Django Rest 框架，序列化器级别过滤器

Question

我有两个模型，分别名为 Account 和 Story。在 Django 上的 models.Manager 的帮助下，我编写了一个检索过去 24 小时内发布的故事的方法。使用 Django，这种方法效果很好。问题是，当我使用 Django Rest Framework 创建序列化程序时，它会提取所有故事。为了防止这种情况，我写了一个名为get_image_file的方法，并在这里使用了我在models.Manager的帮助下写的方法，但是我无法解决问题。结果，我如何使用 Django Rest Framework 仅提取过去 24 年发布的故事，就像我在 Django 方面所做的那样？

序列化器.py

from rest_framework import serializers
from ..models import Account, Story


class StorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Story
        fields = ['image_file']

    def get_image_file(self, obj): 
    #This method doesn't work. DRF pulls all the stories.
        return obj.get_available_stories()

class AccountSerializer(serializers.ModelSerializer):
    
    class Meta:
        model = Account
        fields = '__all__'

    
    stories = StorySerializer(many=True)

models.py

from django.db import models
import datetime

def upload_to(instance, filename):
    username = instance.account.username
    return '%s/%s/%s' %('stories',username,filename)

def upload_pp(instance, filename):
    return '%s/%s/%s' %('profile_photo', instance.username,filename)

class Account(models.Model):
    username_pk = models.CharField(max_length=122)
    username = models.CharField(max_length=55, unique=True)
    profile_photo_id = models.CharField(max_length=155, unique=True)
    profile_photo = models.ImageField(upload_to=upload_pp, null=True, blank=True)
    profile_photo_width = models.IntegerField(null=True, blank=True)
    profile_photo_height = models.IntegerField(null=True, blank=True)

    def __str__(self):
        return self.username


class StoryManager(models.Manager):
    def get_available_stories(self, *args, **kwargs):
        date_from = datetime.datetime.now() - datetime.timedelta(days=1)
        return super(StoryManager, self).filter(image_timestamp__gte = date_from)

class Story(models.Model):
    account = models.ForeignKey(to=Account, on_delete=models.CASCADE, related_name="stories")
    image_file = models.ImageField(upload_to=upload_to, blank=True, null=True, editable=False)
    image_url = models.URLField()
    image_pk = models.CharField(max_length=60, null=True, blank=True, editable=False, unique=True)
    image_timestamp = models.DateTimeField(null=True, blank=True)
    image_width = models.IntegerField(null=True, blank=True)
    image_height = models.IntegerField(null=True, blank=True)
    objects = StoryManager()

    def __str__(self):
        return str(self.account)

Answer 1

一种方法是使用过滤器类。 与 Serializer 类非常相似。

Custom Generic Filter

def filter_queryset(self, request, queryset, view):
    # Override this method to do your filtering.
    # Probably your BaseModel has some filed as created_at
    # Assuming that is a Datetime object
    return queryset.filter(created_at.hour__lte=24)
    # You can even sort this values adding a .sort_by() after the filter