request.build_absolute_uri()

class SimpleMiddleware(object):
def __init__(self, get_response):
    self.get_response = get_response
    # One-time configuration and initialization.

def __call__(self, request):
    # Code to be executed for each request before the view (and later middleware) are called.

    # sets to show Taiwan or Indo version
    # sets the timezone too
    http_host = request.META['HTTP_HOST']
    if(http_host == 'http://www.xxx.tw'):
        request.session['web_to_show'] = settings.TAIWAN
        request.session['timezone_to_use'] = settings.TAIWAN_TIMEZONE
    else:
        request.session['web_to_show'] = settings.INDO
        request.session['timezone_to_use'] = settings.INDONESIA_TIMEZONE

    response = self.get_response(request)

    # Code to be executed for each request/response after the view is called.

    return response

from django.contrib.sites.shortcuts import get_current_site
domain = get_current_site(None)