Question

就像Youtube一样，我希望看到我的帖子（装备）的类别。

我的方法是......

获取属于用户的整个类别列表
获取属于用户和帖子的完整类别列表
比较它们并返回JSON

在建造一个Seriailizer的同时，我觉得我完全是股票。如此令人沮丧...... :(

如果您有任何更好的想法，请随时改变我的方法。

预期的JSON输出位于

{
    ...
    "categories": [
    {
        "id": 1,
        "name": "asd"
        "added": True <- since the post is added to 'asd'
    },
    {
        "id": 2,
        "name": "workout"
        "added": True
    }, 
    ...
    {
        "id": 5,
        "name": "bgm"
        "added": False <- since the post is not added to 'bgm'
    }, 
    ]
}

这是views.py

class OutfitDetailView(generics.RetrieveAPIView):
    queryset = Outfit.objects.all()
    serializer_class = OutfitDetailSerializer
    lookup_field = 'pk'

这是serializers.py（这是一个问题）

class OutfitDetailSerializer(serializers.ModelSerializer):
     ...
   def get_categories(self, obj):
            # Right Here! Get whole categories associated with user
            all_categories = Category.objects.filter(owner=self.context['request'].user)
            # And the categories associated with user AND the post
            categories = obj.categories.filter(owner=self.context['request'].user)

            return CategorySerializer(categories, many=True).data

class CategorySerializer(serializers.ModelSerializer):    
    class Meta:
        model = Category
        fields = (
            'id',
            'name',
            'added' <- here I want to add 'added' field but I don't know how.
        )

如果您需要型号

class Outfit(models.Model):
    ...
    user = models.ForeignKey(settings.AUTH_USER_MODEL, null=True, blank=True)
    content = models.CharField(max_length=30)
    ...

class Category(models.Model):
    name = models.CharField(max_length=20)
    owner = models.ForeignKey(settings.AUTH_USER_MODEL, null=True, blank=True)
    outfits = models.ManyToManyField(Outfit, related_name="categories", blank=True)
    main_img = models.ImageField(
                            upload_to=upload_location_category,
                            null=True,
                            blank=True)
    ...

Answer 1

如果我理解你的错误，你可以尝试：

class OutfitDetailSerializer(serializers.ModelSerializer):

    def get_categories(self, obj):
        user = self.context['request'].user
        categories = Category.objects.filter(owner=user)
        added = categories.extra(select={'added': '1'}).filter(outfits__pk=obj.pk)
        added = list(added.values('added', 'name', 'id'))
        added_f = categories.extra(select={'added': '0'}).exclude(outfits__pk=obj.pk)
        added_f = list(added_f.values('added', 'name', 'id'))
        categories = added + added_f
        return CategorySerializer(categories, many=True).data

请注意values您需要添加CategorySerializer

所需的所有字段

class CategorySerializer(serializers.ModelSerializer):
    added = serializers.BooleanField()
    class Meta:
        model = Category
        fields = (
            'id',
            'name',
            'added'
        )

过滤多个对象并在Serializer中返回“new field”

1 个答案: