Added json serialisation support

- Added to_json and from_json to Document (MongoEngine/mongoengine#1)
- Added to_json and from_json to QuerySet (MongoEngine/mongoengine#131)

docs/changelog.rst

@@ -4,7 +4,9 @@ Changelog
 
 Changes in 0.8
 ==============
-- Updated index creation now tied to Document class ((MongoEngine/mongoengine#102)
+- Added to_json and from_json to Document (MongoEngine/mongoengine#1)
+- Added to_json and from_json to QuerySet (MongoEngine/mongoengine#131)
+- Updated index creation now tied to Document class (MongoEngine/mongoengine#102)
 - Added none() to queryset (MongoEngine/mongoengine#127)
 - Updated SequenceFields to allow post processing of the calculated counter value (MongoEngine/mongoengine#141)
 - Added clean method to documents for pre validation data cleaning (MongoEngine/mongoengine#60)

mongoengine/base/document.py

@@ -2,6 +2,7 @@ import operator
 from functools import partial
 
 import pymongo
+from bson import json_util
 from bson.dbref import DBRef
 
 from mongoengine import signals
@@ -253,6 +254,15 @@ class BaseDocument(object):
         if errors:
             raise ValidationError('ValidationError', errors=errors)
 
+    def to_json(self):
+        """Converts a document to JSON"""
+        return json_util.dumps(self.to_mongo())
+
+    @classmethod
+    def from_json(cls, json_data):
+        """Converts json data to an unsaved document instance"""
+        return cls._from_son(json_util.loads(json_data))
+
     def __expand_dynamic_values(self, name, value):
         """expand any dynamic values to their correct types / values"""
         if not isinstance(value, (dict, list, tuple)):

mongoengine/queryset/queryset.py

@@ -6,6 +6,7 @@ import re
 import warnings
 
 from bson.code import Code
+from bson import json_util
 import pymongo
 from pymongo.common import validate_read_preference
 
@@ -1216,6 +1217,15 @@ class QuerySet(object):
         max_depth += 1
         return self._dereference(self, max_depth=max_depth)
 
+    def to_json(self):
+        """Converts a queryset to JSON"""
+        return json_util.dumps(self._collection_obj.find(self._query))
+
+    def from_json(self, json_data):
+        """Converts json data to unsaved objects"""
+        son_data = json_util.loads(json_data)
+        return [self._document._from_son(data) for data in son_data]
+
     @property
     def _dereference(self):
         if not self.__dereference:

tests/document/__init__.py

@@ -1,4 +1,6 @@
-# TODO EXPLICT IMPORTS
+import sys
+sys.path[0:0] = [""]
+import unittest
 
 from class_methods import *
 from delta import *
@@ -6,6 +8,7 @@ from dynamic import *
 from indexes import *
 from inheritance import *
 from instance import *
+from json_serialisation import *
 
 if __name__ == '__main__':
     unittest.main()

tests/document/instance.py

@@ -346,7 +346,7 @@ class InstanceTest(unittest.TestCase):
             meta = {'shard_key': ('superphylum',)}
 
         Animal.drop_collection()
-        doc = Animal(superphylum = 'Deuterostomia')
+        doc = Animal(superphylum='Deuterostomia')
         doc.save()
         doc.reload()
         Animal.drop_collection()

tests/document/json_serialisation.py

@@ -0,0 +1,81 @@
+import sys
+sys.path[0:0] = [""]
+
+import unittest
+import uuid
+
+from nose.plugins.skip import SkipTest
+from datetime import datetime
+from bson import ObjectId
+
+import pymongo
+
+from mongoengine import *
+
+__all__ = ("TestJson",)
+
+
+class TestJson(unittest.TestCase):
+
+    def setUp(self):
+        connect(db='mongoenginetest')
+
+    def test_json_simple(self):
+
+        class Embedded(EmbeddedDocument):
+            string = StringField()
+
+        class Doc(Document):
+            string = StringField()
+            embedded_field = EmbeddedDocumentField(Embedded)
+
+        doc = Doc(string="Hi", embedded_field=Embedded(string="Hi"))
+
+        self.assertEqual(doc, Doc.from_json(doc.to_json()))
+
+    def test_json_complex(self):
+
+        if pymongo.version_tuple[0] <= 2 and pymongo.version_tuple[1] <= 3:
+            raise SkipTest("Need pymongo 2.4 as has a fix for DBRefs")
+
+        class EmbeddedDoc(EmbeddedDocument):
+            pass
+
+        class Simple(Document):
+            pass
+
+        class Doc(Document):
+            string_field = StringField(default='1')
+            int_field = IntField(default=1)
+            float_field = FloatField(default=1.1)
+            boolean_field = BooleanField(default=True)
+            datetime_field = DateTimeField(default=datetime.now)
+            embedded_document_field = EmbeddedDocumentField(EmbeddedDoc,
+                                        default=lambda: EmbeddedDoc())
+            list_field = ListField(default=lambda: [1, 2, 3])
+            dict_field = DictField(default=lambda: {"hello": "world"})
+            objectid_field = ObjectIdField(default=ObjectId)
+            reference_field = ReferenceField(Simple, default=lambda:
+                                                        Simple().save())
+            map_field = MapField(IntField(), default=lambda: {"simple": 1})
+            decimal_field = DecimalField(default=1.0)
+            complex_datetime_field = ComplexDateTimeField(default=datetime.now)
+            url_field = URLField(default="http://mongoengine.org")
+            dynamic_field = DynamicField(default=1)
+            generic_reference_field = GenericReferenceField(
+                                            default=lambda: Simple().save())
+            sorted_list_field = SortedListField(IntField(),
+                                                default=lambda: [1, 2, 3])
+            email_field = EmailField(default="ross@example.com")
+            geo_point_field = GeoPointField(default=lambda: [1, 2])
+            sequence_field = SequenceField()
+            uuid_field = UUIDField(default=uuid.uuid4)
+            generic_embedded_document_field = GenericEmbeddedDocumentField(
+                                        default=lambda: EmbeddedDoc())
+
+        doc = Doc()
+        self.assertEqual(doc, Doc.from_json(doc.to_json()))
+
+
+if __name__ == '__main__':
+    unittest.main()

