python - 在 Serializer DRF 中添加非模型字段

Question

我正在尝试将栅格模型字段与非模型 config_version 字段组合到我的序列化程序中，如下所示:

class RasterPostSerializer(serializers.ModelSerializer):

    class Meta:
        model = Raster
        fields = (
            'name',
            'description',
            'filepath'
        )


class ConfigurationSerializer(serializers.Serializer):
    config_version = serializers.CharField()
    rasters = RasterPostSerializer(many=True)

    def create(self, validated_data):
        data_field = validated_data['rasters']
        for raster in data_field['rasters']:
            return Raster(name=raster['name'], description=raster['description'], filepath=raster['filepath'])

在使用 serializer.save() 方法之前，我想在我的 view.py 中检查 config_version，但之后 .save() 给我:

The serializer field might be named incorrectly and not match any attribute or key on the `Raster` instance.
Original exception text was: 'Raster' object has no attribute 'config_version'.

这是怎么回事，是否有解决方案？

编辑:我的示例 JSON POST 负载如下所示:

{
  "config_version":"v2",
  "rasters":[
    {
      "name":"XYZ.jpg",
      "description":"some description",
      "filepath":"path in filesystem"
    }
}

config_version 不是常量。它可以动态设置，因为使用 ConfigurationSerializer 的 Controller 将是配置端点 - 将来可能需要添加栅格和其他一些信息。

views.py 中的配置端点看起来像

@api_view(['POST'])
def configuration(request):

if request.method == 'POST':
    serializer = ConfigurationSerializer(data=request.data)

    if serializer.is_valid():
        if serializer.validated_data['config_version'] is 'v2':

            raster_name_list = [raster.name for raster in Raster.objects.all()]
            for instance in serializer.validated_data['rasters']:
                if instance['name'] in raster_name_list:
                    return Response({"Fail": "Raster name '{}' already exists".format(instance['name'])}, status=status.HTTP_304_NOT_MODIFIED)
            serializer.save()
            return Response(serializer.data, status=status.HTTP_201_CREATED)
    return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

Answer 1

您应该返回 ConfigurationSerializer 数据作为创建操作的结果。而且我也不知道你要用 config_version

做什么

class ConfigurationSerializer(serializers.Serializer):
    config_version = serializers.CharField()
    rasters = RasterPostSerializer(many=True)

    def create(self, validated_data):
        config_version = validated_data.get('rasters')
        rasters = validated_data.pop('rasters')
        raster_list = []
        for raster in rasters:
            raster_list.append(Raster.objects.create(**raster))
        return {
            "config_version": config_version,
            "rasters": raster_list
        }