如何在Django Rest Framework嵌套序列化器中动态更改深度？

Question

我有一组嵌套的序列化程序,depth它们各自的Meta类都有一个集合.我想根据传递到视图中的参数以编程方式更改深度.

class ResourceSerializer(serializers.ModelSerializer):
    type         = serializers.PrimaryKeyRelatedField(queryset=EntityType.objects.all())
    tags         = serializers.PrimaryKeyRelatedField(queryset=Tag.objects.all(), many=True)

    class Meta:
        model  = Resource
        fields = ('id', 'type', 'uri', 'tags', 'created_date')
        depth = 1

不幸的是,似乎没有办法depth在运行时覆盖该属性.我目前的解决方案是继承"浅"序列化器并覆盖其Meta类来调整深度.

class ResourceNestedSerializer(ResourceSerializer):
    class Meta(ResourceSerializer.Meta):
        depth = 2

在我看来:

    if nested:
        serializer = ContainerNestedSerializer(containers, many=True)
    else:
        serializer = ContainerSerializer(containers, many=True)
    return Response(serializer.data)

depth在打电话之前有什么方法可以调整serializer.data吗？

Answer 1

这是我的代码，其中包含/排除字段以及动态调整深度。根据你的口味调整它。:)

class DynamicModelSerializer(serializers.ModelSerializer):
"""
A ModelSerializer that takes an additional `fields` argument that
controls which fields should be displayed, and takes in a "nested"
argument to return nested serializers
"""

def __init__(self, *args, **kwargs):
    fields = kwargs.pop("fields", None)
    exclude = kwargs.pop("exclude", None)
    nest = kwargs.pop("nest", None)

    if nest is not None:
        if nest == True:
            self.Meta.depth = 1

    super(DynamicModelSerializer, self).__init__(*args, **kwargs)

    if fields is not None:
        # Drop any fields that are not specified in the `fields` argument.
        allowed = set(fields)
        existing = set(self.fields.keys())
        for field_name in existing - allowed:
            self.fields.pop(field_name)

    if exclude is not None:
        for field_name in exclude:
            self.fields.pop(field_name)