Here is the simplified verison of the Serializer what I have:
class CommentSerializer(serializers.HyperlinkedModelSerializer):
def __init__(self, *args, **kwargs):
init = super().__init__(*args, **kwargs)
return init
username = serializers.ReadOnlyField(source='user.username')
user_id = serializers.ReadOnlyField(source='user.id')
user = UserSerializer(read_only=True)
url_field_name = 'url_api'
# and more definitions
content_type_id = serializers.IntegerField()
site_id = serializers.SerializerMethodField('_siteId')
def _siteId(self, threadedcomment):
site_id = settings.SITE_ID
return site_id
class Meta:
model = ThreadedComment
fields = ('url_api','url','id','title','tree_path','comment','submit_date','submit_date_unix','submit_date_humanized','root_id','is_removed',
'parent_id','last_child_id','newest_activity','depth','username','user_id','object_pk','content_type_id','user',
'site_id',
)
read_only_fields = ('id','title','tree_path','submit_date','root_id','is_removed',
'parent_id','last_child_id','newest_activity','depth','username','user_id',
# 'site_id',
)
class CommentViewSet(viewsets.ModelViewSet):
queryset = ThreadedComment.objects.all().annotate().all()
serializer_class = CommentSerializer
permission_classes = []
filter_backends = [filters.OrderingFilter]
def filter_queryset(self, queryset):
return queryset
def list(self, request):
return super().list(request)
def perform_create(self, serializer):
serializer.save(user=self.request.user)
# site_id = settings.SITE_ID
# serializer.save(user=self.request.user, site_id=site_id, )
return super().perform_create(serializer)
Now I make an http post request on the api as i.e.:
axios.post('/api/comments/', {
"comment":"test.",
"object_pk":34,
"content_type_id":12,
},
It shows me an error:
500 (Internal Server Error)
IntegrityError: NOT NULL constraint failed: django_comments.site_id
The problem (a pure question) is, why the SerializerMethodField doesn't work? I put a breakpoint on the site_id = settings.SITE_ID line, but it doesn't hit, which means the line hasn't even executed.
I also tried putting a set of lines (the commented lines) on perform_create, reading a SO post, but the result is the same, the same error, NOT NULL constraint failed.
I'm certainly passing a value, but it shows it's a null value, saying nothing is passed, what this means? What am I donig wrong here? Thanks.
Related
I want to insert Track record through a condition but it does not happen. Please help me how could I do fix it?
this is views.py
class Track(APIView):
http_method_names = ['post',]
def post(self,request, *args, **kwargs):
employee = Employee.objects.filter(username=kwargs.get('username'), password=kwargs.get('password'))
if employee.exists():
serializer_class = TrackSerializer
try:
if serializer_class.is_valid():
serializer_class.save()
return Response(serializer_class.data, status = status.HTTP_201_CREATED)
except Exception as e:
print(e)
return Response(serializer_class.errors, status = status.HTTP_404_NOT_FOUND)
urls.py
path('track/<username>/<password>/',views.TrackList.as_view(),name = 'track'),
You have to pass data to your serializer
class Track(APIView):
http_method_names = ['post',]
def post(self,request, *args, **kwargs):
employee = Employee.objects.filter(username=kwargs.get('username'), password=kwargs.get('password'))
if employee.exists():
serializer_class = TrackSerializer(data=request.data)
try:
if serializer_class.is_valid():
serializer_class.save()
return Response(serializer_class.data, status = status.HTTP_201_CREATED)
except Exception as e:
print(e)
return Response(serializer_class.errors, status = status.HTTP_404_NOT_FOUND)
Only two parameters come to the input:
param1 = Int, optional
param2 = Char, require
On output - json with 4 elements
key1 = Char
key2 = Int
key3 = Int
key4 = Int
Everything can be null
Now I have it implemented in the view in the get method, but I want to create a Serializer for this and put all the logic there, but I don’t really understand where to transfer the logic - validate, to_representation?
Now it looks something like this
views.py
class ExampleRetrieveApiView(APIView):
def get(self, request, *args, **kwargs):
# A lot of logic related with input parameters.
return Response({
'key1': value1,
'key2': value2,
'key3': value3,
'key4': value4
})
Need to do something like this
views.py
class ExampleRetrieveApiView(APIView):
serializer_class = ExampleSerializer
def get(self, request):
serializer = ExampleSerializer(???)
return Response(serializer.data)
serializers.py
class ExampleSerializer(serializers.Serializer):
???
