我正在尝试使用DRF构建一个django模型,该模型要么在创建后发送对象状态有效负载,要么发送错误有效负载 . 当我尝试做类似的事情,然后我收到以下错误消息:
File "/Users/user/projects/bowling-game/env/lib/python3.6/site-packages/rest_framework/serializers.py", line 527, in to_representation ret[field.field_name] = field.to_representation(attribute) File "/Users/user/projects/bowling-game/env/lib/python3.6/site-packages/rest_framework/serializers.py", line 683, in to_representation self.child.to_representation(item) for item in iterable File "/Users/user/projects/bowling-game/env/lib/python3.6/site-packages/rest_framework/serializers.py", line 683, in <listcomp> self.child.to_representation(item) for item in iterable File "/Users/user/projects/bowling-game/env/lib/python3.6/site-packages/rest_framework/serializers.py", line 510, in to_representation fields = self._readable_fields File "/Users/user/projects/bowling-game/env/lib/python3.6/site-packages/django/utils/functional.py", line 36, in __get__ res = instance.__dict__[self.name] = self.func(instance) File "/Users/user/projects/bowling-game/env/lib/python3.6/site-packages/rest_framework/serializers.py", line 376, in _readable_fields field for field in self.fields.values() File "/Users/user/projects/bowling-game/env/lib/python3.6/site-packages/rest_framework/serializers.py", line 363, in fields for key, value in self.get_fields().items(): File "/Users/user/projects/bowling-game/env/lib/python3.6/site-packages/rest_framework/serializers.py", line 997, in get_fields serializer_class=self.__class__.__name__ AssertionError: Class ErrorSerializer missing "Meta" attribute
我的模型如下:
class BaseModel(models.Model, object):
# Encapsulates all error objects.
errors= []
def add_error(self, error_object):
"""Appends the error to the list of errors."""
self.errors.append(error_object)
class Meta:
abstract = True
app_label = 'game'
class GameRegistration(BaseModel):
"""Instance of this class represents the user playing the bowling game."""
game_id = models.CharField(max_length=32,
help_text='Unique bowling game id', primary_key=True,
default=functools.partial(random_string, char_length=16))
# I will set the request.user to set the details later on, but not now.
user_name = models.CharField(help_text='unique username', default='test', max_length=32)
created_timestamp = models.DateTimeField(default=datetime.datetime.now)
class Meta:
indexes = [
models.Index(fields=['game_id'])
]
class Error(object):
"""
An instance of this class encapsulates the error code and the message to be
returned.
"""
def __init__(self, error_code, error_message):
self.error_code = error_code
self.error_message = error_message
def __repr__(self):
return '{}:{}'.format(self.__class__.__name__, self.__dict__)
我的序列化器实现
class BaseSerializer(serializers.ModelSerializer, object):
pass
class ErrorSerializer(BaseSerializer):
"""Representation of any error resulting in any of the operation."""
error_code = serializers.IntegerField()
error_message = serializers.CharField(max_length=200)
class Meta:
ordering=('error_code',)
class GameRegistrationSerializer(BaseSerializer):
"""Serializer representation of game instance."""
game_id = serializers.PrimaryKeyRelatedField(read_only=True)
def to_representation(self, instance):
return {
'game_id': str(instance.game_id),
'created': instance.created_timestamp
}
class Meta:
model = models.GameRegistration
fields = ('game_id', 'created')
read_only_fields = ('game_id', 'created')
我想要一种在有效负载内序列化 errors
json数组的方法 . 它不受任何django模型的约束 . 它封装了与其他django模型相关的所有错误 . 我的想法是,如果我能够创建 GameRegistration
,那么我将返回以下有效负载
{ 'game_id': 'ABCDabcd1234', 'created': '<created stamp>' }
如果出现错误,我将按如下方式返回有效负载: { 'errors': { 'error_code': 500, 'error_message': 'Server error' } }
1 回答
从
Serializer
类继承BaseSerializer
而不是ModelSerializer
. 因此BaseSerializer
就像ModelSerializer
的问题是,它期望Meta
类具有至少two
个字段fields
和model