mirror of
https://github.com/Hopiu/django-model-utils.git
synced 2026-03-17 04:10:24 +00:00
367 lines
12 KiB
Python
367 lines
12 KiB
Python
import secrets
|
|
import uuid
|
|
import warnings
|
|
from collections.abc import Callable
|
|
|
|
from django.conf import settings
|
|
from django.core.exceptions import ValidationError
|
|
from django.db import models
|
|
from django.utils.timezone import now
|
|
|
|
DEFAULT_CHOICES_NAME = 'STATUS'
|
|
|
|
|
|
class AutoCreatedField(models.DateTimeField):
|
|
"""
|
|
A DateTimeField that automatically populates itself at
|
|
object creation.
|
|
|
|
By default, sets editable=False, default=datetime.now.
|
|
|
|
"""
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
kwargs.setdefault('editable', False)
|
|
kwargs.setdefault('default', now)
|
|
super().__init__(*args, **kwargs)
|
|
|
|
|
|
class AutoLastModifiedField(AutoCreatedField):
|
|
"""
|
|
A DateTimeField that updates itself on each save() of the model.
|
|
|
|
By default, sets editable=False and default=datetime.now.
|
|
|
|
"""
|
|
def get_default(self):
|
|
"""Return the default value for this field."""
|
|
if not hasattr(self, "_default"):
|
|
self._default = self._get_default()
|
|
return self._default
|
|
|
|
def pre_save(self, model_instance, add):
|
|
value = now()
|
|
if add:
|
|
current_value = getattr(model_instance, self.attname, self.get_default())
|
|
if current_value != self.get_default():
|
|
# when creating an instance and the modified date is set
|
|
# don't change the value, assume the developer wants that
|
|
# control.
|
|
value = getattr(model_instance, self.attname)
|
|
else:
|
|
for field in model_instance._meta.get_fields():
|
|
if isinstance(field, AutoCreatedField):
|
|
value = getattr(model_instance, field.name)
|
|
break
|
|
setattr(model_instance, self.attname, value)
|
|
return value
|
|
|
|
|
|
class StatusField(models.CharField):
|
|
"""
|
|
A CharField that looks for a ``STATUS`` class-attribute and
|
|
automatically uses that as ``choices``. The first option in
|
|
``STATUS`` is set as the default.
|
|
|
|
Also has a default max_length so you don't have to worry about
|
|
setting that.
|
|
|
|
Also features a ``no_check_for_status`` argument to make sure
|
|
South can handle this field when it freezes a model.
|
|
"""
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
kwargs.setdefault('max_length', 100)
|
|
self.check_for_status = not kwargs.pop('no_check_for_status', False)
|
|
self.choices_name = kwargs.pop('choices_name', DEFAULT_CHOICES_NAME)
|
|
super().__init__(*args, **kwargs)
|
|
|
|
def prepare_class(self, sender, **kwargs):
|
|
if not sender._meta.abstract and self.check_for_status:
|
|
assert hasattr(sender, self.choices_name), \
|
|
"To use StatusField, the model '%s' must have a %s choices class attribute." \
|
|
% (sender.__name__, self.choices_name)
|
|
self.choices = getattr(sender, self.choices_name)
|
|
if not self.has_default():
|
|
self.default = tuple(getattr(sender, self.choices_name))[0][0] # set first as default
|
|
|
|
def contribute_to_class(self, cls, name):
|
|
models.signals.class_prepared.connect(self.prepare_class, sender=cls)
|
|
# we don't set the real choices until class_prepared (so we can rely on
|
|
# the STATUS class attr being available), but we need to set some dummy
|
|
# choices now so the super method will add the get_FOO_display method
|
|
self.choices = [(0, 'dummy')]
|
|
super().contribute_to_class(cls, name)
|
|
|
|
def deconstruct(self):
|
|
name, path, args, kwargs = super().deconstruct()
|
|
kwargs['no_check_for_status'] = True
|
|
return name, path, args, kwargs
|
|
|
|
|
|
class MonitorField(models.DateTimeField):
|
|
"""
|
|
A DateTimeField that monitors another field on the same model and
|
|
sets itself to the current date/time whenever the monitored field
|
|
changes.
|
|
|
|
"""
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
if kwargs.get("null") and kwargs.get("default") is None:
|
|
warning_message = (
|
|
"{}.default is set to 'django.utils.timezone.now' - when nullable"
|
|
" and no default. This behavior will be deprecated in the next"
|
|
" major release in favor of 'None'. See"
|
|
" https://django-model-utils.readthedocs.io/en/stable/fields.html"
|
|
"#monitorfield for more information."
