Resolve "MVV: Suche (Filter) nach Abschlüssen und Fächern im Backend"

Closes #3387

Merge request studip/studip!2306

6 files changed, 883 insertions, 21 deletions

diff --git a/app/controllers/lvgruppen/lvgruppen.php b/app/controllers/lvgruppen/lvgruppen.php
index 194f171..5bac0fd 100644
--- a/app/controllers/lvgruppen/lvgruppen.php
+++ b/app/controllers/lvgruppen/lvgruppen.php
@@ -41,6 +41,25 @@ class Lvgruppen_LvgruppenController extends MVVController
 
         $search_result = $this->getSearchResult('Lvgruppe');
 
+        $lvg_ids = [];
+        if (count($search_result) > 0) {
+            $lvg_ids = $search_result;
+        } else {
+            if (!empty($_SESSION['mvv_filter_lvg_fach_id'])) {
+                $lvg_ids = $this->findLvgIdsByFach($_SESSION['mvv_filter_lvg_fach_id']);
+            }
+            if (!empty($_SESSION['mvv_filter_lvg_abschluss_id'])) {
+                if (count($lvg_ids) > 0) {
+                    $lvg_ids = array_intersect(
+                        $lvg_ids,
+                        $this->findLvgIdsByAbschluss($_SESSION['mvv_filter_lvg_abschluss_id'])
+                    );
+                } else {
+                    $lvg_ids = $this->findLvgIdsByAbschluss($_SESSION['mvv_filter_lvg_abschluss_id']);
+                }
+            }
+        }
+
         // Nur LvGruppen an Modulen von verantwortlichen Einrichtungen an denen der User
         // eine Rolle hat
         $own_institutes = MvvPerm::getOwnInstitutes();
@@ -342,7 +361,7 @@ class Lvgruppen_LvgruppenController extends MVVController
         $sidebar = Sidebar::get();
 
         $widget = new SelectWidget(
-            _('Verwendung in Semester:'),
+            _('Verwendet in Semester'),
             $this->action_url('set_filter', ['fachbereich_filter' => $selected_fachbereich]),
             'semester_filter'
         );
@@ -368,7 +387,7 @@ class Lvgruppen_LvgruppenController extends MVVController
         $perm_institutes = MvvPerm::getOwnInstitutes();
         if ($perm_institutes !== false) {
             $widget = new SelectWidget(
-                _('Verwendet von Fachbereich:'),
+                _('Verwendet von Fachbereich'),
                 $this->action_url('set_filter', ['semester_filter' => $this->semester_filter]),
                 'fachbereich_filter'
             );
@@ -400,6 +419,52 @@ class Lvgruppen_LvgruppenController extends MVVController
 
             $sidebar->addWidget($widget, 'fachbereich_filter');
         }
+
+        $selected_fach = $_SESSION['mvv_filter_lvg_fach_id'] ?? '';
+        $widget = new SelectWidget(
+            _('Verwendet von Fach'),
+            $this->action_url('set_filter', ['fach_filter' => $selected_fach]),
+            'fach_filter'
+        );
+        $widget->class = 'nested-select';
+        $widget->addElement(
+            new SelectElement('select-none', _('Alle'), $selected_fach === '')
+        );
+        $faecher = Fach::findBySQL(' 1 ORDER BY `name`');
+        foreach ($faecher as $fach) {
+            $widget->addElement(
+                new SelectElement(
+                    $fach->id,
+                    $fach->name,
+                    $selected_fach === $fach->id
+                ),
+                'select-' . $fach->name
+            );
+        }
+        $sidebar->addWidget($widget, 'fach_filter');
+
+        $selected_abschluss = $_SESSION['mvv_filter_lvg_abschluss_id'] ?? '';
+        $widget = new SelectWidget(
+            _('Verwendet von Abschluss'),
+            $this->action_url('set_filter', ['abschluss_filter' => $selected_abschluss]),
+            'abschluss_filter'
+        );
+        $widget->class = 'nested-select';
+        $widget->addElement(
+            new SelectElement('select-none', _('Alle'), $selected_abschlussh === '')
+        );
+        $abschluesse = Abschluss::findBySQL(' 1 ORDER BY `name`');
+        foreach ($abschluesse as $abschluss) {
+            $widget->addElement(
+                new SelectElement(
+                    $abschluss->id,
+                    $abschluss->name,
+                    $selected_abschluss === $abschluss->id
+                ),
+                'select-' . $abschluss->name
+            );
+        }
+        $sidebar->addWidget($widget, 'abschluss_filter');
     }
 
     /**
@@ -415,6 +480,12 @@ class Lvgruppen_LvgruppenController extends MVVController
         $this->semester_filter =
             mb_strlen(Request::get('semester_filter')) ? Request::option('semester_filter') : null;
 
+        // Fach
+        $_SESSION['mvv_filter_lvg_fach_id'] = Request::option('fach_filter', '');
+
+        // Abschluss
+        $_SESSION['mvv_filter_lvg_abschluss_id'] = Request::option('abschluss_filter', '');
+
         // store filter
         $this->reset_page();
         $this->sessSet('filter', $this->filter);
@@ -424,6 +495,9 @@ class Lvgruppen_LvgruppenController extends MVVController
 
     public function reset_filter_action()
     {
+        $_SESSION['mvv_filter_lvg_fach_id'] = '';
+        $_SESSION['mvv_filter_lvg_abschluss_id'] = '';
+
         $this->filter = [];
         $this->sessRemove('filter');
         $this->semester_filter = null;
@@ -467,4 +541,43 @@ class Lvgruppen_LvgruppenController extends MVVController
             }
         );
     }
+
+    /**
+     * Returns the ids of the lvgruppen related to the given subject id.
+     *
+     * @param string $fach_id The id of the selected subject.
+     * @return array The ids of the modules related to the subject.
+     */
+    private function findLvgIdsByFach(string $fach_id): array
+    {
+        $query = "SELECT `mvv_lvgruppe_modulteil`.`lvgruppe_id`
+                  FROM `mvv_lvgruppe_modulteil`
+                  JOIN `mvv_modulteil` USING (`modulteil_id`)
+                  JOIN `mvv_stgteilabschnitt_modul` USING (`modul_id`)
+                  JOIN `mvv_stgteilabschnitt` USING (`abschnitt_id`)
+                  JOIN `mvv_stgteilversion` USING (`version_id`)
+                  JOIN `mvv_stgteil` USING (`stgteil_id`)
+                  WHERE `mvv_stgteil`.`fach_id` = ?";
+        return DBManager::get()->fetchFirst($query, [$fach_id]);
+    }
+
+    /**
+     * Returns the ids of the lvgruppen related to the given degree id.
+     *
+     * @param string $abschluss_id The id of the selected degree.
+     * @return array The ids of the lvgruppen related to the degree.
+     */
+    private function findLvgIdsByAbschluss(string $abschluss_id): array
+    {
+        $query = "SELECT `mvv_lvgruppe_modulteil`.`lvgruppe_id`
+                  FROM `mvv_lvgruppe_modulteil`
+                  JOIN `mvv_modulteil` USING (`modulteil_id`)
+                  JOIN `mvv_stgteilabschnitt_modul` USING (`modul_id`)
+                  JOIN `mvv_stgteilabschnitt` USING (`abschnitt_id`)
+                  JOIN `mvv_stgteilversion` USING (`version_id`)
+                  JOIN `mvv_stg_stgteil` USING (`stgteil_id`)
+                  JOIN `mvv_studiengang` USING (`studiengang_id`)
+                  WHERE `mvv_studiengang`.`abschluss_id` = ?";
+        return DBManager::get()->fetchFirst($query, [$abschluss_id]);
+    }
 }
diff --git a/app/controllers/materialien/files.php b/app/controllers/materialien/files.php
index 65c9b44..804668e 100644
--- a/app/controllers/materialien/files.php
+++ b/app/controllers/materialien/files.php
@@ -38,11 +38,31 @@ class Materialien_FilesController extends MVVController
         $this->initSearchParams();
 
