fields.py 文件源码

def __init__(self, to, **kwargs):
        kwargs['verbose_name'] = kwargs.get('verbose_name', None)
        kwargs['rel'] = GenericRel(
            self, to,
            related_query_name=kwargs.pop('related_query_name', None),
            limit_choices_to=kwargs.pop('limit_choices_to', None),
        )
        # Override content-type/object-id field names on the related class
        self.object_id_field_name = kwargs.pop("object_id_field", "object_id")
        self.content_type_field_name = kwargs.pop("content_type_field", "content_type")

        self.for_concrete_model = kwargs.pop("for_concrete_model", True)

        kwargs['blank'] = True
        kwargs['editable'] = False
        kwargs['serialize'] = False
        # This construct is somewhat of an abuse of ForeignObject. This field
        # represents a relation from pk to object_id field. But, this relation
        # isn't direct, the join is generated reverse along foreign key. So,
        # the from_field is object_id field, to_field is pk because of the
        # reverse join.
        super(GenericRelation, self).__init__(
            to, to_fields=[],
            from_fields=[self.object_id_field_name], **kwargs)