Alles auf Englisch umbenannt: exhibition → event, Variablen und Tabellen angepasst, Views auf neue Felder umgestellt, Controller/Model/SQL konsistent gemacht. Alte Variablennamen raus, jetzt ist alles einheitlich. Fehler aus dem Frontend gefixt.

Controller/VoucherController.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace Blog\Controller;
+
+use Blog\Model\VoucherModel;
+
+class VoucherController {
+
+    private $model;
+    private $view;
+
+    public function __construct($view) {
+        $this->model = new VoucherModel();
+        $this->view = $view;
+    }
+
+    public function showVouchers() {
+        $vouchers = $this->model->getVouchers();
+        $this->view->setVars(['vouchers' => $vouchers]);
+    }
+
+    public function createVoucher() {
+        $data = [
+            'code' => $_POST['code'] ?? null,
+            'discount' => $_POST['discount'] ?? null,
+            'event_id' => $_POST['event_id'] ?? null,
+            'valid_until' => $_POST['valid_until'] ?? null
+        ];
+        $result = $this->model->createVoucher($data);
+        $this->view->setVars(['voucher' => $result]);
+        exit;
+    }
+
+    public function editVoucherForm() {
+        $id = $_GET['voucher_id'];
+        if ($id) {
+            $voucher = $this->model->getVoucher($id);
+            $this->view->setVars(['voucher' => $voucher]);
+        }
+    }
+
+    public function updateVoucher() {
+        $id = $_POST['voucher_id'];
+        $data = [
+            'code' => $_POST['code'] ?? null,
+            'discount' => $_POST['discount'] ?? null,
+            'event_id' => $_POST['event_id'] ?? null,
+            'valid_until' => $_POST['valid_until'] ?? null
+        ];
+        $this->model->updateVoucher($id, $data);
+    }
+
+    public function deleteVoucher() {
+        $id = $_GET['voucher_id'] ?? null;
+        $this->model->deleteVoucher($id);
+    }
+}