         $search_result = $this->getSearchResult('MvvFile');
-        if ($search_result) {
+
+        $file_ids = [];
+        if (count($search_result) > 0) {
+            $file_ids = $search_result;
+        } else {
+            if (!empty($_SESSION['mvv_filter_files_fach_id'])) {
+                $file_ids = $this->findFileIdsByFach($_SESSION['mvv_filter_contacts_fach_id']);
+            }
+            if (!empty($_SESSION['mvv_filter_files_abschluss_id'])) {
+                if (count($file_ids) > 0) {
+                    $file_ids = array_intersect(
+                        $file_ids,
+                        $this->findFileIdsByAbschluss($_SESSION['mvv_filter_contacts_abschluss_id'])
+                    );
+                } else {
+                    $file_ids = $this->findFileIdsByAbschluss($_SESSION['mvv_filter_contacts_abschluss_id']);
+                }
+            }
+        }
+
+        if ($file_ids) {
             $ranges = [];
             $refs = [];
             $this->filter = array_merge(
-                ['mvv_files.mvvfile_id' => $search_result],
+                ['mvv_files.mvvfile_id' => $file_ids],
                 (array) $this->filter
             );
         }
@@ -589,6 +609,13 @@ class Materialien_FilesController extends MVVController
         } else {
             $this->sessRemove('filter');
         }
+
+        // Fach
+        $_SESSION['mvv_filter_files_fach_id'] = Request::option('fach_filter', '');
+
+        // Abschluss
+        $_SESSION['mvv_filter_files_abschluss_id'] = Request::option('abschluss_filter', '');
+
         // store filter
         $this->reset_page();
         $this->sessSet('filter', $this->filter);
@@ -597,6 +624,9 @@ class Materialien_FilesController extends MVVController
 
