I have a problem with filtering objects in View Set... I am trying to show objects only where field 'point' is null.
I always get error: NameError: name 'null' is not defined
Could you please HELP ME ?
My code:
class CompanyMapSerializer(serializers.ModelSerializer):
class Meta:
model = Company
fields = ('name', 'point', 'url', 'pk')
extra_kwargs = {
'url': {'view_name': 'api:company-detail'},
}
def to_representation(self, instance):
ret = super(CompanyMapSerializer, self).to_representation(instance)
ret['point'] = {
'latitude': instance.point.x,
'longitude': instance.point.y
}
return ret
And view set code:
class CompanyMapViewSet(viewsets.ModelViewSet):
queryset = Company.objects.filter(point = null)
serializer_class = CompanyMapSerializer
PageNumberPagination.page_size = 10000
Please help me.
You are not defining what null is, and Python doesn't recognize null as a primitive, you've got two options:
queryset = Company.objects.filter(point = None) # using None
queryset = Company.objects.filter(point__isnull = True) # explicitly asking for Null
These two queries are equally valid.
Related
Need help , i am trying to push nested relations inside DB don't know where I am going wrong in this, is there something wrong with validated_data , which is a list of dict here , thanks in advance
class CatalogSerializer(serializers.ModelSerializer):
catalog_products = CatalogProductsSerializer(source = 'catalogproducts_set',many=True)
class Meta:
model = Catalog
fields = ['created_by','client','catalog_products','created_datetime','is_active']
def create(self,validate_data):
client_id = validate_data.pop('id')
client = User.objects.get(id=client_id),
catalog_obj = Catalog.objects.create(
client = client,
created_by = self.context['user'],
is_active =True,
)
for pricelist_ins in validate_data:
CatalogProducts.objects.create(
catalog = catalog_obj,**pricelist_ins)
return catalog_obj
Basic Viewset
class CatalogViewset(viewsets.ModelViewSet):
queryset = Catalog.objects.all()
serializer_class = CatalogSerializer
permission_classes = []
authentication_classes = []
def create(self, request, *args, **kwargs):
if request.data:
try:
serialized_data = self.get_serializer(data = request.data)
if serialized_data.is_valid(raise_exception=True):
serialized_data.save()
return Response(serialized_data.data,status=200)
except Exception as e:
return Response({'error':str(e)},status=400)
return Response({'status':'invalid request'},status=400)
the error I am getting in Postman
{
"error": "{'catalog_products': [ErrorDetail(string='This field is required.', code='required')]}"
}
data i am posting
{
"id":"2",
"pricing_list":[
{
"from_quantity":"101",
"to_quantiy":"34",
"price":"1000"
},
{
"from_quantity":"10",
"to_quantiy":"501",
"price":"2000"
}
]
}
You have catelogue_products in the fields, it is by default required. But you are not posting any catelogue_products. You need to post data based on the fields of the serializer. validated data will not contain any other data, but valid data that was set in serializer.
To make it optional you may try to add required=False in the serialzier like this:
class CatalogSerializer(serializers.ModelSerializer):
catalog_products = CatalogProductsSerializer(source = 'catalogproducts_set',many=True, required=False)
class Meta:
model = Catalog
fields = ['created_by','client','catalog_products','created_datetime','is_active']
I'm trying to write a test to check that the create method of my Viewset works ok:
#pytest.mark.django_db
def test_create(admin_user):
parent = factories.ParentFactory()
payload = {
'name': 'child',
'parent_id': parent.pk,
}
view = views.ParentViewSet.as_view({'post': 'create'})
request = factory.post('/', payload, format='json')
force_authenticate(request, user=admin_user)
response = view(request)
assert response.status_code == status.HTTP_201_CREATED
assert models.Child.objects.count() == 1
child = models.Child.objects.first()
assert child.name == 'child'
However, I get the following error when I run the code:
psycopg2.errors.NotNullViolation: null value in column "parent_id" violates not-null constraint
But the test for the Parent create method runs fine:
def test_create(admin_user):
payload = {
'name': 'parent',
'children': [
{
'name': 'child',
}
],
}
view = views.ParentViewSet.as_view({'post': 'create'})
request = factory.post('/', payload, format='json')
force_authenticate(request, user=admin_user)
response = view(request)
assert response.status_code == status.HTTP_201_CREATED
assert models.Parent.objects.count() == 1
season = models.Parent.objects.first()
assert season.name == 'parent'
assert season.children.count() == 1
Can someone tell me the correct way to write the payload for the child test create?
