refactoring using get_object_with_direct_siblings

shop/views/catalog.py

@@ -260,7 +260,7 @@ class ProductRetrieveView(generics.RetrieveAPIView):
     :param use_modal_dialog: If ``True`` (default), render a modal dialog to confirm adding the
         product to the cart.
 
-    :param one_product: If ``False`` (no default), product_prev, product_next are added to the context.
+    :param with_direct_siblings: If ``True`` (no default), product_prev, product_next are added to the context.
     """
 
     renderer_classes = (ShopTemplateHTMLRenderer, JSONRenderer, BrowsableAPIRenderer)
@@ -269,7 +269,7 @@ class ProductRetrieveView(generics.RetrieveAPIView):
     serializer_class = ProductSerializer
     limit_choices_to = models.Q()
     use_modal_dialog = True
-    one_product = True
+    with_direct_siblings = False
 
     def dispatch(self, request, *args, **kwargs):
         """
@@ -312,7 +312,7 @@ def get_renderer_context(self):
         renderer_context = super(ProductRetrieveView, self).get_renderer_context()
         if renderer_context['request'].accepted_renderer.format == 'html':
             # add the product as Python object to the context
-            if self.one_product:
+            if not self.with_direct_siblings:
                 product = self.get_object()
                 renderer_context.update(
                     app_label=product._meta.app_label.lower(),
@@ -321,6 +321,7 @@ def get_renderer_context(self):
                 )
             else:
                 product = self.get_object()
+                self.product_prev, self.product_next = self.get_object_with_direct_siblings(product) 
                 renderer_context.update(
                     app_label=product._meta.app_label.lower(),
                     product_prev=self.product_prev,
@@ -333,39 +334,33 @@ def get_renderer_context(self):
     def get_object(self):
         if not hasattr(self, '_product'):
             assert self.lookup_url_kwarg in self.kwargs
-            if self.one_product:
-                filter_kwargs = {
-                    'active': True,
-                    self.lookup_field: self.kwargs[self.lookup_url_kwarg],
-                }
-                if hasattr(self.product_model, 'translations'):
-                    filter_kwargs.update(translations__language_code=get_language_from_request(self.request))
-                queryset = self.product_model.objects.filter(self.limit_choices_to, **filter_kwargs)
-                self._product = get_object_or_404(queryset)
-            else:
-                filter_kwargs = {
-                    'active': True,
-                }
-                slug = self.kwargs[self.lookup_url_kwarg]
-                if hasattr(self.product_model, 'translations'):
-                    filter_kwargs.update(translations__language_code=get_language_from_request(self.request))
-                queryset = self.product_model.objects.filter(self.limit_choices_to, **filter_kwargs)
-                queryset = CMSPagesFilterBackend().filter_queryset(self.request, queryset, self)
-                self.product_prev , self.product_cur, self.product_next = self.prev_cur_next_products(queryset, slug)
-                self._product = get_object_or_404(ProductModel, id=self.product_cur.id)
+            filter_kwargs = {
+                'active': True,
+                self.lookup_field: self.kwargs[self.lookup_url_kwarg],
+            }
+            if hasattr(self.product_model, 'translations'):
+                filter_kwargs.update(translations__language_code=get_language_from_request(self.request))
+            queryset = self.product_model.objects.filter(self.limit_choices_to, **filter_kwargs)
+            self._product = get_object_or_404(queryset)
         return self._product
 
-    def prev_cur_next_products(self, objects, slug):
-        prev = cur = next = None
-        nb = len(list(objects))
-        for index, obj in enumerate(objects):
-            if obj.slug == slug:
-                cur = objects[index]
+    def get_object_with_direct_siblings(self, product):
+        previous = next = None
+        filter_siblings = {
+            'active': True,
+        }
+        if hasattr(self.product_model, 'translations'):
+            filter_siblings.update(translations__language_code=get_language_from_request(self.request))
+        queryset = self.product_model.objects.filter(self.limit_choices_to, **filter_siblings)
+        queryset = CMSPagesFilterBackend().filter_queryset(self.request, queryset, self)
+        nb = queryset.count()
+        for index, obj in enumerate(queryset):
+            if obj.slug == product.slug:
                 if index > 0:
-                    prev = objects[index-1]
+                    previous = queryset[index-1]
                 if index < (nb - 1):
-                    next = objects[index+1]
-        return prev, cur, next
+                    next = queryset[index+1]
+        return previous, next
 
 class OnePageResultsSetPagination(pagination.PageNumberPagination):
     def __init__(self):