Synnefo » snf-cloudcms

import urlparse

import urllib

from django.contrib import messages

from django.http import HttpResponseRedirect

class RequestMessagesMiddleware:

    """

    A middleware that checks for specific get parameters in url, appends

    associated messages and redirects to the same url (removing the parameter

    to avoid circular redirects).

    """

    PARAMS_MAP = {

        'logged_in': ((messages.SUCCESS, 'You have successfully logged in'),),

        'logged_out': ((messages.SUCCESS, 'You have successfully logged out'),),

    }

    def process_request(self, request):

        qs = request.META.get('QUERY_STRING', '')

        if not qs:

            return

        qs = urlparse.parse_qs(qs)

        # parse query string, add messages and keep params used to remove

        # them later from the redirect url

        params_to_remove = []

        for param, messages_tuples in self.PARAMS_MAP.iteritems():

            if param in qs:

                params_to_remove.append(param)

                for message in messages_tuples:

                    msg_type = message[0]

                    msg = message[1]

                    messages.add_message(request, msg_type, msg)

        if not params_to_remove:

            return

        for p in params_to_remove:

            del qs[p]

        # create the redirect url

        redirect_qs = urllib.urlencode(qs)

        return HttpResponseRedirect("/?" + redirect_qs)