Merge branch 'master' into pr/539

Conflicts:
	mongoengine/base/datastructures.py

mongoengine/base/datastructures.py

@@ -1,4 +1,6 @@
 import weakref
+import functools
+import itertools
 from mongoengine.common import _import_class
 
 __all__ = ("BaseDict", "BaseList")
@@ -183,3 +185,97 @@ class BaseList(list):
                 self._instance._mark_as_changed('%s.%s' % (self._name, key))
             else:
                 self._instance._mark_as_changed(self._name)
+
+
+class StrictDict(object):
+    __slots__ = ()
+    _special_fields = set(['get', 'pop', 'iteritems', 'items', 'keys', 'create'])
+    _classes = {}
+    def __init__(self, **kwargs):
+        for k,v in kwargs.iteritems():
+            setattr(self, k, v)
+    def __getitem__(self, key):
+        key = '_reserved_' + key if key in self._special_fields else key
+        try:
+            return getattr(self, key)
+        except AttributeError:
+            raise KeyError(key)
+    def __setitem__(self, key, value):
+        key = '_reserved_' + key if key in self._special_fields else key
+        return setattr(self, key, value)
+    def __contains__(self, key):
+        return hasattr(self, key)
+    def get(self, key, default=None):
+        try:
+            return self[key]
+        except KeyError:
+            return default
+    def pop(self, key, default=None):
+        v = self.get(key, default)
+        try:
+            delattr(self, key)
+        except AttributeError:
+            pass
+        return v
+    def iteritems(self):
+        for key in self:
+            yield key, self[key]
+    def items(self):
+        return [(k, self[k]) for k in iter(self)]
+    def keys(self):
+        return list(iter(self))
+    def __iter__(self):
+        return (key for key in self.__slots__ if hasattr(self, key))
+    def __len__(self):
+        return len(list(self.iteritems()))
+    def __eq__(self, other):
+        return self.items() == other.items()
+    def __neq__(self, other):
+        return self.items() != other.items()
+
+    @classmethod
+    def create(cls, allowed_keys):
+        allowed_keys_tuple = tuple(('_reserved_' + k if k in cls._special_fields else k) for k in allowed_keys)
+        allowed_keys = frozenset(allowed_keys_tuple)
+        if allowed_keys not in cls._classes:
+            class SpecificStrictDict(cls):
+                __slots__ = allowed_keys_tuple
+            cls._classes[allowed_keys] = SpecificStrictDict
+        return cls._classes[allowed_keys]
+
+
+class SemiStrictDict(StrictDict):
+    __slots__ = ('_extras')
+    _classes = {}
+    def __getattr__(self, attr):
+        try:
+            super(SemiStrictDict, self).__getattr__(attr)
+        except AttributeError:
+            try:
+                return self.__getattribute__('_extras')[attr]
+            except KeyError as e:
+                raise AttributeError(e)
+    def __setattr__(self, attr, value):
+        try:
+            super(SemiStrictDict, self).__setattr__(attr, value)
+        except AttributeError:
+            try:
+                self._extras[attr] = value
+            except AttributeError:
+                self._extras = {attr: value}
+
+    def __delattr__(self, attr):
+        try:
+            super(SemiStrictDict, self).__delattr__(attr)
+        except AttributeError:
+            try:
+                del self._extras[attr]
+            except KeyError as e:
+                raise AttributeError(e)
+
+    def __iter__(self):
+        try:
+            extras_iter = iter(self.__getattribute__('_extras'))
+        except AttributeError:
+            extras_iter = ()
+        return itertools.chain(super(SemiStrictDict, self).__iter__(), extras_iter)

mongoengine/base/document.py

@@ -13,24 +13,23 @@ from mongoengine import signals
 from mongoengine.common import _import_class
 from mongoengine.errors import (ValidationError, InvalidDocumentError,
                                 LookUpError)
-from mongoengine.python_support import (PY3, UNICODE_KWARGS, txt_type,
-                                        to_str_keys_recursive)
+from mongoengine.python_support import PY3, txt_type
 
 from mongoengine.base.common import get_document, ALLOW_INHERITANCE
-from mongoengine.base.datastructures import BaseDict, BaseList
+from mongoengine.base.datastructures import BaseDict, BaseList, StrictDict, SemiStrictDict
 from mongoengine.base.fields import ComplexBaseField
 
 __all__ = ('BaseDocument', 'NON_FIELD_ERRORS')
 
 NON_FIELD_ERRORS = '__all__'
 
-
 class BaseDocument(object):
+    __slots__ = ('_changed_fields', '_initialised', '_created', '_data',
+                  '_dynamic_fields', '_auto_id_field', '_db_field_map', '_cls', '__weakref__')
 
     _dynamic = False
-    _created = True
     _dynamic_lock = True
-    _initialised = False
+    STRICT = False
 
     def __init__(self, *args, **values):
         """
@@ -39,6 +38,8 @@ class BaseDocument(object):
         :param __auto_convert: Try and will cast python objects to Object types
         :param values: A dictionary of values for the document
         """
+        self._initialised = False
+        self._created = True
         if args:
             # Combine positional arguments with named arguments.
             # We only want named arguments.
@@ -54,7 +55,11 @@ class BaseDocument(object):
         __auto_convert = values.pop("__auto_convert", True)
         signals.pre_init.send(self.__class__, document=self, values=values)
 
