I want to pass some arguments to DRF Serializer class from Viewset, so for I have tried this:
class OneZeroSerializer(rest_serializer.ModelSerializer):
def __init__(self, *args, **kwargs):
print args # show values that passed
location = rest_serializer.SerializerMethodField('get_alternate_name')
def get_alternate_name(self, obj):
return ''
class Meta:
model = OneZero
fields = ('id', 'location')
Views
class OneZeroViewSet(viewsets.ModelViewSet):
serializer_class = OneZeroSerializer(realpart=1)
#serializer_class = OneZeroSerializer
queryset = OneZero.objects.all()
Basically I want to pass some value based on querystring from views to Serializer class and then these will be allocate to fields.
These fields are not include in Model in fact dynamically created fields.
Same case in this question stackoverflow, but I cannot understand the answer.
Can anyone help me in this case or suggest me better options.
It's very easy with "context" arg for "ModelSerializer" constructor.
For example:
in view:
my_objects = MyModelSerializer(
input_collection,
many=True,
context={'user_id': request.user.id}
).data
in serializers:
class MyModelSerializer(serializers.ModelSerializer):
...
is_my_object = serializers.SerializerMethodField('_is_my_find')
...
def _is_my_find(self, obj):
user_id = self.context.get("user_id")
if user_id:
return user_id in obj.my_objects.values_list("user_id", flat=True)
return False
...
so you can use "self.context" for getting extra params.
Reference
You could in the YourView override get_serializer_context method like that:
class YourView(GenericAPIView):
def get_serializer_context(self):
context = super().get_serializer_context()
context["customer_id"] = self.kwargs['customer_id']
context["query_params"] = self.request.query_params
return context
or like that:
class YourView(GenericAPIView):
def post(self, request, *args, **kwargs):
serializer = self.get_serializer(data=request.data)
serializer.context["customer_id"] = request.user.id
serializer.context["query_params"] = request.query_params
serializer.is_valid(raise_exception=True)
...
and anywhere in your serializer you can get it. For example in a custom method:
class YourSerializer(ModelSerializer):
def get_alternate_name(self, obj):
customer_id = self.context["customer_id"]
query_params = self.context["query_params"]
...
To fulfill the answer of redcyb - consider using in your view the get_serializer_context method from GenericAPIView, like this:
def get_serializer_context(self):
return {'user': self.request.user.email}
A old code I wrote, that might be helpful- done to filter nested serializer:
class MySerializer(serializers.ModelSerializer):
field3 = serializers.SerializerMethodField('get_filtered_data')
def get_filtered_data(self, obj):
param_value = self.context['request'].QUERY_PARAMS.get('Param_name', None)
if param_value is not None:
try:
data = Other_model.objects.get(pk_field=obj, filter_field=param_value)
except:
return None
serializer = OtherSerializer(data)
return serializer.data
else:
print "Error stuff"
class Meta:
model = Model_name
fields = ('filed1', 'field2', 'field3')
How to override get_serializer_class:
class ViewName(generics.ListAPIView):
def get_serializer_class(self):
param_value = self.context['request'].QUERY_PARAMS.get('Param_name', None)
if param_value is not None:
return Serializer1
else:
return Serializer2
def get_queryset(self):
.....
Hope this helps people looking for this.
List of element if your query is a list of elements:
my_data = DataSerializers(queryset_to_investigate,
many=True, context={'value_to_pass': value_passed}
in case off single data query:
my_data = DataSerializers(queryset_to_investigate,
context={'value_to_pass': value_passed}
Then in the serializers:
class MySerializer(serializers.ModelSerializer):
class Meta:
fields = '__all__'
model = 'Name_of_your_model'
def on_representation(self, value):
serialized_data = super(MySerializer, self).to_representation(value)
value_as_passed = self.context['value_to_pass']
# ..... do all you need ......
return serialized_data
As you can see printing the self inside on_representation you can see: query_set: <object (x)>, context={'value_to_pass': value_passed}
This is a simpler way, and you can do this in any function of serializers having self in the parameter list.
These answers are far to complicated; If you have any sort of authentication then add this property to your serializer and call it to access the user sending the request.
class BaseSerializer(serializers.ModelSerializer):
#property
def sent_from_user(self):
return self.context['request'].user
Getting the context kwargs passed to a serializer like;
...
self.fields['category'] = HouseCategorySerializer(read_only=True, context={"all_fields": False})
...
In your serializer, that is HouseCategorySerializer do this in one of your functions
def get_houses(self, instance):
print(self._context.get('all_fields'))
Using self._context.get('keyword') solved my mess quickly, instead of using self.get_extra_context()
Related
This is my code.
class MyViewSet(ModelViewSet):
serializer_class = MySerializer
queryset = MyClass.objects.all()
def get_serializer_class(self):
if request.user.is_superuser:
return self.serializer_class
else:
return OtherSerializer
def perform_create(self, serializer):
if request.user.is_superuser:
if serializer.is_valid():
serializer.save(organization=self.request.user.organization)
else:
employee = Employee.objects.get(user=self.request.user)
serializer.save(employee=employee, organization=self.request.user.organization)
This is my Serializer:
class MySerializer(serializers.ModelSerializer):
class Meta:
model = models.MyClass
def validate(self, data):
employee = data.get('employee')
members = Team.objects.get(id=team.id.members.all())
if employee not in members:
raise serializers.ValidationError('Invalid')
return data
The issue is, My custom validate function is not being called when I call it inside perform_create() in my ViewSet.