     public function reset_filter_action()
     {
+        $_SESSION['mvv_filter_files_fach_id'] = '';
+        $_SESSION['mvv_filter_files_abschluss_id'] = '';
+
         $this->filter = [];
         $this->reset_search();
         $this->sessRemove('filter');
@@ -652,7 +682,9 @@ class Materialien_FilesController extends MVVController
             $this->filter
         );
         unset($institute_filter['searchnames']);
-
+        $file_ids = MvvFile::getIdsFiltered($this->filter, true, false);
+        $count_faecher = $this->countFaecher($file_ids, $_SESSION['mvv_filter_files_fach_id'] ?? '');
+        $count_abschluesse = $this->countAbschluesse($file_ids, $_SESSION['mvv_filter_files_abschluss_id'] ?? '');
         $semesters = new SimpleCollection(array_reverse(Semester::getAll()));
         $filter_template = $template_factory->render('shared/filter', [
             'name_search'        => true,
@@ -666,6 +698,16 @@ class Materialien_FilesController extends MVVController
             'selected_institut'  => $this->filter['mvv_studiengang.institut_id'] ?? '',
             'zuordnungen'        => !empty($this->search_result['MvvFile']) ? MvvFile::getAllRelations($this->search_result['MvvFile']) : [],
             'selected_zuordnung' => $this->filter['mvv_files_ranges.range_type'] ?? '',
+            'faecher'            => SimpleORMapCollection::createFromArray(
+                Fach::findMany(array_keys($count_faecher))
+            )->orderBy('name'),
+            'count_faecher'      => $count_faecher,
+            'selected_fach'      => $_SESSION['mvv_filter_files_fach_id'] ?? '',
+            'abschluesse'        => SimpleORMapCollection::createFromArray(
+                Abschluss::findMany(array_keys($count_abschluesse))
+            )->orderBy('name'),
+            'count_abschluesse'  => $count_abschluesse,
+            'selected_abschluss' => $_SESSION['mvv_filter_files_abschluss_id'] ?? '',
             'action'             => $this->action_url('set_filter'),
             'action_reset'       => $this->action_url('reset_filter')]
         );
@@ -895,4 +937,227 @@ class Materialien_FilesController extends MVVController
             $this->redirect($this->url_for('materialien/files/add_dokument', 'index', $range_type, implode(',', Request::getArray('range_id'))));
         }
     }
+
+    /**
+     * Returns the number of files grouped by subjects for given file ids.
+     *
+     * @param array $module_ids The ids of the files.
+     * @param string $fach_id The id of the selected subject.
+     * @return array Number of files grouped by subjects.
+     */
+    private function countFaecher(array $file_ids, string $fach_id): array
+    {
+        if ($fach_id === '') {
+            $params = [':file_ids' => $file_ids];
+            $where = "`mvv_files_ranges`.`mvvfile_id` IN (:file_ids)";
+        } else {
+            $params = [
+                ':fach_id' => $fach_id,
+                ':file_ids' => $file_ids
+            ];
+            $where = "`fach`.`fach_id` = :fach_id
+                      AND `mvv_files_ranges`.`mvvfile_id` IN (:file_ids)";
+        }
+        $query = "SELECT `counting`.`fach_id`, COUNT(DISTINCT `counting`.`mvvfile_id`)
+                  FROM (
+                      SELECT `fach_id`, `mvvfile_id`
+                      FROM `fach`
+                      JOIN `mvv_stgteil` USING (`fach_id`)
+                      JOIN `mvv_stg_stgteil` USING (`stgteil_id`)
+                      JOIN `mvv_studiengang` USING (`studiengang_id`)
+                      JOIN `mvv_abschl_zuord` USING (`abschluss_id`)
+                      JOIN `mvv_files_ranges`
+                        ON (
+                          `mvv_files_ranges`.`range_id` = `mvv_abschl_zuord`.`kategorie_id`
+                          AND `mvv_files_ranges`.`range_type` = 'AbschlussKategorie'
+                        )
+                      WHERE {$where}
+
+                      UNION ALL
+
+                      SELECT `fach_id`, `mvvfile_id`
+                      FROM `fach`
+                      JOIN `mvv_stgteil` USING (`fach_id`)
+                      JOIN `mvv_stg_stgteil` USING (`stgteil_id`)
+                      JOIN `mvv_studiengang` USING (`studiengang_id`)
+                      JOIN `mvv_files_ranges`
+                        ON (
+                          `mvv_files_ranges`.`range_id` = `mvv_studiengang`.`studiengang_id`
+                          AND `mvv_files_ranges`.`range_type` = 'Studiengang'
+                        )
+                      WHERE {$where}
+
+                      UNION ALL
+
+                      SELECT `fach_id`, `mvvfile_id`
+                      FROM `fach`
+                      JOIN `mvv_stgteil` USING (`fach_id`)
+                      JOIN `mvv_stgteilversion` USING(`stgteil_id`)
+                      JOIN `mvv_files_ranges`
+                        ON (
+                          `mvv_files_ranges`.`range_id` = `mvv_stgteilversion`.`version_id`
+                          AND `mvv_files_ranges`.`range_type` = 'StgteilVersion'
+                        )
+                      WHERE {$where}
+                  ) AS `counting`
+                  GROUP BY `counting`.`fach_id`";
+        return DBManager::get()->fetchPairs($query, $params);
+    }
+
+    /**
+     * Returns the ids of the files related to the given subject id.
+     *
+     * @param string $fach_id The id of the selected subject.
+     * @return array The ids of the files related to the subject.
+     */
+    private function findFileIdsByFach(string $fach_id): array
+    {
+        $query = "SELECT `mvv_files_ranges`.`mvvfile_id`
+                  FROM `mvv_files_ranges`
+                  JOIN `mvv_stgteilversion`
+                    ON (
+                      `mvv_stgteilversion`.`version_id` = `mvv_files_ranges`.`range_id`
+                      AND `mvv_files_ranges`.`range_type` = 'StgteilVersion'
+                    )
+                  JOIN `mvv_stgteil` USING (`stgteil_id`)
+                  WHERE `mvv_stgteil`.`fach_id` = :fach_id
+
+                  UNION
+
+                  SELECT `mvv_files_ranges`.`mvvfile_id`
+                  FROM `mvv_files_ranges`
+                  JOIN `mvv_studiengang`
+                    ON (
+                      `mvv_studiengang`.`studiengang_id` = `mvv_files_ranges`.`range_id`
+                      AND `mvv_files_ranges`.`range_type` = 'Studiengang'
+                    )
+                  JOIN `mvv_stg_stgteil` USING (`studiengang_id`)
+                  JOIN `mvv_stgteil` USING (`stgteil_id`)
+                  WHERE `mvv_stgteil`.`fach_id` = :fach_id
+
+                  UNION
+
+                  SELECT `mvv_files_ranges`.`mvvfile_id`
+                  FROM `mvv_files_ranges`
+                  JOIN `mvv_abschl_zuord`
+                    ON (
+                      `mvv_files_ranges`.`range_id` = `mvv_abschl_zuord`.`kategorie_id`
+                      AND `mvv_files_ranges`.`range_type` = 'AbschlussKategorie'
