front_controller.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
@author: Gordeev Andrey <gordeev.and.and@gmail.com>
The controller provides a centralized entry point that controls and manages
request handling.
"""


class MobileView(object):

 def show_index_page(self):
 print('Displaying mobile index page')


class TabletView(object):

 def show_index_page(self):
 print('Displaying tablet index page')


class Dispatcher(object):

 def __init__(self):
 self.mobile_view = MobileView()
 self.tablet_view = TabletView()

 def dispatch(self, request):
 if request.type == Request.mobile_type:
 self.mobile_view.show_index_page()
 elif request.type == Request.tablet_type:
 self.tablet_view.show_index_page()
 else:
 print('cant dispatch the request')


class RequestController(object):
 """ front controller """

 def __init__(self):
 self.dispatcher = Dispatcher()

 def dispatch_request(self, request):
 if isinstance(request, Request):
 self.dispatcher.dispatch(request)
 else:
 print('request must be a Request object')


class Request(object):
 """ request """

 mobile_type = 'mobile'
 tablet_type = 'tablet'

 def __init__(self, request):
 self.type = None
 request = request.lower()
 if request == self.mobile_type:
 self.type = self.mobile_type
 elif request == self.tablet_type:
 self.type = self.tablet_type


if __name__ == '__main__':
 front_controller = RequestController()
 front_controller.dispatch_request(Request('mobile'))
 front_controller.dispatch_request(Request('tablet'))

 front_controller.dispatch_request(Request('desktop'))
 front_controller.dispatch_request('mobile')


### OUTPUT ###
# Displaying mobile index page
# Displaying tablet index page
# cant dispatch the request
# request must be a Request object