For the part of developing an API using restframe work and DJango, I need to receive few parameters through get method in 'list' function of my Viewset. In client side they are sending data as query prams, I somehow managed to get the data using 'request.query_params.get()' but received data is text format instead of bool, I had to convert this to boolean . see the code how I did this
if 'status' in (request.query_params):
"""receiving input argument is string need to convert that to boolean for further processing"""
input_status=(request.query_params.get('status', None)=='true')
is there any better way to getting data without losing datatype. is it possible to receive 'bool' or 'int' values directly in get parameter?
My model and view set classes are given below
class ModuleType(models.Model):
"""
This module type class used to represent each module of the application. It is inherited from
django content type which holds the complete model informations
"""
#this active field is true this module will be active on our user controller
content_type = models.OneToOneField(
ContentType,
on_delete=models.CASCADE,
related_name='status',
null=True
)
active=models.BooleanField(default=False)
class Meta:
db_table = 'module_types'
My Viewset
class ContentTypeViewSet(viewsets.ModelViewSet):
"""
This api deals all operations related with module management
You will have `list`, `create`, `retrieve`,
update` and `destroy` actions.
Additionally we also provide an action to update status.
"""
queryset = ContentType.objects.all()
serializer_class = ContentTypeSerializer
permission_classes = [permissions.AllowAny]
"""
Over ride list method to list values
"""
def list(self, request):
status='Sucess'
message='details of all modules included'
print(request)
try:
if 'status' in (request.query_params):
#input argument is striing need to convert that to boolean
input_status=(request.query_params.get('status', None)=='true')
validated_value= self.validate_input_params({'status':input_status})
if (validated_value==1):
all_modules = ContentType.objects.filter(status__active=input_status)
message='All value set status as '+str(input_status)
else:
message='Failed to validate all input values'
status='fail'
return Response({"status":status,"data":[],"message":message})
else:
all_modules=ContentType.objects.all()
serializer = self.get_serializer(
all_modules,
many=True
)
return Response({"status":status,"data":serializer.data,'message':message})
except:
message='unknown exception'
status='Fail'
return Response({"status":status,"data":[],"message":message})
Your view will read query params as string.
I suggest you use query_params = dict(request.GET.items())
That way you can parse parameters easier by using dict.
Related
I have a simple Django ForeignKey relationship between two models in postgreSQL. The logic here is the Sample object can optionally have a foreign key into a type of sample control.
from django.contrib.postgres.fields import CICharField
from django.db import models
class Sample(models.Model):
controls_applied = models.ForeignKey(SampleControl, null=True,
blank=True,
on_delete=models.SET_NULL)
class SampleControl(models.Model):
id = CICharField(max_length=200, primary_key=True)
On the admin changelist for Sample, I am trying to create filter that queries all or none of Samples that have a specific control (in this case, we'll use a SampleControl with id='runcontrol'). I'm trying to craft the specific URI string to append to my changelist url as I have other filters I'm trying to run in conjunction.
To get all samples with controls_applied= 'runcontrol', I can simply append the following string to my URL (notice the reference to the id of the foreign key):
?controls_applied__id=runcontrol
But if I want to get all samples that are not run control, it's more complicated. Wasn't sure what to do, so I decided to use 'startswith', which has a convenient 'notstartswith' companion that will do the inverse. When I use this, I see that the following works:
?controls_applied__id__startswith=runcontrol
However, the inverse
?controls_applied__id__notstartswith=runcontrol
gives me an error: Unsupported lookup 'notstartswith' for CICharField or join on the field not permitted, perhaps you meant startswith or istartswith?
Which leads to me the simple question: is there a way to specify NOT EQUALS in the query string of the URL on Django's admin site? Thank you!
I don't think admin URLs are capable of representing an exclude queryset filter, unless you create your own SimpleListFilter.
Try this in your admin.py:
class WithoutControlListFilter(admin.SimpleListFilter):
title = ('Without Control')
parameter_name = 'without_control'
def lookups(self, request, model_admin):
return (
('runcontrol', ('Run Control')),
)
def queryset(self, request, queryset):
return queryset.exclude(controls_applied=self.value())
class SampleAdmin(admin.ModelAdmin):
list_filter = (WithoutControlListFilter,)
There is a bit of info about admin filters in the Django ModelAdmin docs.
