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
-
tags_updated = Signal(providing_args=["affected_tags"])
+
def get_queryset_and_model(queryset_or_model):
"""
Given a ``QuerySet`` or a ``Model``, returns a two-tuple of
try:
return queryset_or_model, queryset_or_model.model
except AttributeError:
- return queryset_or_model._default_manager.all(), queryset_or_model
+ return queryset_or_model.objects.all(), queryset_or_model
############
updated_tags = self.model.get_tag_list(tags)
# Remove tags which no longer apply
- tags_for_removal = [tag for tag in current_tags \
- if tag not in updated_tags]
+ tags_for_removal = [tag for tag in current_tags if tag not in updated_tags]
if len(tags_for_removal):
- self.intermediary_table_model._default_manager.filter(content_type__pk=content_type.pk,
- object_id=obj.pk,
- tag__in=tags_for_removal).delete()
+ self.intermediary_table_model.objects.filter(
+ content_type__pk=content_type.pk,
+ object_id=obj.pk,
+ tag__in=tags_for_removal).delete()
# Add new tags
- tags_to_add = [tag for tag in updated_tags
- if tag not in current_tags]
+ tags_to_add = [tag for tag in updated_tags if tag not in current_tags]
for tag in tags_to_add:
- if tag not in current_tags:
- self.intermediary_table_model._default_manager.create(tag=tag, content_object=obj)
+ existing = self.intermediary_table_model.objects.filter(
+ content_type__pk=content_type.pk, object_id=obj.pk, tag=tag)
+ if not existing:
+ self.intermediary_table_model.objects.create(tag=tag, content_object=obj)
tags_updated.send(sender=type(obj), instance=obj, affected_tags=tags_to_add + tags_for_removal)
Remove tag from an object.
"""
content_type = ContentType.objects.get_for_model(obj)
- self.intermediary_table_model._default_manager.filter(content_type__pk=content_type.pk,
- object_id=obj.pk, tag=tag).delete()
+ self.intermediary_table_model.objects.filter(
+ content_type__pk=content_type.pk, object_id=obj.pk, tag=tag).delete()
+
+ def add_tag(self, obj, tag):
+ """
+ Add tag to an object.
+ """
+ content_type = ContentType.objects.get_for_model(obj)
+ relations = self.intermediary_table_model.objects.filter(
+ content_type__pk=content_type.pk, object_id=obj.pk, tag=tag)
+ if not relations:
+ self.intermediary_table_model.objects.create(tag=tag, content_object=obj)
def get_for_object(self, obj):
"""
``filters`` argument.
"""
# TODO: Do we really need this filters stuff?
- if filters is None: filters = {}
+ if filters is None:
+ filters = {}
- queryset = model._default_manager.filter()
+ queryset = model.objects.filter()
for f in filters.items():
queryset.query.add_filter(f)
usage = self.usage_for_queryset(queryset, counts)
each tag, indicating how many times it has been used against
the Model class in question.
"""
- usage = self.model._default_manager.filter(
+ usage = self.model.objects.filter(
items__content_type=ContentType.objects.get_for_model(queryset.model),
- items__object_id__in=queryset
- )
+ items__object_id__in=queryset)
if counts:
usage = usage.annotate(count=models.Count('id'))
else:
##########
# 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)."
+ """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
return [tag_list]
else:
return tag_list
-
fnp / wolnelektury.git / blobdiff