bacon infused middleware

bacon_infused.rb

# application.rb
#
#   config.middleware.use "BaconInfused"

class BaconInfused
  def initialize(app)
    @app = app
  end

  def call(env)
    s, h, r = @app.call(env)
    if r.content_type == 'text/html'
      r.body = r.body.
        gsub(/Hamburg/, 'BACON').
        gsub(/src=('|")([^'|"]+).png('|")/, 'src="http://bit.ly/1maTrIt"')
    end
    [s, h, r]
  end
end