-        self._data = {}
+        if self.STRICT and not self._dynamic:
+            self._data = StrictDict.create(allowed_keys=self._fields.keys())()
+        else:
+            self._data = SemiStrictDict.create(allowed_keys=self._fields.keys())()
+
         self._dynamic_fields = SON()
 
         # Assign default values to instance
@@ -130,17 +135,25 @@ class BaseDocument(object):
                 self._data[name] = value
                 if hasattr(self, '_changed_fields'):
                     self._mark_as_changed(name)
+        try:
+            self__created = self._created
+        except AttributeError:
+            self__created = True
 
-        if (self._is_document and not self._created and
+        if (self._is_document and not self__created and
            name in self._meta.get('shard_key', tuple()) and
            self._data.get(name) != value):
             OperationError = _import_class('OperationError')
             msg = "Shard Keys are immutable. Tried to update %s" % name
             raise OperationError(msg)
 
+        try:
+            self__initialised = self._initialised
+        except AttributeError:
+            self__initialised = False
         # Check if the user has created a new instance of a class
-        if (self._is_document and self._initialised
-           and self._created and name == self._meta['id_field']):
+        if (self._is_document and self__initialised
+           and self__created and name == self._meta['id_field']):
                 super(BaseDocument, self).__setattr__('_created', False)
 
         super(BaseDocument, self).__setattr__(name, value)
@@ -158,9 +171,11 @@ class BaseDocument(object):
         if isinstance(data["_data"], SON):
             data["_data"] = self.__class__._from_son(data["_data"])._data
         for k in ('_changed_fields', '_initialised', '_created', '_data',
-                  '_fields_ordered', '_dynamic_fields'):
+                   '_dynamic_fields'):
             if k in data:
                 setattr(self, k, data[k])
+        if '_fields_ordered' in data:
+            setattr(type(self), '_fields_ordered', data['_fields_ordered'])
         dynamic_fields = data.get('_dynamic_fields') or SON()
         for k in dynamic_fields.keys():
             setattr(self, k, data["_data"].get(k))
@@ -182,7 +197,7 @@ class BaseDocument(object):
         """Dictionary-style field access, set a field's value.
         """
         # Ensure that the field exists before settings its value
-        if name not in self._fields:
+        if not self._dynamic and name not in self._fields:
             raise KeyError(name)
         return setattr(self, name, value)
 
@@ -214,8 +229,9 @@ class BaseDocument(object):
 
     def __eq__(self, other):
         if isinstance(other, self.__class__) and hasattr(other, 'id'):
-            if self.id == other.id:
-                return True
+            return self.id == other.id
+        if isinstance(other, DBRef):
+            return self._get_collection_name() == other.collection and self.id == other.id
         return False
 
     def __ne__(self, other):
@@ -317,7 +333,7 @@ class BaseDocument(object):
             pk = "None"
             if hasattr(self, 'pk'):
                 pk = self.pk
-            elif self._instance:
+            elif self._instance and hasattr(self._instance, 'pk'):
                 pk = self._instance.pk
             message = "ValidationError (%s:%s) " % (self._class_name, pk)
             raise ValidationError(message, errors=errors)
@@ -401,6 +417,8 @@ class BaseDocument(object):
                 else:
                     data = getattr(data, part, None)
                 if hasattr(data, "_changed_fields"):
+                    if hasattr(data, "_is_document") and data._is_document:
+                        continue
                     data._changed_fields = []
         self._changed_fields = []
 
@@ -562,10 +580,6 @@ class BaseDocument(object):
         # class if unavailable
         class_name = son.get('_cls', cls._class_name)
         data = dict(("%s" % key, value) for key, value in son.iteritems())
-        if not UNICODE_KWARGS:
-            # python 2.6.4 and lower cannot handle unicode keys
-            # passed to class constructor example: cls(**data)
-            to_str_keys_recursive(data)
 
         # Return correct subclass for document type
         if class_name != cls._class_name:
@@ -603,6 +617,8 @@ class BaseDocument(object):
                    % (cls._class_name, errors))
             raise InvalidDocumentError(msg)
 
+        if cls.STRICT:
+            data = dict((k, v) for k,v in data.iteritems() if k in cls._fields)
         obj = cls(__auto_convert=False, **data)
         obj._changed_fields = changed_fields
         obj._created = False
@@ -821,8 +837,17 @@ class BaseDocument(object):
                    # Look up subfield on the previous field
                     new_field = field.lookup_member(field_name)
                 if not new_field and isinstance(field, ComplexBaseField):
-                    fields.append(field_name)
-                    continue
+                    if hasattr(field.field, 'document_type') and cls._dynamic \
+                            and field.field.document_type._dynamic:
+                        DynamicField = _import_class('DynamicField')
+                        new_field = DynamicField(db_field=field_name)
+                    else:
+                        fields.append(field_name)
+                        continue
+                elif not new_field and hasattr(field, 'document_type') and cls._dynamic \
+                        and field.document_type._dynamic:
+                    DynamicField = _import_class('DynamicField')
+                    new_field = DynamicField(db_field=field_name)
                 elif not new_field:
                     raise LookUpError('Cannot resolve field "%s"'
                                       % field_name)
@@ -842,7 +867,11 @@ class BaseDocument(object):
         """Dynamically set the display value for a field with choices"""
         for attr_name, field in self._fields.items():
             if field.choices:
-                setattr(self,
+                if self._dynamic:
+                    obj = self
+                else:
+                    obj = type(self)
+                setattr(obj,
                         'get_%s_display' % attr_name,
                         partial(self.__get_field_display, field=field))
 

mongoengine/base/metaclasses.py

@@ -359,7 +359,8 @@ class TopLevelDocumentMetaclass(DocumentMetaclass):
                     new_class.id = field
 
