module ActiveAdmin::ResourceController::Collection::Sorting

def sort_order(chain)
  params[:order] ||= active_admin_config.sort_order
  table_name = active_admin_config.resource_table_name
  if params[:order] && params[:order] =~ /^([\w\_\.]+)_(desc|asc)$/
    chain.order("#{table_name}.#{$1} #{$2}")
  else
    chain # just return the chain
  end
end