Validate user on update request in Django REST framework - python

I want to have an API where a user can update his own listings. Currently any authenticated user can update any listing which I found using Postman. I want to validate the user so that the API returns an error as a response if the user is not trying to update his own listing. Here is my code:
# serializers.py
class ListingSerializer(serializers.ModelSerializer):
class Meta:
model = Listing
fields = '__all__'
# api.py
class ListingViewSet(ModelViewSet):
permission_classes = [IsAuthenticatedOrReadOnly]
serializer_class = ListingSerializer
def get_queryset(self):
return Listing.objects.all()
def perform_create(self, serializer):
serializer.save(owner=self.request.user)
# urls.py
router = routers.DefaultRouter()
router.register('api/listings', ListingViewSet, 'listings')
urlpatterns = router.urls

You just need to overwrite the perform_update function:
def perform_update(self, serializer):
obj = self.get_object()
if self.request.user != obj.created_by: # Or how ever you validate
raise PermissionDenied('User is not allowed to modify listing')
serializer.save()
You will need:
from django.core.exceptions import PermissionDenied

You can limit the object for all method change the main queryset. In this case if an inapropiate user try to access an invalid object the api return 404.
def get_queryset(self):
return Listing.objects.filter(owner=self.request.user)

Related

Django : class based view with multiple permissions

I am trying to create a class based view with different permissions per function. I have already created my permissions in a file that I import :
utils.py
from rest_framework.permissions import BasePermission
from rest_framework.authentication import TokenAuthentication
from rest_framework.views import APIView
class IsOwner(BasePermission):
"""
Check if the user who made the request is owner.
Use like that : permission_classes = [IsOwner]
"""
def has_object_permission(self, request, view, obj):
# if request.method in permissions.SAFE_METHODS:
# return True
return obj.user == request.user
class IsAdmin(BasePermission):
"""
Check if the user who made the request is admin.
Use like that : permission_classes = [IsAdmin]
"""
def has_permission(self, request, view):
return request.user.is_admin
class BaseView(APIView):
"""
Check if a user is authenticated
"""
authentication_classes = [
TokenAuthentication,
]
class AdminOrOwnerView(APIView):
"""
Check if a user is admin or owner
"""
authentication_classes = ( IsOwner | IsAdmin,)
I want to create a class with different method. The GET method would allow admins to have a view of all users. The POST method would allow any user to connect.
I have already created the serializer for each of these methods but I cannot assign different permissions per method.
This is my class :
class Users(APIView):
def get(self, request):
"""Only for admin"""
try:
user = Users.objects.all()
except User.DoesNotExist():
return HttpResponse(status=404)
serializer = UserSerializer(users, many=True)
return Response(serializer.data)
def post(self, request):
"""For everyone"""
serializer = RegistrationSerializer(data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
return Response(serializer.error)
How I can apply my permissions on each of the methods separately ?
Thank you in advance for your help
You just need to create a permission class like this:
class CustomPermissionClass(BasePermission):
def has_permission(self, request, view):
if request.method == 'GET':
# logic for GET method
elif request.method == 'POST'
# logic for POST metod
# default logic
And add it to your view:
class Users(APIView):
permission_classes = [CustomPermissionClass]

Bulk Update data in Django Rest Framework

I am creating a Notification apps by Django Rest Framework which users can MARK AS READ ALL notification by using PATCH API in frontend. How can I Bulk Update data can do this task.
This serializer and viewset below just for PATCH only one notification object, but I want to do it all with Notifications which have field is_read = False
Edited with the right way
My Serializers:
class NotificationEditSerializer(ModelSerializer):
class Meta:
model = Notification
fields = (
'id',
'is_read'
)
My Viewset:
from rest_framework.response import Response
class NotificationListAPIView(ReadOnlyModelViewSet):
queryset = Notification.objects.all()
permission_classes = [AllowAny]
serializer_class = NotificationEditSerializer
lookup_field = 'id'
#list_route(methods=['PATCH'])
def read_all(self, request):
qs = Notification.objects.filter(is_read=False)
qs.update(is_read=True)
serializer = self.get_serializer(qs, many=True)
return Response(serializer.data)
My URL:
from rest_framework import routers
router.register(r'notifications/read_all', NotificationListAPIView)
You can try to use list_route for example:
from rest_framework.response import Response
from rest_framework.decorators import list_route
class NotificationListAPIView(ReadOnlyModelViewSet):
#YOUR PARAMS HERE
#list_route()
def read_all(self, request):
qs = Notification.objects.filter(is_read=False)
qs.update(is_read=True)
serializer = self.get_serializer(qs, many=True)
return Response(serializer.data)
the api is available by ^YOUCURRENTURL/read_all/$ more details marking-extra-actions-for-routing
NOTE! since DRF 3.10 #list_route() decorator was removed, you should use #action(detail=False) instead, I used #action(detail=False, methods=['PATCH']) to bulk patch, for example Thank you #PolYarBear

