I am using Django rest framework 2.3
I have a class like this
class Quiz():
fields..
# A custom manager for result objects
class SavedOnceManager(models.Manager):
def filter(self, *args, **kwargs):
if not 'saved_once' in kwargs:
kwargs['saved_once'] = True
return super(SavedOnceManager, self).filter(*args, **kwargs)
class Result():
saved_once = models.NullBooleanField(default=False, db_index=True,
null=True)
quiz = models.ForeignKey(Quiz, related_name='result_set')
objects = SavedOnceManager()
As you see I have a custom manager on results so Result.objects.filter()
will only return results that have save_once set to True
Now my Serializers look like this:
class ResultSerializer(serializers.ModelSerializer):
fields...
class QuizSerializer(serializers.ModelSerializer):
results = ResultSerializer(many=True, required=False, source='result_set')
Now if I serializer my quiz it would return only results that have saved_once
set to True
. But for a particular use case I want the serializer to return all objects. I have read that I can do that by passing a queryset
parameter http://www.django-rest-framework.org/api-guide/relations/ in (further notes section). However when I try this
results = ResultSerializer(many=True, required=False, source='result_set',
queryset=
Result.objects.filter(
saved_once__in=[True, False]))
I get TypeError: __init__() got an unexpected keyword argument 'queryset'
And looking at the source code of DRF(in my version atleast) it does not accept a queryset argument.
Looking for some guidance on this to see if this is possible… thanks!
Best Answer
In my opinion, modifying filter like this is not a very good practice. It is very difficult to write a solution for you when I cannot use filter on the Result model without this extra filtering happening. I would suggest not modifying filter in this manner and instead creating a custom manager method which allows you to apply your filter in an obvious way where it is needed, eg/
Therefore, you can query either the saved_once rows or the unfiltered rows as you would expect:
Here is one way which you can use an additional queryset inside a serializer. However, it looks to me that this most likely will not work for you if the default manager is somehow filtering out the saved_once objects. Hence, your problem lies elsewhere.