Coverage for jutil/model.py : 81%

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1from typing import Type, List, Tuple, Any, Optional
3from django.db.models import Model
4from django.utils.encoding import force_text
5from jutil.dict import choices_label
8def get_object_or_none(cls: Any, **kwargs) -> Any:
9 """
10 Returns model instance or None if not found.
11 :param cls: Class or queryset
12 :param kwargs: Filters for get() call
13 :return: Object or None
14 """
15 try:
16 qs = cls._default_manager.all() if hasattr(cls, '_default_manager') else cls # pylint: disable=protected-access
17 return qs.get(**kwargs)
18 except Exception:
19 return None
22def get_model_field_label_and_value(instance, field_name: str) -> Tuple[str, str]:
23 """
24 Returns model field label and value (as text).
25 :param instance: Model instance
26 :param field_name: Model attribute name
27 :return: (label, value) tuple
28 """
29 label = field_name
30 value = str(getattr(instance, field_name))
31 for f in instance._meta.fields: 31 ↛ 37line 31 didn't jump to line 37, because the loop on line 31 didn't complete
32 if f.attname == field_name:
33 label = f.verbose_name
34 if hasattr(f, 'choices') and f.choices: 34 ↛ 35line 34 didn't jump to line 35, because the condition on line 34 was never true
35 value = choices_label(f.choices, value)
36 break
37 val = force_text(value)
38 if val is None: 38 ↛ 39line 38 didn't jump to line 39, because the condition on line 38 was never true
39 val = ''
40 return label, val
43def is_model_field_changed(instance, field_name: str) -> bool:
44 """
45 Compares model instance field value to value stored in DB.
46 If object has not been stored in DB (yet) field is considered unchanged.
47 :param instance: Model instance
48 :param field_name: Model attribute name
49 :return: True if field value has been changed compared to value stored in DB.
50 """
51 assert hasattr(instance, field_name)
52 if not hasattr(instance, 'pk') or instance.pk is None: 52 ↛ 53line 52 didn't jump to line 53, because the condition on line 52 was never true
53 return False
54 qs = instance.__class__.objects.all()
55 params = {'pk': instance.pk, field_name: getattr(instance, field_name)}
56 return qs.filter(**params).first() is None
59def get_model_keys(instance, cls: Optional[Type[Model]] = None,
60 exclude_fields: tuple = ('id',), base_class_suffix: str = '_ptr') -> List[str]:
61 if cls is None: 61 ↛ 62line 61 didn't jump to line 62, because the condition on line 61 was never true
62 cls = instance.__class__
63 return [f.name for f in cls._meta.fields if f.name not in exclude_fields and not f.name.endswith(base_class_suffix)]
66def clone_model(instance, cls: Optional[Type[Model]] = None, commit: bool = True,
67 exclude_fields: tuple = ('id',), base_class_suffix: str = '_ptr', **kw):
68 """
69 Assigns model fields to new object. Ignores exclude_fields list and
70 attributes ending with pointer suffix (default '_ptr')
71 :param instance: Instance to copy
72 :param cls: Class (opt)
73 :param commit: Save or not
74 :param exclude_fields: List of fields to exclude
75 :param base_class_suffix: End of name for base class pointers, e.g. model Car(Vehicle) has implicit vehicle_ptr
76 :return: New instance
77 """
78 if cls is None: 78 ↛ 80line 78 didn't jump to line 80, because the condition on line 78 was never false
79 cls = instance.__class__
80 keys = get_model_keys(instance, cls=cls, exclude_fields=exclude_fields, base_class_suffix=base_class_suffix)
81 new_instance = cls()
82 for k in keys:
83 setattr(new_instance, k, getattr(instance, k))
84 for k, v in kw.items(): 84 ↛ 85line 84 didn't jump to line 85, because the loop on line 84 never started
85 setattr(new_instance, k, v)
86 if commit: 86 ↛ 88line 86 didn't jump to line 88, because the condition on line 86 was never false
87 new_instance.save()
88 return new_instance