How to Customize the Filter in activeadmin

Question

I want to customize my filter in activeadmin panel for applications panel. currently i have a filter like this.

and want the filter like this

i do the code for this as follow

For add category element in filter i do as follow code.

There is 3 tables called

1. applications
2. categories
3. application_categories

and i want the filter data from application_categories as per selection on category from filter.

Structure of tables as follow.

1. applications table :

   1. id
   2. name
   3. status
   4. developer_id
   5. version
   6. language_id ,etc...

2. categories table

   1. id
   2. name
   3. parent_id

3. application_categories table

   1. id
   2. application_id
   3. category_id

In activeadmin resource file
app/admin/applications.rb file code

filter :status, :as => :select, :collection => ["pending", "approved", "declined"]
filter :featured, :as => :select
filter :developer, :collection => proc {(Developer.all).map{|d| [d.company_name, d.id]}}
filter :category , :collection => proc {(Category.all).map{|c| [c.name,c.id]}}
filter :name
filter :version
filter :tags

In application model file
in model app/models/application.rb

belongs_to :developer
belongs_to :bundle
belongs_to :license
belongs_to :language
belongs_to :category

has_many :application_categories, :dependent => :destroy
has_many :categories, :through => :application_categories

It's display category element in filter panel, but when we select any category and click on filter it's generate an error as shown below :

Mysql2::Error: Unknown column 'applications.category_id' in 'on clause': SELECT COUNT(DISTINCT count_column) FROM (SELECT applications . id AS count_column FROM applications LEFT OUTER JOIN categories ON categories . id = applications . category_id WHERE categories . id = 32 LIMIT 30 OFFSET 0) subquery_for_count

Answer 1

In app/admin/applications.rb :

filter :categories

In app/models/application.rb : delete belongs_to :category

If it doesn't work, you have to update your ActiveAdmin gem: bundle update