[SOLVED] How to add custom filter to Active Admin?

How to add custom filter to Active Admin?

Active Admin allows me to define filters that are displayed on the index page like so:

ActiveAdmin.register Promo do

  filter :name
  filter :address
  filter :city
  filter :state
  filter :zip

end

I would like to combine all the fields above into one, so that I can search for Promos that contain the search string in name or full address. My model already has a named scope that I can use:

class Promo < ActiveRecord::Base
  scope :by_name_or_full_address, lambda { |q| where('name LIKE :q OR address LIKE :q OR city LIKE :q OR state LIKE :q OR zip LIKE :q', :q => "%#{q}%") }
end

Solution

Active Admin uses the meta_search gem for its filters. ORed conditions syntax allows to combine several fields in one query, for example

Promo.metasearch(:name_or_address_contains => 'brooklyn')

In Active Admin DSL this translates to

ActiveAdmin.register Promo do

  filter :name_or_address, :as => :string

end