Propagate skiprtypes to subentities cw_skip_copy_for while cloning

We have to consider it at every levels of the container tree, not only for the
top-level entity.

While doing so, it sounded good to move creation of the list to a cached
property to avoid redoing this for each cloned entity of the tree.

cubicweb_compound/entities.py

-# copyright 2015-2016 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# copyright 2015 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
 # contact http://www.logilab.fr -- mailto:contact@logilab.fr
 #
 # This program is free software: you can redistribute it and/or modify it under
@@ -29,9 +29,11 @@
 
 from itertools import chain
 
+from logilab.common.decorators import cachedproperty
+
 from cubicweb.view import EntityAdapter
 from cubicweb.predicates import is_instance, partial_relation_possible
 
 from . import CompositeGraph
 
 
@@ -32,10 +34,10 @@
 from cubicweb.view import EntityAdapter
 from cubicweb.predicates import is_instance, partial_relation_possible
 
 from . import CompositeGraph
 
 
-def copy_entity(original, **attributes):
+def copy_entity(original, cw_skip_copy_for=None, **attributes):
     """Return a copy of an entity.
 
     Only attributes and non-composite relations are copied (relying on
@@ -50,7 +52,9 @@
         attr = rschema.type
         attrs.setdefault(attr, original.cw_attr_value(attr))
     clone = original._cw.create_entity(original.cw_etype, **attrs)
+    if cw_skip_copy_for is not None:
+        _extend_skip_copy_for(clone, cw_skip_copy_for)
     clone.copy_relations(original.eid)
     return clone
 
 
@@ -53,7 +57,14 @@
     clone.copy_relations(original.eid)
     return clone
 
 
+def _extend_skip_copy_for(clone, cw_skip_copy_for):
+    # take care not modifying clone.cw_skip_copy_for **class attribute** to
+    # avoid undesired side effects (e.g. clone called with different
+    # skiprtypes value), so set an instance attribute.
+    clone.cw_skip_copy_for = set(clone.cw_skip_copy_for) | cw_skip_copy_for
+
+
 class IContainer(EntityAdapter):
     """Abstract adapter for entities which are a container root."""
     __abstract__ = True
@@ -203,14 +214,9 @@
         assert clone.cw_etype == self.entity.cw_etype, \
             "clone entity type {} does not match with original's {}".format(
                 clone.cw_etype, self.entity.cw_etype)
-        related = self.graph.child_related(
-            self.entity, follow_relations=self.follow_relations)
-        # take care not modifying clone.cw_skip_copy_for class attribute to avoid undesired side
-        # effects (e.g. clone called with different skiprtypes value), set an instance attribute.
-        clone.cw_skip_copy_for = list(chain(
-            clone.cw_skip_copy_for,
-            ((rtype, 'subject') for rtype in self.skiprtypes),
-            ((rtype, 'object') for rtype in self.skiprtypes)))
+        related = list(self.graph.child_related(
+            self.entity, follow_relations=self.follow_relations))
+        _extend_skip_copy_for(clone, self.skip_swallow_copy_for)
         with self._cw.deny_all_hooks_but(*self.enabled_hook_categories):
             clone.copy_relations(self.entity.eid)
             clones = {self.entity: clone}
@@ -221,6 +227,7 @@
                 if clone is not None:
                     clone.cw_set(**kwargs)
                 else:
-                    clones[child] = copy_entity(child, **kwargs)
+                    clones[child] = copy_entity(
+                        child, self.skip_swallow_copy_for, **kwargs)
             return clones
 
@@ -225,5 +232,13 @@
             return clones
 
+    @cachedproperty
+    def skip_swallow_copy_for(self):
+        return set(chain(
+            # turn skiprtypes into a list suitable for Entity.cw_skip_copy_for
+            ((rtype, 'subject') for rtype in self.skiprtypes),
+            ((rtype, 'object') for rtype in self.skiprtypes),
+        ))
+
 
 def registration_callback(vreg):
     vreg.register_all(globals().values(), __name__)

test/data/schema.py

@@ -107,3 +107,8 @@
     """Indicates a member of a Group."""
     subject = 'Group'
     object = 'Agent'
+
+
+class see_also(RelationDefinition):
+    subject = 'Biography'
+    object = 'Event'

test/test_compound.py

@@ -361,6 +361,16 @@
             self.assertFalse(clone.reverse_member)
             self.assertIs(bob.cw_skip_copy_for, orig_cw_skip_copy_for)
 
+    def test_clone_skiprtypes_sublevel(self):
+        with self.admin_access.repo_cnx() as cnx:
+            event = cnx.create_entity('Event')
+            bio = cnx.create_entity('Biography', event=event, see_also=event)
+            cnx.create_entity('Agent', name=u'bob', biography=bio)
+            cnx.commit()
+
+            clone = clone_agent(cnx, u'bob', skiprtypes=('see_also',))
+            self.assertEqual(clone.biography[0].see_also, ())
+
     def test_clone_full(self):
         with self.admin_access.repo_cnx() as cnx:
             agent = cnx.create_entity('Agent', name=u'bob')