perf: optimize badge checking

combo/data/models.py

@@ -381,23 +381,30 @@ class CellBase(models.Model):
         return self.__class__.__name__.lower() + ' ' + self.extra_css_class
 
     @classmethod
-    def get_all_cell_types(cls):
-        cell_types = []
+    def get_cell_classes(cls, class_filter=lambda x: True):
         for klass in get_cell_classes():
+            if not class_filter(klass):
+                continue
             if not klass.is_enabled():
                 continue
             if klass.visible is False:
                 continue
+            yield klass
+
+    @classmethod
+    def get_all_cell_types(cls):
+        cell_types = []
+        for klass in cls.get_cell_classes():
             cell_types.extend(klass.get_cell_types())
         return cell_types
 
     @classmethod
-    def get_cells(cls, concrete=True, **kwargs):
+    def get_cells(cls, concrete=True, subclasses=(), **kwargs):
         """Returns a queryset of cells of various classes matching **kwargs"""
         queryset = cls.objects.filter(**kwargs).order_by('order')
         if not concrete:
             return queryset
-        return queryset.select_subclasses()
+        return queryset.select_subclasses(*subclasses)
 
     def get_reference(self):
         "Returns a string that can serve as a unique reference to a cell"""

combo/public/views.py

@@ -218,14 +218,13 @@ def skeleton(request):
     cells = list(cells)
     extend_with_parent_cells(cells)
 
-    cell_with_badges = [x for x in CellBase.get_cells() if bool(x.get_badge)]
     ctx = {
         'page': selected_page,
         'page_cells': cells,
         'pages': pages,
         'request': request,
         'render_skeleton': True,
-        'check_badges': bool(cell_with_badges),
+        'check_badges': should_check_badges(),
         'site_base': request.build_absolute_uri('/')[:-1],
     }
 
@@ -337,6 +336,14 @@ def page(request):
 
     return publish_page(request, page)
 
+def should_check_badges():
+    check_badges = False
+    for klass in CellBase.get_cell_classes(lambda x: bool(x.get_badge)):
+        check_badges = klass.objects.all().exists()
+        if check_badges:
+            break
+    return check_badges
+
 def publish_page(request, page, status=200, template_name=None):
     pages = page.get_parents_and_self()
 
@@ -352,10 +359,9 @@ def publish_page(request, page, status=200, template_name=None):
     cells = list(CellBase.get_cells(page_id=page.id))
     extend_with_parent_cells(cells)
     cells = [x for x in cells if x.is_visible(user=request.user)]
-    cell_with_badges = [x for x in CellBase.get_cells() if bool(x.get_badge)]
 
     ctx = {
-        'check_badges': bool(cell_with_badges),
+        'check_badges': should_check_badges(),
         'page': page,
         'page_cells': cells,
         'pages': pages,