Coverage for src / mesh / views / viewmodel / model_proxy.py: 100%

1from abc import ABC 

2from typing import TYPE_CHECKING, Any, Generic, TypeVar 

3 

4from django.db.models import Model 

5 

6if TYPE_CHECKING: 

7 from mesh.models.roles.base_role import Role 

8 

9T = TypeVar("T", bound=Model) 

10 

11 

12class RoleModelProxy(ABC, Generic[T]): 

13 """ 

14 Defines a proxy for a model class when some properties require to be adapted according to the user role rights. 

15 To be used only for template display. 

16 

17 The logic is to overload a model's attribute in the associated interface. 

18 If the attribute is not found in the interface, it falls back to the instance value. 

19 

20 Additionally, we also provide a shortcut to calling rights function with 

21 the current instance as an argument. 

22 """ 

23 

24 model: type[T] 

25 _instance: T 

26 

27 def __init__(self, instance: T, role: "Role") -> None: 

28 self._instance = instance 

29 self.role = role 

30 

31 def __getattr__(self, name: str) -> Any: 

32 """ 

33 Fetches the attribute from the underlying instance. 

34 This gets called only if the attribute is not found normally. 

35 https://docs.python.org/3/reference/datamodel.html#object.__getattr__ 

36 

37 If it doesn't exist, we authorize shortcuts to right function check. 

38 """ 

39 

40 attr = getattr(self._instance, name) 

41 return attr