在验证过程中丢失字段-嵌套序列化器create()-losingfieldsduringvalidation-nestedserializercreate()

I don't understand why specific fields are being dropped within validated_data.

我不理解为什么在validated_data中删除特定字段。

When POSTing input to create() a new instance, the following line: thisLabel = ClassificationLabel.objects.get(identifier=label.identifier) throws an error because the identifier attribute is not present:

在发布要创建()一个新实例的输入时，如下一行:thisLabel = ClassificationLabel.objects.get(identifier=label.identifier)会抛出一个错误，因为标识符属性不存在:

AttributeError at /api/v1/policies/ 

'collections.OrderedDict' object has no attribute 'identifier

的集合。OrderedDict的对象没有属性标识符。

I have the following serializers within Django REST framework:

我在Django REST框架中有以下序列化器:

serializers.py:

serializers.py:

class ClassificationLabelDetailSerializer(serializers.ModelSerializer):

    class Meta:
        model = ClassificationLabel
        fields = ('displayName', 'helpText', 'identifier', 'backgroundColour', 'foregroundColour', 'comment', 'description', 'lastChanged', 'revision')
        read_only_fields = ('identifier', 'lastChanged', 'revision',)


class PolicySerializer(serializers.ModelSerializer):
    labels = ClassificationLabelDetailSerializer(many=True)

    class Meta:
        model = Policy
        fields = ('displayName', 'identifier', 'labels', 'lastChanged', 'description', 'comment')
        read_only_fields = ('identifier', 'lastChanged',)

    def create(self,validated_data):
        labelData = validated_data.pop('labels')
        thisPolicy = Policy.objects.create(**validated_data)
        for label in labelData:
            for k, v in label.items():
                print(k, v)
            thisLabel = ClassificationLabel.objects.get(identifier=label.identifier)#insert organisational filter here
            PolicyMemberClassificationLabel.objects.create(policy=thisPolicy, label=thisLabel, order=index)
        return thisPolicy

models.py:

models.py:

class ClassificationLabel(models.Model):
    displayName = models.CharField(max_length = 32)
    helpText = models.TextField(max_length = 140, blank=True)
    backgroundColour = models.CharField(max_length=8)
    foregroundColour = models.CharField(max_length=8)
    description = models.TextField(max_length = 256, blank=True)
    comment = models.TextField(max_length = 1024, blank=True)
    lastChanged = models.DateTimeField(auto_now=True, editable=False)
    identifier = models.CharField(max_length = 128, blank=True, editable=False)
    revision = models.PositiveIntegerField(default=1, editable=False)

    def __str__(self):
        return self.displayName + " - " + self.identifier

    def save(self, *args, **kwargs):
        self.revision += 1
        #the following code generates a unique identifier and checks it for collisions against existing identifiers
        if not self.identifier:
            stringCheck = False
            while stringCheck is False:
                newString = str(uuid.uuid4())
                newString.replace('-', '')
                doesStringExist = ClassificationLabel.objects.filter(identifier=newString).exists()
                if doesStringExist is False:
                    stringCheck = True
            self.identifier = newString
        super(ClassificationLabel, self).save(*args, **kwargs) # Call the "real" save() method.


class Policy(models.Model):
    description = models.TextField(max_length = 256, blank=True)
    comment = models.TextField(max_length = 1024, blank=True)
    lastChanged = models.DateTimeField(auto_now =True)
    displayName = models.CharField(max_length = 64)
    identifier = models.CharField(max_length = 128, blank=True)
    labels = models.ManyToManyField(ClassificationLabel, through='PolicyMemberClassificationLabel')
    revision = models.PositiveIntegerField(default=1)

    class Meta:
        verbose_name_plural = 'Policies'

    def __str__(self):
        return self.displayName + " - " + self.identifier

    def save(self, *args, **kwargs):
        self.revision += 1
        #the following code generates a unique identifier and checks it for collisions against existing identifiers
        if not self.identifier:
            stringCheck = False
            while stringCheck is False:
                newString = str(uuid.uuid4())
                newString.replace('-', '')
                doesStringExist = Policy.objects.filter(identifier=newString).count()
                if doesStringExist == 0:
                    stringCheck = True
            self.identifier = newString
            super(Policy, self).save() # Call the "real" save() method.


class PolicyMemberClassificationLabel(models.Model):
    label = models.ForeignKey(ClassificationLabel, related_name='memberLabels')
    policy = models.ForeignKey(Policy, related_name='parentPolicy')
    order = models.PositiveSmallIntegerField(blank=True)

when sending the following via POST it's dropping the identifier, lastChanged and revision fields from the nested representation within validated_data.

当通过POST发送以下内容时，它将从validated_data中的嵌套表示中删除标识符、lastChanged和修订字段。

{
  "labels": [
    {
      "displayName": "Test name",
      "helpText": "Wayfarers sartorial authentic, small batch readymade disrupt coloring book. Wayfarers sartorial authentic, small batch readymade disrupt col",
      "identifier": "fa27e9bd-5007-4874-b10c-46b63c7c8a86",
      "backgroundColour": "#808900",
      "foregroundColour": "#000000",
      "comment": "Wayfarers sartorial authentic, small batch readymade disrupt coloring book.",
      "description": "Wayfarers sartorial authentic, small batch readymade disrupt coloring book.",
      "lastChanged": "2017-07-03T09:26:20.450681Z",
      "revision": 2
    },
    {
      "displayName": "Test name 1",
      "helpText": "Wayfarers sartorial authentic, small batch readymade disrupt coloring book.",
      "identifier": "29c968dd-8b83-4374-962d-32b9ef527e1b",
      "backgroundColour": "#9f0500",
      "foregroundColour": "#FFFFFF",
      "comment": "Wayfarers sartorial authentic, small batch readymade disrupt coloring book.",
      "description": "Wayfarers sartorial authentic, small batch readymade disrupt coloring book.",
      "lastChanged": "2017-07-03T09:25:52.955293Z",
      "revision": 2
    }
  ]
}

• I can see that the serializer .is_valid() is True for the PolicySerializer
• 我可以看到serializer .is_valid()对于PolicySerializer是正确的。
• when I look at validated_data those three fields are missing (the rest are there)
• 当我查看validated_data时，这三个字段会丢失(其余的字段都在那里)
• I've tried commenting out the read_only_fields and that doesn't seem to make any difference
• 我尝试过注释read_only_fields，但这似乎没有什么区别
• I've been referencing the DRF documentation here
  • I've ensured that the client's content-type is set correctly, since there was a similar problem here
  • 我已经确保正确地设置了客户机的内容类型，因为这里有一个类似的问题
  • other people seem to be having similar problems
  • 其他人似乎也有类似的问题
• 我在这里引用了DRF文档，我确保了客户机的内容类型设置正确，因为这里有类似的问题，其他人似乎也有类似的问题。

My question: How do I get the identifier field within the validated_data of the nested representation?

我的问题是:如何在嵌套表示的validated_data中获得标识符字段?

2 个解决方案

class ClassificationLabelDetailSerializer(serializers.ModelSerializer):
    identifier = serializers.CharField()

    class Meta:
        model = ClassificationLabel
        fields = ('displayName', 'helpText', 'backgroundColour', 'foregroundColour', 'comment', 'description', 'lastChanged', 'revision')