The one true parallel universe.

berenstein.rb

# inspired by https://gist.github.com/techiferous/235068
require 'nokogiri'

module Rack
  class Berenstein

    def initialize(app, options = {})
      @app = app
      @options = options
    end
    
    def call(env)
      @doc = nil
      @request = Rack::Request.new(env)
      status, @headers, @body = @app.call(env)
      if html?
        @body = doc.at_css("body").content
        @body.gsub!(/berenstain/i, 'Berenstein')
        update_content_length
      end
      [status, @headers, @body]
    end
    
    private

    def html?
      @headers["Content-Type"] && @headers["Content-Type"].include?("text/html")
    end
    
    def doc
      @doc ||= Nokogiri::HTML(body_to_string)
    end
  
    def body_to_string
      s = ""
      @body.each { |x| s << x }
      s
    end
    
    def update_content_length
      @headers['Content-Length'] = Rack::Utils.bytesize(@body).to_s
    end

  end
end