|
|
).format(self.__class__.__name__)
|
|
warnings.warn(warning_message, DeprecationWarning)
|
|
|
|
kwargs.setdefault('default', now)
|
|
monitor = kwargs.pop('monitor', None)
|
|
if not monitor:
|
|
raise TypeError(
|
|
'%s requires a "monitor" argument' % self.__class__.__name__)
|
|
self.monitor = monitor
|
|
when = kwargs.pop('when', None)
|
|
if when is not None:
|
|
when = set(when)
|
|
self.when = when
|
|
super().__init__(*args, **kwargs)
|
|
|
|
def contribute_to_class(self, cls, name):
|
|
self.monitor_attname = '_monitor_%s' % name
|
|
models.signals.post_init.connect(self._save_initial, sender=cls)
|
|
super().contribute_to_class(cls, name)
|
|
|
|
def get_monitored_value(self, instance):
|
|
return getattr(instance, self.monitor)
|
|
|
|
def _save_initial(self, sender, instance, **kwargs):
|
|
if self.monitor in instance.get_deferred_fields():
|
|
# Fix related to issue #241 to avoid recursive error on double monitor fields
|
|
return
|
|
setattr(instance, self.monitor_attname, self.get_monitored_value(instance))
|
|
|
|
def pre_save(self, model_instance, add):
|
|
value = now()
|
|
previous = getattr(model_instance, self.monitor_attname, None)
|
|
current = self.get_monitored_value(model_instance)
|
|
if previous != current:
|
|
if self.when is None or current in self.when:
|
|
setattr(model_instance, self.attname, value)
|
|
self._save_initial(model_instance.__class__, model_instance)
|
|
return super().pre_save(model_instance, add)
|
|
|
|
def deconstruct(self):
|
|
name, path, args, kwargs = super().deconstruct()
|
|
kwargs['monitor'] = self.monitor
|
|
if self.when is not None:
|
|
kwargs['when'] = self.when
|
|
return name, path, args, kwargs
|
|
|
|
|
|
SPLIT_MARKER = getattr(settings, 'SPLIT_MARKER', '<!-- split -->')
|
|
|
|
# the number of paragraphs after which to split if no marker
|
|
SPLIT_DEFAULT_PARAGRAPHS = getattr(settings, 'SPLIT_DEFAULT_PARAGRAPHS', 2)
|
|
|
|
|
|
def _excerpt_field_name(name):
|
|
return '_%s_excerpt' % name
|
|
|
|
|
|
def get_excerpt(content):
|
|
excerpt = []
|
|
default_excerpt = []
|
|
paras_seen = 0
|
|
for line in content.splitlines():
|
|
if not line.strip():
|
|
paras_seen += 1
|
|
if paras_seen < SPLIT_DEFAULT_PARAGRAPHS:
|
|
default_excerpt.append(line)
|
|
if line.strip() == SPLIT_MARKER:
|
|
return '\n'.join(excerpt)
|
|
excerpt.append(line)
|
|
|
|
return '\n'.join(default_excerpt)
|
|
|
|
|
|
class SplitText:
|
|
def __init__(self, instance, field_name, excerpt_field_name):
|
|
# instead of storing actual values store a reference to the instance
|
|
# along with field names, this makes assignment possible
|
|
self.instance = instance
|
|
self.field_name = field_name
|
|
self.excerpt_field_name = excerpt_field_name
|
|
|
|
# content is read/write
|
|
@property
|
|
def content(self):
|
|
return self.instance.__dict__[self.field_name]
|
|
|
|
@content.setter
|
|
def content(self, val):
|
|
setattr(self.instance, self.field_name, val)
|
|
|
|
# excerpt is a read only property
|
|
def _get_excerpt(self):
|
|
return getattr(self.instance, self.excerpt_field_name)
|
|
excerpt = property(_get_excerpt)
|
|
|
|
# has_more is a boolean property
|
|
def _get_has_more(self):
|
|
return self.excerpt.strip() != self.content.strip()
|
|
has_more = property(_get_has_more)
|
|
|
|
def __str__(self):
|
|
return self.content
|
|
|
|
|
|
class SplitDescriptor:
|
|
def __init__(self, field):
|
|
self.field = field
|
|
self.excerpt_field_name = _excerpt_field_name(self.field.name)
|
|
|
|
def __get__(self, instance, owner):
|
|
if instance is None:
|
|
raise AttributeError('Can only be accessed via an instance.')
