EmbeddedDocumentField errors during update when adding new field to DynamicEmbeddedDocument #2486
Description
Summary: When using a DynamicEmbeddedDocument, an InvalidQueryError occurs if you try to set a field that is not defined in the MongoEngine schema. This invalidates the purpose of a dynamic document.
Example:
class B(DynamicEmbeddedDocument): foo = StringField() class A(Document): b = EmbeddedDocumentField(B) # This works A.objects(...).update(set__b__foo="123") # This does not work A.objects(...).update(set__b__bar="123") # mongoengine.errors.InvalidQueryError: Cannot resolve field "bar" Solution:
In my custom fork of MongoEngine, I've updated the EmbeddedDocumentField to account for dynamic documents as such.
class EmbeddedDocumentField(BaseField): def lookup_member(self, member_name): doc_and_subclasses = [self.document_type] + self.document_type.__subclasses__() for doc_type in doc_and_subclasses: field = doc_type._fields.get(member_name) if field: return field # NEW CODE if member_name not in ("S", "$") and any(issubclass(doc_type, DynamicEmbeddedDocument) for doc_type in doc_and_subclasses): return DynamicField(db_field=member_name) Custom Situation: I encountered this error because I had a EmbeddedDocumentListField of DynamicEmbeddedDocuments and I was trying to perform array operators like so:
A.objects(b__foo="abc").modify(set__list_of_b__S__bar="123") If the maintainers find my solution acceptable, I would be happy to write tests and make a PR with it. Otherwise, I will defer to coders with greater expertise in this codebase for the proper strategy here.