [$options['class_name'], $options['assoc_func']];
-            if (!is_callable($to_call)) {
-                throw new RuntimeException('assoc_func: ' . join('::', $to_call) . ' is not callable.' );
-            }
-            $params = $options['assoc_func_params_func'];
-            if ($options['type'] === 'has_many') {
-                $records = function($record) use ($to_call, $params, $options) {
-                    $p = (array)$params($record);
-                    return call_user_func_array($to_call, array_merge(count($p) ? $p : [null], [$options['order_by'] ?? null]));
-                };
-                $this->relations[$relation] = new SimpleORMapCollection($records, $options, $this);
-            } elseif ($options['type'] === 'has_and_belongs_to_many') {
-                $records = function($record) use ($to_call, $params, $options) {$p = (array)$params($record); return call_user_func_array($to_call, array_merge(count($p) ? $p : [null], [$options]));};
-                $this->relations[$relation] = new SimpleORMapCollection($records, $options, $this);
-            } else {
-                $p = (array)$params($this);
-                $records = call_user_func_array($to_call, count($p) ? $p : [null]);
-                $result = is_array($records) ? ($records[0] ?? null) : $records;
-                $this->relations[$relation] = $result;
-            }
-        }
-    }
-
-    /**
-     * clear data for a relationship
-     *
-     * @param string $relation name of relation
-     * @throws InvalidArgumentException if teh relation does not exists
-     * @return void
-     */
-    public function resetRelation($relation)
-    {
-        if (!array_key_exists($relation, $this->relations)) {
-            throw new InvalidArgumentException('Unknown relation: ' . $relation);
-        }
-        $this->relations[$relation] = null;
-    }
-
-    /**
-     * invoke registered callbacks for given type
-     * if one callback returns false the following will not
-     * be invoked
-     *
-     * @param string $type type of callback
-     * @return bool return value from last callback
-     */
-    protected function applyCallbacks($type)
-    {
-        $ok = true;
-        foreach ($this->registered_callbacks()[$type] as $cb) {
-            if ($cb instanceof Closure) {
-                $function =  $cb;
-                $params = [$this, $type, $cb];
-            } else {
-                $function = [$this, $cb];
-                $params = [$type];
-            };
-            $ok = call_user_func_array($function, $params);
-            if ($ok === false) {
-                break;
-            }
-        }
-        return $ok;
-    }
-
-    /**
-     * register given callback for one or many possible callback types
-     * callback param could be a closure or method name of current class
-     *
-     * @param string|array $types types to register callback for
-     * @param callable $cb callback
-     * @throws InvalidArgumentException if the callback type is not known
-     * @return number of registered callbacks
-     */
-    protected static function registerCallback($types, $cb)
-    {
-        trigger_error(__METHOD__ . ' is deprecated. Please use the configuration in configure().', E_USER_DEPRECATED);
-
-        $types = is_array($types) ? $types : words($types);
-        $reg = 0;
-        foreach ($types as $type) {
-            if (isset(static::registered_callbacks()[$type])) {
-                $found = array_search($cb, self::$config[static::class]['registered_callbacks'][$type], true);
-                if ($found === false) {
-                    self::$config[static::class]['registered_callbacks'][$type][] = $cb;
-                    $reg++;
-                }
-            } else {
-                throw new InvalidArgumentException('Unknown callback type: ' . $type);
-            }
-        }
-        return $reg;
-    }
-
-    /**
-     * unregister given callback for one or many possible callback types
-     *
-     * @param string|array $types types to unregister callback for
-     * @param mixed $cb
-     * @throws InvalidArgumentException if the callback type is not known
-     * @return number of unregistered callbacks
-     */
-    protected static function unregisterCallback($types, $cb)
-    {
-        trigger_error(__METHOD__ . ' is deprecated. Please use the configuration in configure().', E_USER_DEPRECATED);
-
-        $types = is_array($types) ? $types : words($types);
-        foreach ($types as $type) {
-            if (isset(static::registered_callbacks()[$type])) {
-                $found = array_search($cb, self::$config[static::class]['registered_callbacks'][$type], true);
-                if ($found !== false) {
-                    $unreg++;
-                    unset(self::$config[static::class]['registered_callbacks'][$type][$found]);
-                }
-            } else {
-                throw new InvalidArgumentException('Unknown callback type: ' . $type);
-            }
-        }
-        return $unreg;
-    }
-
-    /**
-     * default callback used to map specific callbacks to NotificationCenter
-     *
-     * @param string $cb_type callback type
-     * @return void|boolean
-     */
-    protected function cbNotificationMapper($cb_type)
-    {
-        if (isset($this->notification_map()[$cb_type])) {
-            try {
-                foreach(words($this->notification_map()[$cb_type]) as $notification) {
-                    NotificationCenter::postNotification($notification, $this);
-                }
-            } catch (NotificationVetoException $e) {
-                return false;
-            }
-        }
-    }
-
-    /**
-     * default callback used to map specific callbacks to NotificationCenter
-     *
-     * @param string $cb_type callback type
-     * @return void|boolean
-     */
-    protected function cbAfterInitialize($cb_type)
-    {
-        foreach (array_keys($this->db_fields()) as $field) {
-            if (is_object($this->content[$field])) {
-                $this->content_db[$field] = clone $this->content[$field];
-            } else {
-                $this->content_db[$field] = $this->content[$field];
-            }
-        }
-    }
-
-    /**
-     * default setter used to proxy serialized fields with
-     * ArrayObjects
-     *
-     * @param string $field column name
-     * @param mixed $value value
-     * @return mixed
-     */
-     protected function setSerializedValue($field, $value)
-     {
-         $object_type = $this->serialized_fields()[$field];
-         if (is_null($value) || $value instanceof $object_type) {
-             $this->content[$field] = $value;
-         } else {
-             $this->content[$field] = new $object_type($value);
-         }
-         return $this->content[$field];
-     }
-
-    /**
-     * default setter used to proxy I18N fields with
-     * I18NString
-     *
-     * @param string $field column name
-     * @param mixed $value value
-     * @return mixed
-     */
-    protected function setI18nValue($field, $value)
-    {
-        $meta = ['object_id' => $this->getId(),
-                 'table'     => $this->db_table(),
-                 'field'     => $field];
-        if ($value instanceof I18NString) {
-            $value->setMetadata($meta);
-            $this->content[$field] = $value;
-        } else {
-            $this->content[$field] = new I18NString($value, null, $meta);
-        }
-        return $this->content[$field];
-    }
-
-     /**
-      * Cleans up this object. This essentially reset all relations of
-      * this object and marks them as unused so that the garbage collector may
-      * remove the objects.
-      *
-      * Use this function when you ran into memory problems and need to free
-      * some memory;
-      *
-      * @return void
-      */
-     public function cleanup()
-     {
-         foreach ($this->relations as $relation => $object) {
-             if ($object instanceof SimpleORMap || $object instanceof SimpleORMapCollection) {
-                 $this->relations[$relation]->cleanup();
-             }
-             $this->resetRelation($relation);
-         }
-     }
-}
diff --git a/lib/models/SimpleORMapCollection.class.php b/lib/models/SimpleORMapCollection.class.php
deleted file mode 100644
index f06ee17..0000000
--- a/lib/models/SimpleORMapCollection.class.php
+++ /dev/null
@@ -1,261 +0,0 @@
-<?php
-/**
- * SimpleORMapCollection.class.php
- * simple object-relational mapping
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * @author      André Noack <noack@data-quest.de>
- * @copyright   2012 Stud.IP Core-Group
- * @license     http://www.gnu.org/licenses/gpl-2.0.html GPL version 2
- * @category    Stud.IP
- *
- * @extends SimpleCollection<SimpleORMap>
- *
- * @template T of SimpleORMap
- */
-class SimpleORMapCollection extends SimpleCollection
-{
-    /**
-     * @var int Exception error code denoting a wrong type of objects.
-     */
-    const WRONG_OBJECT_TYPE = 1;
-
-    /**
-     * @var int Exception error code denoting that an object of this `id` already exists.
-     */
-    const OBJECT_EXISTS = 2;
-
-    /**
-     * the record object this collection belongs to
-     *
-     * @var ?SimpleORMap
-     */
-    protected $related_record;
-
-    /**
-     * relation options
-     * @var array
-     */
-    protected $relation_options = [];
-
-    /**
-     * creates a collection from an array of objects
-     * all objects should be of the same type
-     *
-     * @throws InvalidArgumentException if first entry is not SimpleOrMap
-     * @param T[] $data array with SimpleORMap objects
-     * @param bool $strict check every element for correct type and unique pk
-     * @return SimpleORMapCollection<T>
-     */
-    public static function createFromArray(array $data, $strict = true)
-    {
-        $ret = new SimpleORMapCollection();
-        if (count($data)) {
-            $first = current($data);
-            if ($first instanceof SimpleORMap) {
-                $ret->setClassName(get_class($first));
-                if ($strict) {
-                    foreach ($data as $one) {
-                        $ret[] = $one;
-                    }
-                } else {
-                    $ret->exchangeArray($data);
-                }
-            } else {
-                throw new InvalidArgumentException('This collection only accepts objects derived from SimpleORMap', self::WRONG_OBJECT_TYPE);
-            }
-        }
-        return $ret;
-    }
-
-    /**
-     * Constructor
-     *
-     * @param ?Closure         $finder  callable to fill collection
-     * @param ?array           $options relationship options
-     * @param SimpleORMap|null $record  related record
-     */
-    public function __construct(Closure $finder = null, array $options = null, SimpleORMap $record = null)
-    {
-        $this->relation_options = $options;
-        $this->related_record = $record;
-        parent::__construct($finder === null ? [] : $finder);
-    }
-
-    /**
-     * Sets the value at the specified index
-     * checks if the value is an object of specified class
-     *
-     * @see ArrayObject::offsetSet()
-     * @throws InvalidArgumentException if the given model does not fit (wrong type or id)
-     *
-     * @todo Add void return type when Stud.IP requires PHP8 minimal
-     */
-    #[ReturnTypeWillChange]
-    public function offsetSet($index, $newval)
-    {
-        if (!is_null($index)) {
-            $index = (int)$index;
-        }
-        if (!is_a($newval, $this->getClassName())) {
-            throw new InvalidArgumentException('This collection only accepts objects of type: ' .  $this->getClassName(), self::WRONG_OBJECT_TYPE);
-        }
-        if ($this->related_record && $this->relation_options['type'] === 'has_many') {
-            $foreign_key_value = call_user_func($this->relation_options['assoc_func_params_func'], $this->related_record);
-            call_user_func($this->relation_options['assoc_foreign_key_setter'], $newval, $foreign_key_value);
-        }
-        if ($newval->id !== null) {
-            $exists = $this->find($newval->id);
-            if ($exists) {
-                throw new InvalidArgumentException('Element could not be appended, element with id: ' . $exists->id . ' is in the way', self::OBJECT_EXISTS);
-            }
-        }
-        parent::offsetSet($index, $newval);
-    }
-
-    /**
-     * sets the allowed class name
-     * @param class-string $class_name
-     * @return void
-     */
-    public function setClassName($class_name)
-    {
-        $this->relation_options['class_name'] = strtolower($class_name);
-        $this->deleted->relation_options['class_name'] = strtolower($class_name);
-    }
-
-    /**
-     * sets the related record
-     *
-     * @param SimpleORMap $record
-     * @return void
-     */
-    public function setRelatedRecord(SimpleORMap $record)
-    {
-        $this->related_record = $record;
-    }
-
-    /**
-     * gets the allowed classname
-     *
-     * @return string
-     */
-    public function getClassName()
-    {
-        return strtolower($this->relation_options['class_name']);
-    }
-
-    /**
-     * reloads the elements of the collection
-     * by calling the finder function
-     *
-     * @throws InvalidArgumentException
-     * @return ?int number of records after refresh
-     */
-    public function refresh()
-    {
-        if (is_callable($this->finder)) {
-            $data = call_user_func($this->finder, $this->related_record);
-            foreach ($data as $one) {
-                if (!is_a($one, $this->getClassName())) {
-                    throw new InvalidArgumentException('This collection only accepts objects of type: ' .  $this->getClassName(), self::WRONG_OBJECT_TYPE);
-                }
-            }
-            $this->exchangeArray($data);
-            $this->deleted->exchangeArray([]);
-            return $this->last_count = $this->count();
-        }
-
-        return null;
-    }
-
-    /**
-     * returns element with given primary key value
-     *
-     * @param string $value primary key value to search for
-     * @return ?T
-     */
-    public function find($value)
-    {
-        return $this->findOneBy('id', $value);
-    }
-
-    /**
-     * returns the collection as grouped array
-     * first param is the column to group by, it becomes the key in
-     * the resulting array, default is pk. Limit returned fields with second param
-     * The grouped entries can optoionally go through the given
-     * callback. If no callback is provided, only the first grouped
-     * entry is returned, suitable for grouping by unique column
-     *
-     * @param string $group_by the column to group by, pk if ommitted
-     * @param mixed $only_these_fields limit returned fields
-     * @param ?callable $group_func closure to aggregate grouped entries
-     * @return array assoc array
-     */
-    public function toGroupedArray($group_by = 'id', $only_these_fields = null, callable $group_func = null)
-    {
-        $result = [];
-        foreach ($this as $record) {
-            $key = $record->getValue($group_by);
-            if (is_array($key)) {
-                $key = join('_', $key);
-            }
-            $result[$key][] = $record->toArray($only_these_fields);
-        }
-        if ($group_func === null) {
-            $group_func = 'current';
-        }
-        return array_map($group_func, $result);
-    }
-
-    /**
-     * mark element(s) for deletion
-     * element(s) with given primary key are moved to
-     * internal deleted collection
-     *
-     * @param string $id primary key of element
-     * @return int number of unsetted elements
-     */
-    public function unsetByPk($id)
-    {
-        return $this->unsetBy('id', $id);
-    }
-
-    /**
-     * merge in another collection, elements must be of
-     * the same type, if an element already exists it is
-     * replaced or ignored depending on second param
-     *
-     * @param SimpleORMapCollection $a_collection
-     * @param string $mode 'replace' or 'ignore'
-     * @return void
-     */
-    public function merge(SimpleCollection $a_collection, string $mode = 'ignore')
-    {
-        $mode = func_get_arg(1);
-        foreach ($a_collection as $element) {
-            try {
-                /**
-                 * @throws InvalidArgumentException
-                 * @see SimpleORMapCollection::offsetSet()
-                 */
-                $this[] = $element;
-            } catch (InvalidArgumentException $e) {
-                if ($e->getCode() === self::OBJECT_EXISTS) {
-                    if ($mode === 'replace') {
-                        $this->unsetByPk($element->id);
-                        $this[] = $element;
-                    } // else $mode means 'ignore'
-                } else {
-                    throw $e;
-                }
-            }
-        }
-        $this->storage = array_values($this->storage);
-    }
-}
diff --git a/lib/models/StudipCacheOperation.php b/lib/models/StudipCacheOperation.php
index e9c8738..d2287c3 100644
--- a/lib/models/StudipCacheOperation.php
+++ b/lib/models/StudipCacheOperation.php
@@ -42,7 +42,7 @@ class StudipCacheOperation extends SimpleORMap
      */
     public static function apply(StudipCache $cache)
     {
-        self::findEachBySQL(function ($item) use ($cache) {
+        self::findEachBySQL(function (StudipCacheOperation $item) use ($cache): void {
             $parameters = unserialize($item->parameters);
             array_unshift($parameters, $item->cache_key);
             call_user_func_array([$cache, $item->operation], $parameters);
diff --git a/lib/models/StudipComment.class.php b/lib/models/StudipComment.php
index 2e0389d..79610f8 100644
--- a/lib/models/StudipComment.class.php
+++ b/lib/models/StudipComment.php
@@ -23,7 +23,7 @@
 // +---------------------------------------------------------------------------+
 
