Creating a function-based filter with DjangoFilterBackend in DRF?

[Lucas Bracher]

TL;DR:

  - filter boolean field is_trashed from a model, using the input variable x

    - when x is False, return only records where is_trashed is False

    - when x is True, return all records

Hi there! :)

I have the following problem: I have a model called Products:

class Product(models.Model):
    label = models.CharField(max_length=255)
    description = models.TextField(blank=True)
    type = models.CharField(
        max_length=50, choices=ProductType.choices())
    is_trashed = models.BooleanField(default=False)

And the viewset ProductViewSet:

class ProductViewSet(GenericViewSet):
    serializer_class = ProductSerializer
    filter_backends = [DjangoFilterBackend]
    filterset_fields = {"type": ("contains", "exact", "in"), "is_trashed": ("exact",)}
    search_fields = ["label"]

The problem is I would like to have a filter with a different behavior. When I pass false on is_trashed I only would like to retrieve those records which indeed is_trashed==False, but when I pass true, I would like to retrieve all records. The only way I can imagine doing that is using a function, but I'm clueless. How can I do that exactly?

Thanks in advance!

Lucas Bracher