Ticket #31288: middleware.py

from django.shortcuts import redirect
from django.urls import resolve
from django.conf import settings


class ReplaceAuthMiddleware:
    def __init__(self, get_response):
        self.get_response = get_response
        self.unauthorized_urls_for_logged_user = settings.REPLACE_URL_IF_LOGGED["replace"]
        self.unauthorized_urls_for_unlogged_user = settings.REPLACE_URL_IF_UNLOGGED["replace"]
        self.redirect_url_for_unauthorized_logged_user = settings.REPLACE_URL_IF_LOGGED["by"]
        self.redirect_url_for_unauthorized_unlogged_user = settings.REPLACE_URL_IF_UNLOGGED["by"]

    def __call__(self, request):

        # Before the response of the view changes, checks if the url is authorized or not.
        if self.unauthorized_url_for_logged_user(request):
            return redirect(self.redirect_url_for_unauthorized_logged_user)
        elif self.unauthorized_url_for_unlogged_user(request):
            return redirect(self.redirect_url_for_unauthorized_unlogged_user)

        # Get the response of the view.
        response = self.get_response(request)

        # After the response of the view changes, checks if the url is authorized or not.
        if self.unauthorized_url_for_logged_user(request):
            return redirect(self.redirect_url_for_unauthorized_logged_user)
        elif self.unauthorized_url_for_unlogged_user(request):
            return redirect(self.redirect_url_for_unauthorized_unlogged_user)

        # Return the default response of the view if no redirection is needed.
        return response

    @staticmethod
    def user_is_logged(request):
        return hasattr(request, 'user') and request.user.is_authenticated

    def unauthorized_url_for_unlogged_user(self, request):
        return not self.user_is_logged(request) and resolve(
            request.path_info).url_name in self.unauthorized_urls_for_unlogged_user

    def unauthorized_url_for_logged_user(self, request):
        return self.user_is_logged(request) and resolve(
            request.path_info).url_name in self.unauthorized_urls_for_logged_user