 /**
- * StudipComment.class.php
+ * StudipComment.php
  *
  *
  *
diff --git a/lib/models/StudipEvaluation.php b/lib/models/StudipEvaluation.php
deleted file mode 100644
index 5441db8..0000000
--- a/lib/models/StudipEvaluation.php
+++ /dev/null
@@ -1,90 +0,0 @@
-<?php
-/**
- * Evaluation.php
- * model class for table Evaluation
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * @author      Florian Bieringer <florian.bieringer@uni-passau.de>
- * @copyright   2014 Stud.IP Core-Group
- * @license     http://www.gnu.org/licenses/gpl-2.0.html GPL version 2
- * @category    Stud.IP
- * @since       3.0
- *
- * @property string $id alias column for eval_id
- * @property string $eval_id database column
- * @property string $author_id database column
- * @property string $title database column
- * @property string $text database column
- * @property int|null $startdate database column
- * @property int|null $stopdate database column
- * @property int|null $timespan database column
- * @property int $mkdate database column
- * @property int $chdate database column
- * @property int $anonymous database column
- * @property int $visible database column
- * @property int $shared database column
- * @property User $author belongs_to User
- * @property SimpleORMapCollection|User[] $participants has_and_belongs_to_many User
- * @property mixed $enddate additional field
- */
-class StudipEvaluation extends SimpleORMap
-{
-    protected static function configure($config = [])
-    {
-        $config['db_table'] = 'eval';
-
-        $config['belongs_to']['author'] = [
-            'class_name' => User::class,
-            'foreign_key' => 'author_id'
-        ];
-        $config['has_and_belongs_to_many']['participants'] = [
-            'class_name' => User::class,
-            'thru_table' => 'eval_user'
-        ];
-
-        $config['additional_fields']['enddate'] = true;
-
-        parent::configure($config);
-    }
-
-    /**
-     * Fetches all evaluations for a specific range_id
-     *
-     * @param String $range_id the range id
-     * @return Array All evaluations for that range
-     */
-    public static function findByRange_id($range_id)
-    {
-        return self::findThru($range_id, [
-            'thru_table'        => 'eval_range',
-            'thru_key'          => 'range_id',
-            'thru_assoc_key'    => 'eval_id',
-            'assoc_foreign_key' => 'eval_id'
-        ]);
-    }
-
-    /**
-     * Returns the enddate of a evaluation. Returns null if stop is manual
-     *
-     * @return stopdate or null
-     */
-    public function getEnddate()
-    {
-        if ($this->stopdate) {
-            return $this->stopdate;
-        }
-        if ($this->timespan) {
-            return $this->startdate + $this->timespan;
-        }
-        return null;
-    }
-
-    function getNumberOfVotes ()
-    {
-        return DBManager::get()->fetchColumn("SELECT count(DISTINCT user_id) FROM eval_user WHERE eval_id = ?", [$this->id]);
-    }
-}
diff --git a/lib/models/StudipNews.class.php b/lib/models/StudipNews.php
index 607f9d3..ccb1828 100644
--- a/lib/models/StudipNews.class.php
+++ b/lib/models/StudipNews.php
@@ -21,7 +21,7 @@
 require_once 'lib/object.inc.php';
 
