I have Foo objects that are "owned" by an Organization. I get the current Organization from the logged-in User in my request handler:
models.py:
class Organization(models.Model):
name = models.CharField(max_length=255)
class Foo(models.Model):
... some other fields ...
organization = models.ForeignKey(Organization, on_delete=models.CASCADE)
serializers.py:
class FooSerializer(serializers.Serializer):
id = serializers.IntegerField(read_only=True)
organization = OrganizationSerializer(read_only=True)
""" Create and return a new instance, given the validated data """
def create(self, validatedData):
return OverlayDesign.objects.create(**validatedData)
""" Update and return an existing instance, given the validated_data """
def update(self, instance, validatedData):
instance.organization = validatedData.get('organization', instance.organization)
instance.save()
return instance
views.py:
def createFoo(request):
data = JSONParser().parse(request)
# Get the organization of the logged-in user
data["organization"] = OrganizationSerializer(request.user.account.organization).data
serializer = FooSerializer(data=data)
if serializer.is_valid():
serializer.save()
return JSONResponse(serializer.data, status=201)
return JSONErrorResponse(serializer.errors, status=400)
When I create a new Foo, I want it to be owned by the current Organization. The problem is that I don't understand why the Organization is not deserialized? No matter what I do I just get:
django.db.utils.IntegrityError: null value in column "organization_id" violates not-null constraint
How should I deliver the current Organization to the FooSerializer ?
OrganizationSerializer is set with the readonly option => you won't get anything to match the current organization.
You should take a look at : http://www.django-rest-framework.org/api-guide/relations/#primarykeyrelatedfield
Related
Context
For a specific use case I need to be able to update a single field of my Visitor model using a GET request instead of a PATCH request.
My relevant Visitor model looks like this:
# models.py
class Visitor(models.Model):
visitor_uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False, db_index=True)
customers = models.ForeignKey(Customer, on_delete=models.CASCADE, related_name='customer_visitors')
audiences = models.ManyToManyField(Audience, related_name='audience_visitors')
cid = models.CharField(max_length=255, unique=True)
uid = models.CharField(max_length=255)
cup = JSONField(null=True)
def __str__(self):
return self.cid
class Meta:
db_table = 'visitor'
I am using a straightforward serializer like this:
# serializers.py
class VisitorSerializer(serializers.ModelSerializer):
class Meta:
model = Visitor
fields = ('customers', 'cid', 'uid', 'cup')
I am able to update just the cup field for a specific Visitor which is looked up using the unique cid field with a PATCH like this:
# views.py
class VisitorViewSet(viewsets.ModelViewSet):
serializer_class = VisitorSerializer
queryset = Visitor.objects.all()
lookup_field = 'cid'
def list(self, request, *args, **kwargs):
instance = self.get_object()
serializer = self.serializer_class(instance, data=request.data, partial=True)
serializer.is_valid(raise_exception=True)
serializer.save()
return Response(serializer.data)
Problem
The problem is that I am unable to update the cup field of a Visitor based on a given unique cid field using a GET request.
What I tried
As this answer by Uri Shalit suggested, I tried to override get_serializer() inside my VisitorViewSet and tried to use it in list() like this:
# views.py
class VisitorViewSet(viewsets.ModelViewSet):
serializer_class = VisitorSerializer
queryset = Visitor.objects.all()
lookup_field = 'cid'
def get_serializer(self, *args, **kwargs):
kwargs['partial'] = True
return super(VisitorViewSet, self).get_serializer(*args, **kwargs)
def list(self, request, *args, **kwargs):
instance = self.get_object()
serializer = self.get_serializer(instance, data=request.data, partial=True)
serializer.is_valid(raise_exception=True)
serializer.save()
return Response(serializer.data)
However, updating just the cup field of a specific Visitor based on the cid field works with a PATCH request but does not update said field with a GET request. There is no error either.
Expected behaviour
Making a GET request which contains cid to identify a Visitor and cup with data that needs to be updated for the given Visitor. I know it breaks REST principles but for this use case I need to do this partial update using a GET request instead of a PATCH request.
Any help or pointers in the right direction would be much appreciated!
Add a classmethod in your model.
class Visitor(models.Model):
visitor_uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False, db_index=True)
customers = models.ForeignKey(Customer, on_delete=models.CASCADE, related_name='customer_visitors')
audiences = models.ManyToManyField(Audience, related_name='audience_visitors')
cid = models.CharField(max_length=255, unique=True)
uid = models.CharField(max_length=255)
cup = JSONField(null=True)
def __str__(self):
return self.cid
class Meta:
db_table = 'visitor'
#classmethod
def update_cup(cls, cid, cup_new):
instance = cls.objects.get(cid=cid)
instance.cup = new_cup
instance.save()
In ModelViewSet override the get_queryset method, see below:
IDK how u calc new_cup I guess u get it as a queryparam
def get_queryset(self):
queryset = Visitor.objects.all()
cup_new = self.request.query_params.get('cup_new', None)
cid = self.request.query_params.get('cid', None)
[obj.update_cup(obj.cid, cup_new) for obj in queryset if obj.cid == cid]
return queryset
I recommend using an api_view to accomplish what you want. api_view is an annotation provided by the rest framework so it should be available already in your case.
