adding capability to extract json (to_json) using the field names and instead of the defined db_names, if those are set

mongoengine/base/document.py

@@ -257,7 +257,7 @@ class BaseDocument(object):
         """
         pass
 
-    def to_mongo(self):
+    def to_mongo(self, use_db_field=True):
         """Return as SON data ready for use with MongoDB.
         """
         data = SON()
@@ -271,7 +271,11 @@ class BaseDocument(object):
                 field = self._dynamic_fields.get(field_name)
 
             if value is not None:
-                value = field.to_mongo(value)
+                EmbeddedDocument = _import_class("EmbeddedDocument")
+                if isinstance(value, (EmbeddedDocument)) and use_db_field==False:
+                    value = field.to_mongo(value, use_db_field)
+                else:
+                    value = field.to_mongo(value)
 
             # Handle self generating fields
             if value is None and field._auto_gen:
@@ -279,7 +283,10 @@ class BaseDocument(object):
                 self._data[field_name] = value
 
             if value is not None:
-                data[field.db_field] = value
+                if use_db_field:
+                    data[field.db_field] = value
+                else:
+                    data[field.name] = value
 
         # If "_id" has not been set, then try and set it
         Document = _import_class("Document")
@@ -342,8 +349,11 @@ class BaseDocument(object):
             raise ValidationError(message, errors=errors)
 
     def to_json(self, *args, **kwargs):
-        """Converts a document to JSON"""
-        return json_util.dumps(self.to_mongo(),  *args, **kwargs)
+        """Converts a document to JSON.
+        :param use_db_field: Set to True by default but enables the output of the json structure with the field names and not the mongodb store db_names in case of set to False
+        """
+        use_db_field = kwargs.pop('use_db_field') if kwargs.has_key('use_db_field') else True
+        return json_util.dumps(self.to_mongo(use_db_field),  *args, **kwargs)
 
     @classmethod
     def from_json(cls, json_data):

mongoengine/fields.py

@@ -311,7 +311,7 @@ class DecimalField(BaseField):
             return value
         return value.quantize(self.precision, rounding=self.rounding)
 
-    def to_mongo(self, value):
+    def to_mongo(self, value, use_db_field=True):
         if value is None:
             return value
         if self.force_string:
@@ -551,10 +551,10 @@ class EmbeddedDocumentField(BaseField):
             return self.document_type._from_son(value)
         return value
 
-    def to_mongo(self, value):
+    def to_mongo(self, value, use_db_field=True):
         if not isinstance(value, self.document_type):
             return value
-        return self.document_type.to_mongo(value)
+        return self.document_type.to_mongo(value, use_db_field)
 
     def validate(self, value, clean=True):
         """Make sure that the document instance is an instance of the
@@ -601,11 +601,11 @@ class GenericEmbeddedDocumentField(BaseField):
 
         value.validate(clean=clean)
 
-    def to_mongo(self, document):
+    def to_mongo(self, document, use_db_field=True):
         if document is None:
             return None
 
-        data = document.to_mongo()
+        data = document.to_mongo(use_db_field)
         if not '_cls' in data:
             data['_cls'] = document._class_name
         return data
@@ -628,7 +628,7 @@ class DynamicField(BaseField):
             cls = value.__class__
             val = value.to_mongo()
             # If we its a document thats not inherited add _cls
-            if (isinstance(value, Document)):
+            if (isinstance(value,   Document)):
                 val = {"_ref": value.to_dbref(), "_cls": cls.__name__}
             if (isinstance(value, EmbeddedDocument)):
                 val['_cls'] = cls.__name__
@@ -1001,7 +1001,7 @@ class GenericReferenceField(BaseField):
             doc = doc_cls._from_son(doc)
         return doc
 
-    def to_mongo(self, document):
+    def to_mongo(self, document, use_db_field=True):
         if document is None:
             return None
 

tests/document/json_serialisation.py

@@ -20,6 +20,28 @@ class TestJson(unittest.TestCase):
     def setUp(self):
         connect(db='mongoenginetest')
 
+    def test_json_names(self):
+        """
+        Going to test reported issue:
+            https://github.com/MongoEngine/mongoengine/issues/654
+        where the reporter asks for the availability to perform
+        a to_json with the original class names and not the abreviated
+        mongodb document keys
+        """
+        class Embedded(EmbeddedDocument):
+            string = StringField(db_field='s')
+
+        class Doc(Document):
+            string = StringField(db_field='s')
+            embedded = EmbeddedDocumentField(Embedded, db_field='e')
+
+        doc = Doc( string="Hello", embedded=Embedded(string="Inner Hello"))
+        doc_json = doc.to_json(sort_keys=True, use_db_field=False,separators=(',', ':'))
+
+        expected_json = """{"embedded":{"string":"Inner Hello"},"string":"Hello"}"""
+
+        self.assertEqual( doc_json, expected_json)
+
     def test_json_simple(self):
 
         class Embedded(EmbeddedDocument):