src/catalogue/signals.py

   1 # This file is part of Wolne Lektury, licensed under GNU Affero GPLv3 or later.
   2 # Copyright © Fundacja Wolne Lektury. See NOTICE for more information.
   3 #
   4 from django.conf import settings
   5 from django.core.cache import caches
   6 from django.core.exceptions import ImproperlyConfigured
   7 from django.db.models.signals import post_save, post_delete
   8 from django.dispatch import receiver
   9 from newtagging.models import tags_updated
  10 from .models import BookMedia, Book, Collection, Fragment, Tag
  11
  12
  13 ####
  14 # BookMedia
  15 ####
  16
  17
  18 @receiver([post_save, post_delete], sender=BookMedia)
  19 def bookmedia_save(sender, instance, **kwargs):
  20     instance.book.set_audio_length()
  21     instance.book.save()
  22
  23
  24 ####
  25 # Collection
  26 ####
  27
  28
  29 @receiver(post_save, sender=Collection)
  30 def collection_save(sender, instance, **kwargs):
  31     caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()
  32
  33
  34 ####
  35 # Book
  36 ####
  37
  38
  39 @receiver(post_save, sender=Book)
  40 def book_save(sender, instance, **kwargs):
  41     # Books come out anywhere.
  42     caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()
  43     # deleting selectively is too much work
  44     try:
  45         caches['template_fragments'].clear()
  46     except ImproperlyConfigured:
  47         pass
  48     instance.clear_cache()
  49
  50
  51 @receiver(post_delete, sender=Book)
  52 def book_delete(sender, instance, **kwargs):
  53     caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()
  54
  55
  56 ####
  57 # Tag
  58 ####
  59
  60
  61 @receiver(Tag.after_change)
  62 def tag_after_change(sender, instance, **kwargs):
  63     caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()
  64
  65     for book in Book.tagged.with_all([instance]).only('pk'):
  66         book.clear_cache()
  67
  68
  69 @receiver(tags_updated)
  70 def receive_tags_updated(sender, instance, affected_tags, **kwargs):
  71     categories = set(tag.category for tag in affected_tags if tag.category not in ('set', 'book'))
  72     if not categories:
  73         return
  74
  75     caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()
  76     if sender in (Book,):
  77         instance.clear_cache()