'ListSerializer'对象不可调用 [英] 'ListSerializer' object is not callable

问题描述

我正在为具有content_type对象的投票应用程序实现Django-Rest框架。我尝试使用用于serializers.py的 rest-framework-generic-relationship 。在我看来，这个错误可能在serializer.py / views.py中，但我是这个框架的新手，感谢您的帮助！

views.py：

  class vote_detail（generics.RetrieveUpdateDestroyAPIView）：
 queryset = VotedItem.objects.all（）
 serializer_class = VoteSerializer（queryset，many = True）
  

serializers.py：

从rest_framework import serializers
from .models import VotedItem
from posts.models import Post
from generic_relations.relations import GenericRelatedField

class PostSerializer（serializers.ModelSerializer）：
class Meta：
model = Post
fields =（'title'，）

class VoteSerializer（serializers.ModelSerializer）：

一个`VotedItem`串行器与一个`GenericRelatedField`映射所有可能的
模型到它们各自的序列化器

V oted_object = GenericRelatedField（{
Post：PostSerializer（），
}）

class Meta：
model = VotedItem
fields =（'user' 'voted_object'）


和models.py：

从__future__导入unicode_literals

from datetime import datetime

from django.utils.encoding import python_2_unicode_compatible
from django .db导入模型
from django.contrib.contenttypes.fields import GenericForeignKey，GenericRelation
from django.contrib.contenttypes.models import ContentType
from django.core.urlresolvers import reverse
从django.utils导入时区
从django.contrib.auth.models import来自social_count.managers的用户
导入VoteManager

SCORES =（
（+1， +1'），
（-1，'-1'），
）

@ python_2_unicode_compatible
class VotedItem（models.Model）：

对对象的投票b一个用户

user = models.ForeignKey（User）
content_type = models.ForeignKey（
ContentType，
null = True，
blank = True ，
on_delete = models.CASCADE，
）
object_id = models.PositiveIntegerField（
null = True，
）
content_object = GenericForeignKey（'content_type' ，'object_id'）
vote = models.SmallIntegerField（choices = SCORES，blank = True，null = True）
flag = models.NullBooleanField（blank = True，null = True）
timestamp = models.DateTimeField（auto_now = False，auto_now_add = True）

objects = VoteManager（）

class Meta：
db_table ='票'
＃每个对象每个用户一个
unique_together =（（'user'，'content_type'，'object_id'），）

def __str __（self）：
return'％ s：％s on％s'％（self.user，self.vote，self.content_object）

def is_upvote（self）：
return self.vote == 1

def is_downvote（self）：
return self.vote == -1

当我访问www.mypage.com/likes/api/1/时，我收到一条错误消息：

 追溯：
 
文件/home/henry/newpine/src/env/local/lib/python2.7/site-packages/django/core/ get_response 
 149. response = self.process_exception_by_middleware（e，request）
 
文件/ home / henry / newpine / src / env / local / lib / python2 .7 / site-packages / django / core / handlers / base.pyin get_response 
 147. response = wrapped_callback（request，* callback_args，** callback_kwargs）
 
文件/ home /henry/newpine/src/env/local/lib/python2.7/site-packages/django/views/decorators/csrf.py在wrapped_view 
 58. return view_func（* args，** kwargs）
 
文件/home/henry/newpine/src/env/local/lib/python2.7/site-packages/django/views/generic/base.py在视图
 68。 return self.dispatch（request，* args，** kwargs）
 
文件/home/henry/newpine/src/env/local/lib/python2.7/site-packages/rest_framework/views .py在调度
 466. response = self.handle_exception（exc）
 
文件/home/henry/newpine/src/env/local/lib/python2.7/site- package / rest_framework / views.py在dispatch 
 463. response = handler（request，* args，** kwargs）
 
文件/ home / henry / newpine / src / env /本地/ lib / python2.7 / site-packages / rest_framework / generics.pyin get 
 286. return self.retrieve（request，* args，** kwargs）
 
文件 /home/henry/newpine/src/env/local/lib/python2.7/site-packages/rest_framework/mixins.py检索
 57. serializer = self.get_serializer（instance）
 
文件/home/henry/newpine/src/env/local/lib/python2.7/site-packages/rest_framework/generics.pyin get_serializer 
 111. return serializer_class（* args，** kwargs）
 