What might be the issue?
validate member function should be defined in the scope of the serializer class not inside class Meta. So you need to left-indent the function validate:
class MySerializer(serializers.ModelSerializer):
class Meta:
model = models.MyClass
def validate(self, data):
employee = data.get('employee')
members = Team.objects.get(id=team.id.members.all())
if employee not in members:
raise serializers.ValidationError('Invalid')
return data
I'm working on a small project Django Rest Framework, I already create add contact function as you can see in my create function. now I'm working on bulk import, but when I submit my data as a list not as a dict I get an error message :
{"non_field_errors":["Invalid data. Expected a dictionary, but got list."]}
this is my code to add a contact,
class ContactView(ListModelMixin, viewsets.GenericViewSet):
queryset = Contact.objects.all()
serializer_class = ContactSerializer
def create(self, request):
serializeObject = ContactSerializer(data = request.data)
if serializeObject.is_valid():
serializeObject.save()
contactObject = Contact.objects.all()
contactSerializer = ContactSerializer(contactObject, many=True)
return Response(contactSerializer.data, status = status.HTTP_201_CREATED)
return Response(serializeObject.errors, status.HTTP_400_BAD_REQUEST)
Now i would like to create another function, for bulk create, since i have a list
This is my header data structure :
[{"Greeting":"amine","first_name":"alain","last_name":"amine","title":"ricardo","language":"ab#xyz.com","email":43822510594,"phone_1":43822510594,"phone_2":"not yet","mobile":43822510594,"fax":"not yet","internal_id":"xname"},{"Greeting":"bill","first_name":"microsoft","last_name":"bill","title":"microsoft","language":"bill#microsoft.com","email":652565455,"phone_1":652565455,"phone_2":"new york","mobile":652565455,"fax":"new york","internal_id":"microsoft"},{"Greeting":"john","first_name":"Yoyo","last_name":"Ruth","title":"xnameagain","language":"rh#xyz.com","email":5465559852,"phone_1":5465559852,"phone_2":"Vancouver","mobile":5465559852,"fax":"Vancouver","internal_id":"yname"}]
This is my serializer:
class ContactSerializer(serializers.ModelSerializer):
class Meta:
model = Contact
fields = "__all__"
I found the Solution on https://www.django-rest-framework.org/api-guide/serializers/#dealing-with-multiple-objects
all what i have to do is to add many=True to create multiple object
serializeObject = ContactSerializer(data = request.data, many=True)
Create method should look like this:
class ContactView(ListModelMixin, viewsets.GenericViewSet):
queryset = Contact.objects.all()
serializer_class = ContactSerializer
def create(self, request):
valid_objects = []
for data in request.data:
serializeObject = ContactSerializer(data=data)
if serializeObject.is_valid():
valid_objects.append(serializeObject)
else:
return Response(serializeObject.errors, status.HTTP_400_BAD_REQUEST)
for obj in valid_objects:
obj.save()
contactObject = Contact.objects.all()
contactSerializer = ContactSerializer(contactObject, many=True)
return Response(contactSerializer.data, status = status.HTTP_201_CREATED)
Advise
They may not be the best practices but it works.
I have two APIView classes and one ModelSerializer class. The APIView classes are using the serializer class. Is there any way to know which APIView class is calling the serializer class?
I need seperate representation_view for these 2 APIView.
APIView Classes
class OwnerAllListAPIView(APIView):
def get(self, request, *args, **kwargs):
user = self.request.user
all_list = ListName.objects.filter(owner=user).all()
list_serializer = core_slr.ListNameSerializer(all_list, many=True)
return response('Owner list', list_serializer.data, status.HTTP_200_OK)
class ListNameDetailAPIView(APIView):
def get(self, request, *args, **kwargs):
list_name = ListName.objects.filter(id=self.kwargs.get('list_name_id')).first()
list_serializer = core_slr.ListNameSerializer(list_name)
return response('list name detail view', list_serializer.data, status.HTTP_200_OK)
Serializer Class
class ListNameSerializer(serializers.ModelSerializer):
class Meta:
model = ListName
fields = [
'id', 'owner', 'name'
]
def to_representation(self, instance):
ret = super(ListNameSerializer, self).to_representation(instance)
ret['owner'] = f"{instance.owner.first_name} {instance.owner.last_name}"
ret['total_question'] = QuestionBank.objects.filter(list_name=instance).count()
return ret
In the to_representation View, I just wanna to know which API is currently calling the serializer.
