update the changelog with everything we've added in v0.10.8

.gitignore

@@ -14,4 +14,6 @@ env/
 .project
 .pydevproject
 tests/test_bugfix.py
-htmlcov/
+htmlcov/
+venv
+venv3

.travis.yml

@@ -1,7 +1,7 @@
 language: python
 
 python:
-- '2.6'
+- '2.6'  # TODO remove in v0.11.0
 - '2.7'
 - '3.3'
 - '3.4'

docs/changelog.rst

@@ -4,9 +4,19 @@ Changelog
 
 Changes in 0.10.8
 =================
+- Added support for QuerySet.batch_size (#1426)
+- Fixed query set iteration within iteration #1427
+- Fixed an issue where specifying a MongoDB URI host would override more information than it should #1421
+- Added ability to filter the generic reference field by ObjectId and DBRef #1425
+- Fixed delete cascade for models with a custom primary key field #1247
 - Added ability to specify an authentication mechanism (e.g. X.509) #1333
 - Added support for falsey primary keys (e.g. doc.pk = 0) #1354
-- Fixed BaseQuerySet#sum/average for fields w/ explicit db_field #1417
+- Fixed QuerySet#sum/average for fields w/ explicit db_field #1417
+- Fixed filtering by embedded_doc=None #1422
+- Added support for cursor.comment #1420
+- Fixed doc.get_<field>_display #1419
+- Fixed __repr__ method of the StrictDict #1424
+- Added a deprecation warning for Python 2.6
 
 Changes in 0.10.7
 =================

mongoengine/connection.py

@@ -25,7 +25,8 @@ _dbs = {}
 
 def register_connection(alias, name=None, host=None, port=None,
                         read_preference=READ_PREFERENCE,
-                        username=None, password=None, authentication_source=None,
+                        username=None, password=None,
+                        authentication_source=None,
                         authentication_mechanism=None,
                         **kwargs):
     """Add a connection.
@@ -70,20 +71,26 @@ def register_connection(alias, name=None, host=None, port=None,
 
     resolved_hosts = []
     for entity in conn_host:
-        # Handle uri style connections
+
+        # Handle Mongomock
         if entity.startswith('mongomock://'):
             conn_settings['is_mock'] = True
             # `mongomock://` is not a valid url prefix and must be replaced by `mongodb://`
             resolved_hosts.append(entity.replace('mongomock://', 'mongodb://', 1))
+
+        # Handle URI style connections, only updating connection params which
+        # were explicitly specified in the URI.
         elif '://' in entity:
             uri_dict = uri_parser.parse_uri(entity)
             resolved_hosts.append(entity)
-            conn_settings.update({
-                'name': uri_dict.get('database') or name,
-                'username': uri_dict.get('username'),
-                'password': uri_dict.get('password'),
-                'read_preference': read_preference,
-            })
+
+            if uri_dict.get('database'):
+                conn_settings['name'] = uri_dict.get('database')
+
+            for param in ('read_preference', 'username', 'password'):
+                if uri_dict.get(param):
+                    conn_settings[param] = uri_dict[param]
+
             uri_options = uri_dict['options']
             if 'replicaset' in uri_options:
                 conn_settings['replicaSet'] = True

mongoengine/fields.py

@@ -1249,7 +1249,7 @@ class GenericReferenceField(BaseField):
         if document is None:
             return None
 
-        if isinstance(document, (dict, SON)):
+        if isinstance(document, (dict, SON, ObjectId, DBRef)):
             return document
 
         id_field_name = document.__class__._meta['id_field']

mongoengine/python_support.py

@@ -1,9 +1,22 @@
-"""Helper functions and types to aid with Python 2.5 - 3 support."""
+"""Helper functions and types to aid with Python 2.6 - 3 support."""
 
 import sys
+import warnings
+
 import pymongo
 
 
+# Show a deprecation warning for people using Python v2.6
+# TODO remove in mongoengine v0.11.0
+if sys.version_info[0] == 2 and sys.version_info[1] == 6:
+    warnings.warn(
+        'Python v2.6 support is deprecated and is going to be dropped '
+        'entirely in the upcoming v0.11.0 release. Update your Python '
+        'version if you want to have access to the latest features and '
+        'bug fixes in MongoEngine.',
+        DeprecationWarning
+    )
+
 if pymongo.version_tuple[0] < 3:
     IS_PYMONGO_3 = False
 else:

mongoengine/queryset/base.py

@@ -82,6 +82,7 @@ class BaseQuerySet(object):
         self._limit = None
         self._skip = None
         self._hint = -1  # Using -1 as None is a valid value for hint
+        self._batch_size = None
         self.only_fields = []
         self._max_time_ms = None
 
