From f182daa85eae94ccfffaa40e04f6370c007d10c4 Mon Sep 17 00:00:00 2001
From: Ross Lawley <ross.lawley@gmail.com>
Date: Mon, 28 Jan 2013 13:32:21 +0000
Subject: [PATCH] Fixed Documents deleted via a queryset don't call any signals
 (#105)

---
 docs/changelog.rst               |  1 +
 mongoengine/queryset/queryset.py | 11 ++++++---
 tests/document/instance.py       | 40 ++++++++++++++++++++++++++++++--
 3 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/docs/changelog.rst b/docs/changelog.rst
index 601c2dbc..8b41d6ee 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -43,6 +43,7 @@ Changes in 0.8.X
 - Undefined data should not override instance methods (#49)
 - Added Django Group and Permission (#142)
 - Added Doc class and pk to Validation messages (#69)
+- Fixed Documents deleted via a queryset don't call any signals (#105)
 
 Changes in 0.7.9
 ================
diff --git a/mongoengine/queryset/queryset.py b/mongoengine/queryset/queryset.py
index b5e33515..65703c32 100644
--- a/mongoengine/queryset/queryset.py
+++ b/mongoengine/queryset/queryset.py
@@ -364,10 +364,15 @@ class QuerySet(object):
         queryset = self.clone()
         doc = queryset._document
 
-        # Handle deletes where skips or limits have been applied
-        if queryset._skip or queryset._limit:
+        has_delete_signal = (
+            signals.pre_delete.has_receivers_for(self._document) or
+            signals.post_delete.has_receivers_for(self._document))
+
+        # Handle deletes where skips or limits have been applied or has a
+        # delete signal
+        if queryset._skip or queryset._limit or has_delete_signal:
             for doc in queryset:
-                doc.delete()
+                doc.delete(safe=safe)
             return
 
         delete_rules = doc._meta.get('delete_rules') or {}
diff --git a/tests/document/instance.py b/tests/document/instance.py
index 3d4e8a97..172f0ccf 100644
--- a/tests/document/instance.py
+++ b/tests/document/instance.py
@@ -19,6 +19,7 @@ from mongoengine.queryset import NULLIFY, Q
 from mongoengine.connection import get_db
 from mongoengine.base import get_document
 from mongoengine.context_managers import switch_db
+from mongoengine import signals
 
 TEST_IMAGE_PATH = os.path.join(os.path.dirname(__file__),
                                '../fields/mongoengine.png')
@@ -1375,7 +1376,6 @@ class InstanceTest(unittest.TestCase):
         author.delete()
         self.assertEqual(len(BlogPost.objects), 0)
 
-
     def test_reverse_delete_rule_cascade_and_nullify_complex_field(self):
         """Ensure that a referenced document is also deleted upon deletion for
         complex fields.
@@ -1410,6 +1410,43 @@ class InstanceTest(unittest.TestCase):
         author.delete()
         self.assertEqual(len(BlogPost.objects), 0)
 
+
+    def test_reverse_delete_rule_cascade_triggers_pre_delete_signal(self):
+        ''' ensure the pre_delete signal is triggered upon a cascading deletion
+        setup a blog post with content, an author and editor
+        delete the author which triggers deletion of blogpost via cascade
+        blog post's pre_delete signal alters an editor attribute
+        '''
+        class Editor(self.Person):
+            review_queue = IntField(default=0)
+
+        class BlogPost(Document):
+            content = StringField()
+            author = ReferenceField(self.Person, reverse_delete_rule=CASCADE)
+            editor = ReferenceField(Editor)
+
+            @classmethod
+            def pre_delete(cls, sender, document, **kwargs):
+                # decrement the docs-to-review count
+                document.editor.update(dec__review_queue=1)
+
+        signals.pre_delete.connect(BlogPost.pre_delete, sender=BlogPost)
+
+        self.Person.drop_collection()
+        BlogPost.drop_collection()
+        Editor.drop_collection()
+
+        author = self.Person(name='Will S.').save()
+        editor = Editor(name='Max P.', review_queue=1).save()
+        BlogPost(content='wrote some books', author=author,
+                 editor=editor).save()
+
+        # delete the author, the post is also deleted due to the CASCADE rule
+        author.delete()
+        # the pre-delete signal should have decremented the editor's queue
+        editor = Editor.objects(name='Max P.').get()
+        self.assertEqual(editor.review_queue, 0)
+
     def test_two_way_reverse_delete_rule(self):
         """Ensure that Bi-Directional relationships work with
         reverse_delete_rule
@@ -1426,7 +1463,6 @@ class InstanceTest(unittest.TestCase):
         Bar.register_delete_rule(Foo, 'bar', NULLIFY)
         Foo.register_delete_rule(Bar, 'foo', NULLIFY)
 
-
         Bar.drop_collection()
         Foo.drop_collection()