fields.py 文件源码

def validate(self, value):
        if not isinstance(value, (Document, DBRef, dict, SON)):
            self.error('GenericReferences can only contain documents')

        if isinstance(value, (dict, SON)):
            if '_ref' not in value or '_cls' not in value:
                self.error('GenericReferences can only contain documents')

        # We need the id from the saved object to create the DBRef
        elif isinstance(value, Document) and value.id is None:
            self.error('You can only reference documents once they have been'
                       ' saved to the database')