Edit:
serializers.py
class ChildSerializer(serializers.ModelSerializer):
class Meta:
model = models.Child
fields = ['id', 'name']
class ParentSerializer(serializers.ModelSerializer):
children = ChildSerializer(many=True)
class Meta:
model = models.Parent
fields = ['id', 'name', 'children']
def create(self, validated_data):
children = validated_data.pop('children')
parent = super().create(validated_data)
for child in children:
child['parent'] = parent
self.fields['children'].create(children)
return parent
views.py
class ParentViewSet(
viewsets.GenericViewSet,
mixins.CreateModelMixin,
mixins.ListModelMixin,
mixins.RetrieveModelMixin,
mixins.DestroyModelMixin,
):
queryset = models.Parent.objects.all().prefetch_related(
'children'
)
serializer_class = serializers.ParentSerializer
class ChildViewSet(
viewsets.GenericViewSet,
mixins.CreateModelMixin,
mixins.ListModelMixin,
mixins.RetrieveModelMixin,
mixins.DestroyModelMixin,
):
queryset = models.Child.objects.all().prefetch_related(
'children'
)
serializer_class = serializers.ChildSerializer
I think you have a field "parent" in the child model, but as you are not including that field in ChildSerializer, even if you send it in the request body, it is not included while creating a Child instance, hence the error you're getting. You have several ways to solve it
1 - You can add parent field to ChildSerializer:
class ChildSerializer(serializers.ModelSerializer):
class Meta:
model = models.Child
fields = ['id', 'name', 'parent']
and send the request like this:
payload = {
'name': 'child',
'parent': parent.pk,
}
2 - If you do not want that, you may keep the ChildSerializer as it is now, and add parent only while saving the child instance, with something like this:
class ChildViewSet(
...
):
queryset = models.Child.objects.all().prefetch_related('children')
serializer_class = serializers.ChildSerializer
def perform_create(self, serializer):
serializer.save(parent_id=self.request.data.get('parent'))
Again you'd need to send the request like this:
payload = {
'name': 'child',
'parent': parent.pk,
}
But in this second scenario, you're not including parent field in request validation, and if a client does not send parent field or sends an invalid value there, you'll get an exception. If you are to go with this solution, I'd advise to somehow validate parent field as well.
How to serialize a fields in related models.
I got a models:
class Order(models.Model):
order_id = models.BigIntegerField(verbose_name='Order ID', unique=True)
order_name = models.CharField(verbose_name='Order name', max_length=255)
order_type = models.IntegerField(verbose_name='Campaign type')
class Types(models.Model):
delimiter = models.CharField(verbose_name='Delimiter', max_length=255)
status = models.BooleanField(verbose_name='Status', default=True)
title = models.CharField(verbose_name='Title', max_length=255)
class User(models.Model):
name = models.CharField(verbose_name='User name', max_length=200, unique=True)
class Report(models.Model):
order = models.ForeignKey(Order, to_field='order_id', verbose_name='Order ID')
user = models.ForeignKey(User, verbose_name='User ID')
ad_type = models.ForeignKey(Types, verbose_name='Type')
imp = models.IntegerField(verbose_name='Total imp')
month = models.DateField(verbose_name='Month', default=datetime.datetime.today)
View:
class ReportLisAPIView(ListAPIView):
serializer_class = ReportSerializer
def get_queryset(self):
month = parse_date(self.kwargs['month']) - relativedelta(day=1)
queryset = (
Report.objects.filter(month=month)
.values_list(
'user', 'user__name', 'order__order_id',
'order__order_name', 'order__order_type'
).all().annotate(Sum('imp'))
)
return queryset
Serializer:
class ReportSerializer(ModelSerializer):
class Meta:
model = Report
depth = 1
I need to get all field like in 'queryset' in get_queryset()
but I got an error:
Got AttributeError when attempting to get a value for field imp on
serializer ReportSerializer. The serializer field might be named
incorrectly and not match any attribute or key on the tuple
instance. Original exception text was: 'tuple' object has no attribute
'imp'.
