Merge branch 'master' of https://github.com/MongoEngine/mongoengine into dax_py3

mongoengine/connection.py

@@ -104,6 +104,18 @@ def register_connection(alias, db=None, name=None, host=None, port=None,
                 conn_settings['authentication_source'] = uri_options['authsource']
             if 'authmechanism' in uri_options:
                 conn_settings['authentication_mechanism'] = uri_options['authmechanism']
+            if IS_PYMONGO_3 and 'readpreference' in uri_options:
+                read_preferences = (
+                    ReadPreference.NEAREST,
+                    ReadPreference.PRIMARY,
+                    ReadPreference.PRIMARY_PREFERRED,
+                    ReadPreference.SECONDARY,
+                    ReadPreference.SECONDARY_PREFERRED)
+                read_pf_mode = uri_options['readpreference'].lower()
+                for preference in read_preferences:
+                    if preference.name.lower() == read_pf_mode:
+                        conn_settings['read_preference'] = preference
+                        break
         else:
             resolved_hosts.append(entity)
     conn_settings['host'] = resolved_hosts

mongoengine/context_managers.py

@@ -145,18 +145,17 @@ class no_sub_classes(object):
         :param cls: the class to turn querying sub classes on
         """
         self.cls = cls
+        self.cls_initial_subclasses = None
 
     def __enter__(self):
         """Change the objects default and _auto_dereference values."""
-        self.cls._all_subclasses = self.cls._subclasses
-        self.cls._subclasses = (self.cls,)
+        self.cls_initial_subclasses = self.cls._subclasses
+        self.cls._subclasses = (self.cls._class_name,)
         return self.cls
 
     def __exit__(self, t, value, traceback):
         """Reset the default and _auto_dereference values."""
-        self.cls._subclasses = self.cls._all_subclasses
-        delattr(self.cls, '_all_subclasses')
-        return self.cls
+        self.cls._subclasses = self.cls_initial_subclasses
 
 
 class query_counter(object):
@@ -215,7 +214,7 @@ class query_counter(object):
         """Get the number of queries."""
         ignore_query = {'ns': {'$ne': '%s.system.indexes' % self.db.name}}
         count = self.db.system.profile.find(ignore_query).count() - self.counter
-        self.counter += 1
+        self.counter += 1       # Account for the query we just fired
         return count
 
 

mongoengine/fields.py

@@ -364,7 +364,8 @@ class FloatField(BaseField):
 
 
 class DecimalField(BaseField):
-    """Fixed-point decimal number field.
+    """Fixed-point decimal number field. Stores the value as a float by default unless `force_string` is used.
+    If using floats, beware of Decimal to float conversion (potential precision loss)
 
     .. versionchanged:: 0.8
     .. versionadded:: 0.3
@@ -375,7 +376,9 @@ class DecimalField(BaseField):
         """
         :param min_value: Validation rule for the minimum acceptable value.
         :param max_value: Validation rule for the maximum acceptable value.
-        :param force_string: Store as a string.
+        :param force_string: Store the value as a string (instead of a float).
+         Be aware that this affects query sorting and operation like lte, gte (as string comparison is applied)
+         and some query operator won't work (e.g: inc, dec)
         :param precision: Number of decimal places to store.
         :param rounding: The rounding rule from the python decimal library:
 
@@ -647,9 +650,17 @@ class EmbeddedDocumentField(BaseField):
     def document_type(self):
         if isinstance(self.document_type_obj, six.string_types):
             if self.document_type_obj == RECURSIVE_REFERENCE_CONSTANT:
-                self.document_type_obj = self.owner_document
+                resolved_document_type = self.owner_document
             else:
-                self.document_type_obj = get_document(self.document_type_obj)
+                resolved_document_type = get_document(self.document_type_obj)
+
+            if not issubclass(resolved_document_type, EmbeddedDocument):
+                # Due to the late resolution of the document_type
+                # There is a chance that it won't be an EmbeddedDocument (#1661)
+                self.error('Invalid embedded document class provided to an '
+                           'EmbeddedDocumentField')
+            self.document_type_obj = resolved_document_type
+
         return self.document_type_obj
 
     def to_python(self, value):
@@ -1029,11 +1040,13 @@ class ReferenceField(BaseField):
 
     .. code-block:: python
 
-        class Bar(Document):
-            content = StringField()
-            foo = ReferenceField('Foo')
+        class Org(Document):
+            owner = ReferenceField('User')
 
-        Foo.register_delete_rule(Bar, 'foo', NULLIFY)
+        class User(Document):
+            org = ReferenceField('Org', reverse_delete_rule=CASCADE)
+
+        User.register_delete_rule(Org, 'owner', DENY)
 
     .. versionchanged:: 0.5 added `reverse_delete_rule`
     """

mongoengine/queryset/transform.py

@@ -147,7 +147,7 @@ def query(_doc_cls=None, **kwargs):
         if op is None or key not in mongo_query:
             mongo_query[key] = value
         elif key in mongo_query:
-            if isinstance(mongo_query[key], dict):
+            if isinstance(mongo_query[key], dict) and isinstance(value, dict):
                 mongo_query[key].update(value)
                 # $max/minDistance needs to come last - convert to SON
                 value_dict = mongo_query[key]
@@ -201,30 +201,37 @@ def update(_doc_cls=None, **update):
     format.
     """
     mongo_update = {}
+
     for key, value in update.items():
         if key == '__raw__':
             mongo_update.update(value)
             continue
+
         parts = key.split('__')
+
         # if there is no operator, default to 'set'
         if len(parts) < 3 and parts[0] not in UPDATE_OPERATORS:
             parts.insert(0, 'set')
+
         # Check for an operator and transform to mongo-style if there is
         op = None
         if parts[0] in UPDATE_OPERATORS:
             op = parts.pop(0)
             # Convert Pythonic names to Mongo equivalents
-            if op in ('push_all', 'pull_all'):
-                op = op.replace('_all', 'All')
-            elif op == 'dec':
+            operator_map = {
+                'push_all': 'pushAll',
+                'pull_all': 'pullAll',
+                'dec': 'inc',
+                'add_to_set': 'addToSet',
+                'set_on_insert': 'setOnInsert'
+            }
+            if op == 'dec':
                 # Support decrement by flipping a positive value's sign
                 # and using 'inc'
-                op = 'inc'
                 value = -value
-            elif op == 'add_to_set':
-                op = 'addToSet'
-            elif op == 'set_on_insert':
-                op = 'setOnInsert'
+            # If the operator doesn't found from operator map, the op value
+            # will stay unchanged
+            op = operator_map.get(op, op)
 
         match = None
         if parts[-1] in COMPARISON_OPERATORS:
@@ -291,6 +298,8 @@ def update(_doc_cls=None, **update):
                     value = field.prepare_query_value(op, value)
             elif op == 'unset':
                 value = 1
+            elif op == 'inc':
+                value = field.prepare_query_value(op, value)
 
         if match:
             match = '$' + match