Pass the input params as a dict. Then, you should use SerializerMethodField() for this:
from rest_framework import serializers
class ExampleSerializer(serializers.Serializer):
key1 = serializers.SerializerMethodField()
key2 = serializers.SerializerMethodField()
key3 = serializers.SerializerMethodField()
key4 = serializers.SerializerMethodField()
def get_key1(self, obj):
# do some calculations, let's say we want to return input1 multiplied by 2
# I'm accessing obj data and if it's empty assigning 0, you can add your own check instead
return obj.get('input1', 0)*2
def get_key2(self, obj):
# same deal, do whatever calculations you want with the input data
return obj.get('input2')
def get_key3(self, obj):
# your logic
return
def get_key4(self, obj):
return
For every field declared as SerializerMethodField, you should have a corresponding get_field method.
It's up to you how to get the input params, you can do it either through query params or body data.
Call the serializer like this in your view, for example with body params:
class ExampleRetrieveApiView(APIView):
def get(self, request):
input_data = {'input1':request.data.get('input1'),
'input2':request.data.get('input2')}
serializer = ExampleSerializer(input_data)
return Response(serializer.data)
views
class ExampleAPIView(APIView):
serializer_class = ExampleSerializer
def get(self, request):
serializer = ExampleSerializer(data=request.query_params)
if serializer.is_valid(raise_exception=True):
return(Response(serializer.data))
serializers
class ExampleSerializer(serializers.Serializer):
param1 = serializers.IntegerField()
param2 = serializers.CharField()
def validate(self, data):
#custom logic
data['param3'] = 'text'
#another params
return data
def to_representation(self, data):
return {
'key1': data['param3']
'key2': data['param4']
#another key for representation
}
I have an object, whose attributes I would like to update. Right now, I am able to update a single attribute eg: name. But the object has several attributes which include name, contact_name, contact_email and contact_phone_number.The following is what I have at the moment.
In views.py
class MerchantViewSet(GetPrefixedIDMixin, viewsets.ModelViewSet):
"""POST support for /merchants/."""
print ("in MerchantViewSet")
queryset = models.Merchant.objects.all()
serializer_class = serializers.CreateMerchantSerializer
lookup_field = "id"
# lookup_value_regex = f"{models.Merchant.id_prefix}_[a-f0-9]{32}"
lookup_value_regex = ".*"
permission_classes = [permissions.MerchantPermission]
def get_queryset(self):
"""Filter the queryset based on the full merchant name or starting with a letter."""
queryset = models.Merchant.objects.all()
search_param = self.request.query_params.get("search", None)
if search_param:
if search_param.startswith("^"):
queryset = queryset.filter(name__istartswith=search_param[1:])
else:
queryset = queryset.filter(name__icontains=search_param)
return queryset
def update(self, request, *args, **kwargs):
request.data["user"] = request.user.id
print (self.get_object().name)
print (request.data)
merchant = self.get_object()
print (response)
print (merchant.name)
for merchants in models.Merchant.objects.all():
print (merchants.id)
if (merchants.id == merchant.id):
merchants.name = request.data["name"]
merchants.save()
I've tried using
response = super(MerchantViewSet, self).update(request, *args, **kwargs)
from what I read in the DRF documentations but using this just returns error 404 when I run my test. Do I simply have to do with I did with name in my code above, with the other attributes? Or is there a more streamlined way to do this?
