Fix HTTP 500 error during add-on product checkout (#1257)

Users encountered HTTP 500 Internal Server Error when purchasing products
with add-ons during checkout. The error was caused by calling .products()
method on dictionaries instead of .items().

Changed .products() to .items() in three files:
- app/eventyay/presale/checkoutflowstep/add_ons_step.py (line 213)
- app/eventyay/base/services/cart.py (line 918)
- app/eventyay/api/serializers/event.py (line 270)

This resolves HTTP 500 errors during checkout and allows users to
complete purchases with add-on products.

Co-authored-by: Mario Behling <[email protected]>

Author: ArnavBallinCode

app/eventyay/api/serializers/event.py

@@ -267,7 +267,7 @@ def create(self, validated_data):
 
         # Product Meta properties
         if product_meta_properties is not None:
-            for key, value in product_meta_properties.products():
+            for key, value in product_meta_properties.items():
                 event.product_meta_properties.create(name=key, default=value, event=event)
 
         # Seats

app/eventyay/base/services/cart.py

@@ -915,7 +915,7 @@ def set_addons(self, addons):
             for iao in product.addons.all():
                 selected = selected_addons[cp.id, iao.addon_category_id]
                 n_per_i = Counter()
-                for (i, v), c in selected.products():
+                for (i, v), c in selected.items():
                     n_per_i[i] += c
                 if sum(selected.values()) > iao.max_count:
                     # TODO: Proper i18n

app/eventyay/presale/checkoutflowstep/add_ons_step.py

@@ -210,7 +210,7 @@ def _clean_category(self, form, category):
 
         total_selected_quantity = sum(a[0] for a in selected.values())
         exceeds_single_allowed = (
-            any(sum(v[0] for k, v in selected.products() if k[0] == i) > 1 for i in category['products'])
+            any(sum(v[0] for k, v in selected.items() if k[0] == i) > 1 for i in category['products'])
             and not category['multi_allowed']
         )