Django RestFramework IsOwnerOrReadOnly - python

I create my permission class for everyone can read an object and only admin create the object. But when I log out and try to create the object, permission class allowing me. What am I missing?
models.py
class Book(models.Model):
title = models.CharField(max_length=20)
content = models.TextField()
page = models.IntegerField()
views.py
class BookAPIView(
mixins.CreateModelMixin,
generics.ListAPIView):
permission_classes = [IsAdminOrReadOnly]
serializer_class = BookSerializer
queryset = Book.objects.all()
def post(self, request, *args, **kwargs):
return self.create(request, *args, **kwargs)
permissions.py
class IsAdminOrReadOnly(permissions.BasePermission):
def has_object_permission(self, request, view, obj):
if request.method == 'GET':
return True
return request.user.is_staff

You need to overwrite has_permission:
class IsAdminOrReadOnly(permissions.BasePermission):
def has_permission(self, request, view):
if request.method == 'GET':
return True
return request.user.is_staff
has_object_permission lets you modify one existing object.

Related

Django Swagger won't allow me to use POST method (no parameters shown)

I'm using djangorestframework together with drf-spectacular modules for a Django project, and I'm trying to build some basic API methods for my Project model. Its structure looks like this:
from django.db import models
# Create your models here.
class Project(models.Model):
title = models.CharField(max_length = 128)
description = models.TextField()
image = models.URLField()
date = models.DateTimeField(auto_now_add=True)
I also have a serializer for the model, looking like this:
from rest_framework import serializers
from api.models.Project import Project
class ProjectSerializer(serializers.ModelSerializer):
class Meta:
model = Project
fields = ['title', 'description', 'image', 'date']
Then, in views.py, I created two functions: project_list_view, which either lets you to GET all the Project objects from the database, or lets you POST a new object. And finally, project_detail_view, which lets you GET a Project object by typing in its pk (integer id). These are my two functions:
#api_view(['GET', 'POST'])
def project_list_view(request):
if request.method == 'GET':
projects = Project.objects.all()
serializer = ProjectSerializer(projects, many=True)
return Response(serializer.data)
elif request.method == "POST":
serializer = ProjectSerializer(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)
#api_view(['GET'])
def project_detail_view(request, pk):
if request.method == "GET":
try:
project = Project.objects.get(pk = pk)
serializer = ProjectSerializer(project, many = False)
return Response(serializer.data, status = status.HTTP_200_OK)
except:
return Response(status=status.HTTP_404_NOT_FOUND)
The GET from project_list_view and project_detail_view work, but my problem lays in the POST method.
My Swagger is set to display its API Schema when accessing http://127.0.0.1:8000/docs/, and as I said, GET methods work properly, but when I'm trying to click on "Try it out" at the POST method, the fields are not displayed. I can only press "Execute" without actually being able to complete anything. After I click on "Execute", Swagger returns a 404 Bad Request response.
This is how POST looks like in Swagger:
My question is: Why won't Swagger display fields for each parameter of the model? Thank you.
Swagger Grabs the fields from a serializer_class variable.
I really recommend you change the format to Class-Based Views.
Something using mixins or generic class.
Your view could be like
class ProjectView(mixins.RetrieveModelMixin, mixins.CreateModelMixin, viewsets.GenericViewSet):
permission_classes = [permissions.IsAuthenticated, ]
serializer_class = ProjectSerializer
queryset = Project.objects.all()
def get(self, request, *args, **kwargs):
return self.list(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
return self.create(request, *args, **kwargs)
More on Mixins and Generic Views

how to pass current authenticated user to django rest framework serializer?