This is my test:
class MerchantsViewSetTest(tests.BigETestCase): # noqa
#classmethod
def setUpClass(cls): # noqa
super(MerchantsViewSetTest, cls).setUpClass()
cls.application = tests.get_application()
tests.create_group("merchant")
cls.consumer_user = tests.create_consumer()
cls.admin = tests.create_administrator()
cls.merchant_geraldine = models.Merchant.objects.create(
name="Test Account 1",
contact_name="Geraldine Groves",
contact_email="geraldine#example.com",
contact_phone_number="+35310000000",
)
cls. merchant_barbara = models.Merchant.objects.create(
name="Account 2",
contact_name="Barbara",
contact_email="barbara#example.com",
contact_phone_number="+35310000432",
)
def test_edit_merchant(self): # noqa
url = reverse("bige_transactions:merchant-detail", kwargs={'id': self.merchant_geraldine.prefixed_id})
# payload
data = {"name": "Edited"}
# Put data
resp_data = self.put(url, data, user=self.admin, status_code=200)
# Check if data was updated
url = reverse("bige_transactions:merchant-list")
# Try without authenticated user
self.get(url, status_code=401)
# Try with authenticated admin user
resp_data = self.get(url, user=self.admin, status_code=200)
print (resp_data)
According to the relevant documentation "Django Rest Frameworks default Filter Backends work out of the box" with DjangoRestMultipleModels. So, I'd expect the following code to work:
class AllModelSummary(MultipleModelAPIView):
filter_backends = (SearchFilter,DjangoFilterBackend,)
search_fields = ('name','description',)
#filter_fields = ('is_foo','is_bar',) # Everything breaks when this is uncommmented
flat = True
def get_queryList(self):
queryList = (
(Foo.objects.all(), FooSerializerMiniList),
(Bar.objects.all(), BarSerializerMiniList)
)
return queryList
def get(self, request, *args, **kwargs):
return self.list(request, *args, **kwargs)
Here's an example of one of those serializers:
class BarSerializerMiniList(serializers.ModelSerializer):
is_foo = serializers.SerializerMethodField()
is_bar = serializers.SerializerMethodField()
def get_is_foo(self,obj):
return False
def get_is_bar(self,obj):
return True
class Meta:
model = Bar
fields = ('pk','name','description','is_bar','is_foo')
The search fields do exactly what they're supposed to do, but if I define filter_fields in the API then I am greeted by this:
'Meta.fields' contains fields that are not defined on this FilterSet: is_foo, is_bar
Any suggestions as to what might be going wrong here would be welcome.
In the end I had to work around the issue as follows:
class AllModelSummary(MultipleModelAPIView):
...
def get_querylist(self):
types = self.request.query_params['types']
queryList = ()
if types:
for t in types.split(','):
if t == 'foo':
queryList = queryList + ((Foo.objects.all(), FooSerializerMiniList),)
elif t == 'bar':
queryList = queryList + ((Bar.objects.all(), BarSerializerMiniList),)
else:
queryList = (
(Foo.objects.all(), FooSerializerMiniList),
(Bar.objects.all(), BarSerializerMiniList),
)
return queryList
Then, appending ?types=foo,bar to the URL does the trick.
I'm following this link (http://www.django-rest-framework.org/api-guide/relations/#writable-nested-serializers) to write nested serializer. But when I pop the 'vars' from validated_data in the create method of HostSerializer, I found it's empty.
I'm using django 1.9.2 and django restframework 3.3.2.
My model:
class Host(models.Model):
name = CharField(max_length=20, primary_key=True)
vm_cpu = IntegerField(default=2)
vm_mem = IntegerField(default=2048)
create_vm = BooleanField(default=True)
def __unicode__(self):
return('%s' % (self.name))
class Variable(models.Model):
name = CharField(max_length=10)
value = CharField(max_length=20)
host = models.ForeignKey(Host, related_name='vars')
def __unicode__(self):
return('%s=%s' % (self.name, self.value))
Serializer
class VariableSerializer(ModelSerializer):
class Meta:
model = Variable
class HostSerializer(ModelSerializer):
vars = VariableSerializer(many=True)
class Meta:
model = Host
def create(self, validated_data):
# i set a break point here and found vars_data is empty
vars_data = validated_data.pop('vars')
host = Host.objects.create(**validated_data)
for v in vars_data:
Variable.objects.create(host = host, **v)
return host
This is the problem I found vars_data is an empty list:
def create(self, validated_data):
# i set a break point here and found vars_data is empty
vars_data = validated_data.pop('vars')
Here's the rest of the code
admin.py
class VariableAdmin(admin.ModelAdmin):
list_display = ['name', 'value']
class HostAdmin(admin.ModelAdmin):
list_display = ['name']
admin.site.register(Variable, VariableAdmin)
admin.site.register(Host, HostAdmin)
urls.py
router = DefaultRouter()
router.register(r'variables', VariableViewSet, base_name='variables')
router.register(r'hosts', HostViewSet, base_name='hosts')
urlpatterns = [
url(r'^', include(router.urls)),
]
views.py
class VariableViewSet(ModelViewSet):
queryset = Variable.objects.all()
serializer_class = VariableSerializer
class HostViewSet(ModelViewSet):
queryset = Host.objects.all()
serializer_class = HostSerializer
My test program
post.py
import json
import requests
file = 'host.json'
url = 'http://localhost:8001/test_nest/hosts/'
with open(file, 'r') as f:
j = f.read()
data = json.loads(j)
r = requests.post(url, data = data)
print r.text
And here's the test data
host.json
{
"name": "host4",
"vars": [
{
"name": "var2-a",
"value": "a1"
},
{
"name": "var2-b",
"value": "a2"
}
],
"vm_cpu": 2,
"vm_mem": 2048,
"create_vm": true
}
I'm new to django. So I'm wondering if it's something simple and obvious. Did I use the wrong viewset? Did I post to the wrong URL? Or I setup the URL structure wrong?