+                    )
+                  JOIN `mvv_studiengang` USING (`abschluss_id`)
+                  JOIN `mvv_stg_stgteil` USING (`studiengang_id`)
+                  JOIN `mvv_stgteil` USING (`stgteil_id`)
+                  WHERE `mvv_stgteil`.`fach_id` = :fach_id";
+
+        return DBManager::get()->fetchFirst($query, [':fach_id' => $fach_id]);
+    }
+
+    /**
+     * Returns the number of files grouped by degrees for given file ids.
+     *
+     * @param array $module_ids The ids of the files.
+     * @param string $abschluss_id The id of the selected degree.
+     * @return array Number of files grouped by degrees.
+     */
+    private function countAbschluesse(array $file_ids, string $abschluss_id): array
+    {
+        if ($abschluss_id === '') {
+            $params = [':file_ids' => $file_ids];
+            $where = "`mvv_files_ranges`.`mvvfile_id` IN (:file_ids)";
+        } else {
+            $params = [
+                ':abschluss_id' => $abschluss_id,
+                ':file_ids'  => $file_ids
+            ];
+            $where = "`abschluss`.`abschluss_id` = :abschluss_id
+                      AND `mvv_files_ranges`.`mvvfile_id` IN (:file_ids)";
+        }
+        $query = "SELECT `counting`.`abschluss_id`, COUNT(DISTINCT `counting`.`mvvfile_id`)
+                  FROM (
+                      SELECT `abschluss_id`, `mvvfile_id`
+                      FROM `abschluss`
+                      JOIN `mvv_studiengang` USING (`abschluss_id`)
+                      JOIN `mvv_stg_stgteil` USING (`studiengang_id`)
+                      JOIN `mvv_stgteilversion` USING (`stgteil_id`)
+                      JOIN `mvv_files_ranges`
+                        ON (
+                          `mvv_files_ranges`.`range_id` = `mvv_stgteilversion`.`version_id`
+                          AND `mvv_files_ranges`.`range_type` = 'StgteilVersion'
+                        )
+                      WHERE {$where}
+
+                      UNION ALL
+
+                      SELECT `abschluss_id`, `mvvfile_id`
+                      FROM `abschluss`
+                      JOIN `mvv_studiengang` USING (`abschluss_id`)
+                      JOIN `mvv_files_ranges`
+                        ON (
+                          `mvv_files_ranges`.`range_id` = `mvv_studiengang`.`studiengang_id`
+                          AND `mvv_files_ranges`.`range_type` = 'Studiengang'
+                        )
+                      WHERE {$where}
+
+                      UNION ALL
+
+                      SELECT `abschluss_id`, `mvvfile_id`
+                      FROM `abschluss`
+                      JOIN `mvv_studiengang` USING (`abschluss_id`)
+                      JOIN `mvv_abschl_zuord` USING (`abschluss_id`)
+                      JOIN `mvv_files_ranges`
+                        ON (
+                          `mvv_files_ranges`.`range_id` = `mvv_abschl_zuord`.`kategorie_id`
+                          AND `mvv_files_ranges`.`range_type` = 'AbschlussKategorie'
+                        )
+                      WHERE {$where}
+                  ) AS `counting`
+                  GROUP BY `counting`.`abschluss_id`";
+
+        return DBManager::get()->fetchPairs($query, $params);
+    }
+
+    /**
+     * Returns the ids of the files related to the given degree id.
+     *
+     * @param string $abschluss_id The id of the selected degree.
+     * @return array The ids of the files related to the degree.
+     */
+    private function findFileIdsByAbschluss(string $abschluss_id): array
+    {
+        $query = "SELECT `mvv_files_ranges`.`mvvfile_id`
+                  FROM `mvv_files_ranges`
+                  JOIN `mvv_abschl_zuord`
+                    ON (
+                      `mvv_abschl_zuord`.`kategorie_id` = `mvv_files_ranges`.`range_id`
+                      AND `mvv_files_ranges`.`range_type` = 'AbschlussKategorie'
+                    )
+                  JOIN `mvv_studiengang` USING(`abschluss_id`)
+                  WHERE `mvv_studiengang`.`abschluss_id` = :abschluss_id
+
+                  UNION
+
+                  SELECT `mvv_files_ranges`.`mvvfile_id`
+                  FROM `mvv_files_ranges`
+                  JOIN `mvv_studiengang`
+                    ON (
+                      `mvv_studiengang`.`studiengang_id` = `mvv_files_ranges`.`range_id`
+                      AND `mvv_files_ranges`.`range_type` = 'Studiengang'
+                    )
+                  WHERE `mvv_studiengang`.`abschluss_id` = :abschluss_id
+
+                  UNION
+
+                  SELECT `mvv_files_ranges`.`mvvfile_id`
+                  FROM `mvv_files_ranges`
+                  JOIN `mvv_stgteilversion`
+                    ON (
+                      `mvv_files_ranges`.`range_id` = `mvv_stgteilversion`.`version_id`
+                      AND `mvv_files_ranges`.`range_type` = 'StgteilVersion'
+                    )
+                  JOIN `mvv_stg_stgteil` USING(`stgteil_id`)
+                  JOIN `mvv_studiengang` USING(`studiengang_id`)
+                  WHERE `mvv_studiengang`.`abschluss_id` = :abschluss_id";
+
+        return DBManager::get()->fetchFirst($query, [':abschluss_id' => $abschluss_id]);
+    }
 }
diff --git a/app/controllers/module/module.php b/app/controllers/module/module.php
index f8c9917..852e9d9 100644
--- a/app/controllers/module/module.php
+++ b/app/controllers/module/module.php
@@ -50,9 +50,29 @@ class Module_ModuleController extends MVVController
         if (empty($this->filter['mvv_modul_inst.institut_id'])) {
             unset($this->filter['mvv_modul_inst.institut_id']);
         }
+
+        $module_ids = [];
+        if (count($search_result) > 0) {
+            $module_ids = $search_result;
+        } else {
+            if ($_SESSION['mvv_filter_module_fach_id']) {
+                $module_ids = $this->findModuleIdsByFach($_SESSION['mvv_filter_module_fach_id']);
+            }
+            if (!empty($_SESSION['mvv_filter_module_abschluss_id'])) {
+                if (count($module_ids) > 0) {
+                    $module_ids = array_intersect(
+                        $module_ids,
+                        $this->findModuleIdsByAbschluss($_SESSION['mvv_filter_module_abschluss_id'])
+                    );
+                } else {
+                    $module_ids = $this->findModuleIdsByAbschluss($_SESSION['mvv_filter_module_abschluss_id']);
+                }
+            }
+        }
+
         $this->filter = array_merge(
             [
-                'mvv_modul.modul_id'         => $search_result,
+                'mvv_modul.modul_id'         => $module_ids,
                 'mvv_modul_inst.gruppe'      => 'hauptverantwortlich',
                 'mvv_modul_inst.institut_id' => MvvPerm::getOwnInstitutes()
             ],
@@ -1286,6 +1306,12 @@ class Module_ModuleController extends MVVController
             $this->filter['mvv_modul_inst.institut_id'] = MvvPerm::getOwnInstitutes();
         }
 
