padrino and sinatra-assetpack rake task assets:precompile

assets.rb

namespace :assets do
  def load_apps
    require File.expand_path('config/boot.rb', Rake.application.original_dir)
    Padrino.mounted_apps
  end

  desc "Precompile all assets"
  task :precompile => 'precompile:build'

  namespace :precompile do
    desc "Build assets"
    task :build do
      load_apps.each do |mounted_app|
        if mounted_app.app_obj.respond_to?(:assets) && mounted_app.app_obj.assets.respond_to?(:build!)
          mounted_app.app_obj.assets.build! do |file|
            puts "+ #{file.gsub(Dir.pwd, '')}"
          end
        end
      end
    end
  end

end