I your serializers try using...
def update(self, instance,validated_data):
instance.vars_data = validated_data.get('vars',instance.vars)
instance.host = Host.objects.create(**validated_data)
for v in vars_data:
v,created=Variable.objects.create(host = host, **v)
instance.v.add(v)
return host
The following code works for me. Maybe you can try it：
models.py
class UserProfile(AbstractUser):
pass
class TobaccoCert(models.Model):
license = models.CharField(primary_key=True, max_length=15)
license_image = models.ImageField(upload_to="certs", blank=True, null=True, verbose_name='cert image')
views.py
class UserViewSet(mixins.CreateModelMixin, viewsets.GenericViewSet):
serializer_class = UserRegSerializer
...
def create(self, request, *args, **kwargs):
data = request.data
# here i make my nested data `certs` and update it to data
image_data = request.FILES.get('images')
_license = data.get('username', None)
certs = {'license': _license, 'license_image': image_data}
data['certs'] = certs
serializer = self.get_serializer(data=data)
serializer.is_valid(raise_exception=True)
user = self.perform_create(serializer) # save it
ret_dict = serializer.data
payload = jwt_payload_handler(user)
ret_dict["token"] = jwt_encode_handler(payload) # 获取token
ret_dict["name"] = user.name if user.name else user.username
headers = self.get_success_headers(serializer.data)
return Response(ret_dict, status=status.HTTP_201_CREATED, headers=headers)
serializer.py
class CertSerializer(serializers.ModelSerializer):
pass
class UserRegSerializer(serializers.ModelSerializer):
# [Serializer relations - Django REST framework](https://www.django-rest-framework.org/api-guide/relations/#writable-nested-serializers)
# this line is vars of your code
certs = CertSerializer(many=True,write_only=True)
...
password = serializers.CharField(
style={'input_type': 'password'}, help_text="passowrd", label="passowrd", write_only=True,
)
class Meta:
model = User
fields = ("username", "mobile", "password", 'province', 'city', 'dist', 'code', 'certs')
def create(self, validated_data):
"""
"""
# here we get certs
certs_data = self.initial_data.get('certs')
# just pop certs because it is useless for user create
certs_empty = validated_data.pop('certs')
user = super().create(validated_data=validated_data)
user.set_password(validated_data["password"])
user.save()
# use certs data to create cert
image_url = self.save_image(certs_data)
_license = validated_data.get('username', None)
TobaccoCert.objects.create(license=_license, license_image=image_url)
return user
In short, you need to add your nested parameters directly in the request parameters. In my example code, it is certs which is vars in your example and then use certs_data = self.initial_data.get('certs') get the parameters you passed in create method.
Another possible way is post your data before your requests:
In postman:
enter image description here
in request:
python - Django Rest Framework writable nested serializer with multiple nested objects - Stack Overflow
In addition, you can try to modify queryDict directly. You can refer to this link and here
Some useful links
django - Need help understanding many and source fields in a serializer - Stack Overflow
python - Django rest framework writeable nested serializer data missing from validated_data - Stack Overflow