I want to access the request object in my Views.py and Serializers.py in DRF.
My Views.py:
class ProductViewSet(viewsets.ReadOnlyModelViewSet):
"""
This viewset automatically provides `list` and `detail` actions.
"""
queryset = Product.objects.all()
serializer_class = ProductSerializer(context={'request': request})
My Serializers.py:
class ProductSerializer(serializers.HyperlinkedModelSerializer):
get_sr_price = serializers.SerializerMethodField('get_sr_price_func')
def get_sr_price_func(self, obj):
return self.request.user ??
class Meta:
model = Product
fields = (
'title', 'slug', 'product_stores', 'get_sr_price')
In Serializers.py I get ProductSerializer' object has no attribute 'request'. Also In views.py I get NameError: name 'request' is not defined
How do I access request object? Do I have to pass it from views to serializers? Also what's the difference between views.py and serializers.py? Generally I write all the business logic in Views.py ; here also should I do all the queries/filters in the views or should I do them in serializers or it doesn't make a difference. New to DRF please help.
You don't need to include request object in the context as the generic views passes request object to the serializer context.
DRF Source code snippet:
# rest_framework/generics.py
def get_serializer_context(self):
"""
Extra context provided to the serializer class.
"""
return {
'request': self.request, # request object is passed here
'format': self.format_kwarg,
'view': self
}
In your serializer, you can access the request object using .context attribute.
The context dictionary can be used within any serializer field logic,
such as a custom .to_representation() method, by accessing the
self.context attribute.
class ProductSerializer(serializers.HyperlinkedModelSerializer):
get_sr_price = serializers.SerializerMethodField('get_sr_price_func')
def get_sr_price_func(self, obj):
return self.context['request'].user # access the request object
Serializers are the way external data is mapped from / to models (Django or simple Python classes).
Views are dealing with how the data will be shown. Throttling, pagination, authentication are managed by the view. They also handle the data set.
DRF provides a context to pass request specific data to the serializer without having to redefine the init. This is likely what you're looking for.
Related
With some help, I solved this issue.
My api is work, but today I found this error when I try to access '/api/v1/docs'
AttributeError at /api/v1/docs/
'NoneType' object has no attribute 'method'
I know that the error is here:
def get_fields(self):
fields = super().get_fields()
if self.context['request'].method in ['POST', 'PATCH', 'PUT']:
fields['products'] = serializers.ListField(
write_only=True,
child=serializers.IntegerField()
)
return fields
When I remove .method, the access to the /api/v1/docs/ works, but my solution to post some products in bundleproducts, doesn't work.
My code:
view.py
class ProductViewSet(viewsets.ModelViewSet):
queryset = Product.objects.all()
serializer_class = ProductSerializer
model = Product
class BundleProductViewSet(viewsets.ModelViewSet):
queryset = BundleProduct.objects.all()
serializer_class = BundleProductSerializer
model = BundleProduct
class BundleViewSet(viewsets.ModelViewSet):
queryset = Bundle.objects.all()
serializer_class = BundleSerializer
model = Bundle
This is probably caused by this serializer being used as a nested serializer in another serializer. So lets say the definition for the serializer in question is:
class MySerializer(serializers.Serializer):
...
And you have another serializer like this:
class OtherSerializer(serializers.Serializer):
my_field = MySerializer()
In this case, when instantiating an instance of OtherSerializer, its context is not passed automatically to MySerializer, so there would not be a request in the context of MySerializer. You can either add the context to nested serializer manually, or in the get_fields method, check that request exists in self.context and proceed accordingly.
Also, I am not sure what you are trying to accomplish, but if you provide a field with
write_only=True
in serializer class definition, the field would not be present when reading the serializer, i.e for get requests in general, which seems like what you are trying to do here. So adding the products field as write_only would have the same effect, you do not need to override get_fields method
In django rest framework i am trying to add an object in a ModelSerializer with some custom functionality.
I want one of the fields to be set to self.request.user and i have the following view:
class GigSubmitView(generics.CreateAPIView):
permission_classes = (ProviderRW,)
serializer_class = serializers.GigSubmitSerializer
queryset = models.Gig.objects
def perform_create(self, serializer):
serializer.save(provider=self.request.user)
However that doesn't seem to be the correct answer. What should i do instead?
You dont need to override the perform create method to access request object in the serializer.
