User assiciations are changable from within the backend interface from the clubs.

src/admin/views/clubposition/view.html.php

@@ -1,6 +1,7 @@
 <?php
 
 use Joomla\CMS\MVC\View\HtmlView;
+use Joomla\CMS\Factory;
 
 // No direct access.
 defined('_JEXEC') or die;
@@ -12,13 +13,37 @@ class ClubsViewClubPosition extends HtmlView
 
     function display($tpl = null)
     {
-        
+        $input = Factory::getApplication()->input->get;
         $positonFactory = new CommonClubsModelFactoryPosition();
         $userFactory = new CommonClubsModelFactoryUser();
         $this->positions = $positonFactory->loadElements();
         $this->users = $userFactory->loadElements();
         
-        $this->id = 'new';
+        $id = $input->getCmd('id', 'new');
+        $assocFactory = new CommonClubsModelFactoryUserassoc();
+        
+        if($id !== 'new')
+        {
+            $id = (int) $id;
+            
+            $this->assoc = $assocFactory->loadById($id);
+        }
+        else
+        {
+            $this->assoc = $assocFactory->createNew();
+        }
+        
+        $this->id = $id;
+        $this->clubid = $input->getInt('club');
+        
+        $this->username = '<i>Derzeit vakant.</i>';
+        $this->usercity = '';
+        if($this->assoc->getUser() !== null)
+        {
+            $u = $this->assoc->getUser();
+            $this->username = htmlentities($u->getName());
+            $this->usercity = htmlentities($u->getCity());
+        }
         
         parent::display($tpl);