带有字符串而不是字典的可写嵌套 Django 序列化程序

Question

Django Rest Framework 文档有一个可写嵌套序列化器的示例，请参阅http://www.django-rest-framework.org/api-guide/relations/#writable-nested-serializers。

我感兴趣的是相关的Track 模型除了外键字段之外只有一个字段（title）。因此，我将其修改为：

models.py

class Album(models.Model):
    album_name = models.CharField(max_length=100)
    artist = models.CharField(max_length=100)

class Track(models.Model):
    album = models.ForeignKey(Album, related_name='tracks', on_delete=models.CASCADE)
    title = models.CharField(max_length=100)

    class Meta:
        unique_together = ('album', 'title')

serializers.py

class TrackSerializer(serializers.ModelSerializer):
    class Meta:
        model = Track
        fields = ('title',)

class AlbumSerializer(serializers.ModelSerializer):
    tracks = TrackSerializer(many=True)

    class Meta:
        model = Album
        fields = ('album_name', 'artist', 'tracks')

    def create(self, validated_data):
        tracks_data = validated_data.pop('tracks')
        album = Album.objects.create(**validated_data)
        for track_data in tracks_data:
            Track.objects.create(album=album, **track_data)
        return album

现在运行：

>>> data = {
    'album_name': 'The Grey Album',
    'artist': 'Danger Mouse',
    'tracks': [
        {'title': 'Public Service Announcement'},
        {'title': 'What More Can I Say'},
        {'title': 'Encore'},
    ],
}
>>> serializer = AlbumSerializer(data=data)
>>> serializer.is_valid()
True
>>> serializer.save()
<Album: Album object>

问题：

我需要将序列化数据中的曲目结构化为曲目标题字符串列表，而不是 {'title': title} 的字典列表，如下所示：

>>> data = {
    'album_name': 'The Grey Album',
    'artist': 'Danger Mouse',
    'tracks': [
        'Public Service Announcement',
        'What More Can I Say',
        'Encore',
    ],
}

我已尝试调整AlbumSerializers 的to_representation 和to_internal_value 方法，但无法使其满足序列化程序可写的要求。我错过了什么？

Answer 1

你可以试试serializermethodfield

tracks = serializers.SerializerMethodField()

def get_tracks(self, obj):
    return obj.tracks.values_list('title', flat=True)

def create(self, validated_data):
    data = self.context['request'].data.copy()
    tracks_data = data.get('tracks', [])
    album = Album.objects.create(**validated_data)
    for track_data in tracks_data:
        Track.objects.create(album=album, **track_data)
    return album