You have 2 options:
use serializer.context['request'] to access request object in serializer
request object is inserted by default in all generic views.
http://www.django-rest-framework.org/api-guide/serializers/#including-extra-context
you can use the current user default method to set the current user
http://www.django-rest-framework.org/api-guide/validators/#currentuserdefault
Lets say i have a model like so:
class MyModel(models.Model):
first_field = models.CharField()
second_field = models.CharField()
and an API view like so:
class MyModelDetailAPI(GenericAPIView):
serializer_class = MyModelSerializer
def patch(self, request, *args, **kwargs):
# Do the update
def post(self, request, *args, **kwargs):
# Do the post
The first_field is a field that is only inserted in the POST method (and is mandatory) but on each update, the user can't change its value so the field in the PATCH method is not mandatory.
How can i write my serializer so that the first_field is required on POST but not required on PATCH. Is there any way of dynamically setting the required field so i can still use the DRF validation mechanism? Some sort of validator dispatcher per request method?
I want something like this for example:
class MyModelSerializer(serializers.ModelSerializer):
class Meta:
model = MyModel
fields = {
'POST': ['first_field']
'PATCH': []
}
I need more space than comments provide to make my meaning clear. So here is what I suggest:
Different formatting means different serializers.
So here you have, for instance a MyModelSerializer and a MyModelCreationSerializer. Either create them independently, or have one inherit the other and specialize it (if it makes sense).
Use the appropriate GenericAPIView hook to return the correct serializer class depending on self.action. A very basic example could be:
class MyModelDetailAPI(GenericAPIView):
# serializer_class = unneeded as we override the hook below
def get_serializer_class(self):
if self.action == 'create':
return MyModelCreationSerializer
return MyModelSerializer
Default actions in regular viewsets are documented here, they are:
create: POST method on base route url
list: GET method on base route url
retrieve: GET method on object url
update: PUT method on object url
partial_update: PATCH method on object url
destroy: DELETE method on object url
Within a listview, with many objects, I want to change their value live by javascript, then save them by a POST/PUT http request to the object updateview, searching I've found that it maybe possible with Django REST framework.
I've read the Django REST framework
manual reference
but didn't understand how to set up the UpdateView call:
model.py
class presetrows(models.Model):
progressivo = models.ForeignKey(preset)
value = models.BigIntegerField(blank=True, null=True)
views.py
class RighePresetListView(ListView):
queryset = presetrows.objects.filter(stato=True)
class RighePresetUpdateView(UpdateView):
model = presetrows
exclude=()
but where should I add the update(request, *args, **kwargs) from django REST?
You don't really needs to define update(request, *args, **kwargs) in DRF views. For update api you can use this
class RighePresetUpdateView(UpdateAPIView):
serializer_class = 'your serializer'
queryset = presetrows.objects.filter(stato=True)
Provides put and patch method handlers implicitly.
I am using django-rest-framework generic views to create objects in a model via POST request. I would like to know how can I return the id of the object created after the POST or more general, any additional information about the created object.
This is the view class that creates (and lists) the object:
class DetectorAPIList(generics.ListCreateAPIView):
serializer_class = DetectorSerializer
permission_classes = (permissions.IsAuthenticatedOrReadOnly,)
parser_classes = (MultiPartParser, FileUploadParser,)
def pre_save(self, obj):
obj.created_by = self.request.user.get_profile()
def get_queryset(self):
return (Detector.objects
.filter(get_allowed_detectors(self.request.user))
.order_by('-created_at'))
The model serializer:
class DetectorSerializer(serializers.ModelSerializer):
class Meta:
model = Detector
fields = ('id', 'name', 'object_class',
'created_by', 'public', 'average_image', 'hash_value')
exclude = ('created_by',)
Thanks!
Here, DetectorSerializer inherits from ModelSerializer as well as your view inherits from generics ListCreateAPIView so when a POST request is made to the view, it should return the id as well as all the attributes defined in the fields of the Serializer.
Because it took me a few minutes to parse this answer when I had the same problem, I thought I'd summarize for posterity:
The generic view ListCreateApiView does return the created object.
This is also clear from the documentation listcreateapiview: the view extends createmodelmixin, which states:
If an object is created this returns a 201 Created response, with a serialized representation of the object as the body of the response.
So if you have this problem take a closer look at your client side!
post$.pipe(tap(res => console.log(res)))
should print the newly created object (assuming rxjs6 and ES6 syntax)
As mentioned above, To retrieve the id for the new created object, We need to override the post method, find the the update code for more details:
class DetectorAPIList(generics.ListCreateAPIView):
serializer_class = DetectorSerializer
permission_classes = (permissions.IsAuthenticatedOrReadOnly,)
parser_classes = (MultiPartParser, FileUploadParser,)
def post(self, request, format=None):
serializer = DetectorSerializer(data=request.data)
if serializer.is_valid():
obj = serializer.save()
return Response(obj.id, status=status.HTTP_201_CREATED)
return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)