@@ -446,7 +447,7 @@ class BaseQuerySet(object):
                 if doc._collection == document_cls._collection:
                     for ref in queryset:
                         cascade_refs.add(ref.id)
-                ref_q = document_cls.objects(**{field_name + '__in': self, 'id__nin': cascade_refs})
+                ref_q = document_cls.objects(**{field_name + '__in': self, 'pk__nin': cascade_refs})
                 ref_q_count = ref_q.count()
                 if ref_q_count > 0:
                     ref_q.delete(write_concern=write_concern, cascade_refs=cascade_refs)
@@ -783,6 +784,19 @@ class BaseQuerySet(object):
         queryset._hint = index
         return queryset
 
+    def batch_size(self, size):
+        """Limit the number of documents returned in a single batch (each
+        batch requires a round trip to the server).
+
+        See http://api.mongodb.com/python/current/api/pymongo/cursor.html#pymongo.cursor.Cursor.batch_size
+        for details.
+
+        :param size: desired size of each batch.
+        """
+        queryset = self.clone()
+        queryset._batch_size = size
+        return queryset
+
     def distinct(self, field):
         """Return a list of distinct values for a given field.
 
@@ -1469,6 +1483,9 @@ class BaseQuerySet(object):
             if self._hint != -1:
                 self._cursor_obj.hint(self._hint)
 
+            if self._batch_size is not None:
+                self._cursor_obj.batch_size(self._batch_size)
+
         return self._cursor_obj
 
     def __deepcopy__(self, memo):

mongoengine/queryset/transform.py

@@ -1,6 +1,7 @@
 from collections import defaultdict
 
-from bson import SON
+from bson import ObjectId, SON
+from bson.dbref import DBRef
 import pymongo
 
 from mongoengine.base.fields import UPDATE_OPERATORS
@@ -26,6 +27,7 @@ MATCH_OPERATORS = (COMPARISON_OPERATORS + GEO_OPERATORS +
                    STRING_OPERATORS + CUSTOM_OPERATORS)
 
 
+# TODO make this less complex
 def query(_doc_cls=None, **kwargs):
     """Transform a query from Django-style format to Mongo format.
     """
@@ -62,6 +64,7 @@ def query(_doc_cls=None, **kwargs):
             parts = []
 
             CachedReferenceField = _import_class('CachedReferenceField')
+            GenericReferenceField = _import_class('GenericReferenceField')
 
             cleaned_fields = []
             for field in fields:
@@ -101,6 +104,16 @@ def query(_doc_cls=None, **kwargs):
                 # 'in', 'nin' and 'all' require a list of values
                 value = [field.prepare_query_value(op, v) for v in value]
 
+            # If we're querying a GenericReferenceField, we need to alter the
+            # key depending on the value:
+            # * If the value is a DBRef, the key should be "field_name._ref".
+            # * If the value is an ObjectId, the key should be "field_name._ref.$id".
+            if isinstance(field, GenericReferenceField):
+                if isinstance(value, DBRef):
+                    parts[-1] += '._ref'
+                elif isinstance(value, ObjectId):
+                    parts[-1] += '._ref.$id'
+
         # if op and op not in COMPARISON_OPERATORS:
         if op:
             if op in GEO_OPERATORS:
@@ -128,11 +141,13 @@ def query(_doc_cls=None, **kwargs):
 
         for i, part in indices:
             parts.insert(i, part)
+
         key = '.'.join(parts)
+
         if op is None or key not in mongo_query:
             mongo_query[key] = value
         elif key in mongo_query:
-            if key in mongo_query and isinstance(mongo_query[key], dict):
+            if isinstance(mongo_query[key], dict):
                 mongo_query[key].update(value)
                 # $max/minDistance needs to come last - convert to SON
                 value_dict = mongo_query[key]

setup.cfg

@@ -9,5 +9,5 @@ tests = tests
 [flake8]
 ignore=E501,F401,F403,F405,I201
 exclude=build,dist,docs,venv,.tox,.eggs,tests
-max-complexity=42
+max-complexity=45
 application-import-names=mongoengine,tests

tests/fields/fields.py

@@ -2810,6 +2810,38 @@ class FieldTest(unittest.TestCase):
         Post.drop_collection()
         User.drop_collection()
 
