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如何在主对象序列化器中传递相关对象参数

django-views django-rest-framework django-models django python

codemyown · 技术社区 · 11 月前

我有一个Room对象,它将具有一些设置。我想让房间和房间设置成为不同的对象,但彼此绑定。每当创建房间时,都会创建房间设置,所以我使用的是信号。但是,在创建房间时,我需要通过信号将RoomSetting参数从room传递到RoomSettings,这样我就可以在创建时设置设置。

models.py

from django.db import models
from users.models import AppUser as UserModel
from django.core.validators import MaxValueValidator, MinValueValidator

import random, string
from datetime import datetime

def generate_unique_key():
    length = 10
    while True:
        key = ''.join(random.choices(string.ascii_uppercase, k=length))
        if Room.objects.filter(key=key).count() == 0:
            break
    return key

class Room(models.Model):
    host = models.ForeignKey(UserModel, on_delete=models.CASCADE, related_name='rooms')
    key = models.CharField(max_length=10, default=generate_unique_key, unique=True, editable=False)
    created_at = models.DateTimeField(auto_now_add=True, editable=False)
    
    def __str__(self):
        return f'{self.key} - {self.host.username}'
    
    def get_chat(self):
        return self.chat

class RoomSettings(models.Model):
    room = models.OneToOneField(Room, on_delete=models.CASCADE, related_name='settings')
    max_users = models.PositiveIntegerField(default=8, validators=[MaxValueValidator(8), MinValueValidator(1)])
    is_public = models.BooleanField(default=True)
    users_can_send_message = models.BooleanField(default=True)

序列化程序.py

from rest_framework import serializers

from .models import Room, RoomSettings
from users.serializers import UserSerializer
from chats.serializers import RoomChatSerializer


class SettingSerializer(serializers.ModelSerializer):
    class Meta:
        model = RoomSettings
        exclude = ['room']

        
class CreateRoomSerializer(serializers.ModelSerializer):
    max_users = serializers.IntegerField()
    is_public = serializers.BooleanField()
    users_can_send_message = serializers.BooleanField()
    class Meta:
        model = Room
        fields = ['max_users', 'is_public', 'users_can_send_message']

信号.py

from django.db.models.signals import post_save
from django.dispatch import receiver

from .models import Room, RoomSettings
from chats.models import Chat

@receiver(post_save, sender=Room)
def post_save_create_room(sender, instance, created, **kwargs):
    if created:
        RoomSettings.objects.create(room=instance, **kwargs)
        Chat.objects.create(room=instance)

views.py

class CreateRoomView(CreateAPIView):
    permission_classes = [IsAuthenticated]
    serializer_class = CreateRoomSerializer
    
    def post(self, request, *args, **kwargs):
        serializer = self.serializer_class(data=request.data)
        if serializer.is_valid():
            room = Room.objects.create(host=self.request.user, **serializer.data)
            return JsonResponse(RoomSerializer(room).data, status=status.HTTP_201_CREATED)

我试图将参数传递给CreateRoomView的端点,但遇到了错误。它应该使用给定的数据创建房间和房间设置。

1 回复 | 直到 11 月前

willeM_ Van Onsem 11 月前

我真的不明白你为什么需要 RoomSettings 首先是模型,尤其是因为你每次都会创建一个 房间设置 记录a Room .a的目的 OneToOneField 是制作额外的模型(在这里 房间设置 )可选,但在这里,你似乎在“玩弄”两个模型,而没有用例将它们一分为二。

只要把这些放在一起一型号:

from django.conf import settings

def generate_unique_key():
    length = 10
    while True:
        key = ''.join(random.choices(string.ascii_uppercase, k=length))
        if not Room.objects.filter(key=key).exists():
            break
    return key


class Room(models.Model):
    host = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name='rooms',
        editable=False,
    )
    key = models.CharField(
        max_length=10, default=generate_unique_key, unique=True, editable=False
    )
    created_at = models.DateTimeField(auto_now_add=True)
    max_users = models.PositiveIntegerField(
        default=8, validators=[MaxValueValidator(8), MinValueValidator(1)]
    )
    is_public = models.BooleanField(default=True)
    users_can_send_message = models.BooleanField(default=True)

    def __str__(self):
        return f'{self.key} - {self.host.username}'

    def get_chat(self):
        return self.chat

这将序列化器简化为:

class RoomSerializer(serializers.ModelSerializer):
    max_users = serializers.IntegerField()
    is_public = serializers.BooleanField()
    users_can_send_message = serializers.BooleanField()

    class Meta:
        model = Room
        fields = ['max_users', 'is_public', 'users_can_send_message']

从而创建对象以:

class CreateRoomView(CreateAPIView):
    permission_classes = [IsAuthenticated]
    serializer_class = RoomSerializer

    def perform_create(self, serializer):
        serializer.save(host=request.user)

注: :通常最好使用 settings.AUTH_USER_MODEL Â ^[Django-doc] 参考用户模型,而不是使用 User modelÂ ^[Django-doc] 直接。有关更多信息,请参阅 referencing the User model section of the documentationÂ ^[Django-doc] .

注: :最好一起工作 .exists() Â ^[Django-doc] 检查记录是否存在,然后使用 .count() Â ^[Django-doc] 因为在找到记录后,计数可能不得不继续寻找记录。