异常类型：类型/ likes / api / 1 / 
异常值：'ListSerializer'对象不可调用
  

解决方案

错误是试图调用serializer_class，它是ListSerializer的一个实例，而不是clas。

不应该这样：

  serializer_class = VoteSerializer（queryset，many = True）
  

成为：

  serializer_class = VoteSerializer 
  

I am trying to implement Django-Rest framework for a voting application with content_type objects. I tried using the rest-framework-generic-relations for serializers.py. It seems to me that the error might be within serializer.py / views.py, but I am new to this framework and would appreciate your help!

views.py:

class vote_detail(generics.RetrieveUpdateDestroyAPIView):
    queryset = VotedItem.objects.all()
    serializer_class = VoteSerializer(queryset, many=True)

serializers.py:

from rest_framework import serializers
from .models import VotedItem
from posts.models import Post
from generic_relations.relations import GenericRelatedField

class PostSerializer(serializers.ModelSerializer):
    class Meta:
        model = Post
        fields = ('title',)

class VoteSerializer(serializers.ModelSerializer):
        """
        A `VotedItem` serializer with a `GenericRelatedField` mapping all possible
        models to their respective serializers.
        """
    voted_object = GenericRelatedField({
        Post: PostSerializer(),
    })

    class Meta:
        model = VotedItem
        fields = ('user', 'voted_object')

and models.py:

from __future__ import unicode_literals

from datetime import datetime

from django.utils.encoding import python_2_unicode_compatible
from django.db import models
from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation
from django.contrib.contenttypes.models import ContentType
from django.core.urlresolvers import reverse
from django.utils import timezone
from django.contrib.auth.models import User
from social_count.managers import VoteManager

SCORES = (
    (+1, '+1'),
    (-1, '-1'),
)

@python_2_unicode_compatible
class VotedItem(models.Model):
    """
    A vote on an object by a User.
    """
    user = models.ForeignKey(User)
    content_type = models.ForeignKey(
        ContentType,
        null=True,
        blank=True,
        on_delete=models.CASCADE,
    )
    object_id = models.PositiveIntegerField(        
        null=True,
    )
    content_object = GenericForeignKey('content_type', 'object_id')
    vote = models.SmallIntegerField(choices=SCORES, blank=True, null=True)
    flag = models.NullBooleanField(blank=True, null=True)
    timestamp = models.DateTimeField(auto_now=False, auto_now_add=True)

    objects = VoteManager()

    class Meta:
        db_table = 'votes'
        # One vote per user per object
        unique_together = (('user', 'content_type', 'object_id'),)

    def __str__(self):
        return '%s: %s on %s' % (self.user, self.vote, self.content_object)

    def is_upvote(self):
        return self.vote == 1

    def is_downvote(self):
        return self.vote == -1

When I visit www.mypage.com/likes/api/1/ I get an error message:

Traceback:

File "/home/henry/newpine/src/env/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  149.                     response = self.process_exception_by_middleware(e, request)

File "/home/henry/newpine/src/env/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  147.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/home/henry/newpine/src/env/local/lib/python2.7/site-packages/django/views/decorators/csrf.py" in wrapped_view
  58.         return view_func(*args, **kwargs)

File "/home/henry/newpine/src/env/local/lib/python2.7/site-packages/django/views/generic/base.py" in view
  68.             return self.dispatch(request, *args, **kwargs)

File "/home/henry/newpine/src/env/local/lib/python2.7/site-packages/rest_framework/views.py" in dispatch
  466.             response = self.handle_exception(exc)

File "/home/henry/newpine/src/env/local/lib/python2.7/site-packages/rest_framework/views.py" in dispatch
  463.             response = handler(request, *args, **kwargs)

File "/home/henry/newpine/src/env/local/lib/python2.7/site-packages/rest_framework/generics.py" in get
  286.         return self.retrieve(request, *args, **kwargs)

File "/home/henry/newpine/src/env/local/lib/python2.7/site-packages/rest_framework/mixins.py" in retrieve
  57.         serializer = self.get_serializer(instance)

File "/home/henry/newpine/src/env/local/lib/python2.7/site-packages/rest_framework/generics.py" in get_serializer
  111.         return serializer_class(*args, **kwargs)

Exception Type: TypeError at /likes/api/1/
Exception Value: 'ListSerializer' object is not callable

解决方案

The error is that it's trying to call the serializer_class, which is an instance of ListSerializer, instead of a clas.

Shouldn't this:

serializer_class = VoteSerializer(queryset, many=True)

Be that:

serializer_class = VoteSerializer

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