Applicatie afmaken en GUI-flow herstellen

Voegt boodschappenlijsten, productbeheer, realtime synchronisatie en browsercache-updates toe. Herstelt login- en sessiegedrag en maakt database-seeding herhaalbaar.\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

controllers/ProductController.js

@@ -1,29 +1,50 @@
 const ProductService =
 require("../services/ProductService");
 
+const db = require("../config/database");
 
 class ProductController {
 
 
-    index(req,res) {
-
+    index(req, res) {
 
         const products =
         ProductService.getProducts();
 
+        const categories = db.prepare(
+            "SELECT * FROM categories ORDER BY name"
+        ).all();
 
         res.render(
             "products/index",
             {
-
                 title:"Producten",
-
-                products
-
+                products,
+                categories
             }
+
         );
 
+    }
 
+    create(req, res) {
+        const name = (req.body.name || "").trim();
+        const categoryId = req.body.category_id
+            ? Number.parseInt(req.body.category_id, 10)
+            : null;
+
+        if (!name || (categoryId !== null && !Number.isInteger(categoryId))) {
+            req.flash("error", "Geef een geldige productnaam en categorie op.");
+            return res.redirect("/products");
+        }
+
+        ProductService.createProduct({
+            name,
+            category_id: categoryId
+        });
+
+        req.flash("success", "Product toegevoegd.");
+        res.redirect("/products");
     }