class E

  EConstants::HTTP__REQUEST_METHODS.each do |request_method|
    define_method '%s?' % request_method.downcase do
      (@__e__request_method_map ||= {request.request_method => true})[request_method]
    end
  end

  def xhr?
    (@__e__requested_with_map ||= {env["HTTP_X_REQUESTED_WITH"] => true})["XMLHttpRequest"]
  end

  # shortcut for Rack::Mime::MIME_TYPES.fetch
  def mime_type type, fallback = nil
    Rack::Mime::MIME_TYPES.fetch type, fallback
  end

  def escape_html *args
    ::CGI.escapeHTML *args
  end

  def unescape_html *args
    ::CGI.unescapeHTML *args
  end

  def escape_element *args
    ::CGI.escapeElement *args
  end

  def unescape_element *args
    ::CGI.unescapeElement *args
  end

  begin # borrowed from [Sinatra Framework](https://github.com/sinatra/sinatra)

    # Set or retrieve the response status code.
    def status(value=nil)
      response.status = value if value
      response.status
    end
    
    # Sugar for redirect (example:  redirect back)
    def back
      request.referer
    end

    # whether or not the status is set to 1xx
    def informational?
      status.between? 100, 199
    end

    # whether or not the status is set to 2xx
    def success?
      status.between? 200, 299
    end

    # whether or not the status is set to 3xx
    def redirect?
      status.between? 300, 399
    end

    # whether or not the status is set to 4xx
    def client_error?
      status.between? 400, 499
    end

    # whether or not the status is set to 5xx
    def server_error?
      status.between? 500, 599
    end

    # whether or not the status is set to 404
    def not_found?
      status == 404
    end
  end

end