reimplement SemClass and SemType as SORM classes, fixes #2785tic-2785

7 files changed, 513 insertions, 900 deletions

diff --git a/lib/classes/JsonApi/Schemas/SemType.php b/lib/classes/JsonApi/Schemas/SemType.php
index 46b2e3c..20312e0 100644
--- a/lib/classes/JsonApi/Schemas/SemType.php
+++ b/lib/classes/JsonApi/Schemas/SemType.php
@@ -31,7 +31,7 @@ class SemType extends SchemaProvider
         $relationships = [];
 
         // SemClass
-        $related = $resource->getClass();
+        $related = $resource->getSemClass();
         $relationships[self::REL_SEM_CLASS] = [
             self::RELATIONSHIP_LINKS => [
                 Link::RELATED => $this->createLinkToResource($related)
diff --git a/lib/classes/SemClass.php b/lib/classes/SemClass.php
deleted file mode 100644
index 5e20af5..0000000
--- a/lib/classes/SemClass.php
+++ /dev/null
@@ -1,638 +0,0 @@
-<?php
-
-/*
- *  Copyright (c) 2012  Rasmus Fuhse <fuhse@data-quest.de>
- *
- *  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.
- */
-
-/**
- * Class to define and manage attributes of seminar classes (or seminar categories).
- * Usually all sem-classes are stored in a global variable $SEM_CLASS which is
- * an array of SemClass objects.
- *
- * SemClass::getClasses() gets you all seminar classes in an array.
- *
- * You can access the attributes of a sem-class like an associative
- * array with $sem_class['default_read_level']. The uinderlying data is stored
- * in the database in the table sem_classes.
- *
- * If you want to have a name of a sem-class like "Lehre", please use
- * $sem_class['name'] and you will get a fully localized name and not the pure
- * database entry.
- *
- * This class manages also which modules are contained in which course-slots,
- * like "what module is used as a forum in my seminars". In the database stored
- * is the name of the module like "CoreForum" or a classname of a plugin or null
- * if the forum is completely disabled by root for this sem-class. Core-modules
- * can only be used within a standard slot. Plugins may also be used as optional
- * modules not contained in a slot.
- *
- * In the field 'modules' in the database is for each modules stored in a json-string
- * if the module is activatable by the teacher or not and if it is activated as
- * a default. Please use the methods SemClass::isSlotModule, SemClass::getSlotModule,
- * SemClass::isModuleAllowed, SemClass::isModuleMandatory, SemClass::isSlotMandatory
- * or even more simple SemClass::getNavigationForSlot (see documentation there).
- */
-class SemClass implements ArrayAccess
-{
-    protected $data = [];
-
-    static protected $studygroup_forbidden_modules = [
-        'CoreAdmin',
-        'CoreParticipants',
-    ];
-
-    static protected $sem_classes = null;
-
-    static public function getDefaultSemClass() {
-        $data = [
-            'name' => "Fehlerhafte Seminarklasse!",
-            'modules' => '{"CoreOverview":{"activated":1,"sticky":1},"CoreAdmin":{"activated":1,"sticky":1}}',
-            'visible' => 1,
-            'is_group' => false
-        ];
-        return new SemClass($data);
-    }
-
-    /**
-     * Generates a dummy SemClass for institutes of this type (as defined in config.inc.php).
-     * @param integer $type   institute type
-     * @return SemClass
-     */
-    static public function getDefaultInstituteClass($type)
-    {
-        global $INST_MODULES;
-
-        // fall back to 'default' if modules are not defined
-        $type = isset($INST_MODULES[$type]) ? $type : 'default';
-
-        $data = [
-            'name'                => _('Generierte Standardinstitutsklasse'),
-            'visible'             => 1,
-            'admin'               => 'CoreAdmin',     // always available
-            'overview'            => 'CoreOverview'   // always available
-        ];
-        $slots = [
-            'forum'               => 'CoreForum',
-            'documents'           => 'CoreDocuments',
-            'scm'                 => 'CoreScm',
-            'wiki'                => 'CoreWiki',
-            'calendar'            => 'CoreCalendar',
-            'elearning_interface' => 'CoreElearningInterface',
-            'personal'            => 'CorePersonal'
-        ];
-        $modules = [
-            'CoreAdmin'           => ['activated' => 1, 'sticky' => 1],
-            'CoreOverview'        => ['activated' => 1, 'sticky' => 1],
-        ];
-
-        foreach ($slots as $slot => $module) {
-            $data[$slot] = $module;
-            $modules[$module] = ['activated' => (int) ($INST_MODULES[$type][$slot] ?? 0), 'sticky' => 0];
-        }
-        $data['modules'] = json_encode($modules);
-
-        return new SemClass($data);
-    }
-
-    /**
-     * Constructor can be set with integer of sem_class_id or an array of
-     * the old $SEM_CLASS style.
