text: from webob import Request
  import re
  
  class DetectMobileBrowser(object):
      """Detect mobile browser
  
      Regexps reg_b and reg_v are taken from
      http://detectmobilebrowser.com/.  The regexps are in the public
      domain.
      
      Regexps updated: 30 June 2010.
      """
      reg_b = re.compile(r"android|avantgo|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\\/|plucker|pocket|psp|symbian|treo|up\\.(browser|link)|vodafone|wap|windows (ce|phone)|xda|xiino", re.I|re.M)
      
      reg_v = re.compile(r"1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\\-(n|u)|c55\\/|capi|ccwa|cdm\\-|cell|chtm|cldc|cmd\\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\\-s|devi|dica|dmob|do(c|p)o|ds(12|\\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\\-|_)|g1 u|g560|gene|gf\\-5|g\\-mo|go(\\.w|od)|gr(ad|un)|haie|hcit|hd\\-(m|p|t)|hei\\-|hi(pt|ta)|hp( i|ip)|hs\\-c|ht(c(\\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\\-(20|go|ma)|i230|iac( |\\-|\\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\\/)|klon|kpt |kwc\\-|kyo(c|k)|le(no|xi)|lg( g|\\/(k|l|u)|50|54|e\\-|e\\/|\\-[a-w])|libw|lynx|m1\\-w|m3ga|m50\\/|ma(te|ui|xo)|mc(01|21|ca)|m\\-cr|me(di|rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\\-2|po(ck|rt|se)|prox|psio|pt\\-g|qa\\-a|qc(07|12|21|32|60|\\-[2-7]|i\\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\\-|oo|p\\-)|sdk\\/|se(c(\\-|0|1)|47|mc|nd|ri)|sgh\\-|shar|sie(\\-|m)|sk\\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\\-|v\\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\\-|tdg\\-|tel(i|m)|tim\\-|t\\-mo|to(pl|sh)|ts(70|m\\-|m3|m5)|tx\\-9|up(\\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|xda(\\-|2|g)|yas\\-|your|zeto|zte\\-", re.I|re.M)
  
      def __init__(self, application, config):
          super(DetectMobileBrowser, self).__init__()
  
          mobile_re_config = config.get('mobile.agents', False)
          if mobile_re_config:
              self.custom_mobile_re = re.compile(mobile_re_config, re.I|re.M)
              self._recognize_ua = self._recognize_ua_custom
          else:
              self.custom_mobile_re = None
              self._recognize_ua = self._recognize_ua_default
     
      def _recognize_ua_custom(self, user_agent):
          return self.custom_mobile_re.search(user_agent)
  
      def _recognize_ua_default(self, user_agent):
          return self.reg_b.search(user_agent) or self.reg_v.search(user_agent[:4])
   
      def perform_detection(self, request):
          user_agent = request.headers.get('User-Agent', None) 
          return user_agent and self._recognize_ua(user_agent)
  
      def __call__(self, request):
          return self.perform_detection(request)
  
  class MobileMiddleware(object):
      def __init__(self, application, config,
                   mobile_browser_detector=DetectMobileBrowser):
          self.application = application
          
          if isinstance(mobile_browser_detector, type):
              self.detect_mobile = mobile_browser_detector(application, config)
          else:
              self.detect_mobile = mobile_browser_detector
              
      def __call__(self, environ, start_response):
          request = Request(environ)
          request.is_mobile = bool(self.detect_mobile(request))
          response = request.get_response(self.application)
          return response(environ, start_response)
  