         # Set primary key if not defined by the document
-        new_class._auto_id_field = False
+        new_class._auto_id_field = getattr(parent_doc_cls,
+                                           '_auto_id_field', False)
         if not new_class._meta.get('id_field'):
             new_class._auto_id_field = True
             new_class._meta['id_field'] = 'id'

mongoengine/connection.py

@@ -20,7 +20,8 @@ _dbs = {}
 
 def register_connection(alias, name, host=None, port=None,
                         is_slave=False, read_preference=False, slaves=None,
-                        username=None, password=None, **kwargs):
+                        username=None, password=None, authentication_source=None,
+                        **kwargs):
     """Add a connection.
 
     :param alias: the name that will be used to refer to this connection
@@ -36,6 +37,7 @@ def register_connection(alias, name, host=None, port=None,
         be a registered connection that has :attr:`is_slave` set to ``True``
     :param username: username to authenticate with
     :param password: password to authenticate with
+    :param authentication_source: database to authenticate against
     :param kwargs: allow ad-hoc parameters to be passed into the pymongo driver
 
     """
@@ -46,10 +48,11 @@ def register_connection(alias, name, host=None, port=None,
         'host': host or 'localhost',
         'port': port or 27017,
         'is_slave': is_slave,
+        'read_preference': read_preference,
         'slaves': slaves or [],
         'username': username,
         'password': password,
-        'read_preference': read_preference
+        'authentication_source': authentication_source
     }
 
     # Handle uri style connections
@@ -93,20 +96,12 @@ def get_connection(alias=DEFAULT_CONNECTION_NAME, reconnect=False):
             raise ConnectionError(msg)
         conn_settings = _connection_settings[alias].copy()
 
-        if hasattr(pymongo, 'version_tuple'):  # Support for 2.1+
-            conn_settings.pop('name', None)
-            conn_settings.pop('slaves', None)
-            conn_settings.pop('is_slave', None)
-            conn_settings.pop('username', None)
-            conn_settings.pop('password', None)
-        else:
-            # Get all the slave connections
-            if 'slaves' in conn_settings:
-                slaves = []
-                for slave_alias in conn_settings['slaves']:
-                    slaves.append(get_connection(slave_alias))
-                conn_settings['slaves'] = slaves
-                conn_settings.pop('read_preference', None)
+        conn_settings.pop('name', None)
+        conn_settings.pop('slaves', None)
+        conn_settings.pop('is_slave', None)
+        conn_settings.pop('username', None)
+        conn_settings.pop('password', None)
+        conn_settings.pop('authentication_source', None)
 
         connection_class = MongoClient
         if 'replicaSet' in conn_settings:
@@ -119,7 +114,19 @@ def get_connection(alias=DEFAULT_CONNECTION_NAME, reconnect=False):
             connection_class = MongoReplicaSetClient
 
         try:
-            _connections[alias] = connection_class(**conn_settings)
+            connection = None
+            connection_settings_iterator = ((alias, settings.copy()) for alias, settings in _connection_settings.iteritems())
+            for alias, connection_settings in connection_settings_iterator:
+                connection_settings.pop('name', None)
+                connection_settings.pop('slaves', None)
+                connection_settings.pop('is_slave', None)
+                connection_settings.pop('username', None)
+                connection_settings.pop('password', None)
+                if conn_settings == connection_settings and _connections.get(alias, None):
+                    connection = _connections[alias]
+                    break
+
+            _connections[alias] = connection if connection else connection_class(**conn_settings)
         except Exception, e:
             raise ConnectionError("Cannot connect to database %s :\n%s" % (alias, e))
     return _connections[alias]
@@ -137,7 +144,8 @@ def get_db(alias=DEFAULT_CONNECTION_NAME, reconnect=False):
         # Authenticate if necessary
         if conn_settings['username'] and conn_settings['password']:
             db.authenticate(conn_settings['username'],
-                            conn_settings['password'])
+                            conn_settings['password'],
+                            source=conn_settings['authentication_source'])
         _dbs[alias] = db
     return _dbs[alias]
 

mongoengine/context_managers.py

@@ -1,6 +1,5 @@
 from mongoengine.common import _import_class
 from mongoengine.connection import DEFAULT_CONNECTION_NAME, get_db
-from mongoengine.queryset import QuerySet
 
 
 __all__ = ("switch_db", "switch_collection", "no_dereference",
@@ -162,12 +161,6 @@ class no_sub_classes(object):
         return self.cls
 