But if I return in get_queryset() just Report.objects.filter(month=month).all() I'll get all objects and related object with all field, without aggregate of imp and not grouping.
So the question is how to make serializer return structure that set in queryset?
The get_queryset method requires to return a queryset but you are returning a tuple beacause of values_list. Either drop it to return a queryset or go with a more generic view like APIView.
I found a way how to do it.
As I use .values_list() it return list object instead of queryset object. So for serializer do understand what is inside the list I defined all fields in serializer. And in to_representation() I return dictionary like it should be.
Serializer:
class ReportSerializer(serializers.ModelSerializer):
user = serializers.IntegerField()
user_name = serializers.CharField()
order_id = serializers.IntegerField()
order_name = serializers.CharField()
order_type = serializers.IntegerField()
imp = serializers.IntegerField()
class Meta:
model = Report
fields = [
'user', 'user_name', 'order_id', 'order_name',
'order_type', 'imp'
]
depth = 1
def to_representation(self, instance):
Reports = namedtuple('Reports', [
'user',
'user_name',
'order_id',
'order_name',
'order_type',
'imp',
])
return super(ReportSerializer, self).to_representation(
Reports(*instance)._asdict()
)
View:
class ReportLisAPIView(ListAPIView):
serializer_class = ReportSerializer
def get_queryset(self):
month = parse_date(self.kwargs['month']) - relativedelta(day=1)
queryset = (
Report.objects.filter(month=month)
.values_list(
'user', 'user__name', 'order__order_id',
'order__order_name', 'order__order_type'
).all().annotate(Sum('imp'))
)
return queryset
def list(self, *args, **kwargs):
queryset = self.get_queryset()
serializer = self.serializer_class(queryset, many=True)
# actualy that's it! part of which is below can be pass and just
# return Response(serializer.data)
result = {
'month': parse_date(self.kwargs['month']).strftime('%Y-%m'),
'reports': []
}
inflcr = {}
for item in serializer.data:
inflcr.setdefault(item['user'], {
'id': item['user'],
'name': item['user_name'],
'campaigns': []
})
orders = {
'id': item['order_id'],
'name': item['order_name'],
'type': item['order_type'],
'impressions': item['imp'],
}
inflcr[item['user']]['campaigns'].append(orders)
result['reports'] = inflcr.values()
return Response(result)
Using django & django-rest-framework, I have the following model (this is simplified but it's all there):
class Device(Model):
#stuff
class DeviceInformation(Model):
device = ForeignKey(Device, reverse='infos')
key = CharField(max_length=32)
value = CharField(max_length=1024)
When serializing a device through django-rest-framework's ModelSerializer, I get something like this:
{
//stuff
infos: [{
'key':'BatteryLevel',
'value':'80%'
},{
'key':'DeviceName',
'value':'my device'
}, //etc
]
}
Which is perfectly normal. However, it would make much more sense to serialize into something like this:
{
//stuff
infos: {
'BatteryLevel':'80%',
'DeviceName':'my device',
//etc
}
}
How do I do that? Is it even possible?
Note that I don't need to deserialize any of these information.
EDIT: my serializers are as follows:
class DeviceInfoSerializer(ModelSerializer):
class Meta:
model = DeviceInformation
fields = ('key', 'value')
read_only_fields = fields
class DeviceSerializer(HyperlinkedModelSerializer):
udid = serializers.CharField(read_only=True)
def __init__(self, *args, **kwargs):
super(DeviceSerializer, self).__init__(*args, **kwargs)
if hasattr(self, 'object') and self.object and not self.many:
self.data['infos'] = DeviceInfoSerializer(
self.object.infos.all(), many=True).data
class Meta:
model = Device
fields = ['udid', 'model', 'tracked']
read_only_fields = ('model', 'tracked')
slug_field = 'udid'
For your readonly-case, the best way is to use SerializerMethodField.