You can easily do that by accessing the context of the Serializer, like the following:
...
def to_representation(self, instance):
ret = super(ListNameSerializer, self).to_representation(instance)
ret['owner'] = f"{instance.owner.first_name} {instance.owner.last_name}"
ret['total_question'] = QuestionBank.objects.filter(list_name=instance).count()
if self.context['view'].action == 'retrieve':
pass # Do something
elif self.context['view'].action == 'list':
pass # Do the Other Thing
return ret
I have serialised one of my models that has a foreign key in. I get 'Parent' object is not iterable
models.py
class Parent(models.Model):
# Parent data
class Child(models.Model):
parent = ForeignKey(Parent)
serializer.py
class ChildSerializers(serializers.ModelSerializer):
parent = serializers.RelatedField(many=True)
class Meta:
model = ReportField
fields = (
'id',
'parent'
)
api.py
class ChildList(APIView):
def get(self, request, format=None):
child = Child.objects.all()
serialized_child = ChildSerializers(child, many=True)
return Response(serialized_child.data)
Im guessing i have to pass the parent list to the child list but not sure of the best way to do it
attempt api.py
class ChildList(APIView):
def get(self, request, format=None):
child = Child.objects.all()
parent = Parent.objects.all()
serialized_child = ChildSerializers(child, many=True)
serialized_parent = ChildSerializers(parent, many=True)
return Response(serialized_child.data, serialized_parent.data)
Why using many=True. Parent is just a single field, no need to use explicit serializer field. Just get rid of these many=True
-answered by mariodev in comment.
You can do something like this using python collections as an intermediate
#serializers.py
class TimelineSerializer(serializers.Serializer):
childs= childSerializer(many=True)
parents = parentSerializer(many=True)
#apiviews.py
from collections import namedtuple
Timeline = namedtuple('Timeline', ('childs', 'parents'))
def list(self, request):
timeline = Timeline(
childs=Child.objects.all(),
parents=Parent.objects.all(),
)
serializer = TimelineSerializer(timeline)
return Response(serializer.data)
If your using a ModalSerializer then you have two foreign keys in a modal, then use "to_representation" function like this
def to_representation(self, instance):
rep = super().to_representation(instance)
rep['pcatalog_name'] = CatalogSerializer(instance.pcatalog_name).data
rep['pcategory_name'] = CategorySerializer(instance.pcategory_name).data
return rep
Replace ForeignKey by ManyToManyField to clarify the serializer field with many = True
I want to add a field to a serializer that contains information specific to the user making the current request (I don't want to create a separate endpoint for this). Here is the way I did it:
The viewset:
class ArticleViewSet(viewsets.ModelViewSet):
queryset = Article.objects.all()
serializer_class = ArticleSerializer
filter_class = ArticleFilterSet
def prefetch_likes(self, ids):
self.current_user_likes = dict([(like.article_id, like.pk) for like in Like.objects.filter(user=self.request.user, article_id__in=ids)])
def get_object(self, queryset=None):
article = super(ArticleViewSet, self).get_object(queryset)
self.prefetch_likes([article.pk])
return article
def paginate_queryset(self, queryset, page_size=None):
page = super(ArticleViewSet, self).paginate_queryset(queryset, page_size)
if page is None:
return None
ids = [article.pk for article in page.object_list]
self.prefetch_likes(ids)
return page
The serializer:
class ArticleSerializer(serializers.ModelSerializer):
class Meta:
model = Article
def to_native(self, obj):
ret = super(ArticleSerializer, self).to_native(obj)
if obj:
view = self.context['view']
ret['has_liked'] = False
if hasattr(view, 'current_user_liked'):
ret['has_liked'] = obj.pk in view.current_user_liked
return ret
Is there a better place to inject the prefetching of liked articles, or a nicer way to do this in general?
you can do it with SerializerMethodField
Example :
class PostSerializer(serializers.ModelSerializer):
fav = serializers.SerializerMethodField('likedByUser')
def likedByUser(self, obj):
request = self.context.get('request', None)
if request is not None:
try:
liked=Favorite.objects.filter(user=request.user, post=obj.id).count()
return liked == 1
except Favorite.DoesNotExist:
return False
return "error"
class Meta:
model = Post
then you should call serializer from view like this:
class PostView(APIVIEW):
def get(self,request):
serializers = PostSerializer(PostObjects,context={'request':request})
I'd be inclined to try and put as much of this as possible on the Like model object and then bung the rest in a custom serializer field.
In serializer fields you can access the request via the context parameter that they inherit from their parent serializer.
So you might do something like this:
class LikedByUserField(Field):
def to_native(self, article):
request = self.context.get('request', None)
return Like.user_likes_article(request.user, article)
The user_likes_article class method could then encapsulate your prefetching (and caching) logic.
I hope that helps.
According to the Django Documentation - SerializerMethodField, I had to change the code of rapid2share slightly.
class ResourceSerializer(serializers.ModelSerializer):
liked_by_user = serializers.SerializerMethodField()
def get_liked_by_user(self, obj : Resource):
request = self.context.get('request')
return request is not None and obj.likes.filter(user=request.user).exists()