 
-class QuerySetNoDeRef(QuerySet):
-    """Special no_dereference QuerySet"""
-    def __dereference(items, max_depth=1, instance=None, name=None):
-            return items
-
-
 class query_counter(object):
     """ Query_counter context manager to get the number of queries. """
 

mongoengine/dereference.py

@@ -36,7 +36,7 @@ class DeReference(object):
         if instance and isinstance(instance, (Document, EmbeddedDocument,
                                               TopLevelDocumentMetaclass)):
             doc_type = instance._fields.get(name)
-            if hasattr(doc_type, 'field'):
+            while hasattr(doc_type, 'field'):
                 doc_type = doc_type.field
 
             if isinstance(doc_type, ReferenceField):
@@ -51,9 +51,19 @@ class DeReference(object):
                     return items
                 elif not field.dbref:
                     if not hasattr(items, 'items'):
-                        items = [field.to_python(v)
-                             if not isinstance(v, (DBRef, Document)) else v
-                             for v in items]
+
+                        def _get_items(items):
+                            new_items = []
+                            for v in items:
+                                if isinstance(v, list):
+                                    new_items.append(_get_items(v))
+                                elif not isinstance(v, (DBRef, Document)):
+                                    new_items.append(field.to_python(v))
+                                else:
+                                    new_items.append(v)
+                            return new_items
+
+                        items = _get_items(items)
                     else:
                         items = dict([
                             (k, field.to_python(v))
@@ -114,11 +124,11 @@ class DeReference(object):
         """Fetch all references and convert to their document objects
         """
         object_map = {}
-        for col, dbrefs in self.reference_map.iteritems():
+        for collection, dbrefs in self.reference_map.iteritems():
             keys = object_map.keys()
             refs = list(set([dbref for dbref in dbrefs if unicode(dbref).encode('utf-8') not in keys]))
-            if hasattr(col, 'objects'):  # We have a document class for the refs
-                references = col.objects.in_bulk(refs)
+            if hasattr(collection, 'objects'):  # We have a document class for the refs
+                references = collection.objects.in_bulk(refs)
                 for key, doc in references.iteritems():
                     object_map[key] = doc
             else:  # Generic reference: use the refs data to convert to document
@@ -126,19 +136,19 @@ class DeReference(object):
                     continue
 
                 if doc_type:
-                    references = doc_type._get_db()[col].find({'_id': {'$in': refs}})
+                    references = doc_type._get_db()[collection].find({'_id': {'$in': refs}})
                     for ref in references:
                         doc = doc_type._from_son(ref)
                         object_map[doc.id] = doc
                 else:
-                    references = get_db()[col].find({'_id': {'$in': refs}})
+                    references = get_db()[collection].find({'_id': {'$in': refs}})
                     for ref in references:
                         if '_cls' in ref:
                             doc = get_document(ref["_cls"])._from_son(ref)
                         elif doc_type is None:
                             doc = get_document(
                                 ''.join(x.capitalize()
-                                    for x in col.split('_')))._from_son(ref)
+                                    for x in collection.split('_')))._from_son(ref)
                         else:
                             doc = doc_type._from_son(ref)
                         object_map[doc.id] = doc

mongoengine/document.py

@@ -13,7 +13,8 @@ from mongoengine.base import (DocumentMetaclass, TopLevelDocumentMetaclass,
                               BaseDocument, BaseDict, BaseList,
                               ALLOW_INHERITANCE, get_document)
 from mongoengine.errors import ValidationError
-from mongoengine.queryset import OperationError, NotUniqueError, QuerySet
+from mongoengine.queryset import (OperationError, NotUniqueError,
+                                  QuerySet, transform)
 from mongoengine.connection import get_db, DEFAULT_CONNECTION_NAME
 from mongoengine.context_managers import switch_db, switch_collection
 
@@ -54,20 +55,21 @@ class EmbeddedDocument(BaseDocument):
     dictionary.
     """
 
+    __slots__ = ('_instance')
+
     # The __metaclass__ attribute is removed by 2to3 when running with Python3
     # my_metaclass is defined so that metaclass can be queried in Python 2 & 3
     my_metaclass  = DocumentMetaclass
     __metaclass__ = DocumentMetaclass
 
-    _instance = None
-
     def __init__(self, *args, **kwargs):
         super(EmbeddedDocument, self).__init__(*args, **kwargs)
+        self._instance = None
         self._changed_fields = []
 
     def __eq__(self, other):
         if isinstance(other, self.__class__):
-            return self.to_mongo() == other.to_mongo()
+            return self._data == other._data
         return False
 
     def __ne__(self, other):
@@ -125,6 +127,8 @@ class Document(BaseDocument):
     my_metaclass  = TopLevelDocumentMetaclass
     __metaclass__ = TopLevelDocumentMetaclass
 