+        // Fach
+        $_SESSION['mvv_filter_module_fach_id'] = Request::option('fach_filter', '');
+
+        // Abschluss
+        $_SESSION['mvv_filter_module_abschluss_id'] = Request::option('abschluss_filter', '');
+
         // store filter
         $this->reset_page();
         $this->sessSet('filter', $this->filter);
@@ -1296,6 +1322,9 @@ class Module_ModuleController extends MVVController
     {
         $this->reset_page();
 
+        $_SESSION['mvv_filter_module_fach_id'] = '';
+        $_SESSION['mvv_filter_module_abschluss_id'] = '';
+
         $this->sessSet('filter', []);
         $this->redirect($this->indexURL());
     }
@@ -1380,6 +1409,21 @@ class Module_ModuleController extends MVVController
             $selected_semester = $semesters->findOneBy('beginn', $this->filter['start_sem.beginn']);
         }
 
+        // Fach
+        $count_faecher = $this->countFaecher($modul_ids, $_SESSION['mvv_filter_module_fach_id'] ?? '');
+        $template->set_attribute('faecher', SimpleORMapCollection::createFromArray(
+            Fach::findMany(array_keys($count_faecher))
+        )->orderBy('name'));
+        $template->set_attribute('count_faecher', $count_faecher);
+        $template->set_attribute('selected_fach', $_SESSION['mvv_filter_module_fach_id'] ?? '');
+
+        // Abschluss
+        $count_abschluesse = $this->countAbschluesse($modul_ids, $_SESSION['mvv_filter_module_abschluss_id'] ?? '');
+        $template->set_attribute('abschluesse', SimpleORMapCollection::createFromArray(
+             Abschluss::findMany(array_keys($count_abschluesse))
+        )->orderBy('name'));
+        $template->set_attribute('count_abschluesse', $count_abschluesse);
+        $template->set_attribute('selected_abschluss', $_SESSION['mvv_filter_module_abschluss_id'] ?? '');
 
