118 lines
3.8 KiB
Python

from datetime import datetime
from django.core.exceptions import ImproperlyConfigured
from django.utils.text import slugify
from ..mixins import AtomicSlugRetryMixin
from ..util import get_language_codes
from ..value import LocalizedValue
from .autoslug_field import LocalizedAutoSlugField
class LocalizedUniqueSlugField(LocalizedAutoSlugField):
"""Automatically provides slugs for a localized field upon saving.".
An improved version of :see:LocalizedAutoSlugField,
which adds:
- Concurrency safety
- Improved performance
When in doubt, use this over :see:LocalizedAutoSlugField.
Inherit from :see:AtomicSlugRetryMixin in your model to
make this field work properly.
By default, this creates a new slug if the field(s) specified
in `populate_from` are changed. Set `immutable=True` to get
immutable slugs.
"""
def __init__(self, *args, **kwargs):
"""Initializes a new instance of :see:LocalizedUniqueSlugField."""
kwargs["uniqueness"] = kwargs.pop("uniqueness", get_language_codes())
self.immutable = kwargs.pop("immutable", False)
super(LocalizedUniqueSlugField, self).__init__(*args, **kwargs)
self.populate_from = kwargs.pop("populate_from")
self.include_time = kwargs.pop("include_time", False)
def deconstruct(self):
"""Deconstructs the field into something the database can store."""
name, path, args, kwargs = super(
LocalizedUniqueSlugField, self
).deconstruct()
kwargs["populate_from"] = self.populate_from
kwargs["include_time"] = self.include_time
if self.immutable is True:
kwargs["immutable"] = self.immutable
return name, path, args, kwargs
def pre_save(self, instance, add: bool):
"""Ran just before the model is saved, allows us to built the slug.
Arguments:
instance:
The model that is being saved.
add:
Indicates whether this is a new entry
to the database or an update.
Returns:
The localized slug that was generated.
"""
if not isinstance(instance, AtomicSlugRetryMixin):
raise ImproperlyConfigured(
(
"Model '%s' does not inherit from AtomicSlugRetryMixin. "
"Without this, the LocalizedUniqueSlugField will not work."
)
% type(instance).__name__
)
slugs = LocalizedValue()
for lang_code, value in self._get_populate_values(instance):
if not value:
continue
slug = slugify(value, allow_unicode=True)
current_slug = getattr(instance, self.name).get(lang_code)
if current_slug and self.immutable:
slugs.set(lang_code, current_slug)
continue
# verify whether it's needed to re-generate a slug,
# if not, re-use the same slug
if instance.pk is not None:
if current_slug is not None:
current_slug_end_index = current_slug.rfind("-")
stripped_slug = current_slug[0:current_slug_end_index]
if slug == stripped_slug:
slugs.set(lang_code, current_slug)
continue
if self.include_time:
slug += "-%d" % datetime.now().microsecond
retries = getattr(instance, "retries", 0)
if retries > 0:
# do not add another - if we already added time
if not self.include_time:
slug += "-"
slug += "%d" % retries
slugs.set(lang_code, slug)
setattr(instance, self.name, slugs)
return slugs