#api_view(["GET"])
def update_function(request):
query_params = request.GET # Getting the parameters from request
cid = query_params["cid"]
cup = query_params["cup"]
visitor = Visitor.objects.get(cid = cid)
visitor["cup"] = cup
serializer = VisitorSerializer(data = visitor, partial=True)
if serializer.is_valid():
serializer.save()
else:
print(serializer.errors)
However I am not sure about the syntax but the approch is sufficient for your problem.
Make sure to add the function to urls.py and have a look to the documentation to get better information than mine Api Views. But dont expect it to have information about you specific problem. In your case you have to understand the api_view concept and adapt it for your needs.
I think I don't understand the problem fully. Why can't you simply override the method get_object() in your view and do custom logic in it to update the object?
def get_object(self):
obj = super().get_object()
serializer = self.get_serializer(obj, data=self.request.data)
serializer.is_valid(raise_exception=True)
serializer.save()
return obj
I'm writing a serializer to provide multiple partial updates to a django model. I'm following the example implementation that appears in the DRF api guide, reproduced below and linked here: https://www.django-rest-framework.org/api-guide/serializers/#customizing-multiple-update.
The following was retrieved from django-rest-framework documentation:
serializer.py
class BookListSerializer(serializers.ListSerializer):
def update(self, instance, validated_data):
# Maps for id->instance and id->data item.
book_mapping = {book.id: book for book in instance}
data_mapping = {item['id']: item for item in validated_data}
# Perform creations and updates.
ret = []
for book_id, data in data_mapping.items():
book = book_mapping.get(book_id, None)
if book is None:
ret.append(self.child.create(data))
else:
ret.append(self.child.update(book, data))
# Perform deletions.
for book_id, book in book_mapping.items():
if book_id not in data_mapping:
book.delete()
return ret
class BookSerializer(serializers.Serializer):
# We need to identify elements in the list using their primary key,
# so use a writable field here, rather than the default which would be read-only.
id = serializers.IntegerField()
...
class Meta:
list_serializer_class = BookListSerializer
In my code I'm getting a NotImplementedError('update() must be implemented.') in my views.py when .save() is called on the serializer that is returned.
My understanding is that the ListsSerializer overrides the .update(), so could anyone help explain why I'm getting the NotImpletmentedError?
views.py
elif request.method == 'PATCH':
data = JSONParser().parse(request)
books = Book.objects.all()
# both partial and many set to True
serializer = BookSerializer(books, data=data, partial=True, many=True)
if serializer.is_valid():
serializer.save()
return JsonResponse(serializer.data)
return JsonResponse(serializer.errors, status=400)
With the help of #luistm, I managed to solve this. Continuing with the DRF example above my implementation of the update() override in the bookSerializer class was as below.
serializer.py
class BookSerializer(serializers.Serializer):
# We need to identify elements in the list using their primary key,
# so use a writable field here, rather than the default which would be read-only.
id = serializers.IntegerField()
...
class Meta:
list_serializer_class = BookListSerializer
def update(self, instance, validated_data):
"""update the page number of the book and save"""
instance.page = validated_data.get('page', instance.page)
instance.save()
return instance
I am passing an (is_followed) parameter from one class based view FollowToggleAPIView to another UserDetailAPIVIew. I do this using Django session (from reading other thread on this platform) in the hope of displaying the follow-status (True or False) of the user_to_toggle variable on the UserSingleProfileSerializer.
