rails--rails/actionpack/lib/action_view/railtie.rb

require "action_view"
require "rails"

module ActionView
  # = Action View Railtie
  class Railtie < Rails::Railtie
    config.action_view = ActiveSupport::OrderedOptions.new

    # setup default js includes
    config.action_view.javascript_expansions = { :defaults => ['prototype', 'effects', 'dragdrop', 'controls', 'rails'] }

    require "action_view/railties/log_subscriber"
    log_subscriber :action_view, ActionView::Railties::LogSubscriber.new

    initializer "action_view.cache_asset_timestamps" do |app|
      unless app.config.cache_classes
        ActiveSupport.on_load(:action_view) do
          ActionView::Helpers::AssetTagHelper.cache_asset_timestamps = false
        end
      end
    end

    initializer "action_view.javascript_expansions" do |app|
      ActiveSupport.on_load(:action_view) do
        ActionView::Helpers::AssetTagHelper.register_javascript_expansion(app.config.action_view.javascript_expansions)
      end
    end

    initializer "action_view.set_configs" do |app|
      ActiveSupport.on_load(:action_view) do
        app.config.action_view.each do |k,v|
          send "#{k}=", v
        end
      end
    end
  end
end