so the error is Page not found(404) when I am requesting the instance that does not exist. I would like to customize the 404 page, instead of displaying the general error.
Here is my new_wiki/urls
from django.urls import path
from . import views
from .views import IndexView, InstanceView, AddPostView, EditPost
urlpatterns = [
# path('', views.index, name="index")
path('', IndexView.as_view(), name="index"),
path('instance/<int:pk>', InstanceView.as_view(), name="instance"),
path('create_post/', AddPostView.as_view(), name="create_post"),
path('instance/edit/<int:pk>', EditPost.as_view(), name="edit_post")
]
And my InstanceView class
class InstanceView(DetailView):
model = Post
template_name = 'new_wiki/instance.html'
I have tried to use the solution from Django documentation:
def detail(request, post_id):
try:
p = Post.objects.get(pk=post_id)
except Post.DoesNotExist:
raise Http404("Poll does not exist")
return render(request, 'new_wiki/instance.html', {'post': p})
but it is still returning the same 404 page. Thank you
You can just render a page with a 404 status:
def detail(request, post_id):
try:
p = Post.objects.get(pk=post_id)
except Post.DoesNotExist:
return render(request, 'new_wiki/404error.html', status=404)
return render(request, 'new_wiki/instance.html', {'post': p})
If you want to specify a custom 404 page in general, you specify the handler404 [Django-doc] in the urls.py:
from django.urls import path
from . import views
from .views import IndexView, InstanceView, AddPostView, EditPost
urlpatterns = [
# path('', views.index, name="index")
path('', IndexView.as_view(), name="index"),
path('instance/<int:pk>', InstanceView.as_view(), name="instance"),
path('create_post/', AddPostView.as_view(), name="create_post"),
path('instance/edit/<int:pk>', EditPost.as_view(), name="edit_post")
]
handler404 = views.handler404
In the view you can then analyze the exception parameter and return a specific
# app/views.py
from django.http import HttpResponseNotFound
def handler404(request, exception):
data = exception.args
if data:
return HttpResponseNotFound(data[0])
return HttpResponseNotFound('some text')
This then works if you set the DEBUG setting [Django-doc] to False:
# settings.py
DEBUG = False
In that case the handler will be invoked when you raise a Http404.
Please use get_object_or_404 method
from django.shortcuts import get_object_or_404
def detail(request, post_id):
p = get_object_or_404(Post,pk=post_id)
return render(request, 'new_wiki/instance.html', {'post': p})
Please check this is working.
"test_put_method_success" is showing AssertionError: 404 != 200. How to solve it? ......................
class BasicTest(APITestCase):
def setUp(self):
self.client = Client()
self.user = User(username="admin", email="admin#gmail.com")
self.user.is_staff = True
self.user.set_password('admin')
self.user.save()
def test_put_method_success(self):
url = "http://127.0.0.1:8000/settings/modules/1/"
data = {
'modulename': "Module test update",
'activation_status': "Active"
}
self.assertTrue(self.client.login(username="admin", password="admin"))
response = self.client.put(url, data, format='json')
print(response.status_code)
self.assertEqual(response.status_code, status.HTTP_200_OK)
urls.py
from rest_framework import routers
router = routers.DefaultRouter()
router.register('modules', views.ModuleView)
urlpatterns = [
path('', include(router.urls)),
]
By default DRF PUT does not create an instance.
You need some extra steps as explained by the documentation.
There is a little problem with my Django application: my project is a blog with several posts. You can access the first post by typing localhost:8000/blog/post/1 in the URL bar. To read the post no. X you have to type localhost:8000/blog/post/X. So I need to display a custom "Error 404" page when an inexistant post is requested (for example localhost:8000/blog/post/32 if there are only 3 posts available). The problem is, instead of throwing a 404 error, it throws a Server Error (500) error however I never coded something to throw this kind of error.
Here is the concerned code parts, but not my full code which I think is useless.