+    __slots__ = ('__objects' )
+
     def pk():
         """Primary key alias
         """
@@ -180,7 +184,7 @@ class Document(BaseDocument):
 
     def save(self, force_insert=False, validate=True, clean=True,
              write_concern=None,  cascade=None, cascade_kwargs=None,
-             _refs=None, **kwargs):
+             _refs=None, save_condition=None, **kwargs):
         """Save the :class:`~mongoengine.Document` to the database. If the
         document already exists, it will be updated, otherwise it will be
         created.
@@ -203,7 +207,8 @@ class Document(BaseDocument):
         :param cascade_kwargs: (optional) kwargs dictionary to be passed throw
             to cascading saves.  Implies ``cascade=True``.
         :param _refs: A list of processed references used in cascading saves
-
+        :param save_condition: only perform save if matching record in db
+            satisfies condition(s) (e.g., version number)
         .. versionchanged:: 0.5
             In existing documents it only saves changed fields using
             set / unset.  Saves are cascaded and any
@@ -217,6 +222,9 @@ class Document(BaseDocument):
             meta['cascade'] = True.  Also you can pass different kwargs to
             the cascade save using cascade_kwargs which overwrites the
             existing kwargs with custom values.
+        .. versionchanged:: 0.8.5
+            Optional save_condition that only overwrites existing documents
+            if the condition is satisfied in the current db record.
         """
         signals.pre_save.send(self.__class__, document=self)
 
@@ -230,7 +238,8 @@ class Document(BaseDocument):
 
         created = ('_id' not in doc or self._created or force_insert)
 
-        signals.pre_save_post_validation.send(self.__class__, document=self, created=created)
+        signals.pre_save_post_validation.send(self.__class__, document=self,
+                                              created=created)
 
         try:
             collection = self._get_collection()
@@ -243,7 +252,12 @@ class Document(BaseDocument):
                 object_id = doc['_id']
                 updates, removals = self._delta()
                 # Need to add shard key to query, or you get an error
-                select_dict = {'_id': object_id}
+                if save_condition is not None:
+                    select_dict = transform.query(self.__class__,
+                                                  **save_condition)
+                else:
+                    select_dict = {}
+                select_dict['_id'] = object_id
                 shard_key = self.__class__._meta.get('shard_key', tuple())
                 for k in shard_key:
                     actual_key = self._db_field_map.get(k, k)
@@ -263,10 +277,12 @@ class Document(BaseDocument):
                 if removals:
                     update_query["$unset"] = removals
                 if updates or removals:
+                    upsert = save_condition is None
                     last_error = collection.update(select_dict, update_query,
-                                                   upsert=True, **write_concern)
+                                                   upsert=upsert, **write_concern)
                     created = is_new_object(last_error)
 
+
             if cascade is None:
                 cascade = self._meta.get('cascade', False) or cascade_kwargs is not None
 
@@ -293,12 +309,12 @@ class Document(BaseDocument):
                 raise NotUniqueError(message % unicode(err))
             raise OperationError(message % unicode(err))
         id_field = self._meta['id_field']
-        if id_field not in self._meta.get('shard_key', []):
+        if created or id_field not in self._meta.get('shard_key', []):
             self[id_field] = self._fields[id_field].to_python(object_id)
 
+        signals.post_save.send(self.__class__, document=self, created=created)
         self._clear_changed_fields()
         self._created = False
-        signals.post_save.send(self.__class__, document=self, created=created)
         return self
 
     def cascade_save(self, *args, **kwargs):
@@ -447,27 +463,41 @@ class Document(BaseDocument):
         DeReference()([self], max_depth + 1)
         return self
 
-    def reload(self, max_depth=1):
+    def reload(self, *fields, **kwargs):
         """Reloads all attributes from the database.
 
+        :param fields: (optional) args list of fields to reload
+        :param max_depth: (optional) depth of dereferencing to follow
+
         .. versionadded:: 0.1.2
         .. versionchanged:: 0.6  Now chainable
+        .. versionchanged:: 0.9  Can provide specific fields to reload
         """
+        max_depth = 1
+        if fields and isinstance(fields[0], int):
+            max_depth = fields[0]
+            fields = fields[1:]
+        elif "max_depth" in kwargs:
+            max_depth = kwargs["max_depth"]
+
         if not self.pk:
             raise self.DoesNotExist("Document does not exist")
         obj = self._qs.read_preference(ReadPreference.PRIMARY).filter(
-                    **self._object_key).limit(1).select_related(max_depth=max_depth)
-
+                    **self._object_key).only(*fields).limit(1
+                    ).select_related(max_depth=max_depth)
 
         if obj:
             obj = obj[0]
         else:
             raise self.DoesNotExist("Document does not exist")
+
         for field in self._fields_ordered:
-            setattr(self, field, self._reload(field, obj[field]))
+            if not fields or field in fields:
+                setattr(self, field, self._reload(field, obj[field]))
+
         self._changed_fields = obj._changed_fields
         self._created = False
-        return obj
+        return self
 
     def _reload(self, key, value):
         """Used by :meth:`~mongoengine.Document.reload` to ensure the

mongoengine/fields.py

@@ -760,7 +760,7 @@ class DictField(ComplexBaseField):
     similar to an embedded document, but the structure is not defined.
 
     .. note::
-        Required means it cannot be empty - as the default for ListFields is []
+        Required means it cannot be empty - as the default for DictFields is {}
 
     .. versionadded:: 0.3
     .. versionchanged:: 0.5 - Can now handle complex / varying types of data
@@ -1554,6 +1554,14 @@ class SequenceField(BaseField):
 
         return super(SequenceField, self).__set__(instance, value)
 
+    def prepare_query_value(self, op, value):
+        """
+        This method is overriden in order to convert the query value into to required
+        type. We need to do this in order to be able to successfully compare query   
+        values passed as string, the base implementation returns the value as is.
+        """
+        return self.value_decorator(value)
+
     def to_python(self, value):
         if value is None:
             value = self.generate()
@@ -1613,7 +1621,12 @@ class UUIDField(BaseField):
 
 
 class GeoPointField(BaseField):
-    """A list storing a latitude and longitude.
+    """A list storing a longitude and latitude coordinate. 
+
+    .. note:: this represents a generic point in a 2D plane and a legacy way of 
+        representing a geo point. It admits 2d indexes but not "2dsphere" indexes 
+        in MongoDB > 2.4 which are more natural for modeling geospatial points. 
+        See :ref:`geospatial-indexes` 
 
     .. versionadded:: 0.4
     """
@@ -1635,7 +1648,7 @@ class GeoPointField(BaseField):
 
 
 class PointField(GeoJsonBaseField):
-    """A geo json field storing a latitude and longitude.
+    """A GeoJSON field storing a longitude and latitude coordinate.
 
     The data is represented as:
 
@@ -1654,7 +1667,7 @@ class PointField(GeoJsonBaseField):
 
 
 class LineStringField(GeoJsonBaseField):
-    """A geo json field storing a line of latitude and longitude coordinates.
+    """A GeoJSON field storing a line of longitude and latitude coordinates.
 
     The data is represented as:
 
@@ -1672,7 +1685,7 @@ class LineStringField(GeoJsonBaseField):
 
 
 class PolygonField(GeoJsonBaseField):
-    """A geo json field storing a polygon of latitude and longitude coordinates.
+    """A GeoJSON field storing a polygon of longitude and latitude coordinates.
 
     The data is represented as:
 

mongoengine/python_support.py

@@ -3,8 +3,6 @@
 import sys
 
 PY3 = sys.version_info[0] == 3
-PY25 = sys.version_info[:2] == (2, 5)
-UNICODE_KWARGS = int(''.join([str(x) for x in sys.version_info[:3]])) > 264
 
 if PY3:
     import codecs
@@ -29,33 +27,3 @@ else:
     txt_type = unicode
 
 str_types = (bin_type, txt_type)
-
-if PY25:
-    def product(*args, **kwds):
-        pools = map(tuple, args) * kwds.get('repeat', 1)
-        result = [[]]
-        for pool in pools:
-            result = [x + [y] for x in result for y in pool]
-        for prod in result:
-            yield tuple(prod)
-    reduce = reduce
-else:
-    from itertools import product
-    from functools import reduce
-
-
-# For use with Python 2.5
-# converts all keys from unicode to str for d and all nested dictionaries
-def to_str_keys_recursive(d):
-    if isinstance(d, list):
-        for val in d:
-            if isinstance(val, (dict, list)):
-                to_str_keys_recursive(val)
-    elif isinstance(d, dict):
-        for key, val in d.items():
-            if isinstance(val, (dict, list)):
-                to_str_keys_recursive(val)
-            if isinstance(key, unicode):
-                d[str(key)] = d.pop(key)
-    else:
-        raise ValueError("non list/dict parameter not allowed")

mongoengine/queryset/base.py

@@ -7,17 +7,20 @@ import pprint
 import re
 import warnings
 
+from bson import SON
 from bson.code import Code
 from bson import json_util
 import pymongo
+import pymongo.errors
 from pymongo.common import validate_read_preference
 
 from mongoengine import signals
+from mongoengine.connection import get_db
+from mongoengine.context_managers import switch_db
 from mongoengine.common import _import_class
 from mongoengine.base.common import get_document
 from mongoengine.errors import (OperationError, NotUniqueError,
                                 InvalidQueryError, LookUpError)
-
 from mongoengine.queryset import transform
 from mongoengine.queryset.field_list import QueryFieldList
 from mongoengine.queryset.visitor import Q, QNode
@@ -50,7 +53,7 @@ class BaseQuerySet(object):
         self._initial_query = {}
         self._where_clause = None
         self._loaded_fields = QueryFieldList()
-        self._ordering = []
+        self._ordering = None
         self._snapshot = False
         self._timeout = True
         self._class_check = True
@@ -146,7 +149,7 @@ class BaseQuerySet(object):
                     queryset._document._from_son(queryset._cursor[key],
                                                  _auto_dereference=self._auto_dereference))
             if queryset._as_pymongo:
-                return queryset._get_as_pymongo(queryset._cursor.next())
+                return queryset._get_as_pymongo(queryset._cursor[key])
             return queryset._document._from_son(queryset._cursor[key],
                                                 _auto_dereference=self._auto_dereference)
         raise AttributeError
@@ -154,6 +157,22 @@ class BaseQuerySet(object):
     def __iter__(self):
         raise NotImplementedError
 