-     * @param integer | array $data
-     */
-    public function __construct($data)
-    {
-        $db = DBManager::get();
-        if (is_int($data)) {
-            $statement = $db->prepare("SELECT * FROM sem_classes WHERE id = :id ");
-            $statement->execute(['id' => $data]);
-            $this->data = $statement->fetch(PDO::FETCH_ASSOC);
-        } else {
-            $this->data = $data;
-        }
-        if (!empty($this->data['modules'])) {
-            $this->data['modules'] = self::object2array(json_decode($this->data['modules']));
-
-        } else {
-            $this->data['modules'] = [];
-        }
-        if (!empty($this->data['studygroup_mode'])) {
-            if (!isset($this->data['modules']['CoreStudygroupAdmin'])) {
-                $this->data['modules']['CoreStudygroupAdmin'] = ['activated' => 1, 'sticky' => 1];
-            }
-        } else {
-            if (!isset($this->data['modules']['CoreAdmin'])) {
-                $this->data['modules']['CoreAdmin'] = ['activated' => 1, 'sticky' => 1];
-            }
-        }
-        foreach (array_keys($this->data['modules']) as $modulename) {
-            if ($this->isModuleForbidden($modulename)) {
-                unset($this->data['modules'][$modulename]);
-            }
-        }
-    }
-
-
-    /**
-     * @param string $module
-     * @return false|int
-     */
-    public function activateModuleInCourses($module)
-    {
-        $plugin = PluginManager::getInstance()->getPlugin($module);
-        if ($plugin) {
-            return Course::findEachBySQL(function ($course) use ($plugin) {
-                return PluginManager::getInstance()->setPluginActivated($plugin->getPluginId(), $course->id, true);
-            },
-                "seminare.status IN (?)",
-                [array_keys($this->getSemTypes())]);
-        } else {
-            return false;
-        }
-    }
-
-    /**
-     * @param string $module
-     * @return false|int
-     */
-    public function deActivateModuleInCourses($module)
-    {
-        $plugin = PluginManager::getInstance()->getPlugin($module);
-        if ($plugin) {
-            return Course::findEachBySQL(function ($course) use ($plugin) {
-                return PluginManager::getInstance()->setPluginActivated($plugin->getPluginId(), $course->id, false);
-            },
-                "seminare.status IN (?)",
-                [array_keys($this->getSemTypes())]);
-        } else {
-            return false;
-        }
-
-    }
-
-    /**
-     * Returns the number of seminars of this sem_class in Stud.IP
-     * @return integer
-     */
-    public function countSeminars()
-    {
-        $db = DBManager::get();
-        $sum = 0;
-        foreach ($GLOBALS['SEM_TYPE'] as $sem_type) {
-            if ($sem_type['class'] == $this->data['id']) {
-                $sum += $sem_type->countSeminars();
-            }
-        }
-        return $sum;
-    }
-
-
-    /**
-     * @param string $modulename
-     * @return bool
-     */
-    public function isModuleForbidden($modulename)
-    {
-        if (!empty($this->data['studygroup_mode'])) {
-            return in_array($modulename, self::$studygroup_forbidden_modules);
-        } else {
-            return strpos($modulename, 'Studygroup') !== false;
-        }
-    }
-
-    /**
-     * Returns the metadata of a module regarding this sem_class object.
-     * @param string $modulename
-     * @return array('sticky' => (bool), 'activated' => (bool))
-     */
-    public function getModuleMetadata($modulename)
-    {
-        return $this->data['modules'][$modulename];
-    }
-
-    /**
-     * Sets the metadata for each module at once.
-     * @param array $module_array: array($module_name => array('sticky' => (bool), 'activated' => (bool)), ...)
-     */
-    public function setModules($module_array)
-    {
-        $this->data['modules'] = $module_array;
-    }
-
-    /**
-     * Returns all metadata of the modules at once.
-     * @return array: array($module_name => array('sticky' => (bool), 'activated' => (bool)), ...)
-     */
-    public function getModules()
-    {
-        return $this->data['modules'];
-    }
-
-    /**
-     * @return StudipModule[]
-     */
-    public function getModuleObjects()
-    {
-        $result = [];
-        foreach (array_keys($this->getModules()) as $module) {
-            $plugin = PluginManager::getInstance()->getPlugin($module);
-            if ($plugin) {
-                $result[$plugin->getPluginId()] = $plugin;
-            }
-        }
-        return $result;
-    }
-
-    /**
-     * @return string[]
-     */
-    public function getActivatedModules()
-    {
-        return array_keys(array_filter($this->data['modules'], function ($meta) {
-            return $meta['activated'];
-        }));
-    }
-
-    /**
-     * @return StudipModule[]
-     */
-    public function getActivatedModuleObjects()
-    {
-        $result = [];
-        foreach ($this->getActivatedModules() as $module) {
-            $plugin = PluginManager::getInstance()->getPlugin($module);
-            if ($plugin) {
-                $result[$plugin->getPluginId()] = $plugin;
-            }
-        }
-        return $result;
-    }
-
-    /**
-     * @return mixed|object
-     */
-    public function getAdminModuleObject()
-    {
-        if ($this->data['studygroup_mode']) {
-            $module = 'CoreStudygroupAdmin';
-        } else {
-            $module = 'CoreAdmin';
-        }
-        return PluginManager::getInstance()->getPlugin($module);
-    }
-
-    /**
-     * Returns true if a module is activated on default for this sem_class.
-     * @param string $modulename
-     * @return boolean
-     */
-    public function isModuleActivated($modulename)
-    {
-        return isset($this->data['modules'][$modulename])
-            && $this->data['modules'][$modulename]['activated'];
-    }
-
-    /**
-     * Returns if a module is allowed to be displayed for this sem_class.
-     * @param string $modulename
-     * @return boolean
-     */
-    public function isModuleAllowed($modulename)
-    {
-        return !$this->isModuleForbidden($modulename)
-            && (
-                empty($this->data['modules'][$modulename])
-                || empty($this->data['modules'][$modulename]['sticky'])
-                || !empty($this->data['modules'][$modulename]['activated'])
-            );
-    }
-
-    /**
-     * Returns if a module is mandatory for this sem_class.
-     * @param string $module
-     * @return boolean
-     */
-    public function isModuleMandatory($module)
-    {
-        return isset($this->data['modules'][$module])
-            && !empty($this->data['modules'][$module]['sticky'])
-            && !empty($this->data['modules'][$module]['activated']);
-    }
-
-    public function getSemTypes()
-    {
-        $types = [];
-        foreach (SemType::getTypes() as $id => $type) {
-            if ($type['class'] == $this->data['id']) {
-                $types[$id] = $type;
-            }
-        }
-        return $types;
-    }
-
-    /**
-     * Checks if the current sem class is usable for course grouping.
-     */
-    public function isGroup()
-    {
-        return $this->data['is_group'];
-    }
-
-    /**
-     * Checks if any SemClasses exist that provide grouping functionality.
-     * @return SimpleCollection
-     */
-    public static function getGroupClasses()
-    {
-        return SimpleCollection::createFromArray(self::getClasses())->findBy('is_group', true);
-    }
-
-    /**
-     * stores all data in the database
-     * @return boolean success
-     */
-    public function store()
-    {
-        $db = DBManager::get();
-        $statement = $db->prepare(
-            "UPDATE sem_classes " .
-                "SET name = :name, " .
-                "description = :description, " .
-                "create_description = :create_description, " .
-                "studygroup_mode = :studygroup_mode, " .
-                "only_inst_user = :only_inst_user, " .
