easy change sidebar position with activeadmin

1) change sidebar position dynamically with before_filter

# app/admin/posts.rb
ActiveAdmin.register Post do
  before_filter :left_sidebar!, :only=>[:show]

# app/admin/comments.rb
ActiveAdmin.register Comment do
  before_filter :right_sidebar!

2) move sidebar to left within all resource (config/initializers/active_admin.rb)

# == Controller Filters
# You can add before, after and around filters to all of your
# Active Admin resources from here.
config.before_filter :left_sidebar!

Add including of css file

@import "active_admin_sidebar";

to the app/assets/stylesheets/active_admin.css.scss