在验证过程中丢失字段 - 嵌套序列化程序create（）
问题描述：
我不明白为什么特定的字段被丢弃在validated_data中。在验证过程中丢失字段 - 嵌套序列化程序create（）
投递输入以创建（）的新实例，下面的行：因为所述标识符属性不存在 thisLabel = ClassificationLabel.objects.get(identifier=label.identifier) 引发错误：
AttributeError at /api/v1/policies/
'collections.OrderedDict' object has no attribute 'identifier
我有以下序列化在Django REST框架内：
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：
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)
发送时通过POST以下它丢弃标识符，从validated_data内嵌套表示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
}
]
}
- 我可以看到，串行.is_valid（）是真正的PolicySerializer
- ，当我看着那些validated_data三个字段缺失（其余均为有）
- 我试着注释掉
read_only_fields而且似乎没有任何区别 - 我一直在引用文档DRF here
我的问题：我如何获取嵌套表示的validated_data中的标识符字段？
答
默认情况下，在模型上的editable设置为False的字段默认为串行器。 [http://www.django-rest-framework.org/api-guide/serializers/#specifying-read-only-fields]
您应该使用创造一个不同的串行其中场将给予明确的，像这样：
class ClassificationLabelDetailSerializer(serializers.ModelSerializer):
identifier = serializers.CharField()
class Meta:
model = ClassificationLabel
fields = ('displayName', 'helpText', 'backgroundColour', 'foregroundColour', 'comment', 'description', 'lastChanged', 'revision')
+0
，谢谢@antash--就是这样。关于此的一些附加说明： 1.如果您删除字段 的'editable = False'参数，则需要执行数据库迁移2.具有'editable = False'的字段不需要包含在' read_only_fields' - 它们自动包含在内 – AndrewO
答
在ClassificationLabelDetailSerializer您设置identifier为read_only场，和文档状态：
只读字段包含在API输出，但在创建或不应该包括在输入 更新操作。
这意味着它们不会被传递到validated_data，因为它们不应该用于写入操作。
从read_only字段中删除identifier，它应该工作。如果您需要使用identifier作为read_only的其他地方的序列化器，则应该为嵌套标签创建另一个序列化器。
那你的“当发送有效载荷”的意思？这是一个POST请求吗？ – zaidfazil
如果这是一个POST请求，那么你需要了解序列化程序将不接受定义为只读的字段。 – zaidfazil
谢谢@FazilZaid - 它是一个POST请求。我会看看是否省略嵌套序列化程序中的read_only_fields更改任何内容 – AndrewO