Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/django/db/models/fields/mixins.py: 41%

1from django.core import checks 

2 

3NOT_PROVIDED = object() 

4 

5 

6class FieldCacheMixin: 

7 """Provide an API for working with the model's fields value cache.""" 

8 

9 def get_cache_name(self): 

10 raise NotImplementedError 

11 

12 def get_cached_value(self, instance, default=NOT_PROVIDED): 

13 cache_name = self.get_cache_name() 

14 try: 

15 return instance._state.fields_cache[cache_name] 

16 except KeyError: 

17 if default is NOT_PROVIDED: 

18 raise 

19 return default 

20 

21 def is_cached(self, instance): 

22 return self.get_cache_name() in instance._state.fields_cache 

23 

24 def set_cached_value(self, instance, value): 

25 instance._state.fields_cache[self.get_cache_name()] = value 

26 

27 def delete_cached_value(self, instance): 

28 del instance._state.fields_cache[self.get_cache_name()] 

29 

30 

31class CheckFieldDefaultMixin: 

32 _default_hint = ("<valid default>", "<invalid default>") 

33 

34 def _check_default(self): 

35 if ( 

36 self.has_default() 

37 and self.default is not None 

38 and not callable(self.default) 

39 ): 

40 return [ 

41 checks.Warning( 

42 "%s default should be a callable instead of an instance " 

43 "so that it's not shared between all field instances." 

44 % (self.__class__.__name__,), 

45 hint=( 

46 "Use a callable instead, e.g., use `%s` instead of " 

47 "`%s`." % self._default_hint 

48 ), 

49 obj=self, 

50 id="fields.E010", 

51 ) 

52 ] 

53 else: 

54 return [] 

55 

56 def check(self, **kwargs): 

57 errors = super().check(**kwargs) 

58 errors.extend(self._check_default()) 

59 return errors