Issue
I am building a larger Django-based web app, but I have a blocking issue with an API view that should return some data.
I the application I have a model (mail.models.Message
) and a matching serializer and viewset.
For a reporting feature, I need to get filtered set of results and have therefoer created a seperate rest_framework.views.APIView for the purpose of the reporting. The model is located in one app and the reporting is in another app.
Here is the model:
class Message(models.Model):
class Meta:
ordering = ('-timestamp',)
get_latest_by = 'timestamp'
id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
from_address = models.CharField("From", max_length=511, blank=True, default="", db_index=True)
from_domain = models.CharField(max_length=255, blank=True, default="", db_index=True)
to_address = models.CharField("To", max_length=511, blank=True, default="", db_index=True)
to_domain = models.CharField(max_length=255, blank=True, default="", db_index=True)
subject = models.TextField(blank=True, default="", db_index=True)
client_ip = models.GenericIPAddressField("Client IP", db_index=True, null=True)
mailscanner_hostname = models.CharField(max_length=255, db_index=True)
spam_score = models.DecimalField(db_index=True, default=0.00, max_digits=7, decimal_places=2)
mcp_score = models.DecimalField(db_index=True, default=0.00, max_digits=7, decimal_places=2)
timestamp = models.DateTimeField(db_index=True)
size = models.FloatField(default=0)
token = models.CharField(max_length=255, null=True)
mailq_id = models.TextField("Mailqueue identification", null=True)
whitelisted = models.BooleanField(db_index=True, default=False)
blacklisted = models.BooleanField(db_index=True, default=False)
is_spam = models.BooleanField(db_index=True, default=False)
is_mcp = models.BooleanField(db_index=True, default=False)
is_rbl_listed = models.BooleanField("Is RBL listed", db_index=True, default=False)
quarantined = models.BooleanField(db_index=True, default=False)
infected = models.BooleanField(db_index=True, default=False)
released = models.BooleanField(db_index=True, default=False)
def __str__(self):
return str(self.id) + "[" + str(self.from_address) + " to " + str(self.to_address) + "]"
And the matching serializer:
class MessageSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = Message
fields = (
'id',
'url',
'from_address',
'from_domain',
'to_address',
'to_domain',
'subject',
'client_ip',
'mailscanner_hostname',
'spam_score',
'timestamp',
'size',
'token',
'whitelisted',
'blacklisted',
'is_spam',
'is_rbl_listed',
'quarantined',
'infected'
)
The model has a lot of indexes on it to improve the performance search and filtering, but I have excluded these.
For the reporting, I have created this special view:
class MessageListApiView(ReportApiView):
serializer_class = MessageSerializer
queryset = Message.objects.all()
def get_queryset(self):
if self.request.method == 'POST':
filters = self.request.data
return MessageQuerySetFilter.filter(MessageQuerySetFilter, self.queryset, filters)
else:
return self.queryset
def post(self, request, format=None):
filters = request.data
qs = self.get_queryset()
serializer = MessageSerializer(qs, context={'request': request})
return Response(serializer.data, 200)
In get_queryset
, I use a special class and the only purpose of that class is to apply the appropriate filtering on the queryset and return it. Doing some testing, I have found the issue occurs when I have to return the Response
.
I get this traceback:
Internal Server Error: /api/reports/messages/
Traceback (most recent call last):
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/django/core/handlers/exception.py", line 35, in inner
response = get_response(request)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/django/core/handlers/base.py", line 128, in _get_response
response = self.process_exception_by_middleware(e, request)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/django/core/handlers/base.py", line 126, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
return view_func(*args, **kwargs)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/django/views/generic/base.py", line 69, in view
return self.dispatch(request, *args, **kwargs)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/rest_framework/views.py", line 494, in dispatch
response = self.handle_exception(exc)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/rest_framework/views.py", line 454, in handle_exception
self.raise_uncaught_exception(exc)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/rest_framework/views.py", line 491, in dispatch
response = handler(request, *args, **kwargs)
File "/Users/kenneth/Code/mailware/src/reports/views.py", line 44, in post
return Response(serializer.data, 200)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/rest_framework/serializers.py", line 537, in data
ret = super(Serializer, self).data
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/rest_framework/serializers.py", line 262, in data
self._data = self.to_representation(self.instance)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/rest_framework/serializers.py", line 504, in to_representation
ret[field.field_name] = field.to_representation(attribute)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/rest_framework/relations.py", line 376, in to_representation
url = self.get_url(value, self.view_name, request, format)
File "/Users/kenneth/Code/mailware/lib/python3.6/site-packages/rest_framework/relations.py", line 312, in get_url
lookup_value = getattr(obj, self.lookup_field)
AttributeError: 'QuerySet' object has no attribute 'pk'
[19/Jan/2018 20:05:24] "POST /api/reports/messages/ HTTP/1.1" 500 16389
The above APIView
class inherits a custom base class, which is what inherits the rest_framework.views.APIView
class. This class is called ReportApiView
and simply sets the paginator_class
and the permission_class
class ReportApiView(APIView):
permission_classes = (IsAuthenticated,)
pagination_class = PageNumberPaginationWithPageCount
In the MessageListApiView
post
method it seems to go wrong in the return
line, but I cannot find the reason why it is not working
Solution
You need to add many=True
to serializer queryset:
serializer = MessageSerializer(qs, many=True, context={'request': request})
Answered By - neverwalkaloner
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