Adding db.system_js - helper for dealing with server-side JS PYTHON-86.

Thanks Michael Schurter for idea and original implementation.

Author: Mike Dirolf

pymongo/database.py

@@ -67,6 +67,7 @@ def __init__(self, connection, name):
         self.__outgoing_manipulators = []
         self.__outgoing_copying_manipulators = []
         self.add_son_manipulator(ObjectIdInjector())
+        self.__system_js = SystemJS(self)
 
     def __check_name(self, name):
         for invalid_char in [" ", ".", "$", "/", "\\"]:
@@ -99,6 +100,16 @@ def method_overwritten(instance, method):
             if method_overwritten(manipulator, "transform_outgoing"):
                 self.__outgoing_manipulators.insert(0, manipulator)
 
+    @property
+    def system_js(self):
+        """A :class:`SystemJS` helper for this :class:`Database`.
+
+        See the documentation for :class:`SystemJS` for more details.
+
+        .. versionadded:: 1.4+
+        """
+        return self.__system_js
+
     @property
     def connection(self):
         """The :class:`~pymongo.connection.Connection` instance for this
@@ -520,3 +531,51 @@ def __call__(self, *args, **kwargs):
         raise TypeError("'Database' object is not callable. If you meant to "
                         "call the '%s' method on a 'Collection' object it is "
                         "failing because no such method exists." % self.__name)
+
+
+class SystemJS(object):
+    """Helper class for dealing with stored JavaScript.
+    """
+
+    def __init__(self, database):
+        """Get a system js helper for the database `database`.
+
+        An instance of :class:`SystemJS` is automatically created for
+        each :class:`Database` instance as :attr:`Database.system_js`,
+        manual instantiation of this class should not be necessary.
+
+        :class:`SystemJS` instances allow for easy manipulation and
+        access to `server-side JavaScript`_:
+
+        .. doctest::
+
+          >>> db.system_js.add1 = "function (x) { return x + 1; }"
+          >>> db.system.js.find({"_id": "add1"}).count()
+          1
+          >>> db.system_js.add1(5)
+          6.0
+          >>> del db.system_js.add1
+          >>> db.system.js.find({"_id": "add1"}).count()
+          0
+
+        .. note:: Requires server version **>= 1.1.1**
+
+        .. versionadded:: 1.4+
+
+        .. _server-side JavaScript: http://www.mongodb.org/display/DOCS/Server-side+Code+Execution#Server-sideCodeExecution-Storingfunctionsserverside
+        """
+        # can't just assign it since we've overridden __setattr__
+        object.__setattr__(self, "_database", database)
+
+    def __setattr__(self, name, code):
+        self._database.system.js.save({"_id": name, "value": Code(code)},
+                                       safe=True)
+
+    def __delattr__(self, name):
+        self._database.system.js.remove({"_id": name}, safe=True)
+
+    def __getattr__(self, name):
+        return lambda *args: self._database.eval("function() { return %s."
+                                                 "apply(this, "
+                                                 "arguments); }" % name,
+                                                 *args)

test/test_database.py

@@ -14,24 +14,30 @@
 
 """Test the database module."""
 
-import unittest
-import random
 import datetime
+import random
 import sys
 sys.path[0:0] = [""]
+import unittest
 
-from pymongo.errors import InvalidName, InvalidOperation
-from pymongo.errors import CollectionInvalid, OperationFailure
-from pymongo.son import SON
-from pymongo.objectid import ObjectId
-from pymongo.database import Database
-from pymongo import ASCENDING, DESCENDING, OFF, SLOW_ONLY, ALL
-from pymongo.connection import Connection
+from pymongo import (ALL,
+                     ASCENDING,
+                     DESCENDING,
+                     OFF,
+                     SLOW_ONLY)
+from pymongo.code import Code
 from pymongo.collection import Collection
+from pymongo.connection import Connection
+from pymongo.database import Database
 from pymongo.dbref import DBRef
-from pymongo.code import Code
+from pymongo.errors import (CollectionInvalid,
+                            InvalidName,
+                            InvalidOperation,
+                            OperationFailure)
+from pymongo.objectid import ObjectId
+from pymongo.son import SON
 from pymongo.son_manipulator import AutoReference, NamespaceInjector
-from test_connection import get_connection
+from test.test_connection import get_connection
 
 
 class TestDatabase(unittest.TestCase):
@@ -458,5 +464,29 @@ def test_marc(self):
         self.assertEqual("buzz", db.users.find_one()["messages"][0]["title"])
         self.assertEqual("bar", db.users.find_one()["messages"][1]["title"])
 
+    def test_system_js(self):
+        db = self.connection.pymongo_test
+        db.system.js.remove()
+
+        self.assertEqual(0, db.system.js.count())
+        db.system_js.add = "function(a, b) { return a + b; }"
+        self.assertEqual(1, db.system.js.count())
+        self.assertEqual(6, db.system_js.add(1, 5))
+
+        del db.system_js.add
+        self.assertEqual(0, db.system.js.count())
+        # TODO enable this after SERVER-602 is fixed
+        # self.assertRaises(OperationFailure, db.system_js.add, 1, 5)
+
+        # TODO right now CodeWScope doesn't work w/ system js
+        # db.system_js.scope = Code("return hello;", {"hello": 8})
+        # self.assertEqual(8, db.system_js.scope())
+
+        self.assertRaises(OperationFailure, db.system_js.non_existant)
+
+        db.system_js.no_param = Code("return 5;")
+        self.assertEqual(5, db.system_js.no_param())
+
+
 if __name__ == "__main__":
     unittest.main()