Manipulators that can edit SON objects as they enter and exit a database.
New manipulators should be defined as subclasses of SONManipulator and can be installed on a database by calling pymongo.database.Database.add_son_manipulator.
pymongo.son_manipulator.
AutoReference
(db)Transparently reference and de-reference already saved embedded objects.
This manipulator should probably only be used when the NamespaceInjector is also being used, otherwise it doesn’t make too much sense - documents can only be auto-referenced if they have an _ns field.
transform_incoming
(son, collection)Replace embedded documents with DBRefs.
transform_outgoing
(son, collection)Replace DBRefs with embedded documents.
will_copy
()We need to copy so the user’s document doesn’t get transformed refs.
pymongo.son_manipulator.
NamespaceInjector
A son manipulator that adds the _ns field.
transform_incoming
(son, collection)Add the _ns field to the incoming object
pymongo.son_manipulator.
ObjectIdInjector
A son manipulator that adds the _id field if it is missing.
transform_incoming
(son, collection)Add an _id field if it is missing.
pymongo.son_manipulator.
ObjectIdShuffler
A son manipulator that moves _id to the first position.
transform_incoming
(son, collection)Move _id to the front if it’s there.
will_copy
()We need to copy to be sure that we are dealing with SON, not a dict.
pymongo.son_manipulator.
SONManipulator
A base son manipulator.
This manipulator just saves and restores objects without changing them.
transform_incoming
(son, collection)Manipulate an incoming SON object.
son - the SON object to be inserted into the database
collection - the collection the object is being inserted into
transform_outgoing
(son, collection)Manipulate an outgoing SON object.
son - the SON object being retrieved from the database
collection - the collection this object was stored in
will_copy
()Will this SON manipulator make a copy of the incoming document?
Derived classes that do need to make a copy should override this method, returning True instead of False. All non-copying manipulators will be applied first (so that the user’s document will be updated appropriately), followed by copying manipulators.