Project name is red_pillers, app name is blog.
in red_pillers/settings.py
DEBUG = False
ALLOWED_HOSTS = ['127.0.0.1', 'localhost']
red_pillers/urls.py
from django.contrib import admin
from django.urls import path, re_path, include
from django.conf.urls import handler404
from . import views
handler404 = 'red_pillers.views.handler404'
urlpatterns = [
re_path('^blog/', include('blog.urls')),
re_path('^$', views.home),
re_path('^admin/', admin.site.urls),
]
red_pillers/views.py
from django.shortcuts import render
def home(request):
return render(request, 'home.html')
def handler404(request):
return render(request, 'errors/404.html', {}, status=404)
blog/pycode/post.py
from django.http import Http404
class Post:
POSTS = [
{'id': 1, 'title': 'First Post', 'body': 'This is my first post'},
{'id': 2, 'title': 'Second Post', 'body': 'This is my second post'},
{'id': 3, 'title': 'Third Post', 'body': 'This is my third post'},
]
#classmethod
def all(cls):
return cls.POSTS
#classmethod
def find(cls, id):
try:
return cls.POSTS[int(id) - 1]
except:
raise Http404('Error 404...')
EDIT: added more code
blog/urls.py
from django.urls import path, re_path
from . import views
urlpatterns = [
re_path('^$', views.index),
re_path('^posts/(?P<id>[0-9]+)$', views.show),
]
blog/views.py
from django.shortcuts import render
from .pycode.post import Post
def index(request):
posts = Post.all()
return render(request, 'blog/index.html', {'posts': posts})
def show(request, id):
post = Post.find(id)
return render(request, 'blog/show.html', {'post': post})
Use get_object_or_404, which will redirect you if it doesn't exist.
I am following this tutorial. At the moment I am at this point but when I start my server with python manage.py runserver 0.0.0.0:8000 and open the url in my browser, I receive following Error:
name 'IndexView' is not defined
This is my urls.py
from django.conf.urls import include, url
from django.contrib import admin
from django.conf.urls import patterns
from rest_framework_nested import routers
from authentication.views import AccountViewSet
router = routers.SimpleRouter()
router.register(r'accounts', AccountViewSet)
urlpatterns = patterns(
'',
url(r'^admin/', include(admin.site.urls)),
url(r'^api/v1/', include(router.urls)),
url('^.*$', IndexView.as_view(), name='index'),
)
I don't know how to solve this problem, since I never saw myself even declaring this IndexView somewhere. It would be awesome if you guys could give me some suggestions on this one.
Edit:
my views.py
from django.shortcuts import render
# Create your views here.
from rest_framework import permissions, viewsets
from authentication.models import Account
from authentication.permissions import IsAccountOwner
from authentication.serializers import AccountSerializer
class AccountViewSet(viewsets.ModelViewSet):
lookup_field = 'username'
queryset = Account.objects.all()
serializer_class = AccountSerializer
def get_permissions(self):
if self.request.method in permissions.SAFE_METHODS:
return (permissions.AllowAny(),)
if self.request.method == 'POST':
return (permissions.AllowAny(),)
return (permissions.IsAuthenticated(), IsAccountOwner(),)
def create(self, request):
serializer = self.serializer_class(data=request.data)
if serializer.is_valid():
Account.objects.create_user(**serializer.validated_data)
return Response(serializer.validated_data, status=status.HTTP_201_CREATED)
return Response({
'status': 'Bad request',
'message': 'Account could not be created with received data.'
}, status = status.HTTP_400_BAD_REQUEST)
You have to create that IndexView and import it in your urls.py.
Currently the interpreter complains since in the urls.py IndexView is unknown.
To create a new view you should create a new class in views.py, something like:
from django.views.generic.base import TemplateView
class IndexView(TemplateView):
template_name = 'index.html'
ps: please read the official Django docs, which is very good!
The IndexView class is in the boilerplate project's views file.
