Merge branch 'master' of git://github.com/flosch/mongoengine

Added unit test for get_or_create, merged flosch's get with
punteney's get.

Conflicts:
	mongoengine/queryset.py

mongoengine/base.py

@@ -6,7 +6,6 @@ import pymongo
 class ValidationError(Exception):
     pass
 
-
 class BaseField(object):
     """A base class for fields in a MongoDB document. Instances of this class
     may be added to subclasses of `Document` to define a document's schema.
@@ -76,7 +75,10 @@ class ObjectIdField(BaseField):
 
     def to_mongo(self, value):
         if not isinstance(value, pymongo.objectid.ObjectId):
-            return pymongo.objectid.ObjectId(str(value))
+            try:
+                return pymongo.objectid.ObjectId(str(value))
+            except Exception, e:
+                raise ValidationError(e.message)
         return value
 
     def prepare_query_value(self, value):

mongoengine/fields.py

@@ -209,20 +209,19 @@ class ReferenceField(BaseField):
         return super(ReferenceField, self).__get__(instance, owner)
 
     def to_mongo(self, document):
-        if isinstance(document, (str, unicode, pymongo.objectid.ObjectId)):
-            # document may already be an object id
-            id_ = document
-        else:
+        id_field_name = self.document_type._meta['id_field']
+        id_field = self.document_type._fields[id_field_name]
+
+        if isinstance(document, Document):
             # We need the id from the saved object to create the DBRef
             id_ = document.id
             if id_ is None:
                 raise ValidationError('You can only reference documents once '
                                       'they have been saved to the database')
+        else:
+            id_ = document
 
-        # id may be a string rather than an ObjectID object
-        if not isinstance(id_, pymongo.objectid.ObjectId):
-            id_ = pymongo.objectid.ObjectId(id_)
-
+        id_ = id_field.to_mongo(id_)
         collection = self.document_type._meta['collection']
         return pymongo.dbref.DBRef(collection, id_)
     

mongoengine/queryset.py

@@ -10,6 +10,13 @@ __all__ = ['queryset_manager', 'Q', 'InvalidQueryError',
 # The maximum number of items to display in a QuerySet.__repr__
 REPR_OUTPUT_SIZE = 20
 
+class DoesNotExist(Exception):
+	pass
+
+
+class MultipleObjectsReturned(Exception):
+    pass
+
 
 class InvalidQueryError(Exception):
     pass
@@ -298,18 +305,43 @@ class QuerySet(object):
 
     def get(self, *q_objs, **query):
         """Retrieve the the matching object raising 
-        'MultipleObjectsReturned' or 'DoesNotExist' exceptions
-        if multiple or no results are found.
+        :class:`~mongoengine.queryset.MultipleObjectsReturned` or 
+        :class:`~mongoengine.queryset.DoesNotExist` exceptions if multiple or
+        no results are found.
         """
         self.__call__(*q_objs, **query)
         count = self.count()
         if count == 1:
             return self[0]
         elif count > 1:
-            raise MultipleObjectsReturned
+            message = u'%d items returned, instead of 1' % count
+            raise MultipleObjectsReturned(message)
         else:
-            raise DoesNotExist
+            raise DoesNotExist('Document not found')
 
+    def get_or_create(self, *q_objs, **query):
+        """Retreive unique object or create, if it doesn't exist. Raises
+        :class:`~mongoengine.queryset.MultipleObjectsReturned` if multiple 
+        results are found. A new document will be created if the document 
+        doesn't exists; a dictionary of default values for the new document
+        may be provided as a keyword argument called :attr:`defaults`.
+        """
+        defaults = query.get('defaults', {})
+        if query.has_key('defaults'):
+            del query['defaults']
+        
+        self.__call__(*q_objs, **query)
+        count = self.count()
+        if count == 0:
+            query.update(defaults)
+            doc = self._document(**query)
+            doc.save()
+            return doc
+        elif count == 1:
+            return self.first()
+        else:
+            message = u'%d items returned, instead of 1' % count
+            raise MultipleObjectsReturned(message)
 
     def first(self):
         """Retrieve the first object matching the query.

tests/fields.py

@@ -259,6 +259,40 @@ class FieldTest(unittest.TestCase):
         User.drop_collection()
         BlogPost.drop_collection()
 
+    def test_reference_query_conversion(self):
+        """Ensure that ReferenceFields can be queried using objects and values
+        of the type of the primary key of the referenced object.
+        """
+        class Member(Document):
+            user_num = IntField(primary_key=True)
+
+        class BlogPost(Document):
+            title = StringField()
+            author = ReferenceField(Member)
+
+        Member.drop_collection()
+        BlogPost.drop_collection()
+
+        m1 = Member(user_num=1)
+        m1.save()
+        m2 = Member(user_num=2)
+        m2.save()
+
+        post1 = BlogPost(title='post 1', author=m1)
+        post1.save()
+
+        post2 = BlogPost(title='post 2', author=m2)
+        post2.save()
+
+        post = BlogPost.objects(author=m1.id).first()
+        self.assertEqual(post.id, post1.id)
+
+        post = BlogPost.objects(author=m2.id).first()
+        self.assertEqual(post.id, post2.id)
+
+        Member.drop_collection()
+        BlogPost.drop_collection()
+
 
 if __name__ == '__main__':
     unittest.main()

tests/queryset.py

@@ -2,7 +2,8 @@ import unittest
 import pymongo
 from datetime import datetime
 
-from mongoengine.queryset import QuerySet, MultipleObjectsReturned, DoesNotExist
+from mongoengine.queryset import (QuerySet, MultipleObjectsReturned, 
+                                  DoesNotExist)
 from mongoengine import *
 
 
@@ -136,7 +137,7 @@ class QuerySetTest(unittest.TestCase):
         self.assertEqual(person.name, "User A")
 
     def test_find_only_one(self):
-        """Ensure that a query using find_one returns a valid result.
+        """Ensure that a query using ``get`` returns at most one result.
         """
         # Try retrieving when no objects exists
         self.assertRaises(DoesNotExist, self.Person.objects.get)
@@ -156,6 +157,33 @@ class QuerySetTest(unittest.TestCase):
         person = self.Person.objects.get(age__lt=30)
         self.assertEqual(person.name, "User A")
 
+    def test_get_or_create(self):
+        """Ensure that ``get_or_create`` returns one result or creates a new
+        document.
+        """
+        person1 = self.Person(name="User A", age=20)
+        person1.save()
+        person2 = self.Person(name="User B", age=30)
+        person2.save()
+
+        # Retrieve the first person from the database
+        self.assertRaises(MultipleObjectsReturned, 
+                          self.Person.objects.get_or_create)
+
+        # Use a query to filter the people found to just person2
+        person = self.Person.objects.get_or_create(age=30)
+        self.assertEqual(person.name, "User B")
+
+        person = self.Person.objects.get_or_create(age__lt=30)
+        self.assertEqual(person.name, "User A")
+
+        # Try retrieving when no objects exists - new doc should be created
+        self.Person.objects.get_or_create(age=50, defaults={'name': 'User C'})
+
+        person = self.Person.objects.get(age=50)
+        self.assertEqual(person.name, "User C")
+
+
     def test_filter_chaining(self):
         """Ensure filters can be chained together.
         """