How to filter IS NULL in ActiveAdmin?

Question

I\'ve a table with an integer column called \"map_id\", I want to add an activeadmin filter to filter if this column IS NULL or IS NOT NULL.

How could this be implem

Answer 1

If anyone is happening on this thread belatedly, there is now an easy way to filter for null or non null in active admin :

filter :attribute_present, :as => :boolean 
filter :attribute_blank,   :as => :boolean  

It is no longer necessary to add a custom method to the scope to accomplish this.