This would change your DeviceSerializer and remove the need for your DeviceInfoSerializer.
class DeviceSerializer(HyperlinkedModelSerializer):
udid = serializers.CharField(read_only=True)
infos = serializers.SerializerMethodField('get_infos')
def get_infos(self, obj):
return {
info.key: info.value
for info in obj.infos.all()
}
class Meta:
model = Device
fields = ['udid', 'model', 'tracked', 'infos']
read_only_fields = ('model', 'tracked', 'infos')
slug_field = 'udid'
How do I serialize django-mptt trees in Tastypie?
I want to use django-mptt's cache_tree_children(). I've tried applying in different Tastypie hooks, but it throws an error.
Without the cache_tree_children method you could probably have your children serialized by simply hooking up a ToManyField with full=True pointing at the children property:
class MenuResource(ModelResource):
children = fields.ToManyField('self', 'children', null=True, full=True)
parent = fields.ToOneField('self', 'parent', null=True)
class Meta:
queryset = Menu.objects.all()
To implement the cache_tree_children function you could write your own ToManyField subclass that overrides the standard dehydrate function. Please note, that I only tested this solution very superficially:
def dehydrate(self, bundle):
if not bundle.obj or not bundle.obj.pk:
if not self.null:
raise ApiFieldError("The model '%r' does not have a primary key and can not be used in a ToMany context." % bundle.obj)
return []
the_m2ms = None
previous_obj = bundle.obj
attr = self.attribute
if isinstance(self.attribute, basestring):
attrs = self.attribute.split('__')
the_m2ms = bundle.obj
for attr in attrs:
previous_obj = the_m2ms
try:
the_m2ms = getattr(the_m2ms, attr, None)
except ObjectDoesNotExist:
the_m2ms = None
if not the_m2ms:
break
elif callable(self.attribute):
the_m2ms = self.attribute(bundle)
if not the_m2ms:
if not self.null:
raise ApiFieldError("The model '%r' has an empty attribute '%s' and doesn't allow a null value." % (previous_obj, attr))
return []
self.m2m_resources = []
m2m_dehydrated = []
# There goes your ``cache_tree_children``
for m2m in cache_tree_children(the_m2ms.all()):
m2m_resource = self.get_related_resource(m2m)
m2m_bundle = Bundle(obj=m2m, request=bundle.request)
self.m2m_resources.append(m2m_resource)
m2m_dehydrated.append(self.dehydrate_related(m2m_bundle, m2m_resource))
return m2m_dehydrated
One of the main advantages of this method is that you don't have to care about detail / list view constraints / differences no more. You even can parameterize this aspect of your resource further down until you got some kind of default behavior that fits your needs. Field-based, that is. Which I think is cool.
This is how I solved it:
class MenuResource(ModelResource):
parent = fields.ForeignKey('self', 'parent', null=True)
class Meta:
serializer = PrettyJSONSerializer()
queryset = Menu.objects.all().select_related('parent')
include_resource_uri = False
fields = ['name']
def get_child_data(self, obj):
data = {
'id': obj.id,
'name': obj.name,
}
if not obj.is_leaf_node():
data['children'] = [self.get_child_data(child) \
for child in obj.get_children()]
return data
def get_list(self, request, **kwargs):
base_bundle = self.build_bundle(request=request)
objects = self.obj_get_list(bundle=base_bundle,
**self.remove_api_resource_names(kwargs))
sorted_objects = self.apply_sorting(objects, options=request.GET)
paginator = self._meta.paginator_class(
request.GET, sorted_objects,
resource_uri=self.get_resource_uri(), limit=self._meta.limit,
max_limit=self._meta.max_limit,
collection_name=self._meta.collection_name
)
to_be_serialized = paginator.page()
from mptt.templatetags.mptt_tags import cache_tree_children
objects = cache_tree_children(objects)
bundles = []
for obj in objects:
data = self.get_child_data(obj)
bundle = self.build_bundle(data=data, obj=obj, request=request)
bundles.append(self.full_dehydrate(bundle))
to_be_serialized[self._meta.collection_name] = bundles
to_be_serialized = self.alter_list_data_to_serialize(request,
to_be_serialized)
return self.create_response(request, to_be_serialized)
If you're not using pagination you can just take that part out. That's what I did.