django receiver - DoesNotExist: WidgetList matching query does not exist - django

Question

I'm currently using #receiver to add a token to new users like so -
#receiver(post_save, sender=settings.AUTH_USER_MODEL)
def create_auth_token(sender, instance=None, created=False, **kwargs):
if created:
Token.objects.create(user=instance)
What I also want to be able to do is create a default WidgetList based on this model:
class WidgetList(MPTTModel):
name = models.CharField(max_length=100)
description = models.CharField(max_length=1024)
owner = models.ForeignKey('MyAppUser')
parent = TreeForeignKey('self', null=True, blank=True, related_name='children', db_index=True)
def __str__(self):
return self.name
class MPTTMEta:
order_insertion_by = ['name']
I tried making another reciever -
#receiver(post_save, sender=settings.AUTH_USER_MODEL)
def create_root_list(sender, instance=None, created=False, **kwargs):
if created:
WidgetList.objects.create(user=instance)
EDIT - on the initial python manage.py migrate I get the following traceback:
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/__init__.py", line 351, in execute_from_command_line
utility.execute()
File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/__init__.py", line 343, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/base.py", line 394, in run_from_argv
self.execute(*args, **cmd_options)
File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/base.py", line 445, in execute
output = self.handle(*args, **options)
File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/commands/migrate.py", line 226, in handle
emit_post_migrate_signal(created_models, self.verbosity, self.interactive, connection.alias)
File "/opt/myproject_app/lib/python2.7/site-packages/django/core/management/sql.py", line 280, in emit_post_migrate_signal
using=db)
File "/opt/myproject_app/lib/python2.7/site-packages/django/dispatch/dispatcher.py", line 201, in send
response = receiver(signal=self, sender=sender, **named)
File "/opt/myproject_app/lib/python2.7/site-packages/guardian/management/__init__.py", line 39, in create_anonymous_user
user.save()
File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/base.py", line 734, in save
force_update=force_update, update_fields=update_fields)
File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/base.py", line 771, in save_base
update_fields=update_fields, raw=raw, using=using)
File "/opt/myproject_app/lib/python2.7/site-packages/django/dispatch/dispatcher.py", line 201, in send
response = receiver(signal=self, sender=sender, **named)
File "/opt/myproject/core/models.py", line 18, in create_root_list
WidgetList.objects.create(user=instance)
File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/manager.py", line 127, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/query.py", line 346, in create
obj = self.model(**kwargs)
File "/opt/myproject_app/lib/python2.7/site-packages/mptt/models.py", line 393, in __init__
super(MPTTModel, self).__init__(*args, **kwargs)
File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/base.py", line 480, in __init__
raise TypeError("'%s' is an invalid keyword argument for this function" % list(kwargs)[0])
TypeError: 'user' is an invalid keyword argument for this function
this is the second traceback if I try to rerun migrate:
Traceback (most recent call last):
File "/opt/myproject_app/lib/python2.7/site-packages/django/core/handlers/base.py", line 132, in get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/opt/myproject_app/lib/python2.7/site-packages/django/views/decorators/csrf.py", line 58, in wrapped_view
return view_func(*args, **kwargs)
File "/opt/myproject_app/lib/python2.7/site-packages/rest_framework/viewsets.py", line 87, in view
return self.dispatch(request, *args, **kwargs)
File "/opt/myproject_app/lib/python2.7/site-packages/rest_framework_encrypted_lookup/views.py", line 41, in dispatch
return super(EncryptedLookupGenericViewSet, self).dispatch(request, *args, **kwargs)
File "/opt/myproject_app/lib/python2.7/site-packages/rest_framework/views.py", line 466, in dispatch
response = self.handle_exception(exc)
File "/opt/myproject_app/lib/python2.7/site-packages/rest_framework/views.py", line 463, in dispatch
response = handler(request, *args, **kwargs)
File "/opt/myproject_app/lib/python2.7/site-packages/rest_framework/mixins.py", line 21, in create
self.perform_create(serializer)
File "/opt/myproject_app/lib/python2.7/site-packages/rest_framework/mixins.py", line 26, in perform_create
serializer.save()
File "/opt/myproject_app/lib/python2.7/site-packages/rest_framework/serializers.py", line 191, in save
self.instance = self.create(validated_data)
File "/opt/myproject/api/serializers.py", line 106, in create
validated_data['parent'] = WidgetList.objects.get(pk=user_parent_list)
File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/manager.py", line 127, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "/opt/myproject_app/lib/python2.7/site-packages/django/db/models/query.py", line 334, in get
self.model._meta.object_name
DoesNotExist: WidgetList matching query does not exist.

Answer 1

Comparing your traceback and your code, you can find that error happens here:
WidgetList.objects.create(user=instance)
Your model WidgetList doesn't even have user field, so it's pretty obvious that you cannot do that. Maybe you were copying & paste the code that caused an error.

Answer 2

There is no user in your model. Which I see you mean owner.
You will get foreign key ref errors as there is not data. Load some parent data using fixture. That would solve this issue.