 /**
- * StudipNews.class.php
+ * StudipNews.php
  *
  * @author   André Noack <noack@data-quest>, Suchi & Berg GmbH <info@data-quest.de>
  * @author   Arne Schröder <schroeder@data-quest>
@@ -44,6 +44,7 @@ require_once 'lib/object.inc.php';
  * @property SimpleORMapCollection|StudipComment[] $comments has_many StudipComment
  * @property SimpleORMapCollection|NewsRoles[] $news_roles has_many NewsRoles
  * @property User $owner belongs_to User
+ * @property int $views additional field
  */
 class StudipNews extends SimpleORMap implements PrivacyObject
 {
@@ -72,8 +73,15 @@ class StudipNews extends SimpleORMap implements PrivacyObject
             'on_delete'         => 'delete'
         ];
 
-        $config['i18n_fields']['topic'] = true;
-        $config['i18n_fields']['body'] = true;
+        $config['additional_fields'] = [
+            'views' => [
+                'get' => function (StudipNews $news): int {
+                    return object_return_views($news->id);
+                },
+            ],
+        ];
+
+        $config['i18n_fields'] = ['topic', 'body'];
 
         // Strip <admin_msg> from news body
         $config['registered_callbacks']['after_initialize'][] = function ($news) {
@@ -292,7 +300,7 @@ class StudipNews extends SimpleORMap implements PrivacyObject
         $news_result    = $statement->fetchGrouped();
 
