misc: don't invalidate cache when evaluating conditions (#22540)

tests/test_form_pages.py

@@ -767,6 +767,32 @@ def test_form_multi_page_condition_no_visible_page(pub):
     formdef.store()
     get_app(pub).get('/test/', status=404)
 
+def test_form_multi_page_many_conditions(pub):
+    formdef = create_formdef()
+    formdef.fields = [
+        fields.PageField(id='0', label='1st page', type='page'),
+        fields.PageField(id='0', label='2nd page', type='page',
+                condition={'type': 'python', 'value': 'True'}),
+    ]
+
+    formdef.store()
+    formdef.data_class().wipe()
+
+    with mock.patch('qommon.publisher.Substitutions.invalidate_cache') as invalidate_cache:
+        resp = get_app(pub).get('/test/')
+        call_count = invalidate_cache.call_count
+
+    for i in range(30):
+        formdef.fields.append(fields.PageField(
+                id=str(i+2), label='page %s' % (i+2), type='page',
+                condition={'type': 'python', 'value': 'True'}))
+    formdef.store()
+
+    # check the cache doesn't get invalidated for every page
+    with mock.patch('qommon.publisher.Substitutions.invalidate_cache') as invalidate_cache:
+        resp = get_app(pub).get('/test/')
+        assert invalidate_cache.call_count == call_count
+
 def test_form_multi_page_post_conditions(pub):
     formdef = create_formdef()
     formdef.fields = [fields.PageField(id='0', label='1st page', type='page'),

wcs/fields.py

@@ -1564,6 +1564,16 @@ class PageField(Field):
             def get_substitution_variables(self):
                 return form_live_data
 
+            def __eq__(self, other):
+                # Assume all ConditionVars are equal (as they are because they
+                # are created using the same live data); this avoids filling
+                # the substitution sources with duplicates and invalidating its
+                # cache.
+                try:
+                    return self.__class__.__name__ == other.__class__.__name__
+                except AttributeError:
+                    return False
+
         get_publisher().substitutions.feed(ConditionVars())
         data = get_publisher().substitutions.get_context_variables()
         # 2) add live data as var_ variables for local evaluation only, for

wcs/qommon/substitution.py

@@ -56,14 +56,15 @@ class Substitutions(object):
     def reset(self):
         self.sources = []
 
-    @invalidate_substitution_cache
     def feed(self, source):
         if source is None:
             # silently ignore a None source, this is for example useful when
             # adding the current user, as it may be None if he is not logged
             # in.
             return
-        self.sources.append(source)
+        if not source in self.sources:
+            self.sources.append(source)
+            self.invalidate_cache()
 
     @classmethod
     def invalidate_cache(cls):