Django REST and ModelViewSet filtering

I was previously using APIViews such as the following:
views.py
class AllProgramsApi(APIView):
def get(self, request):
user = self.request.user
userprograms = Program.objects.filter(user=user)
serializer = ProgramSerializer(userprograms, many=True)
return Response(serializer.data)
here's my model:
class Program(models.Model):
program_name = models.CharField(max_length=50)
program_description = models.CharField(max_length=250)
cycles = models.ManyToManyField(Cycle)
is_favourite = models.BooleanField(default="False")
user = models.ForeignKey(User, on_delete=models.CASCADE)
def get_absolute_url(self):
return reverse('programs:program', kwargs={'pk': self.pk})
def __str__(self):
return self.program_name
Now I've discovered ModelViewSet, which looks very convenient, but I can't seem to be able to filter for the user as I was previously doing in the APIView.
my attempt at views.py with ModelViewSet is the following and it works but I get all the content and not just the content related to a single user.
class AllProgramsApi(ModelViewSet):
serializer_class = ProgramSerializer
queryset = Program.objects.all()
How can I tweak the ModelViewSet so that it displays only the content related to the user who sends the request? What is the best method?
Thanks.
You can use get queryset method,if you know more refer the doc Filtering against the current user
class AllProgramsApi(ModelViewSet):
serializer_class = ProgramSerializer
queryset = Program.objects.all()
def get_queryset(self):
queryset = self.queryset
query_set = queryset.filter(user=self.request.user)
return query_set
there are permission_classes in django you can add permissions as per your requirements or you can create custom permissions
you would get better idea from django permission
or you can create your queryset by defining get_queryset method.

API call to update a field of an object

So I have an model serializer which consists of
class UserSerializer(serializers.ModelSerializer):
class Meta:
model = User
fields = ('id', 'name', 'description')
This is my ViewSet
class UserViewSet(viewsets.ModelViewSet):
queryset = User.objects.all()
serializer_class = UserSerializer
This is my URLs.py file:
from django.conf.urls import include, url
from rest_framework import routers
import views
router = DefaultRouter()
router.register('user', views.UserViewSet)
urlpatterns = [
url(r'^', include(router.urls)),
url(r'^login/', include('rest_framework.urls', namespace='rest_framework'))
]
Using the serializer, I can make it print out the objects inside my database. If I have the object PK/ID, I want to be able to update the field id or name of the object. Is there a way I can do that with a patch/post request using the serializer? I'm new to this so I'd love it if someone can help me out with this.
I'm thinking of just doing a POST request, then have it do this:
user = User.objects.get(id=id)
user.name = "XXXXX"
user.save()
But I want to do this using the serializer, using a PATCH request.
the below code will help to you,
**filename : views.py**
from user.models import User
from users.serializers import UserSerializer
from django.http import Http404
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status
class UserList(APIView):
"""
List all users, or create a new user.
"""
def get(self, request, format=None):
users = User.objects.all()
serializer = UserSerializer(users, many=True)
return Response(serializer.data)
def post(self, request, format=None):
serializer = UserSerializer(data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data, status=status.HTTP_201_CREATED)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
class UserDetail(APIView):
"""
Retrieve, update or delete a user instance.
"""
def get_object(self, pk):
try:
return User.objects.get(pk=pk)
except User.DoesNotExist:
raise Http404
def get(self, request, pk, format=None):
user = self.get_object(pk)
serializer = UserSerializer(user)
return Response(serializer.data)
def put(self, request, pk, format=None):
user = self.get_object(pk)
serializer = UserSerializer(user, data=request.data)
if serializer.is_valid():
serializer.save()
return Response(serializer.data)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
def delete(self, request, pk, format=None):
user = self.get_object(pk)
user.delete()
return Response(status=status.HTTP_204_NO_CONTENT)
**filename : urls.py**
from django.conf.urls import url
from rest_framework.urlpatterns import format_suffix_patterns
from users import views
urlpatterns = [
url(r'^users/$', views.UserList.as_view()),
url(r'^user/(?P<pk>[0-9]+)/$', views.UserDetail.as_view()),
]
urlpatterns = format_suffix_patterns(urlpatterns)
Reference : http://www.django-rest-framework.org/tutorial/3-class-based-views/
Django rest framework comes with some pre-defined concrete generic views such as UpdateAPIView, RetrieveUpdateAPIView.
First you need to create a view for user which uses one of the views which can update. The update views provides handlers for patch method on the view.
RetrieveUpdateAPIView
Used for read or update endpoints to represent a single model instance.
Provides get, put and patch method handlers.
Now, use this to create a view:
class UserDetail(generics.RetrieveUpdateAPIView):
queryset = User.objects.all()
serializer_class = UserSerializer
To access this view you need to have a url which uses user's primary key to access the user:
url(r'users/(?P<pk>\d+)/$', UserDetail.as_view(), name='api-user-detail'),
Then using PATCH call you can update the user's name.
Since you're using a ModelViewset, this capability should be built in. If you use the browsable API to navigate to /user/<pk>/, you'll see the operations you can perform on that object. By default, a ModelViewset provides list(), retrieve(), create(), update(), and destroy() capability.
http://www.django-rest-framework.org/api-guide/viewsets/#modelviewset
You can also override any or all of the provided methods, however an update of a single object is built in to DRF ModelViewsets. Use curl to try a PATCH to /user/<pk>/ with the information you'd like to update.