tests/test_fields.py

@@ -606,7 +606,8 @@ class FieldTest(unittest.TestCase):
             name = StringField()
 
         class CategoryList(Document):
-            categories = SortedListField(EmbeddedDocumentField(Category), ordering='count', reverse=True)
+            categories = SortedListField(EmbeddedDocumentField(Category),
+                                         ordering='count', reverse=True)
             name = StringField()
 
         catlist = CategoryList(name="Top categories")
@@ -1616,8 +1617,9 @@ class FieldTest(unittest.TestCase):
         """Ensure that value is in a container of allowed values.
         """
         class Shirt(Document):
-            size = StringField(max_length=3, choices=(('S', 'Small'), ('M', 'Medium'), ('L', 'Large'),
+            size = StringField(max_length=3, choices=(
-                                                      ('XL', 'Extra Large'), ('XXL', 'Extra Extra Large')))
+                ('S', 'Small'), ('M', 'Medium'), ('L', 'Large'),
+                ('XL', 'Extra Large'), ('XXL', 'Extra Extra Large')))
 
         Shirt.drop_collection()
 
@@ -1633,12 +1635,15 @@ class FieldTest(unittest.TestCase):
         Shirt.drop_collection()
 
     def test_choices_get_field_display(self):
-        """Test dynamic helper for returning the display value of a choices field.
+        """Test dynamic helper for returning the display value of a choices
+        field.
         """
         class Shirt(Document):
-            size = StringField(max_length=3, choices=(('S', 'Small'), ('M', 'Medium'), ('L', 'Large'),
+            size = StringField(max_length=3, choices=(
-                                                      ('XL', 'Extra Large'), ('XXL', 'Extra Extra Large')))
+                    ('S', 'Small'), ('M', 'Medium'), ('L', 'Large'),
-            style = StringField(max_length=3, choices=(('S', 'Small'), ('B', 'Baggy'), ('W', 'wide')), default='S')
+                    ('XL', 'Extra Large'), ('XXL', 'Extra Extra Large')))
+            style = StringField(max_length=3, choices=(
+                ('S', 'Small'), ('B', 'Baggy'), ('W', 'wide')), default='S')
 
         Shirt.drop_collection()
 
@@ -1665,7 +1670,8 @@ class FieldTest(unittest.TestCase):
         """Ensure that value is in a container of allowed values.
         """
         class Shirt(Document):
-            size = StringField(max_length=3, choices=('S', 'M', 'L', 'XL', 'XXL'))
+            size = StringField(max_length=3,
+                              choices=('S', 'M', 'L', 'XL', 'XXL'))
 
         Shirt.drop_collection()
 
@@ -1681,11 +1687,15 @@ class FieldTest(unittest.TestCase):
         Shirt.drop_collection()
 
     def test_simple_choices_get_field_display(self):
-        """Test dynamic helper for returning the display value of a choices field.
+        """Test dynamic helper for returning the display value of a choices
+        field.
         """
         class Shirt(Document):
-            size = StringField(max_length=3, choices=('S', 'M', 'L', 'XL', 'XXL'))
+            size = StringField(max_length=3,
-            style = StringField(max_length=3, choices=('Small', 'Baggy', 'wide'), default='Small')
+                               choices=('S', 'M', 'L', 'XL', 'XXL'))
+            style = StringField(max_length=3,
+                                choices=('Small', 'Baggy', 'wide'),
+                                default='Small')
 
         Shirt.drop_collection()
 
@@ -1736,7 +1746,7 @@ class FieldTest(unittest.TestCase):
         self.assertTrue(putfile == result)
         self.assertEqual(result.the_file.read(), text)
         self.assertEqual(result.the_file.content_type, content_type)
-        result.the_file.delete() # Remove file from GridFS
+        result.the_file.delete()  # Remove file from GridFS
         PutFile.objects.delete()
 