         $template->set_attribute('semester', $semesters);
         $template->set_attribute('selected_semester', $selected_semester->id ?? '');
@@ -1432,4 +1476,102 @@ class Module_ModuleController extends MVVController
         );
         $sidebar->addWidget($widget, 'search');
     }
+
+    /**
+     * Returns the number of modules grouped by subjects for given module ids.
+     *
+     * @param array $module_ids The ids of the modules.
+     * @param string $fach_id The id of the selected subject.
+     * @return array Number of modules grouped by subjects.
+     */
+    private function countFaecher(array $module_ids, string $fach_id): array
+    {
+        if ($fach_id === '') {
+            $params = [':module_ids' => $module_ids];
+            $where = "`mvv_stgteilabschnitt_modul`.`modul_id` IN (:module_ids)";
+        } else {
+            $params = [
+                ':fach_id' => $fach_id,
+                ':module_ids' => $module_ids
+            ];
+            $where = "`fach`.`fach_id` = :fach_id
+                      AND `mvv_stgteilabschnitt_modul`.`modul_id` IN (:module_ids)";
+        }
+        $query = "SELECT `fach`.`fach_id`, COUNT(DISTINCT `modul_id`) AS `count_faecher`
+                  FROM `fach`
+                  JOIN `mvv_stgteil` USING (`fach_id`)
+                  JOIN `mvv_stgteilversion` USING (`stgteil_id`)
+                  JOIN `mvv_stgteilabschnitt` USING (`version_id`)
+                  JOIN `mvv_stgteilabschnitt_modul` USING (`abschnitt_id`)
+                  WHERE {$where}
+                  GROUP BY `fach_id`";
+        return DBManager::get()->fetchPairs($query, $params);
+    }
+
+    /**
+     * Returns the ids of the modules related to the given subject id.
+     *
+     * @param string $fach_id The id of the selected subject.
+     * @return array The ids of the modules related to the subject.
+     */
+    private function findModuleIdsByFach(string $fach_id): array
+    {
+        $query = "SELECT `mvv_stgteilabschnitt_modul`.`modul_id`
+                  FROM `mvv_stgteilabschnitt_modul`
+                  JOIN `mvv_stgteilabschnitt` USING (`abschnitt_id`)
+                  JOIN `mvv_stgteilversion` USING (`version_id`)
+                  JOIN `mvv_stgteil` USING (`stgteil_id`)
+                  WHERE `mvv_stgteil`.`fach_id` = ?";
+        return DBManager::get()->fetchFirst($query, [$fach_id]);
+    }
+
+    /**
+     * Returns the number of modules grouped by degrees for given module ids.
+     *
+     * @param array $module_ids The ids of the modules.
+     * @param string $abschluss_id The id of the selected degree.
+     * @return array Number of modules grouped by degrees.
+     */
+    private function countAbschluesse(array $module_ids, $abschluss_id): array
+    {
+        if ($abschluss_id === '') {
+            $params = [':module_ids' => $module_ids];
+            $where = "`mvv_stgteilabschnitt_modul`.`modul_id` IN (:module_ids)";
+        } else {
+            $params = [
+                ':abschluss_ids' => $abschluss_id,
+                ':module_ids' => $module_ids
+            ];
+            $where = "`abschluss`.`abschluss_id` = :abschluss_ids
+                      AND `mvv_stgteilabschnitt_modul`.`modul_id` IN (:module_ids)";
+        }
+        $query = "SELECT `abschluss`.`abschluss_id`, COUNT(DISTINCT `modul_id`) AS `count_abschluesse`
+                  FROM `abschluss`
+                  JOIN `mvv_studiengang` USING (`abschluss_id`)
+                  JOIN `mvv_stg_stgteil` USING (`studiengang_id`)
+                  JOIN `mvv_stgteilversion` USING (`stgteil_id`)
+                  JOIN `mvv_stgteilabschnitt` USING (`version_id`)
+                  JOIN `mvv_stgteilabschnitt_modul` USING (`abschnitt_id`)
+                  WHERE {$where}
+                  GROUP BY `abschluss_id`";
+        return DBManager::get()->fetchPairs($query, $params);
+    }
+
+    /**
+     * Returns the ids of the modules related to the given degree id.
+     *
+     * @param string $abschluss_id The id of the selected degree.
+     * @return array The ids of the modules related to the degree.
+     */
+    private function findModuleIdsByAbschluss(string $abschluss_id): array
+    {
+        $query = "SELECT `mvv_stgteilabschnitt_modul`.`modul_id`
+                  FROM `mvv_stgteilabschnitt_modul`
+                  JOIN `mvv_stgteilabschnitt` USING (`abschnitt_id`)
+                  JOIN `mvv_stgteilversion` USING (`version_id`)
+                  JOIN `mvv_stg_stgteil` USING (`stgteil_id`)
+                  JOIN `mvv_studiengang` USING (`studiengang_id`)
+                  WHERE `mvv_studiengang`.`abschluss_id` = ?";
+        return DBManager::get()->fetchFirst($query, [$abschluss_id]);
+    }
 }
diff --git a/app/controllers/shared/contacts.php b/app/controllers/shared/contacts.php
index a3da1a7..98670f4 100644
--- a/app/controllers/shared/contacts.php
+++ b/app/controllers/shared/contacts.php
@@ -64,8 +64,28 @@ class Shared_ContactsController extends MVVController
         if (empty($this->filter['mvv_modul_inst.institut_id'])) {
             unset($this->filter['mvv_modul_inst.institut_id']);
         }
-        if ($search_result) {
-            $this->filter['mvv_contacts.contact_id'] = $search_result;
+
+        $contact_ids = [];
+        if (count($search_result) > 0) {
+            $contact_ids = $search_result;
+        } else {
+            if (!empty($_SESSION['mvv_filter_contacts_fach_id'])) {
+                $contact_ids = $this->findContactIdsByFach($_SESSION['mvv_filter_contacts_fach_id']);
+            }
+            if (!empty($_SESSION['mvv_filter_contacts_abschluss_id'])) {
+                if (count($contact_ids) > 0) {
+                    $contact_ids = array_intersect(
+                        $contact_ids,
+                        $this->findContactIdsByAbschluss($_SESSION['mvv_filter_contacts_abschluss_id'])
+                    );
+                } else {
+                    $contact_ids = $this->findContactIdsByAbschluss($_SESSION['mvv_filter_contacts_abschluss_id']);
+                }
+            }
+        }
+
+        if (count($contact_ids) > 0) {
+            $this->filter['mvv_contacts.contact_id'] = $contact_ids;
         }
 
         $own_institutes = MvvPerm::getOwnInstitutes();
@@ -241,6 +261,12 @@ class Shared_ContactsController extends MVVController
             $this->filter['mvv_contacts_ranges.range_type'] = Request::option('zuordnung_filter');
         }
 
+        // Fach
+        $_SESSION['mvv_filter_contacts_fach_id'] = Request::option('fach_filter', '');
+
+        // Abschluss
+        $_SESSION['mvv_filter_contacts_abschluss_id'] = Request::option('abschluss_filter', '');
+
         // store filter
         $this->reset_page();
         $this->sessSet('filter', $this->filter);
@@ -249,6 +275,9 @@ class Shared_ContactsController extends MVVController
 
     public function reset_filter_action()
     {
+        $_SESSION['mvv_filter_contacts_fach_id'] = '';
+        $_SESSION['mvv_filter_contacts_abschluss_id'] = '';
+
         $this->filter = [];
         $this->reset_search();
         $this->sessRemove('filter');
@@ -346,6 +375,9 @@ class Shared_ContactsController extends MVVController
             $this->filter
         );
 
