def add_tag(self, obj, tag_name):
"""
Associates the given object with a tag.
"""
tag_names = parse_tag_input(tag_name)
if not len(tag_names):
raise AttributeError(_('No tags were given: "%s".') % tag_name)
if len(tag_names) > 1:
raise AttributeError(_('Multiple tags were given: "%s".') % tag_name)
tag_name = tag_names[0]
if settings.FORCE_LOWERCASE_TAGS:
tag_name = tag_name.lower()
tag, created = self.get_or_create(name=tag_name)
ctype = ContentType.objects.get_for_model(obj)
TaggedItem._default_manager.get_or_create(
tag=tag, content_type=ctype, object_id=obj.pk)
def update_tags(self, obj, tag_names):
"""
Update tags associated with an object.
"""
ctype = ContentType.objects.get_for_model(obj)
current_tags = list(self.filter(items__content_type__pk=ctype.pk,
items__object_id=obj.pk))
updated_tag_names = parse_tag_input(tag_names)
if settings.FORCE_LOWERCASE_TAGS:
updated_tag_names = [t.lower() for t in updated_tag_names]
# Remove tags which no longer apply
tags_for_removal = [tag for tag in current_tags \
if tag.name not in updated_tag_names]
if len(tags_for_removal):
TaggedItem._default_manager.filter(content_type__pk=ctype.pk,
object_id=obj.pk,
tag__in=tags_for_removal).delete()
# Add new tags
current_tag_names = [tag.name for tag in current_tags]
for tag_name in updated_tag_names:
if tag_name not in current_tag_names:
tag, created = self.get_or_create(name=tag_name)
TaggedItem._default_manager.create(tag=tag, object=obj)
