django-rest框架，多模式继承，ModelSerializers和嵌套序列化程序 [英] django-rest-framework, multitable model inheritance, ModelSerializers and nested serializers

问题描述

我无法在文档或Interwebs中找到此信息。

最新的django-rest-framework，django 1.6.5

如何创建一个可以使用多重继承来实现嵌套模型的嵌套序列化器的ModelSerializer？

例如

  ##### MODELS 
 class OtherModel（Models.Model）：
 stuff = models.CharField（max_length = 255）
 
 class MyBaseModel（models.Model）：
 whaddup = models.CharField（max_length = 255）
 other_model = models.ForeignKey（OtherModel）
 
 class ModelA（MyBaseModel） ：
 attr_a = models.CharField（max_length = 255）
 
 class ModelB（MyBaseModel）：
 attr_b = models.CharField（max_length = 255）
 
 
 #### SERIALIZERS 
 class MyBaseModelSerializer（serializers.ModelSerializer）：
 class Meta：
 model = MyBaseModel 
 
 class OtherModelSerializer（serializer.ModelSerializer ）：
 mybasemodel_set = MyBa seModelSerializer（many = True）
 
 class Meta：
 model = OtherModel 
  

这显然不起作用，但说明了我在这里做的事情。

在OtherModelSerializer中，我希望mybasemodel_set根据我们所拥有的来序列化ModelA或ModelB的特定代表。

如果重要，我也使用django.model_utils和inheritencemanager，所以我可以检索一个queryset，其中每个实例已经是一个适当的子类的实例。

谢谢

解决方案

我可以通过创建一个自定义相关字段p>

  class MyBaseModelField（serializers.RelatedField）：
 def to_native（self，value）：
 if isinstance（value ，ModelA）：
 a_s = ModelASerializer（instance = value）
返回a_s.data 
如果isinstance（value，ModelB）：
 b_s = ModelBSerializ呃（instance = value）
 return b_s.data 
 
 raise NotImplementedError 
 
 
 class OtherModelSerializer（serializer.ModelSerializer）：
 mybasemodel_set = MyBaseModelField（many = True）
 
 class Meta：
 model = OtherModel 
 fields =＃确保我们手动包含反向关系（mybasemodel_set，）
  

我有担心每个对象即时串行化是反向关系查询器是昂贵的，所以我想知道是否有更好的

我尝试的另一种方法是动态更改__init__内的MyBaseModelSerializer上的模型字段，但遇到这里所述的问题：

django休息框架嵌套模型服务器

I can't find this info in the docs or on the interwebs.
latest django-rest-framework, django 1.6.5

How does one create a ModelSerializer that can handle a nested serializers where the nested model is implemented using multitable inheritance?

e.g.

##### MODELS
class OtherModel(Models.Model):
    stuff = models.CharField(max_length=255)

class MyBaseModel(models.Model):
    whaddup = models.CharField(max_length=255)
    other_model = models.ForeignKey(OtherModel)

class ModelA(MyBaseModel):
    attr_a = models.CharField(max_length=255)

class ModelB(MyBaseModel):
    attr_b = models.CharField(max_length=255)


#### SERIALIZERS
class MyBaseModelSerializer(serializers.ModelSerializer):
    class Meta:
        model=MyBaseModel

class OtherModelSerializer(serializer.ModelSerializer):
    mybasemodel_set = MyBaseModelSerializer(many=True)

    class Meta:
        model = OtherModel

This obviously doesn't work but illustrates what i'm trying to do here.
In OtherModelSerializer, I'd like mybasemodel_set to serialize specific represenntations of either ModelA or ModelB depending on what we have.

If it matters, I'm also using django.model_utils and inheritencemanager so i can retrieve a queryset where each instance is already an instance of appropriate subclass.

Thanks

解决方案

I was able to do this by creating a custom relatedfield

class MyBaseModelField(serializers.RelatedField):
    def to_native(self, value):
        if isinstance(value, ModelA):
            a_s = ModelASerializer(instance=value)
            return a_s.data
        if isinstance(value, ModelB):
            b_s = ModelBSerializer(instance=value)
            return b_s.data

        raise NotImplementedError


class OtherModelSerializer(serializer.ModelSerializer):
    mybasemodel_set = MyBaseModelField(many=True)

    class Meta:
        model = OtherModel
        fields = # make sure we manually include the reverse relation (mybasemodel_set, )

I do have concerns that instanting a Serializer for each object is the reverse relation queryset is expensive so I'm wondering if there is a better way to do this.

Another approach i tried was dynamically changing the model field on MyBaseModelSerializer inside of __init__ but I ran into the issue described here:
django rest framework nested modelserializer

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