I want to create a viewset/apiview with a path like this: list/<slug:entry>/ that once I provide the entry it will check if that entry exists in the database.
*Note: on list/ I have a path to a ViewSet. I wonder if I could change the id with the specific field that I want to check, so I could see if the entry exists or not, but I want to keep the id as it is, so
I tried:
class CheckCouponAPIView(APIView):
def get(self, request, format=None):
try:
Coupon.objects.get(coupon=self.kwargs.get('coupon'))
except Coupon.DoesNotExist:
return Response(data={'message': False})
else:
return Response(data={'message': True})
But I got an error: get() got an unexpected keyword argument 'coupon'.
Here's the path: path('check/<slug:coupon>/', CheckCouponAPIView.as_view()),
Is there any good practice that I could apply in my situation?
What about trying something like this,
class CheckCouponAPIView(viewsets.ModelViewSet):
# other fields
lookup_field = 'slug'
From the official DRF Doc,
lookup_field - The model field that should be used to for performing
object lookup of individual model instances. Defaults to pk
Is it possible to use the library 'requests' (HTTP library for python) to post and update nested objects in django rest framework?
I made a new create method in serializers, but I can't post outside the shell, nor with the requests library or in the api webview.
My Serializers:
class QualityParameterSerializer(serializers.ModelSerializer):
class Meta:
model = QualityParameter
fields = ("id","name", "value")
class ProductQualityMonitorSerializer(serializers.ModelSerializer):
parameters = QualityParameterSerializer(many=True)
class Meta:
model = ProductQualityMonitor
fields = ("id","product_name", "area", "timeslot", "processing_line",
"updated_on",'parameters')
def create(self, validated_data):
params_data = validated_data.pop('parameters')
product = ProductQualityMonitor.objects.create(**validated_data)
for param_data in params_data:
QualityParameter.objects.create(product=product, **param_data)
return product
POST HTTP request
If I may suggest the following form for your serializer:
from django.db import transaction
class ProductQualityMonitorSerializer(serializers.ModelSerializer):
parameters = QualityParameterSerializer(many=True)
class Meta:
model = ProductQualityMonitor
fields = (
"id",
"updated_on",
"product_name",
"area",
"timeslot",
"processing_line",
"parameters",
)
def create(self, validated_data):
# we will use transactions, so that if one of the Paramater objects isn't valid
# that we will rollback even the parent ProductQualityMonitor object creation,
# leaving no dangling objects in the database
params_data = validated_data.pop('parameters')
with transaction.atomic():
product = ProductQualityMonitor.objects.create(**validated_data)
# you can create the objects in a batch, hitting the dB only once
params = [QualityParameter(product=product, **param) for param in params_data]
QualityParameter.objects.bulk_create(params)
return product
About using python requests library: you will have to pay attention to the following aspects when posting to a django back-end:
you must provide a valid CSRF token in your request; the way this is done is via csrf-token cookie;
you must provide the proper authentication headers / tokens / cookies; this is your choice, depends how you're implementing this on the DRF back-end
if this is a request from one domain to another domain, then you have to care for CORS setup.
More to the point: what have you tried already and didn't worked ?
I have a model like
class MyModel(models.Model):
uuid = models.CharField(max_length=40, unique=True)
and a serializer
class MyModelSerializer(serializers.ModelSerializer):
class Meta:
model = MyModel
fields = ('uuid')
And I want to receive JSON with MyModel object but it can be existing objects. So, when I use serializer.is_valid() with data about existing object it gives me an error:
for record in request['records']:
# request - body of JSON request,
# 'records' - array of records I want to add or update
serializer = MyModelSerializer(data=record)
if serializer.is_valid():
# Do stuff
serializer.save()
Error:
{"uuid":["This field must be unique."]}
Is there a way to separate behavior for new and existing objects? Particularly, I want to create new MyModel object if it's not it database yet and update existing MyModel object if it's present.
You are basically overloading a single entry point of your REST API by trying to both create new instances and update existing instances using a POST request. In addition, it seems you are trying to create and update multiple instances simultaneously within a single POST request.
Django REST Framework (DRF) expects a POST request to only create new instances. Therefore, sending an existing instance record triggers a unique constraint violation for the uuid field since DRF tries to create that record as a new instance, as the existing instance already has that uuid value.