|
|
content = instance.__dict__[self.field.name]
|
|
if content is None:
|
|
return None
|
|
return SplitText(instance, self.field.name, self.excerpt_field_name)
|
|
|
|
def __set__(self, obj, value):
|
|
if isinstance(value, SplitText):
|
|
obj.__dict__[self.field.name] = value.content
|
|
setattr(obj, self.excerpt_field_name, value.excerpt)
|
|
else:
|
|
obj.__dict__[self.field.name] = value
|
|
|
|
|
|
class SplitField(models.TextField):
|
|
def __init__(self, *args, **kwargs):
|
|
# for South FakeORM compatibility: the frozen version of a
|
|
# SplitField can't try to add an _excerpt field, because the
|
|
# _excerpt field itself is frozen as well. See introspection
|
|
# rules below.
|
|
self.add_excerpt_field = not kwargs.pop('no_excerpt_field', False)
|
|
super().__init__(*args, **kwargs)
|
|
|
|
def contribute_to_class(self, cls, name):
|
|
if self.add_excerpt_field and not cls._meta.abstract:
|
|
excerpt_field = models.TextField(editable=False)
|
|
cls.add_to_class(_excerpt_field_name(name), excerpt_field)
|
|
super().contribute_to_class(cls, name)
|
|
setattr(cls, self.name, SplitDescriptor(self))
|
|
|
|
def pre_save(self, model_instance, add):
|
|
value = super().pre_save(model_instance, add)
|
|
excerpt = get_excerpt(value.content)
|
|
setattr(model_instance, _excerpt_field_name(self.attname), excerpt)
|
|
return value.content
|
|
|
|
def value_to_string(self, obj):
|
|
value = self.value_from_object(obj)
|
|
return value.content
|
|
|
|
def get_prep_value(self, value):
|
|
try:
|
|
return value.content
|
|
except AttributeError:
|
|
return value
|
|
|
|
def deconstruct(self):
|
|
name, path, args, kwargs = super().deconstruct()
|
|
kwargs['no_excerpt_field'] = True
|
|
return name, path, args, kwargs
|
|
|
|
|
|
class UUIDField(models.UUIDField):
|
|
"""
|
|
A field for storing universally unique identifiers. Use Python UUID class.
|
|
"""
|
|
|
|
def __init__(self, primary_key=True, version=4, editable=False, *args, **kwargs):
|
|
"""
|
|
Parameters
|
|
----------
|
|
primary_key : bool
|
|
If True, this field is the primary key for the model.
|
|
version : int
|
|
An integer that set default UUID version.
|
|
editable : bool
|
|
If False, the field will not be displayed in the admin or any other ModelForm,
|
|
default is false.
|
|
|
|
Raises
|
|
------
|
|
ValidationError
|
|
UUID version 2 is not supported.
|
|
"""
|
|
|
|
if version == 2:
|
|
raise ValidationError(
|
|
'UUID version 2 is not supported.')
|
|
|
|
if version < 1 or version > 5:
|
|
raise ValidationError(
|
|
'UUID version is not valid.')
|
|
|
|
if version == 1:
|
|
default = uuid.uuid1
|
|
elif version == 3:
|
|
default = uuid.uuid3
|
|
elif version == 4:
|
|
default = uuid.uuid4
|
|
elif version == 5:
|
|
default = uuid.uuid5
|
|
|
|
kwargs.setdefault('primary_key', primary_key)
|
|
kwargs.setdefault('editable', editable)
|
|
kwargs.setdefault('default', default)
|
|
super().__init__(*args, **kwargs)
|
|
|
|
|
|
class UrlsafeTokenField(models.CharField):
|
|
"""
|
|
A field for storing a unique token in database.
|
|
"""
|
|
|
|
def __init__(self, editable=False, max_length=128, factory=None, **kwargs):
|
|
"""
|
|
Parameters
|
|
----------
|
|
editable: bool
|
|
If true token is editable.
|
|
max_length: int
|
|
Maximum length of the token.
|
|
factory: callable
|
|
If provided, called with max_length of the field instance to generate token.
|
|
|
|
Raises
|
|
------
|
|
TypeError
|
|
non-callable value for factory is not supported.
|
|
"""
|
|
|
|
if factory is not None and not isinstance(factory, Callable):
|
|
raise TypeError("'factory' should either be a callable or 'None'")
|
|
self._factory = factory
|
|
|
|
kwargs.pop('default', None) # passing default value has not effect.
|
|
|
|
super().__init__(editable=editable, max_length=max_length, **kwargs)
|
|
|
|
def get_default(self):
|
|
if self._factory is not None:
|
|
return self._factory(self.max_length)
|
|
# generate a token of length x1.33 approx. trim up to max length
|
|
token = secrets.token_urlsafe(self.max_length)[:self.max_length]
|
|
return token
|
|
|
|
def deconstruct(self):
|
|
name, path, args, kwargs = super().deconstruct()
|
|
kwargs['factory'] = self._factory
|
|
return name, path, args, kwargs
|