C:\...\thinkster-django-angular-boilerplate-release\thinkster_django_angular_boilerplate\views
Copy and paste that content into your project's views file.
from django.views.decorators.csrf import ensure_csrf_cookie
from django.views.generic.base import TemplateView
from django.utils.decorators import method_decorator
class IndexView(TemplateView):
template_name = 'index.html'
#method_decorator(ensure_csrf_cookie)
def dispatch(self, *args, **kwargs):
return super(IndexView, self).dispatch(*args, **kwargs)
in your urls.py
from .views import IndexView
url('^.*$', IndexView.as_view(), name='index'),
(.views or yourProject.views)
in your views.py
do what daveoncode wrote
I am using Django for a project and is already in production.
In the production environment 500.html is rendered whenever a server error occurs.
How do I test the rendering of 500.html in dev environment? Or how do I render 500.html in dev, if I turn-off debug I still get the errors and not 500.html
background: I include some page elements based on a page and some are missing when 500.html is called and want to debug it in dev environment.
I prefer not to turn DEBUG off. Instead I put the following snippet in the urls.py:
if settings.DEBUG:
urlpatterns += patterns('',
(r'^500/$', 'your_custom_view_if_you_wrote_one'),
(r'^404/$', 'django.views.generic.simple.direct_to_template', {'template': '404.html'}),
)
In the snippet above, the error page uses a custom view, you can easily replace it with Django's direct_to_template view though.
Now you can test 500 and 404 pages by calling their urls: http://example.com/500 and http://example.com/404
In Django 1.6 django.views.generic.simple.direct_to_template does not exists anymore, these are my settings for special views:
# urls.py
from django.views.generic import TemplateView
from django.views.defaults import page_not_found, server_error
urlpatterns += [
url(r'^400/$', TemplateView.as_view(template_name='400.html')),
url(r'^403/$', TemplateView.as_view(template_name='403.html')),
url(r'^404/$', page_not_found),
url(r'^500/$', server_error),
]
And if you want to use the default Django 500 view instead of your custom view:
if settings.DEBUG:
urlpatterns += patterns('',
(r'^500/$', 'django.views.defaults.server_error'),
(r'^404/$', 'django.views.generic.simple.direct_to_template', {'template': '404.html'}),
)
Continuing shanyu's answer, in Django 1.3+ use:
if settings.DEBUG:
urlpatterns += patterns('',
(r'^500/$', 'django.views.defaults.server_error'),
(r'^404/$', 'django.views.defaults.page_not_found'),
)
For Django > 3.0, just set the raise_request_exception value to False.
from django.test import TestCase
class ViewTestClass(TestCase):
def test_error_page(self):
self.client.raise_request_exception = False
response = self.client.get(reverse('error-page'))
self.assertEqual(response.status_code, 500)
self.assertTrue(
'some text from the custom 500 page'
in response.content.decode('utf8'))
Documentation: https://docs.djangoproject.com/en/3.2/topics/testing/tools/
NOTE: if the error page raises an exception, that will show up as an ERROR in the test log. You can turn the test logging up to CRITICAL by default to suppress that error.
Are both debug settings false?