-                "default_read_level = :default_read_level, " .
-                "default_write_level = :default_write_level, " .
-                "bereiche = :bereiche, " .
-                "module = :module, " .
-                "show_browse = :show_browse, " .
-                "visible = :visible, " .
-                "course_creation_forbidden = :course_creation_forbidden, " .
-                "modules = :modules, " .
-                "title_dozent = :title_dozent, " .
-                "title_dozent_plural = :title_dozent_plural, " .
-                "title_tutor = :title_tutor, " .
-                "title_tutor_plural = :title_tutor_plural, " .
-                "title_autor = :title_autor, " .
-                "title_autor_plural = :title_autor_plural, " .
-                "admission_prelim_default = :admission_prelim_default, " .
-                "admission_type_default = :admission_type_default, " .
-                "show_raumzeit = :show_raumzeit, " .
-                "is_group = :is_group, " .
-                "unlimited_forbidden = :unlimited_forbidden, " .
-                "admission_turnout_mandatory = :admission_turnout_mandatory," .
-                "chdate = UNIX_TIMESTAMP() " .
-            "WHERE id = :id ".
-        "");
-        \Studip\Cache\Factory::getCache()->expire('DB_SEM_CLASSES_ARRAY');
-        return $statement->execute([
-            'id' => $this->data['id'],
-            'name' => $this->data['name'],
-            'description' => $this->data['description'],
-            'create_description' => $this->data['create_description'],
-            'studygroup_mode' => (int) $this->data['studygroup_mode'],
-            'only_inst_user' => (int) $this->data['only_inst_user'],
-            'default_read_level' => (int) $this->data['default_read_level'],
-            'default_write_level' => (int) $this->data['default_write_level'],
-            'bereiche' => (int) $this->data['bereiche'],
-            'module' => (int) $this->data['module'],
-            'show_browse' => (int) $this->data['show_browse'],
-            'visible' => (int) $this->data['visible'],
-            'course_creation_forbidden' => (int) $this->data['course_creation_forbidden'],
-            'modules' => json_encode((object) $this->data['modules']),
-            'title_dozent' => $this->data['title_dozent']
-                ? $this->data['title_dozent']
-                : null,
-            'title_dozent_plural' => $this->data['title_dozent_plural']
-                ? $this->data['title_dozent_plural']
-                : null,
-            'title_tutor' => $this->data['title_tutor']
-                ? $this->data['title_tutor']
-                : null,
-            'title_tutor_plural' => $this->data['title_tutor_plural']
-                ? $this->data['title_tutor_plural']
-                : null,
-            'title_autor' => $this->data['title_autor']
-                ? $this->data['title_autor']
-                : null,
-            'title_autor_plural' => $this->data['title_autor_plural']
-                ? $this->data['title_autor_plural']
-                : null,
-            'admission_prelim_default' => (int)$this->data['admission_prelim_default'],
-            'admission_type_default' => (int)$this->data['admission_type_default'],
-            'show_raumzeit' => (int) $this->data['show_raumzeit'],
-            'is_group' => (int) $this->data['is_group'],
-            'unlimited_forbidden' => (int) $this->data['unlimited_forbidden'],
-            'admission_turnout_mandatory' => (int) $this->data['admission_turnout_mandatory'],
-        ]);
-    }
-
-    /**
-     * Deletes the sem_class-object and all its sem_types. Will only delete,
-     * if there are no seminars in this sem_class.
-     * Remember to refresh the global $SEM_CLASS and $SEM_TYPE array.
-     * @return boolean : success of deletion
-     */
-    public function delete()
-    {
-        if ($this->countSeminars() === 0) {
-            foreach ($GLOBALS['SEM_TYPE'] as $sem_type) {
-                if ($sem_type['class'] == $this->data['id']) {
-                    $sem_type->delete();
-                }
-            }
-            $GLOBALS['SEM_TYPE'] = SemType::getTypes();
-            $db = DBManager::get();
-            $statement = $db->prepare("
-                DELETE FROM sem_classes
-                WHERE id = :id
-            ");
-            \Studip\Cache\Factory::getCache()->expire('DB_SEM_CLASSES_ARRAY');
-            return $statement->execute([
-                'id' => $this->data['id']
-            ]);
-        } else {
-            return false;
-        }
-    }
-
-    /**
-     * Sets an attribute of sem_class->data
-     * @param string $offset
-     * @param mixed $value
-     */
-    public function set($offset, $value)
-    {
-        $this->data[$offset] = $value;
-    }
-
-    /***************************************************************************
-     *                          ArrayAccess methods                            *
-     ***************************************************************************/
-
-    /**
-     * deprecated, does nothing, should not be used
-     * @param string $offset
-     * @param mixed $value
-     */
-    public function offsetSet($offset, $value): void
-    {
-    }
-
-    /**
-     * Compatibility function with old $SEM_CLASS variable for plugins. Maps the
-     * new array-structure to the old boolean values.
-     * @param integer $offset: name of attribute
-     */
-    public function offsetGet($offset): mixed
-    {
-        switch ($offset) {
-            case "name":
-                return gettext($this->data['name']);
-            case "only_inst_user":
-                return (bool) $this->data['only_inst_user'];
-            case "bereiche":
-                return (bool) $this->data['bereiche'];
-            case "show_browse":
-                return (bool) $this->data['show_browse'];
-            case "visible":
-                return (bool) $this->data['visible'];
-            case "studygroup_mode":
-                return (bool) $this->data['studygroup_mode'];
-            case "admission_prelim_default":
-               return (int) $this->data['admission_prelim_default'];
-            case "admission_type_default":
-               return (int) $this->data['admission_type_default'];
-            case "is_group":
-               return (bool) $this->data['is_group'];
-        }
-        //ansonsten
-        return $this->data[$offset] ?? null;
-    }
-
-    /**
-     * ArrayAccess method to check if an attribute exists.
-     * @param int $offset
-     */
-    public function offsetExists($offset): bool
-    {
-        return isset($this->data[$offset]);
-    }
-
-    /**
-     * deprecated, does nothing, should not be used
-     * @param string $offset
-     */
-    public function offsetUnset($offset): void
-    {
-    }
-
-    /***************************************************************************
-     *                            static methods                               *
-     ***************************************************************************/
-
-    /**
-     * Returns an array of all SemClasses in Stud.IP. Equivalent to global
-     * $SEM_CLASS variable. This variable is statically stored in this class.
-     * @return SemClass[] of SemClass
-     */
-    static public function getClasses()
-    {
-        if (!is_array(self::$sem_classes)) {
-            $db = DBManager::get();
-            self::$sem_classes = [];
-
-            $cache = \Studip\Cache\Factory::getCache();
-            $class_array = unserialize($cache->read('DB_SEM_CLASSES_ARRAY'));
-            if (!$class_array) {
-
-                try {
-                    $statement = $db->prepare(
-                        "SELECT * FROM sem_classes ORDER BY id ASC "
-                    );
-                    $statement->execute();
-                    $class_array = $statement->fetchAll(PDO::FETCH_ASSOC);
-
-                    if ($class_array) {
-                        $cache = \Studip\Cache\Factory::getCache();
-                        $cache->write('DB_SEM_CLASSES_ARRAY', serialize($class_array));
-                    }
-                } catch (PDOException $e) {
-                    //for use without or before migration 92
-                    $class_array = $GLOBALS['SEM_CLASS_OLD_VAR'];
-                    if (is_array($class_array)) {
-                        ksort($class_array);
-                        foreach ($class_array as $id => $class) {
-                            self::$sem_classes[$id] = new SemClass($class);
-                        }
-                    } else {
-                        self::$sem_classes[1] = self::getDefaultSemClass();
-                    }
-                }
-            }
-            foreach ($class_array as $sem_class) {
-                self::$sem_classes[$sem_class['id']] = new SemClass($sem_class);
-            }
-        }
-        return self::$sem_classes;
-    }
-
-    /**
-     * Refreshes the internal $sem_classes cache-variable.
-     * @return array of SemClass
-     */
-    static public function refreshClasses()
-    {
-        \Studip\Cache\Factory::getCache()->expire('DB_SEM_CLASSES_ARRAY');
-        self::$sem_classes = null;
-        return self::getClasses();
-    }
-
-    /**
-     * Static method to recursively transform an object into an associative array.
-     * @param mixed $obj: should be of class StdClass
-     * @return array
-     */
-    static public function object2array($obj)
-    {
-        $arr_raw = is_object($obj) ? get_object_vars($obj) : $obj;
-        foreach ($arr_raw as $key => $val) {
-            $val = (is_array($val) || is_object($val)) ? self::object2array($val) : $val;
-            $arr[$key] = $val;
-        }
-        return $arr;
-    }
-
-
-    /**
-     * Static method only to keep the translationstrings of the values. It is
-     * never used within the system.
-     */
-    static private function localization()
-    {
-        _("Lehre");
-        _("Forschung");
-        _("Organisation");
-        _("Community");
-        _("Arbeitsgruppen");
-        _("importierte Kurse");
-        _("Hauptveranstaltungen");
-
-        _("Hier finden Sie alle in Stud.IP registrierten Lehrveranstaltungen");
-        _("Verwenden Sie diese Kategorie, um normale Lehrveranstaltungen anzulegen");
-        _("Hier finden Sie virtuelle Veranstaltungen zum Thema Forschung an der Universität");
-        _("In dieser Kategorie können Sie virtuelle Veranstaltungen für Forschungsprojekte anlegen.");
-        _("Hier finden Sie virtuelle Veranstaltungen zu verschiedenen Gremien an der Universität");
-        _("Um virtuelle Veranstaltungen für Uni-Gremien anzulegen, verwenden Sie diese Kategorie");
-        _("Hier finden Sie virtuelle Veranstaltungen zu unterschiedlichen Themen");
-        _("Wenn Sie Veranstaltungen als Diskussiongruppen zu unterschiedlichen Themen anlegen möchten, verwenden Sie diese Kategorie.");
-        _("Hier finden Sie verschiedene Arbeitsgruppen an der %s");
-        _("Verwenden Sie diese Kategorie, um unterschiedliche Arbeitsgruppen anzulegen.");
-        _("Veranstaltungen dieser Kategorie dienen als Gruppierungselement, um die Zusammengehörigkeit von Veranstaltungen anderer Kategorien abzubilden.");
-    }
-
-}
diff --git a/lib/classes/SemType.php b/lib/classes/SemType.php
deleted file mode 100644
index 5be1f19..0000000
--- a/lib/classes/SemType.php
+++ /dev/null
@@ -1,257 +0,0 @@
-<?php
-
-/*
- *  Copyright (c) 2012  Rasmus Fuhse <fuhse@data-quest.de>
- *
- *  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.
- */
-
-if (isset($GLOBALS['SEM_TYPE'])) {
-    $GLOBALS['SEM_TYPE_OLD_VAR'] = $GLOBALS['SEM_TYPE'];
-}
-
-/**
- * Class to define and manage attributes of seminar types.
- * Usually all sem-types are stored in a global variable $SEM_TYPE which is
- * an array of SemType objects.
- *
- * SemType::getTypes() gets you all seminar types in an array.
- *
- * This class only represents the name of the type and gives a relation to a
- * sem_class.
- */
-class SemType implements ArrayAccess
-{
-    protected $data = [];
-    static protected $sem_types = null;
-
-    /**
-     * Constructor can be set with integer of sem_class_id or an array of
-     * the old $SEM_CLASS style.
-     * @param integer | array $data
-     */
-    public function __construct($data) {
-        $db = DBManager::get();
-        if (is_int($data)) {
-            $statement = $db->prepare("SELECT * FROM sem_types WHERE id = :id ");
-            $statement->execute(['id' => $data]);
-            $this->data = $statement->fetch(PDO::FETCH_ASSOC);
-        } else {
-            $this->data = $data;
-        }
-    }
-
-    /**
-     * Returns the number of seminars of this sem_type in Stud.IP
-     * @return integer
-     */
-    public function countSeminars() {
-        $db = DBManager::get();
-        $statement = $db->prepare("SELECT COUNT(*) FROM seminare WHERE status = :sem_type ");
-        $statement->execute(['sem_type' => $this->data['id']]);
-        return (int) $statement->fetch(PDO::FETCH_COLUMN, 0);
-    }
-
-    /**
-     * stores all data in the database
-     * @return boolean success
-     */
-    public function store() {
-        $db = DBManager::get();
-        $statement = $db->prepare(
-            "UPDATE sem_types " .
