django-elasticsearch-dsl NestedFiled无法用于ManyToManyField

如何解决django-elasticsearch-dsl NestedFiled无法用于ManyToManyField

除了使用Price属性的BookPrice模型上的 Price 字段之外，我已经能够成功声明，映射和填充所有模型字段到Elasticsearch Index。如果我从文档中删除“价格”字段，那么它将正常工作。

但是，我过去曾经能够成功构建索引，但是我认为我做了一些更改并且失去了代码完整性，并且现在无法正常工作。

我尝试了在帮助论坛和官方文档中找到的所有可能组合，但是没有运气。

我当前正在使用

SchemaDirectiveVisitor

models.py

Elasticsearch == 7.8.0
elasticsearch-dsl == 7.2.1
django-elasticsearch-dsl == 7.1.1

documents.py

class Publisher(models.Model):
    publisher_name = models.CharField(max_length=50)

class BookType(models.Model):
    book_type = models.CharField(max_length=20) # Hard Cover,Soft Cover,Kindle Edition,Digital PDF etc.

class Book(models.Model):
    book_title = models.TextField()
    book_types = models.ManyToManyField(BookType,through='BookPrice',through_fields=('book','book_type'))

class BookPrice(models.Model):
    book_type = models.ForeignKey(Booktype,on_delete=models.CASCADE)
    book = models.ForeignKey(Book,on_delete=models.CASCADE)
    price = models.DecimalField(max_digits=7,decimal_places=2)

错误

@registry.register_document
class BookDocument(Document):
    book_title = fields.TextField(
        attr='book_title',fields={
            'suggest': fields.CompletionField(),})

    publisher = fields.ObjectField(properties={
        'publisher_name': fields.TextField(),})

    book_types = fields.nestedField(properties={
        'id': fields.IntegerField(),'book_type': fields.TextField(),'price': fields.FloatField()
    })

    class Index:
        name = 'books'
        settings = {'number_of_shards': 1,'number_of_replicas': 0}

    class Django:
        model = Book
        fields = [
            'id','slug','published_date','pages',]

        related_models = [BookPrice,BookType]

        def get_queryset(self):
            return super(BookDocument,self).get_queryset().select_related('publisher','book_types')

        def get_instances_from_related(self,related_instance):
            if isinstance(related_instance,BookPrice):
                return related_instance.book
            return related_instance.book_set.all()

解决方法

我使用prepare_foo(self,instance)方法解决了这个问题，并开始工作。 Using prepare_field

documents.py

def prepare_book_types(self,instance):
    return instance.get_price_for_es()

models.py

class Book(models.Model):
   ......

    def get_price_for_es(self):
       book_types= self.bookprice_set.all()
       book_types_price_list = []
       for x in book_types:
           book_types_price_list.append({'id': x.booktype_id,'book_type': x.booktype.book_type,'price': x.price})
       return book_types_price_list