def add_tags(self, instance, tags):
"""
Add tags to item
"""
if is_string(tags):
tags = string_to_list(tags)
delta = [x.strip().lower() for x in (set(tags) - set(instance.tags_list)) if x.strip()]
new_tags = [ Tag.objects.get_or_create(name=x)[0] for x in set(delta) ]
return self._add_tags(instance, new_tags)
def remove_tags(self, instance, tags):
"""
Remove given tags
"""
if is_string(tags):
tags = string_to_list(tags)
tags = set([x.strip().lower() for x in tags if x.strip() ])
tags = [x for x in tags if x in instance.tags_list]
if not tags:
return []
obsolete_tags = Tag.objects.filter(name__in=tags )
return self._remove_tags(instance, obsolete_tags)
def update_tags(self, instance, tags):
"""
Update tags from an item
"""
if not tags:
return []
if not is_tagstar_maintained(instance):
raise ItemNotTagstarMaintained("Item %s is not under Tagstar" % instance.__class__)
if is_string(tags):
tags = string_to_list(tags)
tags = set([x.strip().lower() for x in tags])
instance_tags = instance._init_tags and set([ x.strip().lower() for x in instance._init_tags.split(',')]) or set()
if instance_tags != tags:
new_tags = set( Tag.objects.get_or_create(name=x.strip().lower())[0] for x in (tags - instance_tags) if x.strip() )
obsolete_tags = Tag.objects.filter(name__in=(instance_tags - tags) )
self._add_tags(instance, new_tags)
self._remove_tags(instance, obsolete_tags)
return list(tags)
