Made Offers a bit more robust and operation atomic

src/admin/common/models/club.php

@@ -1,5 +1,7 @@
 <?php
 
+use Joomla\CMS\Factory;
+
 // No direct access.
 defined('_JEXEC') or die;
 
@@ -162,6 +164,11 @@ class CommonClubsModelClub extends AbstractCommonClubsModel
         $offerAssocFactory = new CommonClubsModelFactoryOfferassoc();
         $offerFactory = new CommonClubsModelFactoryOffer();
         
+        $db = Factory::getDbo();
+        $db->transactionStart(true);
+        
+        try
+        {
             foreach($delIds as $id)
             {
                 $delId = (int) $id;
@@ -179,6 +186,14 @@ class CommonClubsModelClub extends AbstractCommonClubsModel
                 $o->save();
             }
         }
+        catch (Exception $ex)
+        {
+            $db->transactionRollback(true);
+            throw $ex;
+        }
+        
+        $db->transactionCommit(true);
+    }
     
     public function getUsers()
     {

src/site/controllers/parts.json.php

@@ -349,8 +349,14 @@ class ClubsHelperControllerClub extends AbstractClubsHelperController
         
         // TODO ACL needed
         
+        try
+        {
             $this->club->setOfferIds($ids);
-        $this->club->save();
+        }
+        catch(ElementNotFoundException $ex)
+        {
+            throw new InvalidUserDataException('Es gab ein Problem mit der Eingabe. Bitte Seite neu laden und Daten erneut eintragen.');
+        }
     }
 }