How to allow null or empty params for UUID filters?

[mhamid3d]

I have a situation where I want to fetch all products based on the currently selected category. However, if there is no category selected, the query will look something like:

localhost:8000/products?category_id=

This is my product filter:

class ProductFilter(Filter): category_id: Optional[uuid.UUID] = None

The problem is, this will throw a validation error because the type given is not a uuid but rather an empty string. If I try to change the type to string, it will later error on the SQL side. The behavior I'm expecting is for all products to be filtered resulting in an empty response.

In SQL it is possible to do something like IS NULL but I don't see a way of doing this with fastapi-filter.

Anyone have any ideas how to tackle this?