Here are my views:
class UserDetailAPIVIew(generics.RetrieveAPIView):
'''
Displays a list of a user's posts
'''
serializer_class = UserSingleProfileSerializer
queryset = User.objects.all()
def get_object(self):
self.object = get_object_or_404(User,
username__iexact=self.kwargs.get('username')
)
return self.object
def get_serializer_context(self):
'''
passing the extra is_following argument to the UserDetailAPIVIew
'''
context = super(UserDetailAPIVIew, self).get_serializer_context()
is_followed = self.request.session.get('followed')
context.update({'followed': is_followed})
return context
class FollowToggleAPIView(APIView):
'''
Uses the custom model manager for user toggle follow
'''
def get(self, request, username, format=None):
user_to_toggle = get_object_or_404(User, username__iexact=username)
me = request.user
message = 'Not allowed'
if request.user.is_authenticated():
is_followed = UserProfile.objects.toggle_follow(me, user_to_toggle)
request.session['followed'] = is_followed
return Response({'followed': is_followed})
return Response({'message': message}, status=400)
The toggle_follow method is defined in the custom model manager as follows:
class UserProfileManager(models.Manager):
def toggle_follow(self, user, to_toggle_user):
''' follow unfollow users '''
user_profile, created = UserProfile.objects.get_or_create(user=user)
if to_toggle_user in user_profile.following.all():
user_profile.following.remove(to_toggle_user)
added = False
else:
user_profile.following.add(to_toggle_user)
added = True
return added
class UserProfile(models.Model):
'''
Extends the Django User model
'''
user = models.OneToOneField(settings.AUTH_USER_MODEL,
related_name='profile')
following = models.ManyToManyField(settings.AUTH_USER_MODEL,
blank=True,
related_name='followed_by')
objects = UserProfileManager()
def get_absolute_url(self):
return reverse_lazy('profiles:detail',
kwargs={'username':self.user.username})
def __str__(self):
return 'Username: {} [ Followers ({});
Following({})]'.format(self.user.username,
self.user.followed_by.all().count(),
self.following.all().count())
The urls.py:
urlpatterns = [
url(r'^(?P<username>[\w.#+-]+)/$', UserDetailAPIVIew.as_view(),
name='user-posts-api'),
url(r'^(?P<username>[\w.#+-]+)/follow/$',
FollowToggleAPIView.as_view(), name='follow-api'),
]
The only problem is that the value of (is_followed) displayed in UserSingleProfileSerializer is set for all user instances at once (not for the specific user we want to follow).
I am certainly not following/unfollowing all users at the same time (since the FollowToggleAPIView targets a specific user by his username).
I want to know how can I transfer the value of (is_followed) only to the specific user (user_to_toggle) in the UserDetailAPIVIew. Thank you in advance.
The session is completely the wrong thing to use here. You're storing a single "followed" value which only records the last user they toggled and has no relation to the profile they're actually viewing.
Instead of doing this, you should simply query in the UserDetailAPIVIew the followed status of the specific user.
def get_serializer_context(self):
context = super(UserDetailAPIVIew, self).get_serializer_context()
is_followed = self.request.user.profile.following.filter(username=self.object).exists()
context.update({'followed': is_followed})
return context
Note also, your toggle method is itself very inefficient - there's no need to retrieve every follow from the database just to check whether the current user is among them. Use exists again:
user_profile, created = UserProfile.objects.get_or_create(user=user)
if user_profile.following.filter(username=to_toggle_user).exists():
I have a custom serializer like this--
class customSerializers(serializers.Serializer):
token = serializers.CharField(max_length=12)
And I have a model like this
class UserToken(models.Model):
user = models.ForeignKey(User)
token = models.CharField(max_length=12)
Now I want to validate my customSerializers token field. The token value has to exists in the UserToken model and belongs to the current user.
** I Don't want to use model serializer.
You should pass user to serializer, then implement validation on the field:
class CustomSerializer(serializers.Serializer):
token = serializers.CharField(max_length=12)
def validate_token(self, value):
user_id = self.context.get('user_id')
return UserToken.objects.filter(user__id=user_id, token=value).exists()
in your view:
serializer = CustomSerializer(... , context={'user_id': request.user.id})
if serializer.is_valid():
...
I am currently working on our user profile. A user can add multiple E-Mail addresses to his/her account.
views.py
#login_required(login_url='/login')
def profile_update_emails(request):
context = {}
...
try:
email = CustomerEmails.objects.get(customer=request.user)
update_emails_form = UpdateEmailsForm(request.POST or None, instance=email)
except CustomerEmails.DoesNotExist:
update_emails_form = UpdateEmailsForm(request.POST or None)
context.update({'update_emails_form': update_emails_form})
if request.POST:
if update_emails_form.is_valid():
update_emails_form.save(commit=False)
update_emails_form.customer = request.user
update_emails_form.save()
messages.success(request, "All good")
return render(request, 'usercp/profile.html', context)
forms.py
class UpdateEmailsForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
super(forms.ModelForm, self).__init__(*args, **kwargs)
for f in self.fields:
self.fields[f].widget.attrs['class'] = 'form-control'
class Meta:
model = CustomerEmails
fields = ('email',)
models.py
class CustomerEmails(models.Model):
customer = models.ForeignKey(Customer)
email = models.CharField(max_length=255, unique=True)
error/trace:
IntegrityError at /usercp/profile/profile_update_emails
(1048, "Column 'customer_id' cannot be null")
Please note I have a custom user model. Which is not the problem here.
I am not quite sure, why the customer field is not getting populated before the second save() though. There are currently no rows in that table for the CustomerEmails model. (I know that this will clash with the .get() in the future, since a user can have multiple e-mails, but first things first)
You need to set the relationship on the model instance, which is returned from the form save, not on the form itself.
obj = update_emails_form.save(commit=False)
obj.customer = request.user
obj.save()