STI model activeadmin controller shows instances of all subclasses

Question

I'm using activeadmin to manage the models of my rails app. I have a User model that uses the can can separate role model and those roles are modelled with inheritance and use STI on ActiveRecord.

The problem is that no matter on which of the roles' activeadmin controller page I'm, the index populated shows all the instances of Role the subclasses

Example:

I create RoleA and RoleB instances. Then I go to the RoleA index page and RoleB is shown in the list. The opposite happens as well.

The Details

I have several different roles which follow the role-object pattern where I have an abstract role and it's subclasses. I use this pattern because one User can have more than one role. On the other side, Roles share basic attributes but differ in some of them, that's why inheritance is use to model those roles

ROLE
|
---> RoleA
|
---> RoleB
|
---> RoleC

I have this migration for the STI

class CreateRoles < ActiveRecord::Migration
  def change
    create_table :roles do |t|
      t.string :name  #this is the name I want the role to show up on screen
      t.references :role_a_attr
      t.references :role_b_attr
      t.string :type
      t.timestamps
    end
  end
end

In my activeadmin controllers I have registered: Role, RoleA, RoleB and RoleC. Role

ActiveAdmin.register Role do
  config.clear_action_items!  # We don't want to create this kind of objects directly

  index do
    column :id
    column :name
    default_actions
  end


end

RoleA

ActiveAdmin.register RoleA do
  #we only want one super admin role
  config.clear_action_items! if RoleA.first


  menu :parent => 'Roles'

  show do
    attributes_table do
      row :id
      row :name
      row :created_at
      row :updated_at

    end

  end
end

RoleB

ActiveAdmin.register RoleB do
  menu :parent => 'Roles'
end

RoleC

ActiveAdmin.register RoleC do
  menu :parent => 'Roles'
end

What am I doing wrong?

Answer 1

Apparently ActiveAdmin does not like the default setting. Rails documentation advices to change the default name anyway, so I did by adding this to my migration file

class CreateRoles < ActiveRecord::Migration
  def change
    create_table :roles do |t|
      # some other attributes

      t.string :object_type #this will be your 'type' column from now on
      t.timestamps
    end

    add_index :roles, :object_type

  end
end

Then on the role class I added

set_inheritance_column 'object_type'

Surprisingly, this change was not getting any effect after doing a rake db:migrate. So I did a db:drop, db:reset, db:migrate and db:seed and everything started working fine.

Side note: Bare in mind that if you are doing a 'big bang' approach on development (you shouldn't) you can lock yourself out of the app when roles start working.