Django 用户自定义模型中缺少字段

Question

在 Django REST 中尝试使用经典序列化程序后，我目前正在尝试使用自定义模型，即我的模型有一个 OneToOneField 字段。

我的模型（models.py）是自定义的User：

class Friend2(models.Model):
    user = models.OneToOneField(User)
    add_field = models.CharField(max_length=15)

我用（基于this SO topic）序列化它（在serializers.py）：

class Friend2Serializer(serializers.HyperlinkedModelSerializer):

    add_field = serializers.CharField(source='friend2.add_field')

    class Meta:
        model = User
        fields = ('id', 'username', 'password', 'email', 'add_field')

    def create(self, validated_data):
        profile_data = validated_data.pop('friend2', None)
        user = super(Friend2Serializer, self).create(validated_data)
        self.create_or_update_user(user, profile_data)
        return user

    def update(self, instance, validated_data):
        profile_data = validated_data.pop('friend2', None)
        self.create_or_update_profile(instance, profile_data)
        return super(Friend2Serializer, self).update(instance, validated_data)

    def create_or_update_user(self, user, profile_data):
        profile, created = Friend2.objects.get_or_create(user=user, defaults=profile_data)
        if not created and profile_data is not None:
            super(Friend2Serializer, self).update(profile, profile_data)

要POST数据注册新用户，我使用如下代码sn-p：

import requests
import json

json_data = {'username': 'mylogin12', 'password': 'mypassword', 'email': 'mymail12@wanadoo.fr', 'add_field' : 'myaddfield'}
r = requests.post('http://127.0.0.1:8000/register_new_user', json=json_data)

在我的views.py:

@api_view(['POST'])
def register_new_user(request):

    if request.method == 'POST':
        print('POST request !')

        print(request.data)
        serializer = Friend2Serializer(data=request.data)

        if serializer.is_valid():

            serializer.save()
            print('save friend!')
            return HttpResponse(status.HTTP_201_CREATED)

        else:
            print(serializer.errors)
            return HttpResponse(status.HTTP_403_FORBIDDEN)

到目前为止，它有效。

但是，当我尝试检索所有注册用户时：

def get_all_users(request):

    all_friends = Friend2.objects.all()

    serial = Friend2Serializer(all_friends, many=True)
    json_data = JSONRenderer().render(serial.data)

    return HttpResponse(json_data, content_type='application/json')

我收到以下错误：

Got AttributeError when attempting to get a value for field `username` on serializer `Friend2Serializer`.
The serializer field might be named incorrectly and not match any attribute or key on the `Friend2` instance.
Original exception text was: 'Friend2' object has no attribute 'username'.

但我不明白为什么 username 字段不存在它是 User 模型的属性。

编辑：：

我尝试根据以下内容修改我的序列化程序：

class Friend2Serializer(serializers.ModelSerializer):

username = serializers.CharField(source='user.username')
password = serializers.CharField(source='user.password')
email = serializers.CharField(source='user.email')
add_field = serializers.CharField(allow_blank=True)

class Meta:
    model = Friend2
    fields = ('username', 'password', 'email', 'add_field')
    depth = 1

def create(self, validated_data):
    profile_data = validated_data.pop('friend2', None)
    user = super(Friend2Serializer, self).create(validated_data)
    self.create_or_update_user(user, profile_data)
    return user

def update(self, instance, validated_data):
    profile_data = validated_data.pop('friend2', None)
    self.create_or_update_profile(instance, profile_data)
    return super(Friend2Serializer, self).update(instance, validated_data)

def create_or_update_user(self, user, profile_data):
    profile, created = Friend2.objects.get_or_create(user=user, defaults=profile_data)
    if not created and profile_data is not None:
        super(Friend2Serializer, self).update(profile, profile_data)

但是现在，我收到以下错误：

raise TypeError("'%s' is an invalid keyword argument for this function" % list(kwargs)[0])

TypeError: 'user' 是此函数的无效关键字参数

Answer 1

Friend2 模型有一个user 字段，而不是username。在您的序列化程序类中将 username 替换为 user。