如何使用Django Rest Framework对序列化字段进行排序

Question

我正在寻找有关如何按值对序列化字段进行排序/分组的建议。这是一个代码示例，解释了我想要实现的目标。

楷模

class Folder(models.Model):
    name = models.CharField()


class File(models.Model):
    filetype = models.CharField()
    name = models.CharField()
    folder = models.ForeignKey(Folder)

序列化器

class FileSerializer(serializers.ModelSerializer):

    class Meta:
        model = File
        fields = ('id', 'filetype', 'name')


class FolderSerializer(serializers.ModelSerializer):

    files = FileSerializer(read_only=True)

    class Meta:
        model = Folder
        fields = ('name', 'files')

这序列化为：

{
    "name": "Test Folder",
    "files": [
        {"id": 1, "filetype": "pdf", "name": "some pdf file"}.
        {"id": 2, "filetype": "pdf", "name": "some other pdf file"},
        {"id": 3, "filetype": "txt", "name": "some text file"}
    ]
}

我正在寻找一种序列化为此的方法：

{
    "name": "Test Folder",
    "files": [
        "pdf": [
            {"id": 1, "name": "some pdf file"},
            {"id": 2, "name": "some other pdf file"}
        ],
        "txt": [
            {"id": 3, "name": "some text file"}
        ]
    ]
}

Answer 1

尝试为此使用SerializerMethodField。您需要实现以下内容：

class FolderSerializer(serializers.ModelSerializer):
    files = serializers.SerializerMethodField()

    class Meta:
        model = Folder
        fields = ('name', 'files')

    def get_files(self, obj):
        result = {'pdf': [], 'txt':[]}
        for file in obj.file_set.all():
            serializer = FileSerializer(file)
            if file.name.endswith('pdf'):
                  result['pdf'].append(serializer.data)
            if file.name.endswith('txt'):
                  result['txt'].append(serializer.data)   
        return result