# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
#
from django.conf import settings
+from django.contrib.contenttypes.fields import GenericForeignKey
+from django.contrib.contenttypes.models import ContentType
from django.core.cache import caches
from django.contrib.auth.models import User
+from django.core.exceptions import ObjectDoesNotExist
from django.db import models
from django.db.models import permalink
from django.db.models.query import Prefetch
)
+class TagRelation(models.Model):
+
+ tag = models.ForeignKey('Tag', verbose_name=_('tag'), related_name='items')
+ content_type = models.ForeignKey(ContentType, verbose_name=_('content type'))
+ object_id = models.PositiveIntegerField(_('object id'), db_index=True)
+ content_object = GenericForeignKey('content_type', 'object_id')
+
+ class Meta:
+ db_table = 'catalogue_tag_relation'
+ unique_together = (('tag', 'content_type', 'object_id'),)
+
+ def __unicode__(self):
+ try:
+ return u'%s [%s]' % (self.content_type.get_object_for_this_type(pk=self.object_id), self.tag)
+ except ObjectDoesNotExist:
+ return u'<deleted> [%s]' % self.tag
+
+
class Tag(TagBase):
"""A tag attachable to books and fragments (and possibly anything).
after_change = Signal(providing_args=['instance', 'languages'])
+ intermediary_table_model = TagRelation
+
class UrlDeprecationWarning(DeprecationWarning):
def __init__(self, tags=None):
super(Tag.UrlDeprecationWarning, self).__init__()
return meta_tags
-# Pickle complains about not having this.
-TagRelation = Tag.intermediary_table_model
-
-
def prefetch_relations(objects, category, only_name=True):
queryset = TagRelation.objects.filter(tag__category=category).select_related('tag')
if only_name:
Models and managers for generic tagging.
"""
-from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType
from django.db import connection, models
-from django.utils.translation import ugettext_lazy as _
from django.db.models.base import ModelBase
-from django.core.exceptions import ObjectDoesNotExist
from django.dispatch import Signal
qn = connection.ops.quote_name
##########
# Models #
##########
-def create_intermediary_table_model(model):
- """Create an intermediary table model for the specific tag model"""
- name = model.__name__ + 'Relation'
-
- class Meta:
- db_table = '%s_relation' % model._meta.db_table
- unique_together = (('tag', 'content_type', 'object_id'),)
- app_label = model._meta.app_label
-
- def obj_unicode(self):
- try:
- return u'%s [%s]' % (self.content_type.get_object_for_this_type(pk=self.object_id), self.tag)
- except ObjectDoesNotExist:
- return u'<deleted> [%s]' % self.tag
-
- # Set up a dictionary to simulate declarations within a class
- attrs = {
- '__module__': model.__module__,
- 'Meta': Meta,
- 'tag': models.ForeignKey(model, verbose_name=_('tag'), related_name='items'),
- 'content_type': models.ForeignKey(ContentType, verbose_name=_('content type')),
- 'object_id': models.PositiveIntegerField(_('object id'), db_index=True),
- 'content_object': GenericForeignKey('content_type', 'object_id'),
- '__unicode__': obj_unicode,
- }
-
- return type(name, (models.Model,), attrs)
-
class TagMeta(ModelBase):
"""Metaclass for tag models (models inheriting from TagBase)."""
def __new__(mcs, name, bases, attrs):
model = super(TagMeta, mcs).__new__(mcs, name, bases, attrs)
if not model._meta.abstract:
- # Create an intermediary table and register custom managers for concrete models
- model.intermediary_table_model = create_intermediary_table_model(model)
+ # Register custom managers for concrete models
TagManager(model.intermediary_table_model).contribute_to_class(model, 'objects')
TaggedItemManager(model).contribute_to_class(model.intermediary_table_model, 'objects')
return model