def all(cls):
		'''Return all tags that are currently applied to any dataset.

		:returns: a list of all tags that are currently applied to any dataset
		:rtype: list of ckan.model.tag.Tag objects

		'''
#		if vocab_id_or_name:
#			vocab = vocabulary.Vocabulary.get(vocab_id_or_name)
#			if vocab is None:
#				# The user specified an invalid vocab.
#				raise ckan.logic.NotFound("could not find vocabulary '%s'"
#						% vocab_id_or_name)
#		   query = meta.Session.query(Tag).filter(Tag.vocabulary_id==vocab.id)
#		else:
		query = meta.Session.query(SemanticTag)
		query = query.distinct().join(TagSemanticTag)
#		query = query.filter_by(state='active')
		return query
Return all tags that are currently applied to any dataset.

		:returns: a list of all tags that are currently applied to any dataset
		:rtype: list of ckan.model.tag.Tag objects