         $objects = [$area => []];
-        foreach($news_result as $id => $result) {
+        foreach ($news_result as $id => $result) {
             $objects[$area][$id] = [
                 'range_id' => $result['range_id'],
                 'title'    => $result['title'] ?? '',
@@ -307,8 +315,7 @@ class StudipNews extends SimpleORMap implements PrivacyObject
             } elseif ($area === 'user') {
                 if ($GLOBALS['user']->id === $result['userid']) {
                     $objects[$area][$id]['title'] = _('Ankündigungen auf Ihrer Profilseite');
-                }
-                else {
+                } else {
                     $objects[$area][$id]['title'] = sprintf(_('Ankündigungen auf der Profilseite von %s'), get_fullname($result['userid']));
                 }
             } elseif ($area === 'global') {
diff --git a/lib/models/StudipScmEntry.class.php b/lib/models/StudipScmEntry.php
index 7001a4a..30c13d3 100644
--- a/lib/models/StudipScmEntry.class.php
+++ b/lib/models/StudipScmEntry.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * StudipScmEntry.class.php
+ * StudipScmEntry.php
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/StudipStudyArea.class.php b/lib/models/StudipStudyArea.php
index 8da8e16..8da8e16 100644
--- a/lib/models/StudipStudyArea.class.php
+++ b/lib/models/StudipStudyArea.php
diff --git a/lib/models/StudyCourse.class.php b/lib/models/StudyCourse.php
index faf6df4..91937ea 100644
--- a/lib/models/StudyCourse.class.php
+++ b/lib/models/StudyCourse.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * StudyCourse.class.php
+ * StudyCourse.php
  * model class for table studiengang
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/ToolActivation.php b/lib/models/ToolActivation.php
index a4a4de2..4209a20 100644
--- a/lib/models/ToolActivation.php
+++ b/lib/models/ToolActivation.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * ToolActivation.class.php
+ * ToolActivation.php
  * model class for table tools_activated
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/User.class.php b/lib/models/User.php
index 056b48a..3fcc3f5 100644
--- a/lib/models/User.class.php
+++ b/lib/models/User.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * User.class.php
+ * User.php
  * model class for combined auth_user_md5/user_info record
  * this class represents one user, the attributes from tables
  * auth_user_md5 and user_info were merged.
@@ -52,6 +52,9 @@
  * @property SimpleORMapCollection|Kategorie[] $profile_categories has_many Kategorie
  * @property SimpleORMapCollection|MvvContact[] $mvv_assignments has_many MvvContact
  * @property SimpleORMapCollection|CourseMemberNotification[] $course_notifications has_many CourseMemberNotification
+ * @property SimpleORMapCollection|BlubberThread[] $blubber_threads has_many BlubberThread
+ * @property SimpleORMapCollection|BlubberComment[] $blubber_comments has_many BlubberComment
+ * @property SimpleORMapCollection|BlubberMention[] $blubber_mentions has_many BlubberMention
  * @property UserInfo $info has_one UserInfo
  * @property UserOnline $online has_one UserOnline
  * @property Courseware\Unit $courseware_units has_one Courseware\Unit
@@ -206,6 +209,20 @@ class User extends AuthUserMd5 implements Range, PrivacyObject, Studip\Calendar\
             'assoc_foreign_key' => 'author_id'
         ];
 
+        // Blubber relations
+        $config['has_many']['blubber_threads'] = [
+            'class_name' => BlubberThread::class,
+            'on_delete'  => 'delete',
+        ];
+        $config['has_many']['blubber_comments'] = [
+            'class_name' => BlubberComment::class,
+            'on_delete'  => 'delete',
+        ];
+        $config['has_many']['blubber_mentions'] = [
+            'class_name' => BlubberMention::class,
+            'on_delete'  => 'delete',
+        ];
+
         $config['additional_fields']['config']['get'] = function ($user) {
             return UserConfig::get($user->id);
         };
@@ -378,7 +395,7 @@ class User extends AuthUserMd5 implements Range, PrivacyObject, Studip\Calendar\
     }
 
     /**
-     * Temporary migrate to User.class.php
+     * Temporary migrate to User.php
      *
      * @param $attributes
      * @return array
@@ -795,9 +812,7 @@ class User extends AuthUserMd5 implements Range, PrivacyObject, Studip\Calendar\
             $activeVotes = [];
             $stoppedVotes = [];
         }
-        // Evaluations
-        $evalDB = new EvaluationDB();
-        $activeEvals = $evalDB->getEvaluationIDs($this->id, EVAL_STATE_ACTIVE);
+
         // Free datafields
         $data_fields = DataFieldEntry::getDataFieldEntries($this->id, 'user');
 
@@ -874,7 +889,7 @@ class User extends AuthUserMd5 implements Range, PrivacyObject, Studip\Calendar\
                 'identifier' => 'commondata'
             ];
         }
-        if (Config::get()->VOTE_ENABLE && ($activeVotes || $stoppedVotes || $activeEvals) && empty($GLOBALS['NOT_HIDEABLE_FIELDS'][$this->perms]['votes'])) {
+        if (Config::get()->VOTE_ENABLE && ($activeVotes || $stoppedVotes) && empty($GLOBALS['NOT_HIDEABLE_FIELDS'][$this->perms]['votes'])) {
             $homepage_elements['votes'] = [
                 'name'       => _('Fragebögen'),
                 'visibility' => $homepage_visibility['votes'] ?? get_default_homepage_visibility($this->id),
@@ -1174,7 +1189,7 @@ class User extends AuthUserMd5 implements Range, PrivacyObject, Studip\Calendar\
         // Restliche Daten übertragen
 
         // ForumsModule migrieren
-        foreach (PluginEngine::getPlugins('ForumModule') as $plugin) {
+        foreach (PluginEngine::getPlugins(ForumModule::class) as $plugin) {
             $plugin->migrateUser($old_id, $new_id);
         }
 
@@ -1211,20 +1226,6 @@ class User extends AuthUserMd5 implements Range, PrivacyObject, Studip\Calendar\
         $statement = DBManager::get()->prepare($query);
         $statement->execute([$new_id, $old_id]);
 
-        // Evaluationen
-        $query = "UPDATE IGNORE eval SET author_id = ? WHERE author_id = ?";
-        $statement = DBManager::get()->prepare($query);
-        $statement->execute([$new_id, $old_id]);
-
-        self::removeDoubles('eval_user', 'eval_id', $new_id, $old_id);
-        $query = "UPDATE IGNORE eval_user SET user_id = ? WHERE user_id = ?";
-        $statement = DBManager::get()->prepare($query);
-        $statement->execute([$new_id, $old_id]);
-
-        $query = "UPDATE IGNORE evalanswer_user SET user_id = ? WHERE user_id = ?";
-        $statement = DBManager::get()->prepare($query);
-        $statement->execute([$new_id, $old_id]);
-
         // Kategorien
         $query = "UPDATE IGNORE kategorien SET range_id = ? WHERE range_id = ?";
         $statement = DBManager::get()->prepare($query);
@@ -1621,4 +1622,29 @@ class User extends AuthUserMd5 implements Range, PrivacyObject, Studip\Calendar\
                 return '';
         }
     }
+
+    /*
+     * Returns whether the user has the given permission (for the given range).
+     *
+     * @param string     $permission
+     * @param Range|null $for_range
+     *
+     * @return bool
+     */
+    public function hasPermissionLevel(string $permission, ?Range $for_range = null): bool
+    {
+        if (func_num_args() === 1) {
+            return $GLOBALS['perm']->have_perm($permission, $this->id);
+        }
+
+        if ($for_range === null) {
+            throw new Exception('No valid range given');
+        }
+
+        if ($for_range instanceof User) {
+            return $GLOBALS['perm']->have_profile_perm($permission, $for_range->id, $this->id);
+        }
+
+        return $GLOBALS['perm']->have_studip_perm($permission, $for_range->id, $this->id);
+    }
 }
diff --git a/lib/models/UserInfo.class.php b/lib/models/UserInfo.php
index 28808a2..62a63fc 100644
--- a/lib/models/UserInfo.class.php
+++ b/lib/models/UserInfo.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * UserInfo.class.php
+ * UserInfo.php
  * model class for table user_info
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/UserOnline.class.php b/lib/models/UserOnline.php
index e18322d..c3efba2 100644
--- a/lib/models/UserOnline.class.php
+++ b/lib/models/UserOnline.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * UserOnline.class.php
+ * UserOnline.php
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -24,4 +24,4 @@ class UserOnline extends SimpleORMap
         $config['db_table'] = 'user_online';
         parent::configure($config);
     }
-}
\ No newline at end of file
+}
diff --git a/lib/models/UserStudyCourse.class.php b/lib/models/UserStudyCourse.php
index cac37c8..aeac38b 100644
--- a/lib/models/UserStudyCourse.class.php
+++ b/lib/models/UserStudyCourse.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * UserStudyCourse.class.php
+ * UserStudyCourse.php
  * model class for table user_studiengang
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/Vote.php b/lib/models/Vote.php
index 0520401..b5cd142 100644
--- a/lib/models/Vote.php
+++ b/lib/models/Vote.php
@@ -1,6 +1,4 @@
 <?php
-require_once 'lib/classes/QuestionType.interface.php';
-
 /**
  * @license GPL2 or any later version
  *
@@ -53,7 +51,7 @@ 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 +98,7 @@ 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);
@@ -113,28 +111,49 @@ class Vote extends QuestionnaireQuestion implements QuestionType
         $output = [];
 
