src/catalogue/signals.py

   1 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   2 # Copyright © Fundacja Nowoczesna Polska. 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 picture.models import Picture, PictureArea
  11 from .models import BookMedia, Book, Collection, Fragment, Tag
  12
  13
  14 ####
  15 # BookMedia
  16 ####
  17
  18
  19 @receiver([post_save, post_delete], sender=BookMedia)
  20 def bookmedia_save(sender, instance, **kwargs):
  21     instance.book.set_audio_length()
  22     instance.book.save()
  23
  24
  25 ####
  26 # Collection
  27 ####
  28
  29
  30 @receiver(post_save, sender=Collection)
  31 def collection_save(sender, instance, **kwargs):
  32     caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()
  33
  34
  35 ####
  36 # Book
  37 ####
  38
  39
  40 @receiver(post_save, sender=Book)
  41 def book_save(sender, instance, **kwargs):
  42     # Books come out anywhere.
  43     caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()
  44     # deleting selectively is too much work
  45     try:
  46         caches['template_fragments'].clear()
  47     except ImproperlyConfigured:
  48         pass
  49     instance.clear_cache()
  50
  51
  52 @receiver(post_delete, sender=Book)
  53 def book_delete(sender, instance, **kwargs):
  54     caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()
  55
  56
  57 ####
  58 # Tag
  59 ####
  60
  61
  62 @receiver(Tag.after_change)
  63 def tag_after_change(sender, instance, **kwargs):
  64     caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()
  65
  66     for model in Book, Picture:
  67         for model_instance in model.tagged.with_all([instance]).only('pk'):
  68             model_instance.clear_cache()
  69
  70     if instance.category == 'author':
  71         for model in Fragment, PictureArea:
  72             for model_instance in model.tagged.with_all([instance]).only('pk'):
  73                 model_instance.clear_cache()
  74
  75
  76 @receiver(tags_updated)
  77 def receive_tags_updated(sender, instance, affected_tags, **kwargs):
  78     categories = set(tag.category for tag in affected_tags if tag.category not in ('set', 'book'))
  79     if not categories:
  80         return
  81
  82     caches[settings.CACHE_MIDDLEWARE_ALIAS].clear()
  83     instance.clear_cache()