Django-REST: Get User by username instead of primary-key

I am using the basic UserViewSet derived from ModelViewSet.
Retrieving a user with a primary-key via api/users/<pk> works fine.
But I also want to be able to retrieve a User by Username.
I have added a new detail route but I always get 404 on my server when I try to get the user with the url /api/users/retrieve_by_username/altoyr.
class UserViewSet(viewsets.ModelViewSet):
queryset = User.objects.all()
serializer_class = UserSerializer
#detail_route(methods=['get'])
def retrieve_by_username(self, request, username=None):
try:
user = User.objects.get(userName=username)
return Response(user)
except User.DoesNotExist:
return Response("No user with username found!", status=status.HTTP_400_BAD_REQUEST)
The Urls are registered via a router:
router = DefaultRouter()
router.register(r'users', views.UserViewSet)
# The API URLs are now determined automatically by the router.
# Additionally, we include the login URLs for the browsable API.
urlpatterns = [
url(r'^', include(router.urls)),
url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))
]
I think I am missing an important part of building rest urls.
You can do this by adding a list route like:
#list_route(methods=['get'], url_path='retrieve_by_username/(?P<username>\w+)')
def getByUsername(self, request, username ):
user = get_object_or_404(User, username=username)
return Response(UserSerializer(user).data, status=status.HTTP_200_OK)
and the url will be like:
/api/users/retrieve_by_username/altoyr
You can override the retrieve() ViewSet action. You'll find more detail here: https://www.django-rest-framework.org/api-guide/viewsets/
from django.shortcuts import get_object_or_404
from rest_framework.response import Response
class UserViewSet(viewsets.ModelViewSet):
queryset = User.objects.all()
serializer_class = UserSerializer
def retrieve(self, request, pk=None):
queryset = User.objects.filter(username=pk)
contact = get_object_or_404(queryset, pk=1)
serializer = ContactSerializer(contact)
return Response(serializer.data)
The answer from Anush Devendra is right but need a little update due to deprecations on v3.9.
action decorator replaces list_route and detail_route
Both list_route and detail_route are now deprecated in favour of the single action decorator. They will be removed entirely in 3.10.
The action decorator takes a boolean detail argument.
Replace detail_route uses with #action(detail=True).
Replace list_route uses with #action(detail=False).
...
from rest_framework.decorators import action
from rest_framework.response import Response
from django.shortcuts import get_object_or_404
from rest_framework import status
class UserViewSet(viewsets.ModelViewSet):
...
#action(methods=['get'], detail=False,
url_path='username/(?P<username>\w+)')
def getByUsername(self, request, username):
user = get_object_or_404(User, username=username)
data = UserSerializer(user, context={'request': request}).data
return Response(data, status=status.HTTP_200_OK)
I add context={'request': request} because I have url as HyperlinkedIdentityField in my serializer. If you don't have it, you probably don't need it.

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