Question

这是我的模型。py：

from django.db import models

class country (models.Model):
    country_name = models.CharField(max_length=200, null=True)
    def __str__(self):
        return self.country_name

class state (models.Model):
    state_name = models.CharField(max_length=200, null=True)
    country = models.ForeignKey(country, on_delete=models.CASCADE, null=True)
    def __str__(self):
        return self.state_name

class city (models.Model):
    city_name = models.CharField(max_length=200, null=True)
    country = models.ForeignKey(country, on_delete=models.CASCADE, null=True)
    state = models.ForeignKey(state, on_delete=models.CASCADE, null=True)
    def __str__(self):
        return self.city_name

class publication(models.Model):
    title= models.CharField(max_length=300, null=True)
    country=models.ForeignKey(country, on_delete=models.CASCADE, null=True)
    state=models.ForeignKey(state, on_delete=models.CASCADE, null=True)
    city=models.ForeignKey(city, on_delete=models.CASCADE, null=True)

    def __str__(self):
        return self.title

这是我的seralizers.py：

from rest_framework import routers, serializers, viewsets
from .models import *
from django.contrib.auth.models import User
from rest_framework import permissions


class publicationSerializer(serializers.HyperlinkedModelSerializer):

    class Meta:
        model = publication
        fields = '__all__'

这是我的view.py：

from django.shortcuts import render
from django.http import HttpResponse, JsonResponse

from .models import *
from .serializers import *
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status,mixins,generics
from django.http import Http404
from rest_framework import renderers



class SnippetHighlight(APIView):
    # def get(self,request):
    def get(self, request):
        queryset = publication.objects.select_related('country','state','city')
        serializer_class = publicationSerializer(queryset,many=True,
        context={'request': request})
        return Response(serializer_class.data)

这是我的urls.py：

from django.conf.urls import url, include
from django.contrib import admin
from rest_framework.urlpatterns import format_suffix_patterns
from api.models import *
from api import views
# from api.serializers import UserSerializer


urlpatterns = [
    url(r'^admin/', admin.site.urls),
    url(r'^snippets/', views.SnippetHighlight.as_view()),
    # url(r'^users/$', views.UserList.as_view()),
    # url(r'^users/(?P<pk>[0-9]+)/$', views.UserDetail.as_view()),
    # url(r'^api-auth/', include('rest_framework.urls')),
]
urlpatterns = format_suffix_patterns(urlpatterns)

显示错误：

AssertionError at /snippets/
`HyperlinkedIdentityField` requires the request in the serializer context. Add `context={'request': request}` when instantiating the serializer.
Request Method: GET
Request URL:    http://127.0.0.1:8000/snippets/
Django Version: 1.11.15
Exception Type: AssertionError
Exception Value:
`HyperlinkedIdentityField` requires the request in the serializer context. Add `context={'request': request}` when instantiating the serializer.
Exception Location: /home/soubhagya/Desktop/rest/env/local/lib/python2.7/site-packages/rest_framework/relations.py in to_representation, line 356
Python Executable:  /home/soubhagya/Desktop/rest/env/bin/python
Python Version: 2.7.12
Python Path:
['/home/soubhagya/Desktop/rest',
'/home/soubhagya/Desktop/rest/env/lib/python2.7',
'/home/soubhagya/Desktop/rest/env/lib/python2.7/plat-x86_64-linux-gnu',
'/home/soubhagya/Desktop/rest/env/lib/python2.7/lib-tk',
'/home/soubhagya/Desktop/rest/env/lib/python2.7/lib-old',
'/home/soubhagya/Desktop/rest/env/lib/python2.7/lib-dynload',
'/usr/lib/python2.7',
'/usr/lib/python2.7/plat-x86_64-linux-gnu',
'/usr/lib/python2.7/lib-tk',
'/home/soubhagya/Desktop/rest/env/local/lib/python2.7/site-packages',
'/home/soubhagya/Desktop/rest/env/lib/python2.7/site-packages']
Server time:    Sun, 23 Sep 2018 10:09:39 +0000

它进入外壳，但不进入浏览器

Answer 1

serializer_class = publicationSerializer(queryset,many=True, 
    context={'request': request})

正如错误消息明确指出的那样：

HyperlinkedIdentityField在串行器上下文中需要该请求。在实例化序列化程序时添加context={'request': request}。

Answer 2

错误消息确切说明了什么地方。

HyperlinkedIdentityField需要序列化程序中的请求上下文。实例化时添加context={'request': request} 序列化器。

Django Rest Framework文档中还有一个HyperlinkedModelSerializer的示例，您可以在其中看到它的使用情况：

serializer = AccountSerializer(queryset, context={'request': request})

在实例化序列化程序时，按照错误消息中的说明添加context={'request': request}。

通过APIVIEW提取时djano rest框架错误

2 个答案: