Detect and compensate for Sass / Compass on Heroku

sass_heroku.rb

# drop into "initializers" dir

heroku = !!ENV['HEROKU_TYPE']
css_dir = heroku ? 'tmp' : 'public'
location = Rails.root + 'app/styles'

unless Sass::Plugin.template_location_array.any? { |pair| pair.first.to_s == location.to_s }
  Sass::Plugin.add_template_location(location, Rails.root + css_dir + 'stylesheets')
end

if heroku
  Sass::Plugin.template_location_array.each do |template_location, css_location|
    css_location.sub!(%r{/public/stylesheets$}, "/#{css_dir}/stylesheets")
  end
  
  # add Rack middleware to serve compiled stylesheets from "tmp/stylesheets"
  Rails.configuration.middleware.insert_after 'Sass::Plugin::Rack', 'Rack::Static',
    :urls => ['/stylesheets'], :root => "#{Rails.root}/tmp"
end