middleman--middleman/lib/middleman/features/live_reload.rb

module Middleman::Features::LiveReload
  class << self
    def registered(app)
      return unless Middleman::Server.environment == :development

      begin
        require 'livereload'
      rescue LoadError
        puts "Livereload not available. Install it with: gem install livereload"
      end

      new_config = ::LiveReload::Config.new do |config|
        ::Tilt.mappings.each do |key, v|
          config.exts << key
        end
      end
      
      pid = fork {      
        require 'livereload'
        ::LiveReload.run [Middleman::Server.views], new_config
      }

    end
    alias :included :registered
  end
end