         $options = $this['questiondata']['options'] ? $this['questiondata']['options']->getArrayCopy() : [];
+        $multiplechoice = (bool) $this['questiondata']['multiplechoice'];
+
+        if ($multiplechoice) {
+            foreach ($options as $key => $option) {
+                $answerOption = [];
+                $countNobodys = 0;
+
+                foreach ($this->answers as $answer) {
+                    $answerData = $answer['answerdata']->getArrayCopy();
+
+                    if ($answer['user_id'] && $answer['user_id'] != 'nobody') {
+                        $userId = $answer['user_id'];
+                    } else {
+                        $countNobodys++;
+                        $userId = _('unbekannt') . ' ' . $countNobodys;
+                    }
+
+                    if (in_array($key, (array) $answerData['answers'])) {
+                        $answerOption[$userId] = 1;
+                    } else {
+                        $answerOption[$userId] = 0;
+                    }
+                }
+                $output[$option] = $answerOption;
+            }
+        } else {
 
-        foreach ($options as $key => $option) {
             $answerOption = [];
             $countNobodys = 0;
 
             foreach ($this->answers as $answer) {
                 $answerData = $answer['answerdata']->getArrayCopy();
 
-                if ($answer['user_id'] && $answer['user_id'] != 'nobody') {
+                if ($answer['user_id'] && $answer['user_id'] !== 'nobody') {
                     $userId = $answer['user_id'];
                 } else {
-                    $countNobodys++;
-                    $userId = _('unbekannt').' '.$countNobodys;
-                }
-
-                if (in_array($key, (array) $answerData['answers'])) {
-                    $answerOption[$userId] = 1;
-                } else {
-                    $answerOption[$userId] = 0;
+                    $userId = _('unbekannt') . ' ' . ++$countNobodys;
                 }
+                $answerOption[$userId] = $options[$answerData['answers']];
             }
-            $output[$option] = $answerOption;
+
+            $question = strip_tags($this['questiondata']['description']);
+            $output[$question] = $answerOption;
         }
         return $output;
     }
diff --git a/lib/models/WebserviceAccessRule.class.php b/lib/models/WebserviceAccessRule.php
index 48da0ef..120ac47 100644
--- a/lib/models/WebserviceAccessRule.class.php
+++ b/lib/models/WebserviceAccessRule.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * WebserviceAccessRule.class.php
+ * WebserviceAccessRule.php
  * model class for table webservice_access_rules
  * this class represents one record of the table webservice_access_rules
  * the column ip_range is converted from a comma separated list to an ArrayObject and vice-versa,
diff --git a/lib/models/WikiPage.class.php b/lib/models/WikiPage.php
index d349aa1..b5f0101 100644
--- a/lib/models/WikiPage.class.php
+++ b/lib/models/WikiPage.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * WikiPage.class.php
+ * WikiPage.php
  * model class for table wiki
  *
  * This program is free software; you can redistribute it and/or
@@ -92,7 +92,7 @@ class WikiPage extends SimpleORMap implements PrivacyObject
 
