Django rest ModelViewSet many-to-many create - django

Question

I have my model relationships as following: A Reader will have a Wishlist and a Wishlist will have many Books:
class Reader(models.Model):
user = models.OneToOneField(User)
...
# A library has many readers
which_library = models.ForeignKey('Library', related_name='readers', on_delete=models.CASCADE)
class Book(models.Model):
book_id = models.AutoField(primary_key=True)
title = models.CharField(max_length=30)
...
# A library has many books
which_library = models.ForeignKey('Library', related_name='books', on_delete=models.CASCADE)
# Record the date whenever a new book is added, it will be helpful for showing new arrivals
when_added = models.DateTimeField(auto_now_add=True, blank=True, null= True)
reader = models.ManyToManyField('Reader', related_name='wishlist')
My serializers:
class ReaderSerializer(serializers.ModelSerializer):
username = serializers.CharField(source='user.username')
email = serializers.CharField(source='user.email')
password = serializers.CharField(source='user.password')
class Meta:
model = Reader
#fields = '__all__'
#depth = 1
fields = ('id', 'username', 'email', 'password', 'phone', 'address', 'dob', 'which_library')
def update(self, instance, validated_data):
...
instance.which_library = validated_data.get('which_library', instance.which_library)
instance.save()
return instance
def create(self, validated_data):
user_data = validated_data.pop('user')
user = User.objects.create(**user_data)
user.set_password(user_data['password'])
user.save()
reader = Reader.objects.create(user=user, **validated_data)
return reader
class BookSerializer(serializers.ModelSerializer):
wishlist = ReaderSerializer(many=True, read_only=True)
class Meta:
model = Book
fields = '__all__'
I can already perform CRUD operations with Reader, I want to now add books to a specific Reader's wishlist. My view:
class ReaderViewSet(viewsets.ModelViewSet):
serializer_class = ReaderSerializer
def get_queryset(self):
readers = Reader.objects.filter(which_library=self.kwargs.get('library_id'))
return readers
#detail_route(methods=['post'])
def wishlist(self):
return Response('OK')
URL that I hit:
router.register(r'readers/(?P<library_id>[0-9]+)', ReaderViewSet, base_name='readers')
Here I am expecting that on hitting api/readers/<library_id>/<book_id>/wishlist/addI will be able to perform
add operation to the Wishlist.
How can I achieve that?

Answer 1

You can use detail_route's argument url_path to change url of endpoint. Also you can add additional arguments like book_id directly to detail_routed method, so your method can look like this:
#detail_route(methods=['post'], url_path='(?P<book_id>[0-9]+)/wishlist/add')
def wishlist(self, library_id=None, book_id=None):
reader = self.request.user.reader
book = Book.objects.get(pk=book_id)
reader.wishlist.add(book)
return Response('OK')
And it should be accessible from api/readers/<library_id>/<book_id>/wishlist/add url.