+    def test_generic_reference_filter_by_dbref(self):
+        """Ensure we can search for a specific generic reference by
+        providing its ObjectId.
+        """
+        class Doc(Document):
+            ref = GenericReferenceField()
+
+        Doc.drop_collection()
+
+        doc1 = Doc.objects.create()
+        doc2 = Doc.objects.create(ref=doc1)
+
+        doc = Doc.objects.get(ref=DBRef('doc', doc1.pk))
+        self.assertEqual(doc, doc2)
+
+    def test_generic_reference_filter_by_objectid(self):
+        """Ensure we can search for a specific generic reference by
+        providing its DBRef.
+        """
+        class Doc(Document):
+            ref = GenericReferenceField()
+
+        Doc.drop_collection()
+
+        doc1 = Doc.objects.create()
+        doc2 = Doc.objects.create(ref=doc1)
+
+        self.assertTrue(isinstance(doc1.pk, ObjectId))
+
+        doc = Doc.objects.get(ref=doc1.pk)
+        self.assertEqual(doc, doc2)
+
     def test_binary_fields(self):
         """Ensure that binary fields can be stored and retrieved.
         """

tests/queryset/queryset.py

@@ -337,6 +337,34 @@ class QuerySetTest(unittest.TestCase):
         query = query.filter(boolfield=True)
         self.assertEqual(query.count(), 1)
 
+    def test_batch_size(self):
+        """Ensure that batch_size works."""
+        class A(Document):
+            s = StringField()
+
+        A.drop_collection()
+
+        for i in range(100):
+            A.objects.create(s=str(i))
+
+        # test iterating over the result set
+        cnt = 0
+        for a in A.objects.batch_size(10):
+            cnt += 1
+        self.assertEqual(cnt, 100)
+
+        # test chaining
+        qs = A.objects.all()
+        qs = qs.limit(10).batch_size(20).skip(91)
+        cnt = 0
+        for a in qs:
+            cnt += 1
+        self.assertEqual(cnt, 9)
+
+        # test invalid batch size
+        qs = A.objects.batch_size(-1)
+        self.assertRaises(ValueError, lambda: list(qs))
+
     def test_update_write_concern(self):
         """Test that passing write_concern works"""
         self.Person.drop_collection()

tests/test_connection.py

@@ -174,19 +174,9 @@ class ConnectionTest(unittest.TestCase):
         c.mongoenginetest.system.users.remove({})
 
     def test_connect_uri_without_db(self):
-        """Ensure connect() method works properly with uri's without database_name
+        """Ensure connect() method works properly if the URI doesn't
+        include a database name.
         """
-        c = connect(db='mongoenginetest', alias='admin')
-        c.admin.system.users.remove({})
-        c.mongoenginetest.system.users.remove({})
-
-        c.admin.add_user("admin", "password")
-        c.admin.authenticate("admin", "password")
-        c.mongoenginetest.add_user("username", "password")
-
-        if not IS_PYMONGO_3:
-            self.assertRaises(ConnectionError, connect, "testdb_uri_bad", host='mongodb://test:password@localhost')
-
         connect("mongoenginetest", host='mongodb://localhost/')
 
         conn = get_connection()
@@ -196,8 +186,31 @@ class ConnectionTest(unittest.TestCase):
         self.assertTrue(isinstance(db, pymongo.database.Database))
         self.assertEqual(db.name, 'mongoenginetest')
 
-        c.admin.system.users.remove({})
-        c.mongoenginetest.system.users.remove({})
+    def test_connect_uri_default_db(self):
+        """Ensure connect() defaults to the right database name if
+        the URI and the database_name don't explicitly specify it.
+        """
+        connect(host='mongodb://localhost/')
+
+        conn = get_connection()
+        self.assertTrue(isinstance(conn, pymongo.mongo_client.MongoClient))
+
+        db = get_db()
+        self.assertTrue(isinstance(db, pymongo.database.Database))
+        self.assertEqual(db.name, 'test')
+
+    def test_uri_without_credentials_doesnt_override_conn_settings(self):
+        """Ensure connect() uses the username & password params if the URI
+        doesn't explicitly specify them.
+        """
+        c = connect(host='mongodb://localhost/mongoenginetest',
+                    username='user',
+                    password='pass')
+
+        # OperationFailure means that mongoengine attempted authentication
+        # w/ the provided username/password and failed - that's the desired
+        # behavior. If the MongoDB URI would override the credentials
+        self.assertRaises(OperationFailure, get_db)
 
     def test_connect_uri_with_authsource(self):
         """Ensure that the connect() method works well with