如何在Django Rest Framework中过滤嵌套的序列化？ [英] How do you filter a nested serializer in Django Rest Framework?

问题描述

在Django Rest Framework中，如何将序列化程序嵌套在另一个序列化程序中，如何过滤？

In Django Rest Framework, how do you filter a serializer when it's nested in another serializer?

我的过滤器被强加在DRF视图中，但是当您调用串行器从另一个序列化程序中，嵌套的序列化程序的视图从未被调用，所以嵌套的结果显示为未过滤。

My filters are imposed in the DRF viewsets, but when you call a serializer from inside another serializer, the viewset of the nested serializer never gets called, so the nested results appear unfiltered.

我尝试在原始视图中添加过滤器，但是似乎没有过滤嵌套的结果，因为嵌套的结果被调用为一个单独的pre-fretched查询。 （嵌套的序列化程序是一个反向查找，你会看到。）

I have tried adding a filter on originating viewset, but it doesn't seem to filter the nested results because the nested results get called as a separate pre-fretched query. (The nested serializer is a reverse lookup, you see.)

是否可以在嵌套的序列化程序本身中添加一个get_queryset（）覆盖（将其从视图中移出） ），添加过滤器在那里？我也尝试过，没有运气。

Is it possible to add a get_queryset() override in the nested serializer itself (moving it out of the viewset), to add the filter there? I've tried that, too, with no luck.

这是我试过的，但似乎没有被调用：

This is what I tried, but it doesn't even seem to get called:

class QuestionnaireSerializer(serializers.ModelSerializer):
    edition = EditionSerializer(read_only=True)
    company = serializers.StringRelatedField(read_only=True)

    class Meta:
        model = Questionnaire

    def get_queryset(self):
        query = super(QuestionnaireSerializer, self).get_queryset(instance)
        if not self.request.user.is_staff:
            query = query.filter(user=self.request.user, edition__hide=False)
        return query

任何帮助赞赏

John

推荐答案

您可以对 ListSerializer 并覆盖 to_representation 方法。

You can subclass the ListSerializer and overwrite the to_representation method.

默认情况下， to_representation 方法调用 data.all（）嵌套查询集。所以在调用该方法之前，您有效地需要使 data = data.filter（** your_filters）。然后，您需要在嵌套序列化程序的元素上添加子类ListSerializer作为list_serializer_class。

By default the to_representation method calls data.all() on the nested queryset. So you effectively need to make data = data.filter(**your_filters) before the method is called. Then you need to add your subclassed ListSerializer as the list_serializer_class on the meta of the nested serializer.

1. 子类ListSerializer，覆盖 to_representation 然后调用super


2. 将子类化的ListSerializer添加到嵌套的Serializer上的元 list_serializer_class li>
   

1. subclass ListSerializer, overwriting to_representation and then calling super
2. add subclassed ListSerializer as the meta list_serializer_class on the nested Serializer

以下是您样本的相关代码。

Here is the relevant code for your sample.

class FilteredListSerializer(serializers.ListSerializer):

    def to_representation(self, data):
        data = data.filter(user=self.request.user, edition__hide=False)
        return super(FilteredListSerializer, self).to_representation(data)


class EditionSerializer(serializers.ModelSerializer):

    class Meta:
        list_serializer_class = FilteredListSerializer
        model = Edition


class QuestionnaireSerializer(serializers.ModelSerializer):
    edition = EditionSerializer(read_only=True)
    company = serializers.StringRelatedField(read_only=True)

    class Meta:
        model = Questionnaire

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