Django REST Framework POST/PUT 的深度不同？

Question

我正在使用 Django REST Framework 为我的 Web 应用程序创建 API。我有一个“评论”类，它在Meta 类中设置了depth=2。当GETComments 时，这很有效。当我尝试发送POST 或PUT 请求时（即创建一个新的Comment），我被告知我需要包含对象而不是ForeignKey ID。

这是我的序列化程序类：

class CommentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Comment
        depth = 2 

型号：

class Comment(models.Model):
    user = models.ForeignKey(User, null=True, blank=True,
        related_name='comments')
    budget = models.ForeignKey(Budget, related_name='comments')
    published = models.BooleanField(default=False)
    body = models.TextField()
    created = models.DateTimeField(auto_now_add=True)

查看代码：

class Comments(generics.ListCreateAPIView):

    model = Comment
    serializer_class = CommentSerializer

    def pre_save(self, obj):
        obj.user = self.request.user

输出（JSON）中显示的错误是：

{"user": ["This field is required."], "budget": [{"non_field_errors": ["Invalid data"]}]}

当这个原始数据被发送时：

{"budget": 2, "published": true, "body": "Another comment"}

Answer 1

我遇到了同样的问题，所以我解决了制作自定义泛型方法。这是上述答案的更好实现

class CustomListCreateAPIView(mixins.ListModelMixin,
                              mixins.CreateModelMixin,
                              generics.GenericAPIView):
    """
    Concrete view for listing a queryset or creating a model instance.
    """
    def get_serializer_class(self):
        method = self.request.method
        if method == 'PUT' or method == 'POST':
            return self.writeSerializers
        else:
            return self.readSerializers

    def get(self, request, *args, **kwargs):
        return self.list(request, *args, **kwargs)

    def post(self, request, *args, **kwargs):
        return self.create(request, *args, **kwargs)

类似的路德，

class CustomRetrieveUpdateDestroyAPIView(mixins.RetrieveModelMixin,
                                         mixins.UpdateModelMixin,
                                         mixins.DestroyModelMixin,
                                         generics.GenericAPIView):
    """
    Concrete view for retrieving, updating or deleting a model instance.
    """
    def get_serializer_class(self):
        method = self.request.method
        if method == 'PUT' or method == 'POST':
            return self.writeSerializers
        else:
            return self.readSerializers

    def get(self, request, *args, **kwargs):
        return self.retrieve(request, *args, **kwargs)

    def put(self, request, *args, **kwargs):
        return self.update(request, *args, **kwargs)

    def patch(self, request, *args, **kwargs):
        return self.partial_update(request, *args, **kwargs)

    def delete(self, request, *args, **kwargs):
        return self.destroy(request, *args, **kwargs)  # enter code here

现在我只在 Views.py 中给出 writeSerializers 和 readSerializers 值

还有一种创建读写序列化器的简单方法。

class employeeWriteSerializer(serializers.ModelSerializer):
    class Meta:
        model = employee
        fields = ('username','email',..)
        
class employeeReadSerializer(serializers.ModelSerializer):
     class Meta(employeeWriteSerializer.Meta):
         depth = 1

它可以节省时间和重复工作，您还可以在自定义通用 Api（Retitve 工作）中添加身份验证类。谢谢。

Answer 2

您可以通过覆盖get_serializer_class() 函数来设置不同的序列化程序，如下所示：

def get_serializer_class(self): method = self.request.method if method == 'PUT' or method == 'POST': return YourWriteSerializer else: return YourReadSerializer

我想添加这个，因为我在谷歌搜索了一段时间后来到这里。

Answer 3

我相信定义引用外键关系的序列化程序字段的正确方法是通过serializers.PrimaryKeyRelatedField 之类的方法。我不相信模型序列化器会自动使用这个字段类而不在序列化器类中明确定义它。

http://www.django-rest-framework.org/api-guide/relations/#primarykeyrelatedfield

我想PrimaryKeyRelatedField 序列化程序可以正确处理 JSON 数据提交，就像您在示例中使用的那样。

Answer 4

我知道这有点晚了，但我最终使用了 2 个这样的序列化程序：

class CommentReadSerializer(serializers.ModelSerializer):
    class Meta:
        model = Comment
        depth = 2

class CommentWriteSerializer(serializers.ModelSerializer):
    class Meta:
        model = Comment

然后这样使用：

class Comments(generics.ListCreateAPIView):

    model = Comment
    serializer_class = CommentReadSerializer

    def create(self, request, *args, **kwargs):
        serializer = CommentWriteSerializer(data=request.DATA, files=request.FILES)
        if serializer.is_valid():
            self.pre_save(serializer.object)
            self.object = serializer.save(force_insert=True)
            self.post_save(self.object, created=True)
            headers = self.get_success_headers(serializer.data)
            serializer = CommentReadSerializer(serializer.object)
            return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)