-                "SET name = :name, " .
-                "class = :class, " .
-                "chdate = UNIX_TIMESTAMP() " .
-            "WHERE id = :id ".
-        "");
-        \Studip\Cache\Factory::getCache()->expire('DB_SEM_TYPES_ARRAY');
-        return $statement->execute([
-            'id' => $this->data['id'],
-            'name' => $this->data['name'],
-            'class' => $this->data['class']
-        ]);
-    }
-
-    /**
-     * Deletes the sem_type-object. Will only delete,
-     * if there are no seminars in this sem_type.
-     * Remember to refresh the global $SEM_TYPE array.
-     * @return boolean : success of deletion
-     */
-    public function delete() {
-        if ($this->countSeminars() === 0) {
-            $db = DBManager::get();
-            $statement = $db->prepare("
-                DELETE FROM sem_types
-                WHERE id = :id
-            ");
-            \Studip\Cache\Factory::getCache()->expire('DB_SEM_TYPES_ARRAY');
-            return $statement->execute([
-                'id' => $this->data['id']
-            ]);
-        } else {
-            return false;
-        }
-    }
-
-    /**
-     * Sets an attribute of sem_type->data
-     * @param string $offset
-     * @param mixed $value
-     */
-    public function set($offset, $value) {
-        $this->data[$offset] = $value;
-    }
-
-    public function getClass() {
-        return $GLOBALS['SEM_CLASS'][$this->data['class']] ?? SemClass::getDefaultSemClass();
-    }
-
-    /***************************************************************************
-     *                          ArrayAccess methods                            *
-     ***************************************************************************/
-
-    /**
-     * deprecated, does nothing, should not be used
-     * @param string $offset
-     * @param mixed $value
-     */
-
-    public function offsetSet($offset, $value): void
-    {
-    }
-
-    /**
-     * Compatibility function with old $SEM_TYPE variable for plugins. Maps the
-     * new array-structure to the old boolean values.
-     * @param integer $offset: name of attribute
-     */
-    public function offsetGet($offset): mixed
-    {
-        switch ($offset) {
-            case "name":
-                return gettext($this->data['name']);
-            case in_array($offset, ["title_dozent", "title_tutor", "title_autor"]):
-                $sem_class = $this->getClass();
-                $title = [$sem_class[$offset], $sem_class[$offset.'_plural']];
-                return $title[0] || $title[1] ? $title : $this->data[$offset];
-        }
-        //ansonsten
-        return $this->data[$offset];
-    }
-
-    /**
-     * ArrayAccess method to check if an attribute exists.
-     * @param mixed $offset
-     */
-    public function offsetExists($offset): bool
-    {
-        return isset($this->data[$offset]);
-    }
-
-    /**
-     * deprecated, does nothing, should not be used
-     * @param string $offset
-     */
-    public function offsetUnset($offset): void
-    {
-    }
-
-    /***************************************************************************
-     *                            static methods                               *
-     ***************************************************************************/
-
-    /**
-     * Returns an array of all SemTypes in Stud.IP. Equivalent to global
-     * $SEM_TYPE variable. This variable is statically stored in this class.
-     * @return array of SemType
-     */
-    static public function getTypes() {
-        if (!is_array(self::$sem_types)) {
-            $db = DBManager::get();
-            self::$sem_types = [];
-
-            $cache = \Studip\Cache\Factory::getCache();
-            $types_array = unserialize($cache->read('DB_SEM_TYPES_ARRAY'));
-            if (!$types_array) {
-                try {
-                    $statement = $db->prepare(
-                        "SELECT * FROM sem_types ORDER BY id ASC "
-                    );
-                    $statement->execute();
-                    $types_array = $statement->fetchAll(PDO::FETCH_ASSOC);
-                    if ($types_array) {
-                        $cache = \Studip\Cache\Factory::getCache();
-                        $cache->write('DB_SEM_TYPES_ARRAY', serialize($types_array));
-                    }
-                } catch (PDOException $e) {
-                    //for use without or before migration 92
-                    $type_array = $GLOBALS['SEM_TYPE_OLD_VAR'];
-                    if (is_array($type_array)) {
-                        ksort($type_array);
-                        foreach ($type_array as $id => $type) {
-                            self::$sem_types[$id] = new SemType($type);
-                        }
-                    } else {
-                        self::$sem_types[1] = new SemType(['name' => 'default', 'class' => 1, 'id' => 1]);
-                    }
-                }
-            }
-            foreach ($types_array as $sem_type) {
-                self::$sem_types[$sem_type['id']] = new SemType($sem_type);
-            }
-        }
-        return self::$sem_types;
-    }
-
-    static public function refreshTypes() {
-        self::$sem_types = null;
-        \Studip\Cache\Factory::getCache()->expire('DB_SEM_TYPES_ARRAY');
-        return self::getTypes();
-    }
-
-    /**
-     * Gets all SemTypes that are allowed as group parents.
-     * @return array
-     */
-    public static function getGroupingSemTypes()
-    {
-        return SimpleCollection::createFromArray(array_flatten(SemClass::getGroupClasses()->getSemTypes()))->pluck('id');
-    }
-
-    /**
-     * Gets all SemTypes that are allowed as group parents.
-     * @return array
-     */
-    public static function getNonGroupingSemTypes()
-    {
-        $non_grouping = SimpleCollection::createFromArray(SemClass::getClasses())->findBy('is_group', false)->findBy('studygroup_mode', false);
-        return SimpleCollection::createFromArray(array_flatten($non_grouping->getSemTypes()))->pluck('id');
-    }
-
-    /**
-     * Static method only to keep the translationstrings of the values. It is
-     * never used within the system.