settings.DEBUG = False
settings.TEMPLATE_DEBUG = False
How i do and test custom error handlers
Define custom View based on TemplateView
# views.py
from django.views.generic import TemplateView
class ErrorHandler(TemplateView):
""" Render error template """
error_code = 404
template_name = 'index/error.html'
def dispatch(self, request, *args, **kwargs):
""" For error on any methods return just GET """
return self.get(request, *args, **kwargs)
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['error_code'] = self.error_code
return context
def render_to_response(self, context, **response_kwargs):
""" Return correct status code """
response_kwargs = response_kwargs or {}
response_kwargs.update(status=self.error_code)
return super().render_to_response(context, **response_kwargs)
Tell django to use custom error handlers
# urls.py
from index.views import ErrorHandler
# error handing handlers - fly binding
for code in (400, 403, 404, 500):
vars()['handler{}'.format(code)] = ErrorHandler.as_view(error_code=code)
Testcase for custom error handlers
# tests.py
from unittest import mock
from django.test import TestCase
from django.core.exceptions import SuspiciousOperation, PermissionDenied
from django.http import Http404
from index import views
class ErrorHandlersTestCase(TestCase):
""" Check is correct error handlers work """
def raise_(exception):
def wrapped(*args, **kwargs):
raise exception('Test exception')
return wrapped
def test_index_page(self):
""" Should check is 200 on index page """
response = self.client.get('/')
self.assertEqual(response.status_code, 200)
self.assertTemplateUsed(response, 'index/index.html')
#mock.patch('index.views.IndexView.get', raise_(Http404))
def test_404_page(self):
""" Should check is 404 page correct """
response = self.client.get('/')
self.assertEqual(response.status_code, 404)
self.assertTemplateUsed(response, 'index/error.html')
self.assertIn('404 Page not found', response.content.decode('utf-8'))
#mock.patch('index.views.IndexView.get', views.ErrorHandler.as_view(error_code=500))
def test_500_page(self):
""" Should check is 500 page correct """
response = self.client.get('/')
self.assertEqual(response.status_code, 500)
self.assertTemplateUsed(response, 'index/error.html')
self.assertIn('500 Server Error', response.content.decode('utf-8'))
#mock.patch('index.views.IndexView.get', raise_(SuspiciousOperation))
def test_400_page(self):
""" Should check is 400 page correct """
response = self.client.get('/')
self.assertEqual(response.status_code, 400)
self.assertTemplateUsed(response, 'index/error.html')
self.assertIn('400 Bad request', response.content.decode('utf-8'))
#mock.patch('index.views.IndexView.get', raise_(PermissionDenied))
def test_403_page(self):
""" Should check is 403 page correct """
response = self.client.get('/')
self.assertEqual(response.status_code, 403)
self.assertTemplateUsed(response, 'index/error.html')
self.assertIn('403 Permission Denied', response.content.decode('utf-8'))
urls.py
handler500 = 'project.apps.core.views.handler500'
handler404 = 'project.apps.core.views.handler404'
views.py
from django.template.loader import get_template
from django.template import Context
from django.http import HttpResponseServerError, HttpResponseNotFound
def handler500(request, template_name='500.html'):
t = get_template(template_name)
ctx = Context({})
return HttpResponseServerError(t.render(ctx))
def handler404(request, template_name='404.html'):
t = get_template(template_name)
ctx = Context({})
return HttpResponseNotFound(t.render(ctx))
tests.py
from django.test import TestCase
from django.test.client import RequestFactory
from project import urls
from ..views import handler404, handler500
class TestErrorPages(TestCase):
def test_error_handlers(self):
self.assertTrue(urls.handler404.endswith('.handler404'))
self.assertTrue(urls.handler500.endswith('.handler500'))
factory = RequestFactory()
request = factory.get('/')
response = handler404(request)
self.assertEqual(response.status_code, 404)
self.assertIn('404 Not Found!!', unicode(response))
response = handler500(request)
self.assertEqual(response.status_code, 500)
self.assertIn('500 Internal Server Error', unicode(response))
Update for Django > 1.6 and without getting
page_not_found() missing 1 required positional argument: 'exception'
Inspired by this answer:
# urls.py
from django.views.defaults import page_not_found, server_error, permission_denied, bad_request
[...]
if settings.DEBUG:
# This allows the error pages to be debugged during development, just visit
# these url in browser to see how these error pages look like.
urlpatterns += [
path('400/', bad_request, kwargs={'exception': Exception('Bad Request!')}),
path('403/', permission_denied, kwargs={'exception': Exception('Permission Denied')}),
path('404/', page_not_found, kwargs={'exception': Exception('Page not Found')}),
path('500/', server_error),
You can simply define the handler404 and handler500 for errors in your main views.py file as detailed in this answer:
https://stackoverflow.com/a/18009660/1913888
This will return the error that you desire when Django routes to that handler. No custom URL configuration is needed to route to a different URL name.