         # Ensure file-like objects are stored
@@ -1801,7 +1811,6 @@ class FieldTest(unittest.TestCase):
             the_file = FileField()
         DemoFile.objects.create()
 
-
     def test_file_field_no_default(self):
 
         class GridDocument(Document):
@@ -1817,7 +1826,6 @@ class FieldTest(unittest.TestCase):
             doc_a = GridDocument()
             doc_a.save()
 
-
             doc_b = GridDocument.objects.with_id(doc_a.id)
             doc_b.the_file.replace(f, filename='doc_b')
             doc_b.save()
@@ -1859,7 +1867,7 @@ class FieldTest(unittest.TestCase):
 
         # Second instance
         test_file_dupe = TestFile()
-        data = test_file_dupe.the_file.read() # Should be None
+        data = test_file_dupe.the_file.read()  # Should be None
 
         self.assertTrue(test_file.name != test_file_dupe.name)
         self.assertTrue(test_file.the_file.read() != data)
@@ -2328,7 +2336,6 @@ class FieldTest(unittest.TestCase):
             self.assertEqual(error_dict['comments'][1]['content'],
                               u'Field is required')
 
-
         post.comments[1].content = 'here we go'
         post.validate()
 

tests/test_queryset.py

@@ -1,7 +1,10 @@
 from __future__ import with_statement
 import sys
 sys.path[0:0] = [""]
+
 import unittest
+import uuid
+from nose.plugins.skip import SkipTest
 
 from datetime import datetime, timedelta
 
@@ -74,7 +77,6 @@ class QuerySetTest(unittest.TestCase):
         def test_generic_reference():
             list(BlogPost.objects(author2__name="test"))
 
-
     def test_find(self):
         """Ensure that a query returns a valid set of results.
         """
@@ -3672,6 +3674,72 @@ class QueryFieldListTest(unittest.TestCase):
         self.assertRaises(ConfigurationError, Bar.objects,
                             read_preference='Primary')
 
+    def test_json_simple(self):
+
+        class Embedded(EmbeddedDocument):
+            string = StringField()
+
+        class Doc(Document):
+            string = StringField()
+            embedded_field = EmbeddedDocumentField(Embedded)
+
+        Doc.drop_collection()
+        Doc(string="Hi", embedded_field=Embedded(string="Hi")).save()
+        Doc(string="Bye", embedded_field=Embedded(string="Bye")).save()
+
+        Doc().save()
+        json_data = Doc.objects.to_json()
+        doc_objects = list(Doc.objects)
+
+        self.assertEqual(doc_objects, Doc.objects.from_json(json_data))
+
+    def test_json_complex(self):
+        if pymongo.version_tuple[0] <= 2 and pymongo.version_tuple[1] <= 3:
+            raise SkipTest("Need pymongo 2.4 as has a fix for DBRefs")
+
+        class EmbeddedDoc(EmbeddedDocument):
+            pass
+
+        class Simple(Document):
+            pass
+
+        class Doc(Document):
+            string_field = StringField(default='1')
+            int_field = IntField(default=1)
+            float_field = FloatField(default=1.1)
+            boolean_field = BooleanField(default=True)
+            datetime_field = DateTimeField(default=datetime.now)
+            embedded_document_field = EmbeddedDocumentField(EmbeddedDoc,
+                                        default=lambda: EmbeddedDoc())
+            list_field = ListField(default=lambda: [1, 2, 3])
+            dict_field = DictField(default=lambda: {"hello": "world"})
+            objectid_field = ObjectIdField(default=ObjectId)
+            reference_field = ReferenceField(Simple, default=lambda:
+                                                        Simple().save())
+            map_field = MapField(IntField(), default=lambda: {"simple": 1})
+            decimal_field = DecimalField(default=1.0)
+            complex_datetime_field = ComplexDateTimeField(default=datetime.now)
+            url_field = URLField(default="http://mongoengine.org")
+            dynamic_field = DynamicField(default=1)
+            generic_reference_field = GenericReferenceField(
+                                            default=lambda: Simple().save())
+            sorted_list_field = SortedListField(IntField(),
+                                                default=lambda: [1, 2, 3])
+            email_field = EmailField(default="ross@example.com")
+            geo_point_field = GeoPointField(default=lambda: [1, 2])
+            sequence_field = SequenceField()
+            uuid_field = UUIDField(default=uuid.uuid4)
+            generic_embedded_document_field = GenericEmbeddedDocumentField(
+                                        default=lambda: EmbeddedDoc())
+
+        Simple.drop_collection()
+        Doc.drop_collection()
+
+        Doc().save()
+        json_data = Doc.objects.to_json()
+        doc_objects = list(Doc.objects)
+
+        self.assertEqual(doc_objects, Doc.objects.from_json(json_data))
 
 
 if __name__ == '__main__':