-     */
-    static private function localization() {
-        _("Vorlesung");
-        _("Seminar");
-        _("Übung");
-        _("Praktikum");
-        _("Colloquium");
-        _("Kolloquium");
-        _("Forschungsgruppe");
-        _("sonstige");
-        _("Gremium");
-        _("Projektgruppe");
-        _("Kulturforum");
-        _("Veranstaltungsboard");
-        _("Studiengruppe");
-
-    }
-
-}
diff --git a/lib/classes/coursewizardsteps/BasicDataWizardStep.php b/lib/classes/coursewizardsteps/BasicDataWizardStep.php
index 2e265c3..35ad6dc 100644
--- a/lib/classes/coursewizardsteps/BasicDataWizardStep.php
+++ b/lib/classes/coursewizardsteps/BasicDataWizardStep.php
@@ -50,7 +50,7 @@ class BasicDataWizardStep implements CourseWizardStep
         $typestruct = [];
         $admission_turnout_mandatory_types = [];
         foreach (SemType::getTypes() as $type) {
-            $class = $type->getClass();
+            $class = $type->getSemClass();
             // Creates a studygroup.
             if (!empty($values['studygroup'])) {
                 // Get all studygroup types.
@@ -385,8 +385,8 @@ class BasicDataWizardStep implements CourseWizardStep
                 $errors[] = _('Sie müssen die Nutzungsbedingungen akzeptieren.');
             }
         }
-        $sem_type = new SemType((int)$values['coursetype']);
-        $sem_class = $sem_type->getClass();
+        $sem_type = $GLOBALS['SEM_TYPE'][(int)$values['coursetype']];
+        $sem_class = $sem_type->getSemClass();
         if ($sem_class['admission_turnout_mandatory'] && !$values['maxmembers']) {
             $errors[] = _('Sie müssen die maximale Teilnehmendenzahl angeben');
         }
diff --git a/lib/models/Course.php b/lib/models/Course.php
index db729c6..7910931 100644
--- a/lib/models/Course.php
+++ b/lib/models/Course.php
@@ -1827,7 +1827,7 @@ class Course extends SimpleORMap implements Range, PrivacyObject, StudipItem, Fe
      */
      public function getSemClass()
      {
-         return $this->getSemType()->getClass();
+         return $this->getSemType()->getSemClass();
      }
 
     /**
diff --git a/lib/models/SemClass.php b/lib/models/SemClass.php
new file mode 100644
index 0000000..6eb2029
--- /dev/null
+++ b/lib/models/SemClass.php
@@ -0,0 +1,375 @@
+<?php
+
+/*
+ *  Copyright (c) 2012  Rasmus Fuhse <fuhse@data-quest.de>
+ *
+ *  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.
+ */
+
+/**
+ * Class to define and manage attributes of seminar classes (or seminar categories).
+ * Usually all sem-classes are stored in a global variable $SEM_CLASS which is
+ * an array of SemClass objects.
+ *
+ * SemClass::getClasses() gets you all seminar classes in an array.
+ *
+ * You can access the attributes of a sem-class like an associative
+ * array with $sem_class['default_read_level']. The uinderlying data is stored
+ * in the database in the table sem_classes.
+ *
+ * If you want to have a name of a sem-class like "Lehre", please use
+ * $sem_class['name'] and you will get a fully localized name and not the pure
+ * database entry.
+ *
+ * This class manages also which modules are contained in which course-slots,
+ * like "what module is used as a forum in my seminars". In the database stored
+ * is the name of the module like "CoreForum" or a classname of a plugin or null
+ * if the forum is completely disabled by root for this sem-class. Core-modules
+ * can only be used within a standard slot. Plugins may also be used as optional
+ * modules not contained in a slot.
+ *
+ * In the field 'modules' in the database is for each modules stored in a json-string
+ * if the module is activatable by the teacher or not and if it is activated as
+ * a default. Please use the methods SemClass::isSlotModule, SemClass::getSlotModule,
+ * SemClass::isModuleAllowed, SemClass::isModuleMandatory, SemClass::isSlotMandatory
+ * or even more simple SemClass::getNavigationForSlot (see documentation there).
+ */
+class SemClass extends SimpleORMap
+{
+    static protected $sem_classes = null;
+
+    static protected $studygroup_forbidden_modules = [
+        'CoreAdmin',
+        'CoreParticipants',
+    ];
+
+    /**
+     * Configure the database mapping.
+     */
+    protected static function configure($config = [])
+    {
+        $config['db_table'] = 'sem_classes';
+
+        $config['serialized_fields']['modules'] = 'JSONArrayObject';
+
+        $config['has_many']['sem_types'] = [
+            'class_name'        => SemType::class,
+            'assoc_foreign_key' => 'class',
+            'on_delete'         => 'delete'
+        ];
+
+        $config['registered_callbacks']['after_store'][] = 'SemClass::refreshClasses';
+        $config['registered_callbacks']['after_delete'][] = 'SemClass::refreshClasses';
+
+        parent::configure($config);
+    }
+
+    public static function getDefaultSemClass() {
+        return self::build([
+            'name' => _('Fehlerhafte Seminarklasse'),
+            'modules' => [
+                'CoreOverview' => ['activated' => 1, 'sticky' => 1],
+                'CoreAdmin'    => ['activated' => 1, 'sticky' => 1]
+            ],
+            'visible' => 1,
+            'is_group' => false
+        ]);
+    }
+
+    /**
+     * Generates a dummy SemClass for institutes of this type (as defined in config.inc.php).