+        $contact_ids = MvvContact::getIdsFiltered($this->filter);
+        $count_faecher = $this->countFaecher($contact_ids, $_SESSION['mvv_filter_contacts_fach_id'] ?? '');
+        $count_abschluesse = $this->countAbschluesse($contact_ids, $_SESSION['mvv_filter_contacts_abschluss_id'] ?? '');
         $semesters = new SimpleCollection(array_reverse(Semester::getAll()));
         $filter_template = $template_factory->render('shared/filter', [
             'semester'           => $semesters,
@@ -365,6 +397,16 @@ class Shared_ContactsController extends MVVController
             'status'             => $this->findStatusByIds(),
             'selected_status'    => $this->filter['mvv_contacts.contact_status'] ?? '',
             'status_array'       => ['intern' => ['name' => _('Intern')], 'extern' => ['name' =>_('Extern')]],
+            'faecher'            => SimpleORMapCollection::createFromArray(
+                Fach::findMany(array_keys($count_faecher))
+            )->orderBy('name'),
+            'count_faecher'      => $count_faecher,
+            'selected_fach'      => $_SESSION['mvv_filter_contacts_fach_id'] ?? '',
+            'abschluesse'        => SimpleORMapCollection::createFromArray(
+                Abschluss::findMany(array_keys($count_abschluesse))
+            )->orderBy('name'),
+            'count_abschluesse'  => $count_abschluesse,
+            'selected_abschluss' => $_SESSION['mvv_filter_contacts_abschluss_id'] ?? '',
             'action'             => $this->action_url('set_filter'),
             'action_reset'       => $this->action_url('reset_filter')
         ]);
@@ -991,4 +1033,231 @@ class Shared_ContactsController extends MVVController
         }
         return $result;
     }
+
+    /**
+     * Returns the number of contacts grouped by subjects for given contact ids.
+     *
+     * @param array $contact_ids The ids of the contacts.
+     * @param string $fach_id The id of the selected subject.
+     * @return array Number of contacts grouped by subjects.
+     */
+    private function countFaecher(array $contact_ids, string $fach_id): array
+    {
+        if ($fach_id === '') {
+            $params = [':contact_ids' => $contact_ids];
+            $where = "`mvv_contacts_ranges`.`contact_id` IN (:contact_ids)";
+        } else {
+            $params = [
+                ':fach_id' => $fach_id,
+                ':contact_ids' => $contact_ids
+            ];
+            $where = "`fach`.`fach_id` = :fach_id
+                      AND `mvv_contacts_ranges`.`contact_id` IN (:contact_ids)";
+        }
+        $query = "SELECT `counting`.`fach_id`, COUNT(DISTINCT `counting`.`contact_id`)
+                  FROM (
+                      SELECT `fach_id`, `contact_id`
+                      FROM `fach`
+                      JOIN `mvv_stgteil` USING (`fach_id`)
+                      JOIN `mvv_contacts_ranges`
+                        ON (
+                          `mvv_contacts_ranges`.`range_id` = `mvv_stgteil`.`stgteil_id`
+                          AND `mvv_contacts_ranges`.`range_type` = 'StudiengangTeil'
+                        )
+                      WHERE {$where}
+
+                      UNION ALL
+
+                      SELECT `fach_id`, `contact_id`
+                      FROM `fach`
+                      JOIN `mvv_stgteil` USING (`fach_id`)
+                      JOIN `mvv_stg_stgteil` USING (`stgteil_id`)
+                      JOIN `mvv_studiengang` USING (`studiengang_id`)
+                      JOIN `mvv_contacts_ranges`
+                        ON (
+                          `mvv_contacts_ranges`.`range_id` = `mvv_studiengang`.`studiengang_id`
+                          AND `mvv_contacts_ranges`.`range_type` = 'Studiengang'
+                        )
+                      WHERE {$where}
+
+                      UNION ALL
+
+                      SELECT `fach_id`, `contact_id`
+                      FROM `fach`
+                      JOIN `mvv_stgteil` USING (`fach_id`)
+                      JOIN `mvv_stgteilversion` USING (`stgteil_id`)
+                      JOIN `mvv_stgteilabschnitt` USING (`version_id`)
+                      JOIN `mvv_stgteilabschnitt_modul` USING (`abschnitt_id`)
+                      JOIN `mvv_contacts_ranges`
+                        ON (
+                          `mvv_contacts_ranges`.`range_id` = `mvv_stgteilabschnitt_modul`.`modul_id`
+                          AND `mvv_contacts_ranges`.`range_type` = 'Modul'
+                        )
+                      WHERE {$where}
+                  ) AS `counting`
+                  GROUP BY `counting`.`fach_id`";
+        return DBManager::get()->fetchPairs($query, $params);
+    }
+
+    /**
+     * Returns the ids of the contacts related to the given subject id.
+     *
+     * @param string $fach_id The id of the selected subject.
+     * @return array The ids of the contacts related to the subject.
+     */
+    private function findContactIdsByFach(string $fach_id): array
+    {
+        $query = "SELECT `mvv_contacts_ranges`.`contact_id`
+                  FROM `mvv_contacts_ranges`
+                  JOIN `mvv_stgteilabschnitt_modul`
+                    ON (
+                      `mvv_stgteilabschnitt_modul`.`modul_id` = `mvv_contacts_ranges`.`range_id`
+                      AND `mvv_contacts_ranges`.`range_type` = 'Modul'
+                    )
+                  JOIN `mvv_stgteilabschnitt` USING (`abschnitt_id`)
+                  JOIN `mvv_stgteilversion` USING (`version_id`)
+                  JOIN `mvv_stgteil` USING (`stgteil_id`)
+                  WHERE `mvv_stgteil`.`fach_id` = :fach_id
+
+                  UNION
+
+                  SELECT `mvv_contacts_ranges`.`contact_id`
+                  FROM `mvv_contacts_ranges`
+                  JOIN `mvv_studiengang`
+                    ON (
+                      `mvv_studiengang`.`studiengang_id` = `mvv_contacts_ranges`.`range_id`
+                      AND `mvv_contacts_ranges`.`range_type` = 'Studiengang'
+                    )
+                  JOIN `mvv_stg_stgteil` USING (`studiengang_id`)
+                  JOIN `mvv_stgteil` USING (`stgteil_id`)
+                  WHERE `mvv_stgteil`.`fach_id` = :fach_id
+
+                  UNION
+
+                  SELECT `mvv_contacts_ranges`.`contact_id`
+                  FROM `mvv_contacts_ranges`
+                  JOIN `mvv_stgteil`
+                    ON (
+                      `mvv_contacts_ranges`.`range_id` = `mvv_stgteil`.`stgteil_id`
+                      AND `mvv_contacts_ranges`.`range_type` = 'StudiengangTeil'
+                    )
+                  WHERE `mvv_stgteil`.`fach_id` = :fach_id";
+
+        return DBManager::get()->fetchFirst($query, [':fach_id' => $fach_id]);
+    }
+
+    /**
+     * Returns the number of contacts grouped by degrees for given contact ids.
+     *
+     * @param array $contact_ids The ids of the contacts.
+     * @param string $abschluss_id The id of the selected degree.
+     * @return array Number of contacts grouped by degrees.
+     */
+    private function countAbschluesse(array $contact_ids, string $abschluss_id): array
+    {
+        if ($abschluss_id === '') {
+            $params = [':contact_ids' => $contact_ids];
+            $where = "`mvv_contacts_ranges`.`contact_id` IN (:contact_ids)";
+        } else {
+            $params = [
+                ':abschluss_id' => $abschluss_id,
+                ':contact_ids'  => $contact_ids
+            ];
+            $where = "`abschluss`.`abschluss_id` = :abschluss_id
+                      AND `mvv_contacts_ranges`.`contact_id` IN (:contact_ids)";
+        }
+        $query = "SELECT `counting`.`abschluss_id`, COUNT(DISTINCT `counting`.`contact_id`)
+                  FROM (
+                      SELECT `abschluss_id`, `contact_id`
+                      FROM `abschluss`
+                      JOIN `mvv_studiengang` USING (`abschluss_id`)
+                      JOIN `mvv_stg_stgteil` USING (`studiengang_id`)
+                      JOIN `mvv_stgteil` USING (`stgteil_id`)
+                      JOIN `mvv_contacts_ranges`
+                        ON (
+                          `mvv_contacts_ranges`.`range_id` = `mvv_stgteil`.`stgteil_id`
+                          AND `mvv_contacts_ranges`.`range_type` = 'StudiengangTeil'
+                        )
+                      WHERE {$where}
+
+                      UNION ALL
+
+                      SELECT `abschluss_id`, `contact_id`
+                      FROM `abschluss`
+                      JOIN `mvv_studiengang` USING (`abschluss_id`)
+                      JOIN `mvv_contacts_ranges`
+                        ON (
+                          `mvv_contacts_ranges`.`range_id` = `mvv_studiengang`.`studiengang_id`
+                          AND `mvv_contacts_ranges`.`range_type` = 'Studiengang'
+                        )
+                      WHERE {$where}
+
+                      UNION ALL
+
+                      SELECT `abschluss_id`, `contact_id`
+                      FROM `abschluss`
+                      JOIN `mvv_studiengang` USING (`abschluss_id`)
+                      JOIN `mvv_stg_stgteil` USING (`studiengang_id`)
+                      JOIN `mvv_stgteilversion` USING (`stgteil_id`)
+                      JOIN `mvv_stgteilabschnitt` USING (`version_id`)
+                      JOIN `mvv_stgteilabschnitt_modul` USING (`abschnitt_id`)
+                      JOIN `mvv_contacts_ranges`
+                        ON (
+                          `mvv_contacts_ranges`.`range_id` = `mvv_stgteilabschnitt_modul`.`modul_id`
+                          AND `mvv_contacts_ranges`.`range_type` = 'Modul'
+                        )
+                      WHERE {$where}
+                  ) AS `counting`
+                  GROUP BY `counting`.`abschluss_id`";
+
+        return DBManager::get()->fetchPairs($query, $params);
+    }
+
+    /**
+     * Returns the ids of the contacts related to the given degree id.
+     *
+     * @param string $abschluss_id The id of the selected degree.
+     * @return array The ids of the contacts related to the degree.
+     */
+    private function findContactIdsByAbschluss(string $abschluss_id): array
+    {
+        $query = "SELECT `mvv_contacts_ranges`.`contact_id`
+                  FROM `mvv_contacts_ranges`
+                  JOIN `mvv_stgteilabschnitt_modul`
+                    ON (
+                      `mvv_stgteilabschnitt_modul`.`modul_id` = `mvv_contacts_ranges`.`range_id`
+                      AND `mvv_contacts_ranges`.`range_type` = 'Modul'
+                    )
+                  JOIN `mvv_stgteilabschnitt` USING (`abschnitt_id`)
+                  JOIN `mvv_stgteilversion` USING (`version_id`)
+                  JOIN `mvv_stg_stgteil` USING (`stgteil_id`)
+                  JOIN `mvv_studiengang` USING (`studiengang_id`)
+                  WHERE `mvv_studiengang`.`abschluss_id` = :abschluss_id
+
+                  UNION
+
+                  SELECT `mvv_contacts_ranges`.`contact_id`
+                  FROM `mvv_contacts_ranges`
+                  JOIN `mvv_studiengang`
+                    ON (
+                      `mvv_studiengang`.`studiengang_id` = `mvv_contacts_ranges`.`range_id`
+                      AND `mvv_contacts_ranges`.`range_type` = 'Studiengang'
+                    )
+                  WHERE `mvv_studiengang`.`abschluss_id` = :abschluss_id
+
+                  UNION
+
+                  SELECT `mvv_contacts_ranges`.`contact_id`
+                  FROM `mvv_contacts_ranges`
+                  JOIN `mvv_stgteil`
+                    ON (
+                      `mvv_contacts_ranges`.`range_id` = `mvv_stgteil`.`stgteil_id`
+                      AND `mvv_contacts_ranges`.`range_type` = 'StudiengangTeil'
+                    )
+                  JOIN `mvv_stg_stgteil` USING (`stgteil_id`)
+                  JOIN `mvv_studiengang` USING (`studiengang_id`)
+                  WHERE `mvv_studiengang`.`abschluss_id` = :abschluss_id";
+
+        return DBManager::get()->fetchFirst($query, [':abschluss_id' => $abschluss_id]);
+    }
 }
diff --git a/app/controllers/studiengaenge/studiengaenge.php b/app/controllers/studiengaenge/studiengaenge.php
index e0dec62..d053f48 100644
--- a/app/controllers/studiengaenge/studiengaenge.php
+++ b/app/controllers/studiengaenge/studiengaenge.php
@@ -975,8 +975,9 @@ class Studiengaenge_StudiengaengeController extends MVVController
         if (mb_strlen(Request::get('kategorie_filter'))) {
             $this->filter['mvv_abschl_zuord.kategorie_id'] = Request::option('kategorie_filter');
         }
-        if (mb_strlen(Request::get('kategorie_filter'))) {
-            $this->filter['mvv_abschl_zuord.kategorie_id'] = Request::option('kategorie_filter');
+        // Fach
+        if (mb_strlen(Request::get('fach_filter'))) {
+            $this->filter['mvv_stgteil.fach_id'] = Request::option('fach_filter');
         }
         // Verantwortliche Einrichtung
         if (mb_strlen(Request::get('institut_filter'))) {
@@ -1057,6 +1058,7 @@ class Studiengaenge_StudiengaengeController extends MVVController
         $semesters = $semesters->orderBy('beginn desc');
         $selected_semester = $semesters->findOneBy('beginn', $this->filter['start_sem.beginn']);
 
