python - Django Rest Framework具有多个嵌套对象的可写嵌套序列化器

我正在尝试创建可写的嵌套序列化程序。我的父模型是Game，嵌套模型是Measurements。我正在尝试使用AJAX将这些数据发布到我的DRF应用程序中。但是，当尝试发布数据时，嵌套的Measurements为空的OrderedDict()。

这是我的模型:

class Game(models.Model):
    start_timestamp = models.DateTimeField(auto_now_add=False)
    end_timestamp = models.DateTimeField(auto_now_add=False)
    date_added = models.DateTimeField(auto_now_add=True)


class Measurement(models.Model):
    game = models.ForeignKey(Game, on_delete=models.PROTECT, related_name='measurements')
    measurement_type = models.CharField(max_length=56)
    measurement = models.CharField(max_length=56)
    timestamp = models.DateTimeField(auto_now_add=False)
    date_added = models.DateTimeField(auto_now_add=True)

这是我的序列化器:

class MeasurementSerializer(serializers.ModelSerializer):
        timestamp = serializers.DateTimeField(input_formats=(['%Y-%m-%d %H:%M:%S.%Z', 'iso-8601']), required=False)

        class Meta:
            model = Measurement
            fields = ('measurement_type', 'measurement', 'timestamp')


class GameSerializer(serializers.ModelSerializer):
    start_timestamp = serializers.DateTimeField(input_formats=(['%Y-%m-%d %H:%M:%S.%Z', 'iso-8601']))
    end_timestamp = serializers.DateTimeField(input_formats=(['%Y-%m-%d %H:%M:%S.%Z', 'iso-8601']))
    measurements = MeasurementSerializer(many=True)

    class Meta:
        model = Game
        fields = ('id', 'start_timestamp', 'end_timestamp', 'measurements')

    def create(self, validated_data):
        measurements = validated_data.pop('measurements')
        game = Game.objects.create(**validated_data)
        for measurement in measurements:
            Measurement.objects.create(game=game, **measurement)
        return game

我对游戏的看法如下:

class GameList(generics.ListCreateAPIView):
    queryset = Game.objects.all()
    serializer_class = GameSerializer

我遵循this tutorial的结构。

我正在尝试通过AJAX将以下代码发布到此API:

 $.ajax({
         url: base_url + '/games/',
         dataType: "json",
         data: {
                "start_timestamp": "2016-02-16 14:51:43.000000",
                "end_timestamp": "2016-02-16 14:53:43.000000",
                "measurements":[
                    {'measurement_type':'type1', 'measurement':'71', 'timestamp':'2016-02-16 14:53:43.000000'},
                    {'measurement_type':'type1', 'measurement':'72', 'timestamp':'2016-02-16 14:54:43.000000'},
                    {'measurement_type':'type1', 'measurement':'73', 'timestamp':'2016-02-16 14:55:43.000000'},
                ]
                },
         type: 'POST'
     })
     .error(function(r){})
     .success(function(data){})
 });

发布此数据后，我在GameSerializer的create方法中发现validate_data.pop('measurements')包含3个空字典的列表(OrderedDict())。

更新:我发现通过request.data传入的initial_data的结构如下:

'emotion_measurements[0][measurement_type]' (4397175560) = {list} ['type1']
'emotion_measurements[0][measurement]' (4397285512) = {list} ['71']
'emotion_measurements[0][timestamp]' (4397285600) = {list} ['2016-02-16 14:53:43.000000']
'emotion_measurements[1][measurement_type]' (4397175040) = {list} ['type1']
'emotion_measurements[1][measurement]' (4397285864) = {list} ['72']
'emotion_measurements[1][timestamp]' (4397285952) = {list} ['2016-02-16 14:54:43.000000']
'emotion_measurements[2][measurement_type]' (4397175040) = {list} ['type1']
'emotion_measurements[2][measurement]' (4397285864) = {list} ['73']
'emotion_measurements[2][timestamp]' (4397285952) = {list} ['2016-02-16 14:55:43.000000']

有人遇到过这个问题吗？谢谢!

更新＃2

通过在我的MeasurementSerializer中添加以下内容，我能够解决此问题(尽管我认为这比解决方案更能解决问题):

def to_internal_value(self, data):
        formatted_data = json.dumps(data)
        formatted_data = formatted_data.replace("[", "").replace("]","")
        formatted_data = json.loads(formatted_data)
        return formatted_data

当我认为我需要Dict时，传入的Measurement数据是QueryDict。在键和值周围还有一些额外的括号，因此我也必须删除它们。

仍在寻找比这更好的答案!

最佳答案

这里的问题在前端。默认情况下，服务器将数据解释为application/x-www-form-urlencoded，为了使其理解您正在向其发送json，需要在contentType请求中指定$.ajax:

$.ajax({
     url: base_url + '/games/',
     dataType: "json",
     data: {...},
     contentType: 'application/json; charset=UTF-8',  // add this line
     type: 'POST'
 })
 .error(function(r){})
 .success(function(data){});

现在，您的validated_data.pop('measurements')的create()方法中的GameSerializer应该会与measurements产生三个对象(但不要忘记从Update＃2重做您的解决方法)。