Source code for txmongo.dbref

# Copyright 2009 10gen, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
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# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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"""Tools for manipulating DBRefs (references to MongoDB documents)."""

from bson.son import SON
from txmongo.collection import Collection
import types


[docs]class DBRef(object): """A reference to a document stored in a Mongo database. """ def __init__(self, collection, id, database=None): """Initialize a new DBRef. Raises TypeError if collection or database is not an instance of (str, unicode). `database` is optional and allows references to documents to work across databases. :Parameters: - `collection`: name of the collection the document is stored in - `id`: the value of the document's _id field - `database` (optional): name of the database to reference .. versionadded:: 1.1.1 The `database` parameter. """ if isinstance(collection, Collection): collection = collection._collection_name if not isinstance(collection, types.StringTypes): raise TypeError("collection must be an instance of (str, unicode)") if not isinstance(database, (types.StringTypes, types.NoneType)): raise TypeError("database must be an instance of (str, unicode)") self.__collection = collection self.__id = id self.__database = database def collection(self): """Get the name of this DBRef's collection as unicode. """ return self.__collection collection = property(collection) def id(self): """Get this DBRef's _id. """ return self.__id id = property(id) def database(self): """Get the name of this DBRef's database. Returns None if this DBRef doesn't specify a database. .. versionadded:: 1.1.1 """ return self.__database database = property(database)
[docs] def as_doc(self): """Get the SON document representation of this DBRef. Generally not needed by application developers """ doc = SON([("$ref", self.collection), ("$id", self.id)]) if self.database is not None: doc["$db"] = self.database return doc
def __repr__(self): if self.database is None: return "DBRef(%s, %r)" % (self.collection, self.id) return "DBRef(%s, %r, %s)" % (self.collection, self.id, self.database) def __cmp__(self, other): if isinstance(other, DBRef): return cmp([self.__database, self.__collection, self.__id], [other.__database, other.__collection, other.__id]) return NotImplemented def __hash__(self): """Get a hash value for this :class:`DBRef`. .. versionadded:: 1.1 """ return hash((self.__collection, self.__id, self.__database))