Ransack: finding record without a :has_one assoc

Question

Given a ModelA which has_one ModelB.

What should I write if I want to add a checkbox in the ModelA form to filter the results to only show ModelsA who are NOT associated with ModelB.

I tried:

f.check_box :modelb_null, {}, true, nil

and

f.check_box :modelb_id_null, {}, true, nil

without success.

Answer 1

You do need to call a specific field on the association, not just the model name, and ID makes the most sense as per your second attempt.

I got this working using the blank predicate:

f.check_box :modelb_id_blank, {}, true, nil