I have a model like this:
class Professional(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
dummy_text = models.CharField(max_length=300)
a serializer like this:
class ProfessionalSerializer(serializers.ModelSerializer):
class Meta:
model = Professional
fields = '__all__'
and a view like this one:
class CreateProfessional(generics.CreateAPIView):
serializer_class = ProfessionalSerializer
The thing is, I need to pass the current authenticated user for a given request as the user for my serializer, I'm getting an error because obviously the user field is required as stated in my model, but I can't find an elegant way to do so, how could I go about it?
Set the user as a read_only_fields in the serializer meta. This will prevent accepting the user data from the payload.
class ProfessionalSerializer(serializers.ModelSerializer):
class Meta:
model = Professional
fields = '__all__'
read_only_fields = ["user"]
Then, override the perform_create(...) method of the view class
class CreateProfessional(generics.CreateAPIView):
serializer_class = ProfessionalSerializer
def perform_create(self, serializer):
serializer.save(user=self.request.user)
You can make validate method with like validate_user and do following code inside.
self.context['view'].request.user()
class CreateProfessional(generics.CreateAPIView):
serializer_class = ProfessionalSerializer
def create(self, request, *args, **kwargs):
serializer = self.serializer_class(data=request.data, context={'request': request})
serializer.is_valid(raise_exception=True)
serializer.save()
class ProfessionalSerializer(serializers.ModelSerializer):
class Meta:
model = Professional
fields = '__all__'
def create(self, validated_data):
user = self.context['request'].user
like this you can get your current user
I found a very nice way to do it, I dont wan't to return custom responses, I will let that to the framework, what I did was the following in my view:
def get_serializer(self, *args, **kwargs):
# redefine method to parameterize the serializer
# while leaving the response handling to the
# framework
serializer_class = self.get_serializer_class()
kwargs['context'] = self.get_serializer_context()
kwargs['context']['user'] = self.request.user
return serializer_class(*args, **kwargs)
and in my serializer:
class EntitySerializer(serializers.ModelSerializer):
class Meta:
model = Entity
fields = '__all__'
extra_kwargs = {'user': {'required': False}}
def create(self, validated_data):
user = self.context['request'].user
entity = Entity.objects.create(user=user, **validated_data)
return entity
You can use ModelViewSet instead of single API Views. ModelViewSet handles all the crud operations automatically.
Let's say you have the model
class Professional(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
dummy_text = models.CharField(max_length=300)
and the serializer
class ProfessionalSerializer(serializers.ModelSerializer):
class Meta:
model = Professional
fields = '__all__'
So you can add a ModelViewSet
class ProfessionalViewSet(ModelViewSet):
queryset = Professional.objects.all()
permission_classes = [IsAuthenticated]
serializer_class = ProfessionalSerializer
this will handle all the crud operations for your model. Following example class will show you the methods that a viewset has.
class UserViewSet(viewsets.ViewSet):
"""
Example empty viewset demonstrating the standard
actions that will be handled by a router class.
If you're using format suffixes, make sure to also include
the `format=None` keyword argument for each action.
"""
def list(self, request):
pass
def create(self, request):
pass
def retrieve(self, request, pk=None):
pass
def update(self, request, pk=None):
pass
def partial_update(self, request, pk=None):
pass
def destroy(self, request, pk=None):
pass
these will handle all the actions. checkout the documentation for more
you'll also have to add the router to handle all the urls automatically which is also covered in the documentation (above link). Following is an example(urls.py).
from myapp.views import UserViewSet
from rest_framework.routers import DefaultRouter
router = DefaultRouter()
router.register(r'users', UserViewSet, basename='user')
urlpatterns = router.urls

Get image file and fields in Django rest framework

I am trying to upload image via django restframe work and return a custom response
views.py
class Imageuploadviewset(viewsets.ModelViewSet):
queryset = UploadModel.objects.all()
serializer_class = UploadSerializer
def retrieve(self, request, *args, **kwargs):
instance = self.get_object()
serializer = self.get_serializer(instance)
return Response({'something': 'serializer'})
def list(self, request, *args, **kwargs):
return Response({'Model': 'Skin Disease Diagnosis'})
models.py
class UploadModel(models.Model):
name=models.CharField(max_length=50)
image=models.ImageField('images/')
urls.py
router = DefaultRouter()
router.register(r'UploadModel', views.Imageuploadviewset)
urlpatterns = [
path('',views.home,name='home'),
path('api/', include(router.urls)),
]
Serializer.py
class UploadSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model=UploadModel
fields='__all__'
Query is that how to play with name and image upload, run some functions on them and return a response. I am not sure how to get those.
Instead of retrieve and list i need the create function
def create(self, request):
img=request.FILES['image']
user=request.POST['name']
pred=somefunction(ai,img)
return Response({'user':user,'prediction':pred})

