fix errors in mvv models, fixes #1230

Closes #1230

Merge request studip/studip!741

lib/classes/ModuleManagementInterface.php

+<?php
+/**
+ * This interface ensures that all objects of ModuleManagementModel have
+ * the same constructor signature. Otherwise, we can not guarantee that the
+ * use of "new static()" in ModuleManagement code will always do the right
+ * things.
+ *
+ * @author Jan-Hendrik Willms <tleilax+studip@gmail.com>
+ * @license GPL2 or any later version
+ */
+interface ModuleManagementInterface
+{
+    public function __construct($id = null);
+}

lib/models/Lvgruppe.php

@@ -364,7 +364,7 @@ class Lvgruppe extends ModuleManagementModelTreeItem
      */
     public function getTrailParent()
     {
-        return Modul::findCached($this->getTrailParent_id());
+        return Modul::findCached($this->getTrailParentId());
     }
 
     /**

lib/models/ModuleManagementModel.php

@@ -16,7 +16,7 @@
 
 require_once 'config/mvv_config.php';
 
-abstract class ModuleManagementModel extends SimpleORMap
+abstract class ModuleManagementModel extends SimpleORMap implements ModuleManagementInterface
 {
     /**
      * Usable as option for ModuleManagementModel::getDisplayName().
@@ -133,7 +133,7 @@ abstract class ModuleManagementModel extends SimpleORMap
     /**
      * Returns an object by given id with all relations and additional fields.
      *
-     * @param tring $id The id of the object.
+     * @param string $id The id of the object.
      * @return ModuleManagementModel
      */
     public static function getEnriched($id)
@@ -493,7 +493,7 @@ abstract class ModuleManagementModel extends SimpleORMap
      * @param array $params Array with the parameters used in query
      * @param int $row_count Number of rows to return
      * @param int $offset Offset where the result set starts
-     * @return object SimpleOrMapCollection with all found objects or empty array
+     * @return SimpleOrMapCollection with all found objects or empty array
      */
     public static function getEnrichedByQuery($query = null, $params = [],
             $row_count = null, $offset = null)

lib/models/ModuleManagementModelTreeItem.php

@@ -14,8 +14,6 @@
  * @since       3.5
  */
 
-require_once 'ModuleManagementModel.php';
-
 abstract class ModuleManagementModelTreeItem extends ModuleManagementModel implements MvvTreeItem
 {
     /**

lib/models/Modulteil.php

@@ -99,7 +99,7 @@ class Modulteil extends ModuleManagementModelTreeItem
     /**
      * Retrieves all Modulteile of the given Modul.
      *
-     * @param type $modul_id The id of a Modul.
+     * @param string $modul_id The id of a Modul.
      * @return SimpleORMapCollection A collection of Modulteile.
      */
     public static function findByModul($modul_id)
@@ -119,7 +119,7 @@ class Modulteil extends ModuleManagementModelTreeItem
     /**
      * Retrieves all Modulteile the given LV-Gruppe is assigned to.
      *
-     * @param type $lvgruppe_id The id of a LV-Gruppe.
+     * @param string $lvgruppe_id The id of a LV-Gruppe.
      * @return SimpleORMapCollection A collection of Modulteile.
      */
     public static function findByLvgruppe($lvgruppe_id)

lib/models/MvvCourse.php

@@ -37,7 +37,7 @@ class MvvCourse extends ModuleManagementModelTreeItem
      */
     public function getTrailParent()
     {
-        return LvGruppe::findCached($this->getTrailParent_id());
+        return LvGruppe::findCached($this->getTrailParentId());
     }
 
     /**
@@ -58,7 +58,7 @@ class MvvCourse extends ModuleManagementModelTreeItem
 
     public function getDisplayName($options = self::DISPLAY_DEFAULT)
     {
-        $this->getName();
+        return $this->name;
     }
 
     /**

lib/models/MvvFileFileref.php

@@ -44,12 +44,14 @@ class MvvFileFileref extends ModuleManagementModel
      *
      * @return string Name of the file.
      */
-    public function getFilename()
+    public function getFilename(): string
     {
         if ($this->file_ref) {
             $filetype = $this->file_ref->getFileType();
             return $filetype->getFilename();
         }
+
+        throw new Exception("Could not load file ref for file");
     }
 
     /**
@@ -92,5 +94,7 @@ class MvvFileFileref extends ModuleManagementModel
                 }
             }
         }
+
+        return false;
     }
 }