如何覆盖与响应 django rest framework 序列化程序一起返回的返回序列化程序对象

Posted 2023-02-24

【中文标题】如何覆盖与响应 django rest framework 序列化程序一起返回的返回序列化程序对象

【英文标题】：how to override returned serializer object that is returned with the response django rest framework serializer

【发布时间】：2019-11-20 13:33:28

【问题描述】：

我有一个 django rest 框架项目。我想在发出 get 请求以显示与数据库结构不相似的特定方式时覆盖返回的 json 对象结构。

我当前的返回对象是这样显示的：

    
        "id": 9,
        "namespace": "steve",
        "path": "something/another",
        "value": "this is a value",
        "person": 1
    ,
    
        "id": 11,
        "namespace": "namespace1",
        "path": "path2",
        "value": "anyoher value",
        "person": 2
    ,
    
        "id": 12,
        "namespace": "namespace1",
        "path": "path3",
        "value": "this dsiaalks",
        "person": 2
    ,
    
        "id": 13,
        "namespace": "namespace2",
        "path": "path4",
        "value": "asdfasdfasdf",
        "person": 2
    ,

我想换个

"person":2 

显示

"user":
    "userId":testUser

testUser 是 id 为 2 的用户的用户名 *

这是我目前的 serailzer：

from rest_framework import serializers
from .models import Preference
from django.contrib.auth.models import User


class PreferenceSerializer(serializers.ModelSerializer):
    person = serializers.PrimaryKeyRelatedField(queryset=User.objects.all(),)

    class Meta:
        model = Preference
        fields = ('id', 'namespace', 'path', 'value', 'person')

这是当前的模型：

from django.db import models
from django.contrib.auth.models import User
from owf_framework.people.models import Person

class Preference(models.Model):
    id = models.BigAutoField(primary_key=True, null=False)
    version = models.BigIntegerField(default=1, null=False)
    path = models.CharField(max_length=200, null=False)
    namespace = models.CharField(max_length=200, null=False)
    value = models.TextField(null=False)
    user_id = models.BigIntegerField(null=False, default=1)
    person = models.ForeignKey(User, on_delete=models.CASCADE)

    def __str__(self):
        return self.namespace

    class Meta:
        db_table = 'preference'

字段 person 是用户的外键。

【参考方案1】：

希望这会有所帮助：

serializers.py

from rest_framework import serializers
from .models import Preference
from django.contrib.auth.models import User


class PreferenceSerializer(serializers.ModelSerializer):
    person = serializers.PrimaryKeyRelatedField(queryset=User.objects.all(),)

    class Meta:
        model = Preference
        fields = ('id', 'namespace', 'path', 'value', 'person')

    def to_representation(self, instance):
        ret = super(PreferenceSerializer, self).to_representation(instance)
        # check the request is list view or detail view
        is_list_view = isinstance(self.instance, list)
        if is_list_view:
            person_id = ret.pop('person', None)
            user_obj = User.objects.filter(id=person_id).first()
            user_name = user_obj.username if user_obj else ""
            extra_ret = 
                "user": 
                    "userId": user_name
                
            
            ret.update(extra_ret)
        return ret

【参考方案2】：

我认为您可以使用模型方法。示例：

models.py

from django.db import models
from django.contrib.auth.models import User
from owf_framework.people.models import Person

class Preference(models.Model):
    id = models.BigAutoField(primary_key=True, null=False)
    version = models.BigIntegerField(default=1, null=False)
    path = models.CharField(max_length=200, null=False)
    namespace = models.CharField(max_length=200, null=False)
    value = models.TextField(null=False)
    user_id = models.BigIntegerField(null=False, default=1)
    person = models.ForeignKey(User, on_delete=models.CASCADE)

    def __str__(self):
        return self.namespace

    def get_person(self):
        return self.person.username

    class Meta:
        db_table = 'preference'

那么你就是序列化器：

from rest_framework import serializers
from .models import Preference
from django.contrib.auth.models import User


class PreferenceSerializer(serializers.ModelSerializer):
    person = serializers.PrimaryKeyRelatedField(queryset=User.objects.all(),)

    class Meta:
        model = Preference
        fields = ('id', 'namespace', 'path', 'value', 'person', 'get_person')

【参考方案3】：

我的建议是不要覆盖序列化程序。序列化程序应该只按原样序列化您拥有的数据。在您的情况下，您可以创建一个 ViewSet（不是 ModelViewSet），在 retrieve() 方法中使用过滤器定义您的查询，然后轻松配置您需要的响应。

【参考方案4】：

我认为这对你有帮助：

from rest_framework.serializers import ModelSerializer, SerializerMethodField

class PrefrenceSerializer(ModelSerializer):
    user = SerializerMethodField()

    class Meta:
        model = Prefrence
        exclude = ['person']

    def get_user(self, obj):

        return 
            "userId": obj.person.userId