A solution to make your REST API more "RESTful" would be to separate the creation and updating of records into POST and PUT requests respectively. It is unclear if you are using the generic API views provided by DRF, but you can use the CreateAPIView to POST new instances, then create a separate UpdateAPIView to PUT and/or PATCH existing instances. Even better you could allow retrieval via GET for both of these endpoints using the generic views ListCreateAPIView and RetrieveUpdateAPIView.
Finally, for handling bulk requests (i.e. multi-instances in a single request) you can either override the built-in view methods or use a 3rd-party package such as django-rest-framework-bulk.
I had a situation where I had a deep create method, with 2 levels of hierarchy above the end point, that it was important that all models were idempotent.
I override the validation in the serializer, and created it by hand.
It is important that you add the field to the class at the top (otherwise the validator won't be run)
class ParticipantSerializer(serializers.HyperlinkedModelSerializer):
device = DeviceSerializer(required=False)
uuid = serializers.CharField()
def validate_uuid(self, value):
if value is not None and isinstance(value, basestring) and len(value) < 256:
return value
else:
if value is not None:
raise serializers.ValidationError("UUID can't be none")
elif isinstance(value, basestring):
raise serializers.ValidationError("UUID must be a string")
elif len(value) < 256:
raise serializers.ValidationError("UUID must be below 256 characters")
else:
raise serializers.ValidationError("UUID has failed validation")
class Meta:
model = Participant
fields = ("uuid", "platform", "device")
I managed to get data from the tables MemberDeclareRecept and Member with the following config files. Here I am looking for the MemberDeclareRecept.pk. But how can I get all the data if I search the Member.CoId instead?
The MemberSearchByCode view gives all the members in the table but I can't get the specific member.
Here are my models
class Member(models.Model):
Name = models.CharField(max_length=40,null=True)
FirstName = models.CharField(max_length=40,null=True)
DateBirth = models.DateField(,null=True)
CoId = models.CharField(max_length=6,null=True)
class MemberDeclareRecept(models.Model):
SyMember=models.ForeignKey(Member,verbose_name='Name member ',null=True,related_name='Member')
DateDeclareRecept=models.DateField(('Date received',null=True)
And the serializers that are being used
class MemberDeclareSerializer(serializers.ModelSerializer):
member = serializers.StringRelatedField(read_only=True)
SyRecept=serializers.StringRelatedField(read_only=True)
class Meta:
model = MemberDeclareRecept
fields=('id','member','SyRecept')
And the views that I am currently using
class MemberDeclareDetail(generics.ListCreateAPIView):
queryset=MemberDeclareRecep.objects.all()
serializer_class =MemberDeclareSerializer
def get_object(self,pk):
try:
return self.queryset.get(pk=pk)
except MemberDeclareRecep.DoesNotExist:
raise Http404
def get(self, request, pk,format=None):
entries = self.get_object(pk)
serializer = MemberDeclareSerializer(entries)
return Response(serializer.data)
class MemberSearchByCode(generics.ListAPIView):
serializer_class =MemberSerializer
def get_queryset(self):
member=self.request.QUERY_PARAMS.get(Co_id',None)
if membre is not None:
queryset = queryset.filter(member__Name=member
return queryset
It appears as though you've found an answer, based on the comment, and it's included below.
class MemberSearch(generics.ListAPIView):
serializer_class=MemberDeclareSerializer
def get_queryset(self):
member = self.kwargs['Co_id']
return member_declare_recept.objects.filter(member__Co_id=member)
It is important to note that this is not filtering the queryset based on query parameters, this is filtering it based on parameters present in the url. If you were filtering it based on query parameters, which is useful if you will need to get a list of all objects at once, the url that you would be using would be like
/api/members/?company=[co_id]
Which would make the company id optional. In your case though, the id is being embedded within the url itself. This is typically referred to as hierarchal urls, and it's generally not recommended, but your urls end up like
/api/company/[co_id]/members
Which is preferable for some, and even required in certain cases.
Now, if you wanted to use the query parameter instead of the url parameter for filtering, only a slight change would be required in your code.
class MemberSearch(generics.ListAPIView):
serializer_class=MemberDeclareSerializer
def get_queryset(self):
company_id = self.request.query_parameters.get('company', None)
if not company_id:
return member_declare_recept.objects.all()
return member_declare_recept.objects.filter(member__Co_id=company_id)
This has the additional advantage of also being support directly through django-filter and the DjangoFilterBackend.