+        $count_faecher = $this->countFaecher($studiengang_ids, $this->filter['mvv_stgteil.fach_id'] ?? '');
         $filter_template = $template_factory->render('shared/filter', [
             'semester'             => $semesters,
             'selected_semester'    => $selected_semester ? $selected_semester->id : '',
@@ -1074,6 +1076,11 @@ class Studiengaenge_StudiengaengeController extends MVVController
             'selected_institut'    => $this->filter['mvv_studiengang.institut_id'],
             'fachbereiche'         => Fach::getAllAssignedInstitutes($studiengang_ids),
             'selected_fachbereich' => $this->filter['mvv_fach_inst.institut_id'] ?? '',
+            'faecher'              => SimpleORMapCollection::createFromArray(
+                Fach::findMany(array_keys($count_faecher))
+            )->orderBy('name'),
+            'selected_fach'        => $this->filter['mvv_stgteil.fach_id'] ?? '',
+            'count_faecher'        => $count_faecher,
             'action'               => $this->action_url('set_filter'),
             'action_reset'         => $this->action_url('reset_filter')
         ]);
@@ -1130,6 +1137,35 @@ class Studiengaenge_StudiengaengeController extends MVVController
 
     }
 
+    /**
+     * Returns the number of study courses grouped by subjects for given study cours ids.
+     *
+     * @param array $studiengang_ids The ids of the study courses.
+     * @param string $fach_id The id of the selected subject.
+     * @return array Number of study courses grouped by subjects.
+     */
+    private function countFaecher(array $studiengang_ids, string $fach_id): array
+    {
+        if ($fach_id === '') {
+            $params = [':studiengang_ids' => $studiengang_ids];
+            $where = "`mvv_stg_stgteil`.`studiengang_id` IN (:studiengang_ids)";
+        } else {
+            $params = [
+                ':fach_id' => $fach_id,
+                ':studiengang_ids' => $studiengang_ids
+            ];
+            $where = "`fach`.`fach_id` = :fach_id
+                      AND `mvv_stg_stgteil`.`studiengang_id` IN (:studiengang_ids)";
+        }
+        $query = "SELECT `fach`.`fach_id`, COUNT(DISTINCT `studiengang_id`) AS `count_faecher`
+                  FROM `fach`
+                  JOIN `mvv_stgteil` USING(`fach_id`)
+                  JOIN `mvv_stg_stgteil` USING(`stgteil_id`)
+                  WHERE {$where}
+                  GROUP BY `fach_id`";
+        return DBManager::get()->fetchPairs($query, $params);
+    }
+
     public function approve_action($studiengang_id)
     {
         $this->studiengang_id = $studiengang_id;
diff --git a/app/views/shared/filter.php b/app/views/shared/filter.php
index 6674ef3..2b1e027 100644
--- a/app/views/shared/filter.php
+++ b/app/views/shared/filter.php
@@ -1,4 +1,16 @@
-<? if (!empty($selected_status) || !empty($selected_kategorie) || !empty($selected_abschluss) || !empty($selected_fachbereich) || !empty($selected_zuordnung) || !empty($selected_institut) || !empty($selected_name) || (!empty($selected_semester) && !empty($default_semester) && $selected_semester != $default_semester)) : ?>
+<? if (!empty($selected_status)
+    || !empty($selected_fach)
+    || !empty($selected_kategorie)
+    || !empty($selected_abschluss)
+    || !empty($selected_fachbereich)
+    || !empty($selected_zuordnung)
+    || !empty($selected_institut)
+    || !empty($selected_name)
+    || (
+        !empty($selected_semester)
+        && !empty($default_semester)
+        && $selected_semester !== $default_semester)
+    ) : ?>
 <div style="width: 100%; text-align: right;">
     <a href="<?= $action_reset ?>">
         <?= Icon::create('refresh', 'clickable', ['title' => _('Filter zurücksetzen')])->asImg(); ?>
@@ -9,14 +21,14 @@
 <form id="index_filter" action="<?= $action ?>" method="post">
     <? if (!empty($name_search)) : ?>
         <label class="mvv-name-search">
-            <?= $name_caption ?: _('Name') ?>:
+            <?= $name_caption ?: _('Name') ?>
             <input type="text" name="name_filter" value="<?= htmlReady($selected_name) ?>">
             <input type="submit" value="<?= _('Suchen') ?>">
         </label>
     <? endif ?>
     <? if (!empty($semester)) : ?>
     <label>
-        <?= $semester_caption ?? _('Semester') . ':' ?><br>
+        <?= $semester_caption ?? _('Semester') ?><br>
         <select name="semester_filter" class="sidebar-selectlist submit-upon-select">
             <option value="all"<?= (!$selected_semester ? ' selected' : '') ?>><?= _('Alle Semester') ?></option>
             <? foreach ($semester as $sem) : ?>
@@ -27,7 +39,7 @@
     <? endif; ?>
     <? if (!empty($zuordnungen)) : ?>
     <label>
-        <?= _('Zugeordnet zu Objekten') ?>:
+        <?= _('Zugeordnet zu Objekten') ?>
         <select name="zuordnung_filter" class="sidebar-selectlist submit-upon-select">
             <option value=""><?= _('Alle') ?></option>
             <? foreach ($zuordnungen as $object_type => $zuordnung) : ?>
@@ -39,7 +51,7 @@
     <? endif; ?>
     <? if (!empty($status)) : ?>
     <label>
-        <?= _('Status') ?>:<br>
+        <?= _('Status') ?><br>
         <select name="status_filter" class="sidebar-selectlist submit-upon-select">
             <option value=""><?= _('Alle') ?></option>
             <? foreach ($status_array as $key => $stat) : ?>
@@ -54,14 +66,35 @@
         </select>
     </label>
     <? endif; ?>
+    <? if (!empty($faecher)) : ?>
+        <label>
+            <?= _('Fach') ?><br>
+            <select name="fach_filter" class="sidebar-selectlist submit-upon-select nested-select">
+                <option value=""><?= _('Alle') ?></option>
+                <? foreach ($faecher as $fach) : ?>
+                    <option value="<?= htmlReady($fach->id) ?>"
+                        <?= $fach->id === $selected_fach ? 'selected' : '' ?>
+                    >
+                        <?= htmlReady($fach->name) . ' (' . $count_faecher[$fach->id] . ')' ?>
+                    </option>
+                <? endforeach; ?>
+            </select>
+        </label>
+    <? endif; ?>
     <? if (!empty($kategorien)) : ?>
     <label>
-        <?= _('Kategorie') ?>:<br>
+        <?= _('Kategorie') ?><br>
         <select name="kategorie_filter" class="sidebar-selectlist submit-upon-select">
             <option value=""><?= _('Alle') ?></option>
             <? foreach ($kategorien as $kategorie) : ?>
                 <option value="<?= $kategorie->id ?>"
-                    <? if ($kategorie->id === $selected_kategorie || (isset($abschluesse) && isset($abschluesse[$selected_abschluss]) && $abschluesse[$selected_abschluss]->kategorie_id == $kategorie->id)) : ?> selected<? endif; ?>>
+                    <? if (
+                        $kategorie->id === $selected_kategorie
+                        || (
+                            isset($abschluesse, $abschluesse[$selected_abschluss])
+                            && $abschluesse[$selected_abschluss]->kategorie_id == $kategorie->id
+                        )
+                    ) echo 'selected'; ?>>
                     <?= htmlReady($kategorie->name) . ' (' . $kategorie->count_objects . ')'  ?>
                 </option>
             <? endforeach; ?>
@@ -70,11 +103,15 @@
     <? endif; ?>
     <? if (!empty($abschluesse)) : ?>
     <label>
-        <?= _('Abschluss') ?>:<br>
+        <?= _('Abschluss') ?><br>
         <select name="abschluss_filter" class="sidebar-selectlist submit-upon-select">
             <option value=""><?= _('Alle') ?></option>
             <? foreach ($abschluesse as $abschluss) : ?>
-            <option value="<?= $abschluss->getId() ?>"<?= ($abschluss->getId() == $selected_abschluss ? ' selected' : '') ?>><?= htmlReady($abschluss->name) . ' (' . $abschluss->count_objects . ')' ?></option>
+            <option value="<?= htmlReady($abschluss->id) ?>"
+                <?= $abschluss->getId() == $selected_abschluss ? ' selected' : '' ?>
+            >
+                <?= htmlReady($abschluss->name) . ' (' . ($abschluss->count_objects ?? $count_abschluesse[$abschluss->id]) . ')' ?>
+            </option>
             <? endforeach; ?>
         </select>
     </label>
@@ -83,7 +120,7 @@
         <? $perm_institutes = MvvPerm::getOwnInstitutes() ?>
         <? if ($perm_institutes !== false) : ?>
         <label>
-            <?= _('Verantw. Einrichtung') ?>:<br>
+            <?= _('Verantwortliche Einrichtung') ?><br>
             <select name="institut_filter" class="sidebar-selectlist nested-select submit-upon-select">
                 <option value=""><?= _('Alle') ?></option>
                 <? foreach ($institute as $institut) : ?>
@@ -108,7 +145,7 @@
         <? $perm_institutes = MvvPerm::getOwnInstitutes() ?>
         <? if ($perm_institutes !== false) : ?>
         <label>
-            <?= _('Fachbereiche') ?>:<br>
+            <?= _('Fachbereiche') ?><br>
             <select name="fachbereich_filter" class="sidebar-selectlist nested-select institute-list submit-upon-select">
                 <option value=""><?= _('Alle') ?></option>
                 <? foreach ($fachbereiche as $fachbereich) : ?>