     protected function createVersion()
     {
-        $this->user_id = User::findCurrent()->id;
+        $last_version = $this->versions[0];
         if (
             !$this->isNew()
             && $this->content['content'] !== $this->content_db['content']
@@ -100,6 +100,7 @@ class WikiPage extends SimpleORMap implements PrivacyObject
                 $this->content_db['user_id'] !== $this->content['user_id']
                 || $this->content_db['chdate'] < time() - 60 * 30
             )
+            && (!$last_version || $last_version['content'] !== $this['content'])
         ) {
             //Neue Version anlegen:
             WikiVersion::create([
diff --git a/lib/models/calendar/CalendarCourseDate.class.php b/lib/models/calendar/CalendarCourseDate.class.php
deleted file mode 100644
index 49179bd..0000000
--- a/lib/models/calendar/CalendarCourseDate.class.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-
-/**
- * CalendarCourseDate is a specialisation of CourseDate for
- * course dates that are displayed in the personal calendar.
- */
-class CalendarCourseDate extends CourseDate
-{
-    public static function getEvents(DateTime $begin, DateTime $end, string $range_id): array
-    {
-        return parent::findBySQL(
-            "JOIN `seminar_user`
-               ON `seminar_user`.`seminar_id` = `termine`.`range_id`
-             WHERE `seminar_user`.`user_id` = :user_id
-               AND `seminar_user`.`bind_calendar` = '1'
-               AND `termine`.`date` BETWEEN :begin AND :end
-               AND (
-                   IFNULL(`termine`.`metadate_id`, '') = ''
-                   OR `termine`.`metadate_id` NOT IN (
-                       SELECT `metadate_id`
-                       FROM `schedule_seminare`
-                       WHERE `user_id` = :user_id
-                         AND `visible` = 0
-                   )
-               )
-               ORDER BY date",
-            [
-                'begin'   => $begin->getTimestamp(),
-                'end'     => $end->getTimestamp(),
-                'user_id' => $range_id
-            ]
-        );
-    }
-}
diff --git a/lib/models/calendar/CalendarCourseDate.php b/lib/models/calendar/CalendarCourseDate.php
new file mode 100644
index 0000000..370dcd1
--- /dev/null
+++ b/lib/models/calendar/CalendarCourseDate.php
@@ -0,0 +1,80 @@
+<?php
+
+/**
+ * CalendarCourseDate is a specialisation of CourseDate for
+ * course dates that are displayed in the personal calendar.
+ */
+class CalendarCourseDate extends CourseDate
+{
+    public static function getEvents(DateTime $begin, DateTime $end, string $range_id): array
+    {
+        $events = [];
+        parent::findEachBySQL(
+            function ($e) use (&$events, $range_id) {
+                if (self::checkRelated($e, $range_id)) {
+                    $events[] = $e;
+                }
+            },
+            "JOIN `seminar_user`
+               ON `seminar_user`.`seminar_id` = `termine`.`range_id`
+             WHERE `seminar_user`.`user_id` = :user_id
+               AND `seminar_user`.`bind_calendar` = '1'
+               AND `termine`.`date` BETWEEN :begin AND :end
+               AND (
+                   IFNULL(`termine`.`metadate_id`, '') = ''
+                   OR `termine`.`metadate_id` NOT IN (
+                       SELECT `metadate_id`
+                       FROM `schedule_seminare`
+                       WHERE `user_id` = :user_id
+                         AND `visible` = 0
+                   )
+               )
+               ORDER BY date",
+            [
+                'begin'   => $begin->getTimestamp(),
+                'end'     => $end->getTimestamp(),
+                'user_id' => $range_id
+            ]
+        );
+        return $events;
+    }
+
+    /**
+     * Checks if given user is the responsible lecturer or is member of a
+     * related group.
+     *
+     * @global object $perm The global perm object.
+     * @param CalendarCourseDate $event The course event to check against.
+     * @param string $user_id The id of the user.
+     * @return boolean
+     */
+    protected static function checkRelated(CalendarCourseDate $event, string $user_id): bool
+    {
+        $check_related = false;
+        $permission = $GLOBALS['perm']->get_studip_perm($event->range_id, $user_id);
+        switch ($permission) {
+            case 'dozent' :
+                $related_persons = $event->dozenten->pluck('user_id');
+                if (count($related_persons) > 0) {
+                    $check_related = in_array($user_id, $related_persons);
+                } else {
+                    $check_related = true;
+                }
+                break;
+            case 'tutor' :
+                $check_related = true;
+                break;
+            default :
+                $group_ids = $event->statusgruppen->pluck('statusgruppe_id');
+                if (count($group_ids) > 0) {
+                    $member = StatusgruppeUser::findBySQL(
+                        'statusgruppe_id IN(?) AND user_id = ?',
+                        [$group_ids, $user_id]);
+                    $check_related = count($member) > 0;
+                } else {
+                    $check_related = true;
+                }
+        }
+        return $check_related;
+    }
+}
diff --git a/lib/models/calendar/CalendarCourseExDate.class.php b/lib/models/calendar/CalendarCourseExDate.php
index eb23aeb..eb23aeb 100644
--- a/lib/models/calendar/CalendarCourseExDate.class.php
+++ b/lib/models/calendar/CalendarCourseExDate.php
diff --git a/lib/models/calendar/CalendarDate.class.php b/lib/models/calendar/CalendarDate.php
index e9269c6..0318dab 100644
--- a/lib/models/calendar/CalendarDate.class.php
+++ b/lib/models/calendar/CalendarDate.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * CalendarDate.class.php - Model class for calendar dates.
+ * CalendarDate.php - Model class for calendar dates.
  *
  * CalendarDate represents a date in the personal calendar.
  *
@@ -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) {
@@ -402,8 +402,8 @@ class CalendarDate extends SimpleORMap implements PrivacyObject
         $sorm = self::findThru($storage->user_id, [
             'thru_table'        => 'calendar_date_assignments',
             'thru_key'          => 'range_id',
-            'thru_assoc_key'    => 'event_id',
-            'assoc_foreign_key' => 'event_id',
+            'thru_assoc_key'    => 'calendar_date_id',
+            'assoc_foreign_key' => 'id',
         ]);
         if ($sorm) {
             $field_data = [];
diff --git a/lib/models/calendar/CalendarDateAssignment.class.php b/lib/models/calendar/CalendarDateAssignment.php
index fbd21a7..e0e2135 100644
--- a/lib/models/calendar/CalendarDateAssignment.class.php
+++ b/lib/models/calendar/CalendarDateAssignment.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * CalendarDateAssignment.class.php - Model class for calendar date assignments.
+ * CalendarDateAssignment.php - Model class for calendar date assignments.
  *
  * CalendarDateAssignment represents the assignment of a calendar date
  *  to a specific calendar. The calendar is represented by a range-ID
@@ -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);
@@ -250,7 +250,7 @@ class CalendarDateAssignment extends SimpleORMap implements Event
         ]);
 
 
-        $sql_repetition = $sql . " AND `calendar_dates`.`begin` < :end AND `calendar_dates`.`repetition_type` IN ('DAYLY', 'WEEKLY', 'MONTHLY', 'YEARLY')
+        $sql_repetition = $sql . " AND `calendar_dates`.`begin` < :end AND `calendar_dates`.`repetition_type` IN ('DAILY', 'WEEKLY', 'MONTHLY', 'YEARLY')
                     AND `calendar_dates`.`repetition_end` > :begin
             ";
 
diff --git a/lib/models/calendar/CalendarDateException.class.php b/lib/models/calendar/CalendarDateException.php
index b53a728..b53a728 100644
--- a/lib/models/calendar/CalendarDateException.class.php
+++ b/lib/models/calendar/CalendarDateException.php
diff --git a/lib/models/resources/BrokenResource.class.php b/lib/models/resources/BrokenResource.php
index 5266b4f..fc44e82 100644
--- a/lib/models/resources/BrokenResource.class.php
+++ b/lib/models/resources/BrokenResource.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceLabel.class.php - model class for a resource label
+ * ResourceLabel.php - model class for a resource label
  *
  * The BrokenResource class represents resources whose class
  * cannot be found due to missing Resource specialisations
diff --git a/lib/models/resources/Building.class.php b/lib/models/resources/Building.php
index 0edb983..a1c071a 100644
--- a/lib/models/resources/Building.class.php
+++ b/lib/models/resources/Building.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * Building.class.php - model class for a resource which is a building
+ * Building.php - model class for a resource which is a building
  *
  * The building class is a derived class from the Resource class
  * which includes specialisations for Building resource types.
diff --git a/lib/models/resources/GlobalResourceLock.class.php b/lib/models/resources/GlobalResourceLock.php
index b1753f5..ed748e1 100644
--- a/lib/models/resources/GlobalResourceLock.class.php
+++ b/lib/models/resources/GlobalResourceLock.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * GlobalResourceLock.class.php - model class for resource locks
+ * GlobalResourceLock.php - model class for resource locks
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/resources/Location.class.php b/lib/models/resources/Location.php
index 8e79382..9da2e11 100644
--- a/lib/models/resources/Location.class.php
+++ b/lib/models/resources/Location.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * Location.class.php - model class for a resource which is a location
+ * Location.php - model class for a resource which is a location
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/resources/Resource.class.php b/lib/models/resources/Resource.php
index 531bc4c..32fce2b 100644
--- a/lib/models/resources/Resource.class.php
+++ b/lib/models/resources/Resource.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * Resource.class.php - model class for a resource
+ * Resource.php - model class for a resource
  *
  * The Resource class is the base class of the new
  * Room and Resource management system in Stud.IP.
@@ -2296,29 +2296,14 @@ class Resource extends SimpleORMap implements StudipItem
             return 'admin';
         }
 
-        //Check for a temporary permission first:
 
         $perm_string = '';
         $temp_perm   = null;
 
