combo/apps/wcs/models.py

@@ -822,6 +822,19 @@ class CardMixin:
         return escape(self.custom_title) or self.cached_title or None
 
 
+class LazyValue:
+    sentinel = object()
+
+    def __init__(self, getter):
+        self.value = self.sentinel
+        self.getter = getter
+
+    def __call__(self):
+        if self.value is self.sentinel:
+            self.value = self.getter()
+        return self.value
+
+
 @register_cell_class
 class WcsCardCell(CardMixin, CellBase):
     carddef_reference = models.CharField(_('Card Model'), max_length=150)
@@ -872,6 +885,12 @@ class WcsCardCell(CardMixin, CellBase):
     class Meta:
         verbose_name = _('Card(s)')
 
+    def get_card_ids(self, context):
+        lazy_value = context.get(self.global_context_key)
+        if lazy_value is not None:
+            return lazy_value()
+        return []
+
     def save(self, *args, **kwargs):
         super().save(*args, **kwargs)
 
@@ -960,14 +979,14 @@ class WcsCardCell(CardMixin, CellBase):
             # don't call wcs on page loading
             return
         if self.carddef_reference and self.global_context_key not in context:
-            card_ids = self.get_card_ids(context, request)
-            context[self.global_context_key] = card_ids
+            # self.resolve_card_ids(context, request)
+            context[self.global_context_key] = LazyValue(lambda: self.resolve_card_ids(context, request))
 
     def get_repeat_template(self, context):
         if self.display_mode == 'table':
             # don't repeat cell if table display mode
             return []
-        return len(context.get(self.global_context_key) or [])
+        return len(self.get_card_ids(context))
 
     def get_related_card_path(self):
         if self.related_card_path == '__all__':
@@ -1026,7 +1045,7 @@ class WcsCardCell(CardMixin, CellBase):
 
     def get_card_data_from_ids(self, card_id, context):
         # get the correct card from all known cards for ids in context
-        card_ids = context.get(self.global_context_key)
+        card_ids = self.get_card_ids(context)
         if not card_ids:
             return None
         if len(card_ids) == 1:
@@ -1324,7 +1343,7 @@ class WcsCardCell(CardMixin, CellBase):
         except (VariableDoesNotExist, TemplateSyntaxError):
             return []
 
-    def get_card_ids(self, original_context, request):
+    def resolve_card_ids(self, original_context, request):
         if not self.carddef_reference:
             # not configured
             return []
@@ -1367,10 +1386,10 @@ class WcsCardCell(CardMixin, CellBase):
         return []
 
     def get_card_id(self, context):
-        repeat_index = getattr(self, 'repeat_index', context.get('repeat_index'))
+        repeat_index = getattr(self, 'repeat_index', context.get('repeat_index')) or 0
         if repeat_index is not None:
             try:
-                return context.get(self.global_context_key)[repeat_index]
+                return self.get_card_ids(context)[repeat_index]
             except (IndexError, TypeError):
                 return None
 
@@ -1475,7 +1494,7 @@ class WcsCardCell(CardMixin, CellBase):
             card_page = matching_pages[0]
             extra_context['card_page_base_url'] = card_page.get_online_url()
 
-        card_ids = context.get(self.global_context_key)
+        card_ids = self.get_card_ids(context)
         if not card_ids and self.related_card_path != '__all__':
             extra_context['card_objects'] = []
         else:

tests/wcs/test_card.py

@@ -1360,7 +1360,7 @@ def test_card_cell_table_mode_render_identifier(mock_send, nocache, app):
 
 
 @mock.patch('requests.Session.send', side_effect=mocked_requests_send)
-def test_card_cell_table_mode_render_identifier_from_related(mock_send, nocache, app):
+def test_card_cell_table_mode_render_identifier_from_related(mock_send, app):
     page = Page.objects.create(title='xxx', slug='foo', template_name='standard')
     WcsCardCell.objects.create(
         page=page,
@@ -1407,6 +1407,8 @@ def test_card_cell_table_mode_render_identifier_from_related(mock_send, nocache,
     check(urls)
 
     # direct and multiple relation (items)
+    # clear cache to see call to /api/cards/card_a/1/
+    cache.clear()
     cell2.carddef_reference = 'default:card_b'  # reset
     cell2.related_card_path = 'sluga/cardsb'
     cell2.save()
@@ -1419,6 +1421,43 @@ def test_card_cell_table_mode_render_identifier_from_related(mock_send, nocache,
     check(urls)
 
 
+@mock.patch('requests.Session.send', side_effect=mocked_requests_send)
+def test_card_cell_table_mode_lazy_card_ids(mock_send, nocache, app):
+    '''Check if templated card_ids are resolved for other non related cells on
+    the same page, like a templated text cell.'''
+    page = Page.objects.create(title='xxx', slug='foo', template_name='standard')
+    WcsCardCell.objects.create(
+        page=page,
+        placeholder='content',
+        order=0,
+        display_mode='table',
+        slug='sluga',
+        carddef_reference='default:card_a',
+        card_ids='{{ cards|objects:"card_model_1"|getlist:"id"|join:"," }}',
+        related_card_path='',
+    )
+    TextCell.objects.create(
+        page=page,
+        placeholder='content',
+        order=1,
+        slug='slugb',
+        text='{{ cards|objects:"card_model_x"|getlist:"id"|join:"," }}',
+    )
+
+    resp = app.get(page.get_online_url())
+    cell_divs = resp.pyquery('div.cell')
+    assert len(cell_divs) == 2
+    send_counts = {}
+    for cell_div in cell_divs.items():
+        mock_send.reset_mock()
+        cell_url = cell_div.attr['data-ajax-cell-url']
+        extra_context = cell_div.attr['data-extra-context']
+        app.get(cell_url + '?ctx=' + extra_context)
+        send_counts[cell_div.attr['id']] = len(mock_send.call_args_list)
+    # rendering of "slugb" text cell should not make any request.
+    assert send_counts == {'sluga': 2, 'slugb': 0}
+
+
 @mock.patch('requests.Session.send', side_effect=mocked_requests_send)
 def test_card_cell_table_mode_render_title(mock_send, context):
     page = Page.objects.create(title='xxx', template_name='standard')
@@ -2275,10 +2314,10 @@ def test_card_cell_card_mode_render_custom_schema_link_entry(mock_send, context,
     assert PyQuery(result).find('.value a').attr['class'] is None
 
     # empty label or no value/no file field/unknown field: no link in output
-    context[cell.global_context_key] = [12]
+    context[cell.global_context_key] = lambda: [12]
     result = cell.render(context)
     assert PyQuery(result).find('.value a') == []
-    context[cell.global_context_key] = [11]
+    context[cell.global_context_key] = lambda: [11]
     cell.modify_global_context(context, request)
     cell.repeat_index = 0
     cell.custom_schema['cells'][0]['link_field'] = 'fielda'
@@ -2559,12 +2598,7 @@ def test_card_cell_card_mode_render_identifier_from_related(mock_send, nocache,
     # multiple ids configured on first cell
     cell.card_ids = '{{ cards|objects:"card_a"|getlist:"id"|join:"," }}'
     cell.save()
-    failing(
-        urls=[
-            # get first cell data
-            '/api/cards/card_a/list',
-        ]
-    )
+    failing(urls=[])
 
     # related_card_path configured on first cell
     cell.card_ids = '1'  # reset