Django elasticsearch DSL，带有自定义模型字段（hashid字段）

Question

我有一个模型，它为id使用django hashid字段

class Artwork(Model):

    id = HashidAutoField(primary_key=True, min_length=8, alphabet="0123456789abcdefghijklmnopqrstuvwxyz")

    title = ....

这是另一个模型的相关项

class ArtworkFeedItem(FeedItem):
    artwork = models.OneToOneField('artwork.Artwork', related_name='artwork_feeditem', on_delete=models.CASCADE)

现在我正在尝试设置[django elasticsearch dsl]（https://github.com/django-es/django-elasticsearch-dsl），并为此设置Document

@registry.register_document
class ArtworkFeedItemDocument(Document):
    class Index:
        name = 'feed'
        settings = {
            'number_of_shards': 1,
            'number_of_replicas': 0
        }

    artwork = fields.ObjectField(
        properties={
            'id': fields.TextField(),
            'title': fields.TextField(
                attr='title',
                fields={
                    'suggest': fields.Completion(),
                }
            )
        }

    )

    class Django:
        model = ArtworkFeedItem
        fields = []
        related_models = [Artwork]

然而，当我尝试使用python manage.py search_index --rebuild来rebuild索引时，我得到了以下异常

elasticsearch.exceptions.SerializationError: ({'index': {'_id': Hashid(135): l2vylzm9, '_index': 'feed'}}, TypeError("Unable to serialize Hashid(135): l2vylzm9 (type: <class 'hashid_field.hashid.Hashid'>)",))

Django elasticsearch dsl显然不知道如何处理这样的hashid字段

我想也许我可以做我自己喜欢的

from elasticsearch_dsl import Field
class HashIdField(Field):
    """
    Custom DSL field to support HashIds
    """

    name = "hashid"

    def _serialize(self, data):
        return data.hashid

然后在'id': HashIdField中使用它，但这给了我另一个例外

elasticsearch.exceptions.RequestError: RequestError(400, 'mapper_parsing_exception', 'No handler for type [hashid] declared on field [id]')

有人知道我怎样才能让它工作吗

Answer 1

对于任何感兴趣的人，我通过重写Document的generate_id方法来解决这个问题，这样使用的_id就只是一个普通字符串：

    @classmethod
    def generate_id(cls, object_instance):
        return object_instance.id.hashid