Refactors the product_category view to be much simpler

registrasion/views.py

@@ -93,19 +93,18 @@ def product_category(request, category_id):
     PRODUCTS_FORM_PREFIX = "products"
     VOUCHERS_FORM_PREFIX = "vouchers"
 
+    # Handle the voucher form *before* listing products.
+    # Products can change as vouchers are entered.
+    v = handle_voucher(request, VOUCHERS_FORM_PREFIX)
+    voucher_form, voucher_handled = v
+
+    # Handle the products form
     category_id = int(category_id)  # Routing is [0-9]+
     category = rego.Category.objects.get(pk=category_id)
     current_cart = CartController.for_user(request.user)
 
     attendee = rego.Attendee.get_instance(request.user)
 
-    # Handle the voucher form *before* listing products.
-    v = handle_voucher(request, VOUCHERS_FORM_PREFIX)
-    voucher_form, voucher_handled = v
-    if voucher_handled:
-        # Do not handle product form
-        pass
-
     products = rego.Product.objects.filter(category=category)
     products = products.order_by("order")
     products = ProductController.available_products(
@@ -115,17 +114,33 @@ def product_category(request, category_id):
 
     ProductsForm = forms.ProductsForm(products)
 
-    if request.method == "POST":
-        cat_form = ProductsForm(
-            request.POST,
-            request.FILES,
-            prefix=PRODUCTS_FORM_PREFIX)
-
-        if voucher_handled:
-            # The voucher form was handled here.
-            pass
-        elif cat_form.is_valid():
+    # Create initial data for each of products in category
+    items = rego.ProductItem.objects.filter(
+        product__category=category,
+        cart=current_cart.cart,
+    )
+    quantities = []
+    for product in products:
+        # Only add items that are enabled.
         try:
+            quantity = items.get(product=product).quantity
+        except ObjectDoesNotExist:
+            quantity = 0
+        quantities.append((product, quantity))
+
+    cat_form = ProductsForm(
+        request.POST or None,
+        product_quantities=quantities,
+        prefix=PRODUCTS_FORM_PREFIX,
+    )
+
+    if (
+        not voucher_handled and
+        request.method == "POST" and
+        cat_form.is_valid()):
+
+        try:
+            if cat_form.has_changed():
                 handle_valid_cat_form(cat_form, current_cart)
         except ValidationError:
             pass
@@ -134,8 +149,7 @@ def product_category(request, category_id):
         # in an active+valid cart
 
         if category.required:
-                carts = rego.Cart.reserved_carts()
-                carts = carts.filter(user=request.user)
+            carts = rego.Cart.reserved_carts().filter(user=request.user)
             items = rego.ProductItem.objects.filter(
                 product__category=category,
                 cart=carts,
@@ -152,27 +166,8 @@ def product_category(request, category_id):
                 attendee.save()
             return redirect("dashboard")
 
-    else:
-        # Create initial data for each of products in category
-        items = rego.ProductItem.objects.filter(
-            product__category=category,
-            cart=current_cart.cart,
-        )
-        quantities = []
-        for product in products:
-            # Only add items that are enabled.
-            try:
-                quantity = items.get(product=product).quantity
-            except ObjectDoesNotExist:
-                quantity = 0
-            quantities.append((product, quantity))
-
-        cat_form = ProductsForm(
-            prefix=PRODUCTS_FORM_PREFIX,
-            product_quantities=quantities,
-        )
-
     discounts = discount.available_discounts(request.user, [], products)
+
     data = {
         "category": category,
         "discounts": discounts,