+     * @param integer $type   institute type
+     * @return SemClass
+     */
+    public static function getDefaultInstituteClass($type)
+    {
+        global $INST_MODULES;
+
+        // fall back to 'default' if modules are not defined
+        $type = isset($INST_MODULES[$type]) ? $type : 'default';
+
+        $data = [
+            'name'                => _('Generierte Standardinstitutsklasse'),
+            'visible'             => 1,
+            'admin'               => 'CoreAdmin',     // always available
+            'overview'            => 'CoreOverview'   // always available
+        ];
+        $slots = [
+            'forum'               => 'CoreForum',
+            'documents'           => 'CoreDocuments',
+            'scm'                 => 'CoreScm',
+            'wiki'                => 'CoreWiki',
+            'calendar'            => 'CoreCalendar',
+            'elearning_interface' => 'CoreElearningInterface',
+            'personal'            => 'CorePersonal'
+        ];
+        $modules = [
+            'CoreAdmin'           => ['activated' => 1, 'sticky' => 1],
+            'CoreOverview'        => ['activated' => 1, 'sticky' => 1],
+        ];
+
+        foreach ($slots as $slot => $module) {
+            $data[$slot] = $module;
+            $modules[$module] = ['activated' => (int) ($INST_MODULES[$type][$slot] ?? 0), 'sticky' => 0];
+        }
+        $data['modules'] = $modules;
+
+        return self::build($data);
+    }
+
+    /**
+     * @param string $module
+     * @return false|int
+     */
+    public function activateModuleInCourses($module)
+    {
+        $plugin = PluginManager::getInstance()->getPlugin($module);
+        if ($plugin) {
+            return Course::findEachBySQL(function ($course) use ($plugin) {
+                return PluginManager::getInstance()->setPluginActivated($plugin->getPluginId(), $course->id, true);
+            },
+                "seminare.status IN (?)",
+                [array_keys($this->getSemTypes())]);
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * @param string $module
+     * @return false|int
+     */
+    public function deActivateModuleInCourses($module)
+    {
+        $plugin = PluginManager::getInstance()->getPlugin($module);
+        if ($plugin) {
+            return Course::findEachBySQL(function ($course) use ($plugin) {
+                return PluginManager::getInstance()->setPluginActivated($plugin->getPluginId(), $course->id, false);
+            },
+                "seminare.status IN (?)",
+                [array_keys($this->getSemTypes())]);
+        } else {
+            return false;
+        }
+
+    }
+
+    /**
+     * Returns the number of seminars of this sem_class in Stud.IP
+     * @return integer
+     */
+    public function countSeminars()
+    {
+        $sum = 0;
+        foreach ($this->sem_types as $sem_type) {
+            $sum += $sem_type->countSeminars();
+        }
+        return $sum;
+    }
+
+
+    /**
+     * @param string $modulename
+     * @return bool
+     */
+    public function isModuleForbidden($modulename)
+    {
+        if (!empty($this->studygroup_mode)) {
+            return in_array($modulename, self::$studygroup_forbidden_modules);
+        } else {
+            return strpos($modulename, 'Studygroup') !== false;
+        }
+    }
+
+    /**
+     * Returns the metadata of a module regarding this sem_class object.
+     * @param string $modulename
+     * @return array('sticky' => (bool), 'activated' => (bool))
+     */
+    public function getModuleMetadata($modulename)
+    {
+        return $this->modules[$modulename];
+    }
+
+    /**
+     * @return StudipModule[]
+     */
+    public function getModuleObjects()
+    {
+        $result = [];
+        foreach (array_keys($this->modules->getArrayCopy()) as $module) {
+            $plugin = PluginManager::getInstance()->getPlugin($module);
+            if ($plugin) {
+                $result[$plugin->getPluginId()] = $plugin;
+            }
+        }
+        return $result;
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getActivatedModules()
+    {
+        return array_keys(array_filter($this->modules->getArrayCopy(), function ($meta) {
+            return $meta['activated'];
+        }));
+    }
+
+    /**
+     * @return StudipModule[]
+     */
+    public function getActivatedModuleObjects()
+    {
+        $result = [];
+        foreach ($this->getActivatedModules() as $module) {
+            $plugin = PluginManager::getInstance()->getPlugin($module);
+            if ($plugin) {
+                $result[$plugin->getPluginId()] = $plugin;
+            }
+        }
+        return $result;
+    }
+
+    /**
+     * @return mixed|object
+     */
+    public function getAdminModuleObject()
+    {
+        if ($this->studygroup_mode) {
+            $module = 'CoreStudygroupAdmin';
+        } else {
+            $module = 'CoreAdmin';
+        }
+        return PluginManager::getInstance()->getPlugin($module);
+    }
+
+    /**
+     * Returns true if a module is activated on default for this sem_class.
+     * @param string $modulename
+     * @return boolean
+     */
+    public function isModuleActivated($modulename)
+    {
+        return isset($this->modules[$modulename])
+            && $this->modules[$modulename]['activated'];
+    }
+
+    /**
+     * Returns if a module is allowed to be displayed for this sem_class.
+     * @param string $modulename
+     * @return boolean
+     */
+    public function isModuleAllowed($modulename)
+    {
+        return !$this->isModuleForbidden($modulename)
+            && (
+                empty($this->modules[$modulename])
+                || empty($this->modules[$modulename]['sticky'])
+                || !empty($this->modules[$modulename]['activated'])
+            );
+    }
+
+    /**
+     * Returns if a module is mandatory for this sem_class.
+     * @param string $module
+     * @return boolean
+     */
+    public function isModuleMandatory($module)
+    {
+        return isset($this->modules[$module])
+            && !empty($this->modules[$module]['sticky'])
+            && !empty($this->modules[$module]['activated']);
+    }
+
+    public function getSemTypes()
+    {
+        $types = [];
+        foreach ($this->sem_types as $type) {
+            $types[$type->id] = $type;
+        }
+        return $types;
+    }
+
+    /**
+     * Checks if the current sem class is usable for course grouping.
+     */
+    public function isGroup()
+    {
+        return $this->is_group;
+    }
+
+    /**
+     * Checks if any SemClasses exist that provide grouping functionality.
+     * @return SimpleCollection
+     */
+    public static function getGroupClasses()
+    {
+        return SimpleCollection::createFromArray(self::getClasses())->findBy('is_group', true);
+    }
+
+    /**
+     * Returns an array of all SemClasses in Stud.IP. Equivalent to global
+     * $SEM_CLASS variable. This variable is statically stored in this class.
+     * @return SemClass[] of SemClass
+     */
+    public static function getClasses()
+    {
+        if (!is_array(self::$sem_classes)) {
+            $cache = \Studip\Cache\Factory::getCache();
+            $class_array = $cache->read('DB_SEM_CLASSES_ARRAY');
+
+            if (!is_array($class_array)) {
+                $class_array = self::findBySQL('1 ORDER BY id');
+                $cache->write('DB_SEM_CLASSES_ARRAY', $class_array);
+            }
+
+            foreach ($class_array as $sem_class) {
+                self::$sem_classes[$sem_class->id] = $sem_class;
+            }
+        }
+
+        return self::$sem_classes;
+    }
+
+    /**
+     * Refreshes the internal $sem_classes cache-variable.