         $begin = time();
         $end   = $begin;
-
-        //If $time range is set and contains two DateTime objects
-        //we can include that in the search for temporary permissions.
-        if ($time_range) {
-            if ($time_range[0] instanceof DateTime) {
-                $begin = $time_range[0]->getTimestamp();
-            } else {
-                $begin = $time_range[0];
-            }
-            if ($time_range[1] instanceof DateTime) {
-                $end = $time_range[1]->getTimestamp();
-            } else {
-                $end = $time_range[1];
-            }
-        }
-
+        //Check for a temporary permission first:
+        //check only against current timestamp
         if (!$permanent_only) {
             $temp_perm = ResourceTemporaryPermission::findOneBySql(
                 '(resource_id = :resource_id) AND (user_id = :user_id)
@@ -2375,8 +2360,18 @@ class Resource extends SimpleORMap implements StudipItem
             $perm_string = $global_perm;
         }
         //Now we must check for global resource locks:
-
         if ($perm_string && $time_range && $this->lockable) {
+
+            if ($time_range[0] instanceof DateTime) {
+                $begin = $time_range[0]->getTimestamp();
+            } else {
+                $begin = $time_range[0];
+            }
+            if ($time_range[1] instanceof DateTime) {
+                $end = $time_range[1]->getTimestamp();
+            } else {
+                $end = $time_range[1];
+            }
             if (GlobalResourceLock::isLocked($begin, $end)) {
                 //A permission level exists for the user.
                 //The user gets "user" permissions in case
diff --git a/lib/models/resources/ResourceBooking.class.php b/lib/models/resources/ResourceBooking.php
index f55b3b3..977cf32 100644
--- a/lib/models/resources/ResourceBooking.class.php
+++ b/lib/models/resources/ResourceBooking.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceBooking.class.php - model class for resource bookings
+ * ResourceBooking.php - model class for resource bookings
  *
  * The ResourceBooking class is responsible for storing
  * bookings of resources in a specified time range
@@ -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/'
         );
 
@@ -1755,18 +1755,16 @@ class ResourceBooking extends SimpleORMap implements PrivacyObject, Studip\Calen
                 //(lib/resources.js, method dropEventInRoomGroupBookingPlan)
                 $interval_api_urls = [
                     'resize' => \URLHelper::getURL(
-                        'api.php/resources/booking/'
-                      . $this->id . '/move',
+                        'dispatch.php/resources/ajax/move_booking/' . $this->id,
                         [
-                            'quiet' => '1',
+                            'quiet' => true,
                             'interval_id' => $interval->id
                         ]
                     ),
                     'move' => \URLHelper::getURL(
-                        'api.php/resources/booking/'
-                      . $this->id . '/move',
+                        'dispatch.php/resources/ajax/move_booking/' . $this->id,
                         [
-                            'quiet' => '1',
+                            'quiet' => true,
                             'interval_id' => $interval->id
                         ]
                     )
@@ -1784,11 +1782,11 @@ class ResourceBooking extends SimpleORMap implements PrivacyObject, Studip\Calen
                 $text_colour,
                 $colour,
                 $booking_is_editable,
-                'ResourceBookingInterval',
+                ResourceBookingInterval::class,
                 $interval->id,
-                'ResourceBooking',
+                ResourceBooking::class,
                 $this->id,
-                'Resource',
+                Resource::class,
                 $this->resource_id,
                 $booking_view_urls,
                 $interval_api_urls,
@@ -1917,7 +1915,7 @@ 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/ResourceBookingInterval.class.php b/lib/models/resources/ResourceBookingInterval.php
index 7908e40..47f01cc 100644
--- a/lib/models/resources/ResourceBookingInterval.class.php
+++ b/lib/models/resources/ResourceBookingInterval.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceBookingInterval.class.php - model class for storing
+ * ResourceBookingInterval.php - model class for storing
  * all resource bookings time intervals, including those for
  * repetitions.
  *
diff --git a/lib/models/resources/ResourceCategory.class.php b/lib/models/resources/ResourceCategory.php
index f4ae14d..cfe323a 100644
--- a/lib/models/resources/ResourceCategory.class.php
+++ b/lib/models/resources/ResourceCategory.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceCategory.class.php - model class for resource categories
+ * ResourceCategory.php - model class for resource categories
  *
  * The ResourceCategory class can be used as a Factory for
  * Resource objects.
@@ -85,7 +85,7 @@ class ResourceCategory extends SimpleORMap
     public static function find($id)
     {
         $all = self::findAll();
-        return $all[$id] ?: null;
+        return $all[$id] ?? null;
     }
 
     /**
diff --git a/lib/models/resources/ResourceCategoryProperty.class.php b/lib/models/resources/ResourceCategoryProperty.php
index b1460cd..c9ac66e 100644
--- a/lib/models/resources/ResourceCategoryProperty.class.php
+++ b/lib/models/resources/ResourceCategoryProperty.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceCategoryProperty.class.php - model class for
+ * ResourceCategoryProperty.php - model class for
  * resource category properties
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/resources/ResourceLabel.class.php b/lib/models/resources/ResourceLabel.php
index d9c869f..c465723 100644
--- a/lib/models/resources/ResourceLabel.class.php
+++ b/lib/models/resources/ResourceLabel.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceLabel.class.php - model class for a resource label
+ * ResourceLabel.php - model class for a resource label
  *
  * The ResourceLabel class represents headings or subheadings whose
  * only purpose is helping with organising the resource tree.
diff --git a/lib/models/resources/ResourcePermission.class.php b/lib/models/resources/ResourcePermission.php
index bd33708..044db83 100644
--- a/lib/models/resources/ResourcePermission.class.php
+++ b/lib/models/resources/ResourcePermission.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourcePermission.class.php - model class for resource permissions.
+ * ResourcePermission.php - model class for resource permissions.
  *
  * Description of the resources permission system:
  * - admin: An admin may do everything in the resource management:
diff --git a/lib/models/resources/ResourceProperty.class.php b/lib/models/resources/ResourceProperty.php
index 4bbc4ec..4f7a329 100644
--- a/lib/models/resources/ResourceProperty.class.php
+++ b/lib/models/resources/ResourceProperty.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceProperty.class.php - model class for resource properties
+ * ResourceProperty.php - model class for resource properties
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/resources/ResourcePropertyDefinition.class.php b/lib/models/resources/ResourcePropertyDefinition.php
index 82d29c9..b87e8e6 100644
--- a/lib/models/resources/ResourcePropertyDefinition.class.php
+++ b/lib/models/resources/ResourcePropertyDefinition.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourcePropertyDefinition.class.php - model class for resource property definitions
+ * ResourcePropertyDefinition.php - model class for resource property definitions
  *
  * The ResourcePropertyDefinition class can be used as a Factory
  * for ResourceProperty objects.
@@ -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/ResourcePropertyGroup.class.php b/lib/models/resources/ResourcePropertyGroup.php
index ad53902..f6ea825 100644
--- a/lib/models/resources/ResourcePropertyGroup.class.php
+++ b/lib/models/resources/ResourcePropertyGroup.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourcePropertyGroup.class.php - model class for resource property groups
+ * ResourcePropertyGroup.php - model class for resource property groups
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/resources/ResourceRequest.class.php b/lib/models/resources/ResourceRequest.php
index 6b22b44..df77b19 100644
--- a/lib/models/resources/ResourceRequest.class.php
+++ b/lib/models/resources/ResourceRequest.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceRequest.class.php - Contains a model class for resource requests.
+ * ResourceRequest.php - Contains a model class for resource requests.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -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);
@@ -2244,24 +2244,19 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
 
     protected function convertToEventData(array $time_intervals, User $user)
     {
-        $booking_plan_request_bg     =
-            ColourValue::find('Resources.BookingPlan.Request.Bg');
-        $booking_plan_request_fg     =
-            ColourValue::find('Resources.BookingPlan.Request.Fg');
-        $booking_plan_preparation_bg =
-            ColourValue::find('Resources.BookingPlan.PreparationTime.Bg');
-        $booking_plan_preparation_fg =
-            ColourValue::find('Resources.BookingPlan.PreparationTime.Fg');
+        $booking_plan_request_bg = ColourValue::find('Resources.BookingPlan.Request.Bg');
+        $booking_plan_request_fg = ColourValue::find('Resources.BookingPlan.Request.Fg');
+        $booking_plan_preparation_bg = ColourValue::find('Resources.BookingPlan.PreparationTime.Bg');
+        $booking_plan_preparation_fg = ColourValue::find('Resources.BookingPlan.PreparationTime.Fg');
 
