1# Imports 

2 

3from django.contrib.auth import get_user_model 

4from .constants import IMPERSONATION_FOR_ID, IMPERSONATION_SESSION_KEY 

5from .utils import user_is_allowed_to_impersonate 

6 

7# Exports 

8 

9__all__ = ( 

10 "UserImpersonationMiddleware", 

11) 

12 

13# Processors 

14 

15 

16class UserImpersonationMiddleware: 

17 """Facilitate user impersonation.""" 

18 

19 def __init__(self, get_response): 

20 self.get_response = get_response 

21 

22 def __call__(self, request): 

23 # Do nothing if the current user isn't allowed to impersonate. 

24 if not user_is_allowed_to_impersonate(request.user): 

25 return self.get_response(request) 

26 

27 # Always assume the user is not impersonating by default. 

28 request.user.is_impersonated = False 

29 request.impersonator = None 

30 

31 # noinspection PyPep8Naming 

32 UserModel = get_user_model() 

33 

34 if request.user.is_authenticated and IMPERSONATION_SESSION_KEY in request.session: 

35 try: 

36 for_id = request.session[IMPERSONATION_FOR_ID] 

37 user = UserModel.objects.get(pk=for_id) 

38 

39 request.impersonator = request.user 

40 request.user = user 

41 request.user.is_impersonated = True 

42 except UserModel.DoesNotExist: 

43 pass 

44 

45 return self.get_response(request)