Problem with mixing Detail View and Form Mixin django

I am trying to create a comment system for the blog portion of my app with Django. I have attempted to mix my detail view with the form mixin and I'm struggling a bit. When the form is submitted, it doesn't save and no error is present. If any of you can help I would greatly appreciate it.
Here is my View
class DetailPostView(FormMixin, DetailView):
model = Post
template_name = "blog/post_detail.html"
context_object_name = "posts"
form_class = CommentForm
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context["form"] = CommentForm
return context
def post(self, request, *args, **kwargs):
self.object = self.get_object()
form = self.get_form()
if form.is_valid():
return self.form_valid(form)
else:
return self.form_invalid(form)
def get_success_url(self):
return reverse("post-detail", kwargs={"pk": self.object.pk})
The model
class Comment(models.Model):
comment = models.ForeignKey(Post, on_delete=models.CASCADE)
title = models.CharField(max_length=200)
content = models.TextField()
author = models.CharField(max_length=50)
created_on = models.DateTimeField(auto_now_add=True)
class Meta:
ordering = ["-created_on"]
def __str__(self):
return self.title
The reason that this happens is because you construct a new form that you pass to the context data, as a result, it will not render any errors, since you construct a form without validating the request data and render that form, you thus do not display the form that rejected the data in the first place.
But you do not need to do that. Django's FormMixin [Django-doc] already takes care of that. You thus should not override the .get_context_data(…) method [Django-doc].
Another problem is that you did not save your form, you can override a the form_valid method, or you can inherit from ModelFormMixin [Django-doc].
Finally you better first create the form, and then assign self.object, otherwise it will pass this as an instance to the form:
from django.views.generic.edit import ModelFormMixin
class DetailPostView(ModelFormMixin, DetailView):
model = Post
template_name = 'blog/post_detail.html'
context_object_name = 'posts'
form_class = CommentForm
# no get_context_data override
def post(self, request, *args, **kwargs):
# first construct the form to avoid using it as instance
form = self.get_form()
self.object = self.get_object()
if form.is_valid():
return self.form_valid(form)
else:
return self.form_invalid(form)
def get_success_url(self):
return reverse('post-detail', kwargs={'pk': self.object.pk})

Understanding Django Rest Framework's ModelViewSet Router

I have my Comment model:
class Comment(models.Model):
"""A comment is a content shared by a user in some post."""
user = models.ForeignKey('users.User', on_delete=models.CASCADE, null=False)
post = models.ForeignKey('posts.Post', on_delete=models.CASCADE, null=False)
content = models.TextField(max_length=1000, null=False, blank=False)
def __str__(self):
"""Return the comment str."""
return "'{}'".format(self.content)
Its serializer:
class CommentSerializer(serializers.ModelSerializer):
"""Comment model serializer."""
user = serializers.PrimaryKeyRelatedField(read_only=True)
class Meta:
model = Comment
fields = '__all__'
def create(self, validated_data):
"""Create a new comment in some post, by request.user."""
validated_data['user'] = self.context['request'].user
return super().create(validated_data)
def list(self, request):
"""List all the comments from some post."""
if 'post' not in request.query_params:
raise ValidationError('Post id must be provided.')
q = self.queryset.filter(post=request.query_params['post'])
serializer = CommentSerializer(q, many=True)
return Response(serializer.data)
The viewset:
class CommentViewSet(viewsets.ModelViewSet):
serializer_class = CommentSerializer
queryset = Comment.objects.all()
def get_permissions(self):
permissions = []
if self.action == 'create' or self.action == 'destroy':
permissions.append(IsAuthenticated)
return [p() for p in permissions]
def get_object(self):
"""Return comment by primary key."""
return get_object_or_404(Comment, id=self.kwargs['pk']) # this is the drf's get_object_or_404 function
def destroy(self, request, *args, **kwargs):
"""Delete a comment created by request.user from a post."""
pdb.set_trace()
instance = self.get_object()
if instance.user != request.user:
raise ValidationError('Comment does not belong to the authenticated user.')
self.perform_destroy(instance)
def retrieve(self, request, pk=None):
pass
def update(self, request, pk=None):
pass
def partial_update(self, request, pk=None):
pass
So far so good when it comes to list, create and retrieve. But when it comes to delete/destroy (Idk the difference) I don't know how to get the URL for the DELETE request.
I'm using Postman to do so.
Urls.py:
router = routers.SimpleRouter()
router.register(r'comments', CommentViewSet, basename='comments')
pdb.set_trace() # Put a pdb here to see what does router.urls have.
urlpatterns = [
# Non api/simple django views
path('create_comment/', create_comment, name='create_comment'),
path('delete_comment/', delete_comment, name='delete_comment'),
# rest api views
path('rest/', include(router.urls))
]
When I debug the router.urls, the terminal shows this:
[<URLPattern '^comments/$' [name='comments-list']>, <URLPattern '^comments/(?P<pk>[^/.]+)/$' [name='comments-detail']>]
Why there is no url for create and destroy?
I could create some Comments from the api, and I didn't even know how did I get the POST request url for the create function, I just guessed lol, but that's not what you want when you're programming right?
I have checked the Routers documentation but I don't get it. Please give some help! Many thanks.
The answer is simple, Django uses the comments-list list for create and list operation and comments-detail for update and delete operations.
That is, there are only two URL end-points, but it supports several actions, which can be performed by changing the HTTP methods
You can use HTTP GET foo-bar/comments/ to retrieve all comments where as HTTP POST foo-bar/comments/ can be used to create a new comment.

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