apps/catalogue/models/listeners.py

   1 # -*- coding: utf-8 -*-
   2 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   3 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   4 #
   5 from django.conf import settings
   6 from django.db.models.signals import post_save, pre_delete, post_delete
   7 import django.dispatch
   8 from catalogue.models import Tag, BookMedia, Book, Fragment
   9 from catalogue import tasks
  10 from newtagging.models import tags_updated
  11
  12
  13 def _tags_updated_handler(sender, affected_tags, **kwargs):
  14     # reset tag global counter
  15     # we want Tag.changed_at updated for API to know the tag was touched
  16     for tag in affected_tags:
  17         tasks.touch_tag(tag)
  18
  19     # if book tags changed, reset book tag counter
  20     if isinstance(sender, Book) and \
  21                 Tag.objects.filter(pk__in=(tag.pk for tag in affected_tags)).\
  22                     exclude(category__in=('book', 'theme', 'set')).count():
  23         sender.reset_tag_counter()
  24     # if fragment theme changed, reset book theme counter
  25     elif isinstance(sender, Fragment) and \
  26                 Tag.objects.filter(pk__in=(tag.pk for tag in affected_tags)).\
  27                     filter(category='theme').count():
  28         sender.book.reset_theme_counter()
  29 tags_updated.connect(_tags_updated_handler)
  30
  31
  32 def _pre_delete_handler(sender, instance, **kwargs):
  33     """ refresh Book on BookMedia delete """
  34     if sender == BookMedia:
  35         instance.book.save()
  36 pre_delete.connect(_pre_delete_handler)
  37
  38
  39 def _post_save_handler(sender, instance, **kwargs):
  40     """ refresh all the short_html stuff on BookMedia update """
  41     if sender == BookMedia:
  42         instance.book.save()
  43 post_save.connect(_post_save_handler)
  44
  45
  46 if not settings.NO_SEARCH_INDEX:
  47     @django.dispatch.receiver(post_delete, sender=Book)
  48     def _remove_book_from_index_handler(sender, instance, **kwargs):
  49         """ remove the book from search index, when it is deleted."""
  50         import search
  51         search.JVM.attachCurrentThread()
  52         idx = search.Index()
  53         idx.open(timeout=10000)  # 10 seconds timeout.
  54         try:
  55             idx.remove_book(instance)
  56             idx.index_tags()
  57         finally:
  58             idx.close()