+     * @return array of SemClass
+     */
+    public static function refreshClasses()
+    {
+        \Studip\Cache\Factory::getCache()->expire('DB_SEM_CLASSES_ARRAY');
+        self::$sem_classes = null;
+        return self::getClasses();
+    }
+
+    /**
+     * Static method only to keep the translationstrings of the values. It is
+     * never used within the system.
+     */
+    static private function localization()
+    {
+        _("Lehre");
+        _("Forschung");
+        _("Organisation");
+        _("Community");
+        _("Arbeitsgruppen");
+        _("importierte Kurse");
+        _("Hauptveranstaltungen");
+
+        _("Hier finden Sie alle in Stud.IP registrierten Lehrveranstaltungen");
+        _("Verwenden Sie diese Kategorie, um normale Lehrveranstaltungen anzulegen");
+        _("Hier finden Sie virtuelle Veranstaltungen zum Thema Forschung an der Universität");
+        _("In dieser Kategorie können Sie virtuelle Veranstaltungen für Forschungsprojekte anlegen.");
+        _("Hier finden Sie virtuelle Veranstaltungen zu verschiedenen Gremien an der Universität");
+        _("Um virtuelle Veranstaltungen für Uni-Gremien anzulegen, verwenden Sie diese Kategorie");
+        _("Hier finden Sie virtuelle Veranstaltungen zu unterschiedlichen Themen");
+        _("Wenn Sie Veranstaltungen als Diskussiongruppen zu unterschiedlichen Themen anlegen möchten, verwenden Sie diese Kategorie.");
+        _("Hier finden Sie verschiedene Arbeitsgruppen an der %s");
+        _("Verwenden Sie diese Kategorie, um unterschiedliche Arbeitsgruppen anzulegen.");
+        _("Veranstaltungen dieser Kategorie dienen als Gruppierungselement, um die Zusammengehörigkeit von Veranstaltungen anderer Kategorien abzubilden.");
+    }
+}
diff --git a/lib/models/SemType.php b/lib/models/SemType.php
new file mode 100644
index 0000000..4453bb0
--- /dev/null
+++ b/lib/models/SemType.php
@@ -0,0 +1,133 @@
+<?php
+
+/*
+ *  Copyright (c) 2012  Rasmus Fuhse <fuhse@data-quest.de>
+ *
+ *  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.
+ */
+
+/**
+ * Class to define and manage attributes of seminar types.
+ * Usually all sem-types are stored in a global variable $SEM_TYPE which is
+ * an array of SemType objects.
+ *
+ * SemType::getTypes() gets you all seminar types in an array.
+ *
+ * This class only represents the name of the type and gives a relation to a
+ * sem_class.
+ */
+class SemType extends SimpleORMap
+{
+    static protected $sem_types = null;
+
+    /**
+     * Configure the database mapping.
+     */
+    protected static function configure($config = [])
+    {
+        $config['db_table'] = 'sem_types';
+
+        $config['has_many']['courses'] = [
+            'class_name'        => Course::class,
+            'assoc_foreign_key' => 'status'
+        ];
+
+        $config['belongs_to']['sem_class'] = [
+            'class_name'  => SemClass::class,
+            'foreign_key' => 'class'
+        ];
+
+        $config['registered_callbacks']['after_store'][] = 'SemType::refreshTypes';
+        $config['registered_callbacks']['after_delete'][] = 'SemType::refreshTypes';
+
+        parent::configure($config);
+    }
+
+    /**
+     * Returns the number of seminars of this sem_type in Stud.IP
+     * @return integer
+     */
+    public function countSeminars()
+    {
+        return Course::countBySql('status = ?', [$this->id]);
+    }
+
+    public function getSemClass()
+    {
+        return $GLOBALS['SEM_CLASS'][$this->class] ?? SemClass::getDefaultSemClass();
+    }
+
+    /**
+     * Returns an array of all SemTypes in Stud.IP. Equivalent to global
+     * $SEM_TYPE variable. This variable is statically stored in this class.
+     * @return array of SemType
+     */
+    public static function getTypes()
+    {
+        if (!is_array(self::$sem_types)) {
+            $cache = \Studip\Cache\Factory::getCache();
+            $types_array = $cache->read('DB_SEM_TYPES_ARRAY');
+
+            if (!is_array($types_array)) {
+                $types_array = self::findBySQL('1 ORDER BY id');
+                $cache->write('DB_SEM_TYPES_ARRAY', $types_array);
+            }
+
+            foreach ($types_array as $sem_type) {
+                self::$sem_types[$sem_type->id] = $sem_type;
+            }
+        }
+
+        return self::$sem_types;
+    }
+
+    public static function refreshTypes()
+    {
+        \Studip\Cache\Factory::getCache()->expire('DB_SEM_TYPES_ARRAY');
+        self::$sem_types = null;
+        return self::getTypes();
+    }
+
+    /**
+     * Gets all SemTypes that are allowed as group parents.
+     * @return array
+     */
+    public static function getGroupingSemTypes()
+    {
+        return SimpleCollection::createFromArray(array_flatten(SemClass::getGroupClasses()->getSemTypes()))->pluck('id');
+    }
+
+    /**
+     * Gets all SemTypes that are allowed as group parents.
+     * @return array
+     */
+    public static function getNonGroupingSemTypes()
+    {
+        $non_grouping = SimpleCollection::createFromArray(SemClass::getClasses())->findBy('is_group', false)->findBy('studygroup_mode', false);
+        return SimpleCollection::createFromArray(array_flatten($non_grouping->getSemTypes()))->pluck('id');
+    }
+
+    /**
+     * Static method only to keep the translationstrings of the values. It is
+     * never used within the system.
+     */
+    static private function localization()
+    {
+        _("Vorlesung");
+        _("Seminar");
+        _("Übung");
+        _("Praktikum");
+        _("Colloquium");
+        _("Kolloquium");
+        _("Forschungsgruppe");
+        _("sonstige");
+        _("Gremium");
+        _("Projektgruppe");
+        _("Kulturforum");
+        _("Veranstaltungsboard");
+        _("Studiengruppe");
+    }
+}