Fix #349

umongo/fields.py

@@ -310,7 +310,7 @@ class ObjectIdField(BaseField, ma_bonus_fields.ObjectId):
 
 class ReferenceField(BaseField, ma_bonus_fields.Reference):
 
-    def __init__(self, document, *args, reference_cls=Reference, **kwargs):
+    def __init__(self, document, *args, reference_cls=None, **kwargs):
         """
         :param document: Can be a :class:`umongo.embedded_document.DocumentTemplate`,
             another instance's :class:`umongo.embedded_document.DocumentImplementation` or

umongo/frameworks/motor_asyncio.py

@@ -430,7 +430,8 @@ def _patch_field(self, field):
             field.io_validate_recursive = _dict_io_validate
         if isinstance(field, ReferenceField):
             field.io_validate.append(_reference_io_validate)
-            field.reference_cls = MotorAsyncIOReference
+            if field.reference_cls is None:
+                field.reference_cls = MotorAsyncIOReference
         if isinstance(field, EmbeddedField):
             field.io_validate_recursive = _embedded_document_io_validate
 

umongo/frameworks/pymongo.py

@@ -354,7 +354,8 @@ def _patch_field(self, field):
             field.io_validate_recursive = _dict_io_validate
         if isinstance(field, ReferenceField):
             field.io_validate.append(_reference_io_validate)
-            field.reference_cls = PyMongoReference
+            if field.reference_cls is None:
+                field.reference_cls = PyMongoReference
         if isinstance(field, EmbeddedField):
             field.io_validate_recursive = _embedded_document_io_validate
 

umongo/frameworks/txmongo.py

@@ -367,7 +367,8 @@ def _patch_field(self, field):
             field.io_validate_recursive = _dict_io_validate
         if isinstance(field, ReferenceField):
             field.io_validate.append(_reference_io_validate)
-            field.reference_cls = TxMongoReference
+            if field.reference_cls is None:
+                field.reference_cls = TxMongoReference
         if isinstance(field, EmbeddedField):
             field.io_validate_recursive = _embedded_document_io_validate