Coverage for jutil/model.py : 86%

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1from datetime import timedelta, datetime
2from time import sleep
3from typing import Type, List, Tuple, Any, Optional
4from django.db.models import Model
5from django.utils.encoding import force_text
6from django.utils.timezone import now
7from jutil.dict import choices_label
10def get_object_or_none(cls: Any, **kwargs) -> Any:
11 """
12 Returns model instance or None if not found.
13 :param cls: Class or queryset
14 :param kwargs: Filters for get() call
15 :return: Object or None
16 """
17 try:
18 qs = cls._default_manager.all() if hasattr(cls, '_default_manager') else cls # pylint: disable=protected-access
19 return qs.get(**kwargs)
20 except Exception:
21 return None
24def wait_object_or_none(cls: Any, timeout: float = 5.0, sleep_interval: float = 1.0, **kwargs) -> Any:
25 """
26 Returns model instance or None if not found after specified timeout.
27 Waits timeout before returning if no object available.
28 Waiting is done by sleeping specified intervals.
29 :param cls: Class or queryset
30 :param timeout: Timeout in seconds
31 :param sleep_interval: Sleep interval in seconds
32 :param kwargs: Filters for get() call
33 :return: Object or None
34 """
35 t0: Optional[datetime] = None
36 t1: Optional[datetime] = None
37 qs0 = cls._default_manager if hasattr(cls, '_default_manager') else cls # pylint: disable=protected-access
38 while t0 is None or t0 < t1: # type: ignore
39 obj = qs0.all().filter(**kwargs).first()
40 if obj is not None:
41 return obj
42 t0 = now()
43 if t1 is None:
44 t1 = t0 + timedelta(seconds=timeout)
45 sleep(sleep_interval)
46 return qs0.all().filter(**kwargs).first()
49def get_model_field_label_and_value(instance, field_name: str) -> Tuple[str, str]:
50 """
51 Returns model field label and value (as text).
52 :param instance: Model instance
53 :param field_name: Model attribute name
54 :return: (label, value) tuple
55 """
56 label = field_name
57 value = str(getattr(instance, field_name))
58 for f in instance._meta.fields: 58 ↛ 64line 58 didn't jump to line 64, because the loop on line 58 didn't complete
59 if f.attname == field_name:
60 label = f.verbose_name
61 if hasattr(f, 'choices') and f.choices: 61 ↛ 62line 61 didn't jump to line 62, because the condition on line 61 was never true
62 value = choices_label(f.choices, value)
63 break
64 val = force_text(value)
65 if val is None: 65 ↛ 66line 65 didn't jump to line 66, because the condition on line 65 was never true
66 val = ''
67 return label, val
70def is_model_field_changed(instance, field_name: str) -> bool:
71 """
72 Compares model instance field value to value stored in DB.
73 If object has not been stored in DB (yet) field is considered unchanged.
74 :param instance: Model instance
75 :param field_name: Model attribute name
76 :return: True if field value has been changed compared to value stored in DB.
77 """
78 assert hasattr(instance, field_name)
79 if not hasattr(instance, 'pk') or instance.pk is None: 79 ↛ 80line 79 didn't jump to line 80, because the condition on line 79 was never true
80 return False
81 qs = instance.__class__.objects.all()
82 params = {'pk': instance.pk, field_name: getattr(instance, field_name)}
83 return qs.filter(**params).first() is None
86def get_model_keys(instance, cls: Optional[Type[Model]] = None,
87 exclude_fields: tuple = ('id',), base_class_suffix: str = '_ptr') -> List[str]:
88 if cls is None: 88 ↛ 89line 88 didn't jump to line 89, because the condition on line 88 was never true
89 cls = instance.__class__
90 return [f.name for f in cls._meta.fields if f.name not in exclude_fields and not f.name.endswith(base_class_suffix)]
93def clone_model(instance, cls: Optional[Type[Model]] = None, commit: bool = True,
94 exclude_fields: tuple = ('id',), base_class_suffix: str = '_ptr', **kw):
95 """
96 Assigns model fields to new object. Ignores exclude_fields list and
97 attributes ending with pointer suffix (default '_ptr')
98 :param instance: Instance to copy
99 :param cls: Class (opt)
100 :param commit: Save or not
101 :param exclude_fields: List of fields to exclude
102 :param base_class_suffix: End of name for base class pointers, e.g. model Car(Vehicle) has implicit vehicle_ptr
103 :return: New instance
104 """
105 if cls is None: 105 ↛ 107line 105 didn't jump to line 107, because the condition on line 105 was never false
106 cls = instance.__class__
107 keys = get_model_keys(instance, cls=cls, exclude_fields=exclude_fields, base_class_suffix=base_class_suffix)
108 new_instance = cls()
109 for k in keys:
110 setattr(new_instance, k, getattr(instance, k))
111 for k, v in kw.items(): 111 ↛ 112line 111 didn't jump to line 112, because the loop on line 111 never started
112 setattr(new_instance, k, v)
113 if commit: 113 ↛ 115line 113 didn't jump to line 115, because the condition on line 113 was never false
114 new_instance.save()
115 return new_instance