Example rack middlewares

rack_middleware.rb

class Canadianize
  def initialize(app, arg = "")
    @app = app
    @arg = arg
  end

  def call(env)
    status, headers, content = @app.call(env)
    content[0] += @arg + ", eh?"
    [ status, headers, content ]
  end
end

class Gauchanize
  def initialize(app, arg = "")
    @app = app
    @arg = arg
  end

  def call(env)
    status, headers, content = @app.call(env)
    content[0] = "Bah, " + content[0] + @arg
    [ status, headers, content ]
  end
end

use Canadianize, ", simple"
use Gauchanize

run proc {
  [200, 
   {'Content-Type' => 'text/html'},
   ["Hello, world"]]
}