In Django versions < 3.0, you should do as follows:
client.py
from django.core.signals import got_request_exception
from django.template import TemplateDoesNotExist
from django.test import signals
from django.test.client import Client as DjangoClient, store_rendered_templates
from django.urls import resolve
from django.utils import six
from django.utils.functional import SimpleLazyObject, curry
class Client(DjangoClient):
"""Test client that does not raise Exceptions if requested."""
def __init__(self,
enforce_csrf_checks=False,
raise_request_exception=True, **defaults):
super(Client, self).__init__(enforce_csrf_checks=enforce_csrf_checks,
**defaults)
self.raise_request_exception = raise_request_exception
def request(self, **request):
"""
The master request method. Composes the environment dictionary
and passes to the handler, returning the result of the handler.
Assumes defaults for the query environment, which can be overridden
using the arguments to the request.
"""
environ = self._base_environ(**request)
# Curry a data dictionary into an instance of the template renderer
# callback function.
data = {}
on_template_render = curry(store_rendered_templates, data)
signal_uid = "template-render-%s" % id(request)
signals.template_rendered.connect(on_template_render,
dispatch_uid=signal_uid)
# Capture exceptions created by the handler.
exception_uid = "request-exception-%s" % id(request)
got_request_exception.connect(self.store_exc_info,
dispatch_uid=exception_uid)
try:
try:
response = self.handler(environ)
except TemplateDoesNotExist as e:
# If the view raises an exception, Django will attempt to show
# the 500.html template. If that template is not available,
# we should ignore the error in favor of re-raising the
# underlying exception that caused the 500 error. Any other
# template found to be missing during view error handling
# should be reported as-is.
if e.args != ('500.html',):
raise
# Look for a signalled exception, clear the current context
# exception data, then re-raise the signalled exception.
# Also make sure that the signalled exception is cleared from
# the local cache!
response.exc_info = self.exc_info # Patch exception handling
if self.exc_info:
exc_info = self.exc_info
self.exc_info = None
if self.raise_request_exception: # Patch exception handling
six.reraise(*exc_info)
# Save the client and request that stimulated the response.
response.client = self
response.request = request
# Add any rendered template detail to the response.
response.templates = data.get("templates", [])
response.context = data.get("context")
response.json = curry(self._parse_json, response)
# Attach the ResolverMatch instance to the response
response.resolver_match = SimpleLazyObject(
lambda: resolve(request['PATH_INFO'])
)
# Flatten a single context. Not really necessary anymore thanks to
# the __getattr__ flattening in ContextList, but has some edge-case
# backwards-compatibility implications.
if response.context and len(response.context) == 1:
response.context = response.context[0]
# Update persistent cookie data.
if response.cookies:
self.cookies.update(response.cookies)
return response
finally:
signals.template_rendered.disconnect(dispatch_uid=signal_uid)
got_request_exception.disconnect(dispatch_uid=exception_uid)
tests.py
from unittest import mock
from django.contrib.auth import get_user_model
from django.core.urlresolvers import reverse
from django.test import TestCase, override_settings
from .client import Client # Important, we use our own Client here!
class TestErrors(TestCase):
"""Test errors."""
#classmethod
def setUpClass(cls):
super(TestErrors, cls).setUpClass()
cls.username = 'admin'
cls.email = 'admin#localhost'
cls.password = 'test1234test1234'
cls.not_found_url = '/i-do-not-exist/'
cls.internal_server_error_url = reverse('password_reset')
def setUp(self):
super(TestErrors, self).setUp()
User = get_user_model()
User.objects.create_user(
self.username,
self.email,
self.password,
is_staff=True,
is_active=True
)
self.client = Client(raise_request_exception=False)
# Mock in order to trigger Exception and resulting Internal server error
#mock.patch('django.contrib.auth.views.PasswordResetView.form_class', None)
#override_settings(DEBUG=False)
def test_errors(self):
self.client.login(username=self.username, password=self.password)
with self.subTest("Not found (404)"):
response = self.client.get(self.not_found_url, follow=True)
self.assertNotIn('^admin/', str(response.content))
with self.subTest("Internal server error (500)"):
response = self.client.get(self.internal_server_error_url,
follow=True)
self.assertNotIn('TypeError', str(response.content))
Starting from Django 3.0 you could skip the custom Client definition and just use the code from tests.py.