+    def _has_data(self):
+        """ Retrieves whether cursor has any data. """
+
+        queryset = self.order_by()
+        return False if queryset.first() is None else True
+
+    def __nonzero__(self):
+        """ Avoid to open all records in an if stmt in Py2. """
+
+        return self._has_data()
+
+    def __bool__(self):
+        """ Avoid to open all records in an if stmt in Py3. """
+
+        return self._has_data()
+
     # Core functions
 
     def all(self):
@@ -175,7 +194,7 @@ class BaseQuerySet(object):
         .. versionadded:: 0.3
         """
         queryset = self.clone()
-        queryset = queryset.limit(2)
+        queryset = queryset.order_by().limit(2)
         queryset = queryset.filter(*q_objs, **query)
 
         try:
@@ -389,7 +408,7 @@ class BaseQuerySet(object):
                 ref_q = document_cls.objects(**{field_name + '__in': self})
                 ref_q_count = ref_q.count()
                 if (doc != document_cls and ref_q_count > 0
-                   or (doc == document_cls and ref_q_count > 0)):
+                    or (doc == document_cls and ref_q_count > 0)):
                     ref_q.delete(write_concern=write_concern)
             elif rule == NULLIFY:
                 document_cls.objects(**{field_name + '__in': self}).update(
@@ -443,6 +462,8 @@ class BaseQuerySet(object):
                 return result
             elif result:
                 return result['n']
+        except pymongo.errors.DuplicateKeyError, err:
+            raise NotUniqueError(u'Update failed (%s)' % unicode(err))
         except pymongo.errors.OperationFailure, err:
             if unicode(err) == u'multi not coded yet':
                 message = u'update() method requires MongoDB 1.1.3+'
@@ -466,6 +487,59 @@ class BaseQuerySet(object):
         return self.update(
             upsert=upsert, multi=False, write_concern=write_concern, **update)
 
+    def modify(self, upsert=False, full_response=False, remove=False, new=False, **update):
+        """Update and return the updated document.
+
+        Returns either the document before or after modification based on `new`
+        parameter. If no documents match the query and `upsert` is false,
+        returns ``None``. If upserting and `new` is false, returns ``None``.
+
+        If the full_response parameter is ``True``, the return value will be
+        the entire response object from the server, including the 'ok' and
+        'lastErrorObject' fields, rather than just the modified document.
+        This is useful mainly because the 'lastErrorObject' document holds
+        information about the command's execution.
+
+        :param upsert: insert if document doesn't exist (default ``False``)
+        :param full_response: return the entire response object from the
+            server (default ``False``)
+        :param remove: remove rather than updating (default ``False``)
+        :param new: return updated rather than original document
+            (default ``False``)
+        :param update: Django-style update keyword arguments
+
+        .. versionadded:: 0.9
+        """
+
+        if remove and new:
+            raise OperationError("Conflicting parameters: remove and new")
+
+        if not update and not upsert and not remove:
+            raise OperationError("No update parameters, must either update or remove")
+
+        queryset = self.clone()
+        query = queryset._query
+        update = transform.update(queryset._document, **update)
+        sort = queryset._ordering
+
+        try:
+            result = queryset._collection.find_and_modify(
+                query, update, upsert=upsert, sort=sort, remove=remove, new=new,
+                full_response=full_response, **self._cursor_args)
+        except pymongo.errors.DuplicateKeyError, err:
+            raise NotUniqueError(u"Update failed (%s)" % err)
+        except pymongo.errors.OperationFailure, err:
+            raise OperationError(u"Update failed (%s)" % err)
+
+        if full_response:
+            if result["value"] is not None:
+                result["value"] = self._document._from_son(result["value"])
+        else:
+            if result is not None:
+                result = self._document._from_son(result)
+
+        return result
+
     def with_id(self, object_id):
         """Retrieve the object matching the id provided.  Uses `object_id` only
         and raises InvalidQueryError if a filter has been applied. Returns
@@ -522,6 +596,19 @@ class BaseQuerySet(object):
 
         return self
 
+    def using(self, alias):
+        """This method is for controlling which database the QuerySet will be evaluated against if you are using more than one database.
+
+        :param alias: The database alias
+
+        .. versionadded:: 0.8
+        """
+
+        with switch_db(self._document, alias) as cls:
+            collection = cls._get_collection()
+
+        return self.clone_into(self.__class__(self._document, collection))
+
     def clone(self):
         """Creates a copy of the current
           :class:`~mongoengine.queryset.QuerySet`
@@ -923,10 +1010,39 @@ class BaseQuerySet(object):
             map_reduce_function = 'inline_map_reduce'
         else:
             map_reduce_function = 'map_reduce'
-            mr_args['out'] = output
+
+            if isinstance(output, basestring):
+                mr_args['out'] = output
+
+            elif isinstance(output, dict):
+                ordered_output = []
+
+                for part in ('replace', 'merge', 'reduce'):
+                    value = output.get(part)
+                    if value:
+                        ordered_output.append((part, value))
+                        break
+
+                else:
+                    raise OperationError("actionData not specified for output")
+
+                db_alias = output.get('db_alias')
+                remaing_args = ['db', 'sharded', 'nonAtomic']
+
+                if db_alias:
+                    ordered_output.append(('db', get_db(db_alias).name))
+                    del remaing_args[0]
+
+
+                for part in remaing_args:
+                    value = output.get(part)
+                    if value:
+                        ordered_output.append((part, value))
+
+                mr_args['out'] = SON(ordered_output)
 
         results = getattr(queryset._collection, map_reduce_function)(
-                          map_f, reduce_f, **mr_args)
+            map_f, reduce_f, **mr_args)
 
         if map_reduce_function == 'map_reduce':
             results = results.find()
@@ -1189,8 +1305,9 @@ class BaseQuerySet(object):
             if self._ordering:
                 # Apply query ordering
                 self._cursor_obj.sort(self._ordering)
-            elif self._document._meta['ordering']:
-                # Otherwise, apply the ordering from the document model
+            elif self._ordering is None and self._document._meta['ordering']:
+                # Otherwise, apply the ordering from the document model, unless
+                # it's been explicitly cleared via order_by with no arguments
                 order = self._get_order_by(self._document._meta['ordering'])
                 self._cursor_obj.sort(order)
 
@@ -1362,7 +1479,7 @@ class BaseQuerySet(object):
                 for subdoc in subclasses:
                     try:
                         subfield = ".".join(f.db_field for f in
-                                        subdoc._lookup_field(field.split('.')))
+                                            subdoc._lookup_field(field.split('.')))
                         ret.append(subfield)
                         found = True
                         break
@@ -1392,7 +1509,7 @@ class BaseQuerySet(object):
                 pass
             key_list.append((key, direction))
 
-        if self._cursor_obj:
+        if self._cursor_obj and key_list:
             self._cursor_obj.sort(key_list)
         return key_list
 
@@ -1450,6 +1567,7 @@ class BaseQuerySet(object):
                     # type of this field and use the corresponding
                     # .to_python(...)
                     from mongoengine.fields import EmbeddedDocumentField
+
                     obj = self._document
                     for chunk in path.split('.'):
                         obj = getattr(obj, chunk, None)
@@ -1460,6 +1578,7 @@ class BaseQuerySet(object):
                     if obj and data is not None:
                         data = obj.to_python(data)
             return data
+
         return clean(row)
 
     def _sub_js_fields(self, code):
@@ -1468,6 +1587,7 @@ class BaseQuerySet(object):
         substituted for the MongoDB name of the field (specified using the
         :attr:`name` keyword argument in a field's constructor).
         """
+
         def field_sub(match):
             # Extract just the field name, and look up the field objects
             field_name = match.group(1).split('.')

mongoengine/queryset/queryset.py

@@ -155,3 +155,10 @@ class QuerySetNoCache(BaseQuerySet):
             queryset = self.clone()
         queryset.rewind()
         return queryset
+
+
+class QuerySetNoDeRef(QuerySet):
+    """Special no_dereference QuerySet"""
+
+    def __dereference(items, max_depth=1, instance=None, name=None):
+        return items

mongoengine/queryset/transform.py

@@ -3,6 +3,7 @@ from collections import defaultdict
 import pymongo
 from bson import SON
 
+from mongoengine.connection import get_connection
 from mongoengine.common import _import_class
 from mongoengine.errors import InvalidQueryError, LookUpError
 
@@ -38,7 +39,7 @@ def query(_doc_cls=None, _field_operation=False, **query):
             mongo_query.update(value)
             continue
 
-        parts = key.split('__')
+        parts = key.rsplit('__')
         indices = [(i, p) for i, p in enumerate(parts) if p.isdigit()]
         parts = [part for part in parts if not part.isdigit()]
         # Check for an operator and transform to mongo-style if there is
@@ -115,14 +116,26 @@ def query(_doc_cls=None, _field_operation=False, **query):
             if key in mongo_query and isinstance(mongo_query[key], dict):
                 mongo_query[key].update(value)
                 # $maxDistance needs to come last - convert to SON
-                if '$maxDistance' in mongo_query[key]:
-                    value_dict = mongo_query[key]
+                value_dict = mongo_query[key]
+                if ('$maxDistance' in value_dict and '$near' in value_dict):
                     value_son = SON()
-                    for k, v in value_dict.iteritems():
-                        if k == '$maxDistance':
-                            continue
-                        value_son[k] = v
-                    value_son['$maxDistance'] = value_dict['$maxDistance']
+                    if isinstance(value_dict['$near'], dict):
+                        for k, v in value_dict.iteritems():
+                            if k == '$maxDistance':
+                                continue
+                            value_son[k] = v
+                        if (get_connection().max_wire_version <= 1):
+                            value_son['$maxDistance'] = value_dict['$maxDistance']
+                        else:
+                            value_son['$near'] = SON(value_son['$near'])
+                            value_son['$near']['$maxDistance'] = value_dict['$maxDistance']
+                    else:
+                        for k, v in value_dict.iteritems():
+                            if k == '$maxDistance':
+                                continue
+                            value_son[k] = v
+                        value_son['$maxDistance'] = value_dict['$maxDistance']
+
                     mongo_query[key] = value_son
             else:
                 # Store for manually merging later

mongoengine/queryset/visitor.py

@@ -1,8 +1,9 @@
 import copy
 
-from mongoengine.errors import InvalidQueryError
-from mongoengine.python_support import product, reduce
+from itertools import product
+from functools import reduce
 
+from mongoengine.errors import InvalidQueryError
 from mongoengine.queryset import transform
 
 __all__ = ('Q',)