Active Admin CollectionAction route being skipped, action treated as ID - ruby-on-rails

Question

I'm trying to create a collection_action in ActiveAdmin which allows me to rearrange the position after a drop and add. I want to be able to drag and drop the list in the index and have the new positions sent via Ajax through a post request
This is what I have so far:
ActiveAdmin.register Subscriber do
collection_action :reorder, :method => :post do
end
controller do
def reorder
#item = ResponsiveWeb.find(params[:id])
#item.position = params[:position]
#item.saved
render nothing: true
end
private
def item_params
params.require(:responsive_web).permit(:id, :position)
end
end
These are the routes:
Prefix Verb URI Pattern Controller#Action
new_admin_user_session GET /admin/login(.:format) active_admin/devise/sessions#new
admin_user_session POST /admin/login(.:format) active_admin/devise/sessions#create
destroy_admin_user_session DELETE|GET /admin/logout(.:format) active_admin/devise/sessions#destroy
admin_user_password POST /admin/password(.:format) active_admin/devise/passwords#create
new_admin_user_password GET /admin/password/new(.:format) active_admin/devise/passwords#new
edit_admin_user_password GET /admin/password/edit(.:format) active_admin/devise/passwords#edit
PATCH /admin/password(.:format) active_admin/devise/passwords#update
PUT /admin/password(.:format) active_admin/devise/passwords#update
admin_root GET /admin(.:format) admin/dashboard#index
batch_action_admin_admin_users POST /admin/admin_users/batch_action(.:format) admin/admin_users#batch_action
admin_admin_users GET /admin/admin_users(.:format) admin/admin_users#index
POST /admin/admin_users(.:format) admin/admin_users#create
new_admin_admin_user GET /admin/admin_users/new(.:format) admin/admin_users#new
edit_admin_admin_user GET /admin/admin_users/:id/edit(.:format) admin/admin_users#edit
admin_admin_user PATCH /admin/admin_users/:id(.:format) admin/admin_users#update
PUT /admin/admin_users/:id(.:format) admin/admin_users#update
DELETE /admin/admin_users/:id(.:format) admin/admin_users#destroy
admin_dashboard GET /admin/dashboard(.:format) admin/dashboard#index
sort_admin_responsive_web POST /admin/responsive_webs/:id/sort(.:format) admin/responsive_webs#sort
reorder_admin_responsive_webs POST /admin/responsive_webs/reorder(.:format) admin/responsive_webs#reorder
However when I reorder I get the 404 not found error and when I check the error logs it says, Couldn't find ResponsiveWeb with id=reorder.
Any help will be greatly appreciated!

Answer 1

To declare a collection action, active admin provide another dsl. Here is an example. You can try that.
collection_action :reorder, method: :post do
# your resources or whatever you need
end
One thing, active admin resource DSL provide a permit_params, so you don't need to declare it on your controller.
Hope this answer helps.
Here is the reference:
http://activeadmin.info/docs/8-custom-actions.html