         $user_is_resource_autor = false;
-        if ($this->resource_id && ($this->resource instanceof Resource)) {
+        if ($this->resource_id && $this->resource instanceof Resource) {
             $user_is_resource_autor = $this->resource->userHasPermission(
                 $user,
                 'autor'
             );
         }
-        $request_is_editable =
-            $user_is_resource_autor || ($user->id == $this->user_id);
+        $request_is_editable = $user_is_resource_autor || ($user->id == $this->user_id);
 
         $request_api_urls  = [];
         $request_view_urls = [];
@@ -2269,18 +2264,12 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
         if ($request_is_editable) {
             $request_api_urls = [
                 'resize' => URLHelper::getURL(
-                    'api.php/resources/request/'
-                    . $this->id . '/move',
-                    [
-                        'quiet' => '1'
-                    ]
+                    'dispatch.php/resources/ajax/move_request/'. $this->id,
+                    ['quiet' => true]
                 ),
-                'move'   => URLHelper::getURL(
-                    'api.php/resources/request/'
-                    . $this->id . '/move',
-                    [
-                        'quiet' => '1'
-                    ]
+                'move' => URLHelper::getURL(
+                    'dispatch.php/resources/ajax/move_request/'. $this->id,
+                    ['quiet' => true]
                 )
             ];
 
@@ -2290,13 +2279,14 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
                     . $this->id
                 )
             ];
-            if ($this->resource_id && ($this->resource instanceof Resource)) {
-                if ($this->resource->userHasBookingRights($user)) {
-                    $request_view_urls['edit'] = URLHelper::getURL(
-                        'dispatch.php/resources/room_request/resolve/'
-                        . $this->id
-                    );
-                }
+            if (
+                $this->resource_id
+                && $this->resource instanceof Resource
+                && $this->resource->userHasBookingRights($user)
+            ) {
+                $request_view_urls['edit'] = URLHelper::getURL(
+                    'dispatch.php/resources/room_request/resolve/'. $this->id
+                );
             }
         }
 
@@ -2306,7 +2296,7 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
             $real_begin = $interval['begin'];
             if ($this->preparation_time) {
                 $real_begin += (int)$this->preparation_time;
-                $begin      = new DateTime();
+                $begin = new DateTime();
                 $begin->setTimestamp($interval['begin']);
                 $end = new DateTime();
                 $end->setTimestamp($real_begin);
@@ -2320,9 +2310,9 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
                     $request_is_editable,
                     '',
                     '',
-                    'ResourceRequest',
+                    ResourceRequest::class,
                     $this->id,
-                    'Resource',
+                    Resource::class,
                     $this->resource_id,
                     $request_view_urls,
                     $request_api_urls
@@ -2342,11 +2332,11 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
                 $booking_plan_request_fg->__toString(),
                 $booking_plan_request_bg->__toString(),
                 $request_is_editable,
-                'ResourceRequest',
+                ResourceRequest::class,
                 $this->id,
-                'Resource',
+                Resource::class,
                 $this->resource_id,
-                'Resource',
+                Resource::class,
                 $this->resource_id,
                 $request_view_urls,
                 $request_api_urls
diff --git a/lib/models/resources/ResourceRequestAppointment.class.php b/lib/models/resources/ResourceRequestAppointment.php
index 929733b..63384a2 100644
--- a/lib/models/resources/ResourceRequestAppointment.class.php
+++ b/lib/models/resources/ResourceRequestAppointment.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceRequestAppointment.class.php - Contains a model class for
+ * ResourceRequestAppointment.php - Contains a model class for
  * the resource_request_appointments table.
  *
  * ResourceRequestAppointment is a model class to connect
diff --git a/lib/models/resources/ResourceRequestProperty.class.php b/lib/models/resources/ResourceRequestProperty.php
index 2952be9..c387daa 100644
--- a/lib/models/resources/ResourceRequestProperty.class.php
+++ b/lib/models/resources/ResourceRequestProperty.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceRequestProperty.class.php - model class for
+ * ResourceRequestProperty.php - model class for
  * resource request properties
  *
  * This program is free software; you can redistribute it and/or
diff --git a/lib/models/resources/ResourceTemporaryPermission.class.php b/lib/models/resources/ResourceTemporaryPermission.php
index ddbc397..ad7b33a 100644
--- a/lib/models/resources/ResourceTemporaryPermission.class.php
+++ b/lib/models/resources/ResourceTemporaryPermission.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * ResourceTemporaryPermission.class.php
+ * ResourceTemporaryPermission.php
  * Contains the ResourceTemporaryPermission class
  *
  * The ResourceTemporaryPermission class represents temporary permissions
diff --git a/lib/models/resources/Room.class.php b/lib/models/resources/Room.php
index 7f1668e..c8e393c 100644
--- a/lib/models/resources/Room.class.php
+++ b/lib/models/resources/Room.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * Room.class.php - model class for a resource which is a room
+ * Room.php - model class for a resource which is a room
  *
  * The Room class is a derived class of the Resource class.
  * It containts specialisations for room resources.
diff --git a/lib/models/resources/RoomRequest.class.php b/lib/models/resources/RoomRequest.php
index 6db9c38..4ba11bc 100644
--- a/lib/models/resources/RoomRequest.class.php
+++ b/lib/models/resources/RoomRequest.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * RoomRequest.class.php - model class for table resource_requests
+ * RoomRequest.php - model class for table resource_requests
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/resources/SeparableRoom.class.php b/lib/models/resources/SeparableRoom.php
index 9ec1ccf..d1bf125 100644
--- a/lib/models/resources/SeparableRoom.class.php
+++ b/lib/models/resources/SeparableRoom.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * SeparableRoom.class.php - model class for a separable room
+ * SeparableRoom.php - model class for a separable room
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
diff --git a/lib/models/resources/SeparableRoomPart.class.php b/lib/models/resources/SeparableRoomPart.php
index e7e99e7..8a45ce7 100644
--- a/lib/models/resources/SeparableRoomPart.class.php
+++ b/lib/models/resources/SeparableRoomPart.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * SeparableRoomItem.class.php - model class for a separable room item
+ * SeparableRoomItem.php - model class for a separable room item
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as