+ rel_info = book.related_info()
+ names = [(related_tag_name(tag), Tag.create_url('author', tag['slug']))
+ for tag in rel_info['tags'].get('author', ())]
+ if 'parents' in rel_info:
+ books = [(name, Book.create_url(slug))
+ for name, slug in rel_info['parents']]
+ names.extend(reversed(books))
+ names.append((self.title, self.get_absolute_url()))