X-Git-Url: https://git.mdrn.pl/wolnelektury.git/blobdiff_plain/d99d71844b7b97800dcab7cbb81c3a4185acbb48..e4e3b8bd323e57df11b10e06e2a1fbf1b134ca54:/apps/catalogue/models.py?ds=sidebyside diff --git a/apps/catalogue/models.py b/apps/catalogue/models.py index baf00a122..d0a620a96 100644 --- a/apps/catalogue/models.py +++ b/apps/catalogue/models.py @@ -2,25 +2,32 @@ # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later. # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information. # +from datetime import datetime + from django.db import models from django.db.models import permalink, Q +from django.core.cache import cache from django.utils.translation import ugettext_lazy as _ from django.contrib.auth.models import User from django.core.files import File from django.template.loader import render_to_string -from django.template.defaultfilters import slugify from django.utils.safestring import mark_safe from django.utils.translation import get_language from django.core.urlresolvers import reverse +from django.db.models.signals import post_save, m2m_changed, pre_delete from django.conf import settings from newtagging.models import TagBase, tags_updated from newtagging import managers -from catalogue.fields import JSONField +from catalogue.fields import JSONField, OverwritingFileField +from catalogue.utils import ExistingFile from librarian import dcparser, html, epub, NoDublinCore +import mutagen from mutagen import id3 +from slughifi import slughifi +from sortify import sortify TAG_CATEGORIES = ( @@ -40,6 +47,9 @@ MEDIA_FORMATS = ( ('daisy', _('DAISY file')), ) +# not quite, but Django wants you to set a timeout +CACHE_FOREVER = 2419200 # 28 days + class TagSubcategoryManager(models.Manager): def __init__(self, subcategory): super(TagSubcategoryManager, self).__init__() @@ -59,10 +69,16 @@ class Tag(TagBase): main_page = models.BooleanField(_('main page'), default=False, db_index=True, help_text=_('Show tag on main page')) user = models.ForeignKey(User, blank=True, null=True) - book_count = models.IntegerField(_('book count'), blank=False, null=True) + book_count = models.IntegerField(_('book count'), blank=True, null=True) gazeta_link = models.CharField(blank=True, max_length=240) wiki_link = models.CharField(blank=True, max_length=240) + created_at = models.DateTimeField(_('creation date'), auto_now_add=True, db_index=True) + changed_at = models.DateTimeField(_('creation date'), auto_now=True, db_index=True) + + class UrlDeprecationWarning(DeprecationWarning): + pass + categories_rev = { 'autor': 'author', 'epoka': 'epoch', @@ -121,19 +137,20 @@ class Tag(TagBase): real_tags = [] ambiguous_slugs = [] category = None + deprecated = False tags_splitted = tags.split('/') - for index, name in enumerate(tags_splitted): - if name in Tag.categories_rev: + for name in tags_splitted: + if category: + real_tags.append(Tag.objects.get(slug=name, category=category)) + category = None + elif name in Tag.categories_rev: category = Tag.categories_rev[name] else: - if category: - real_tags.append(Tag.objects.get(slug=name, category=category)) - category = None - else: - try: - real_tags.append(Tag.objects.exclude(category='book').get(slug=name)) - except Tag.MultipleObjectsReturned, e: - ambiguous_slugs.append(name) + try: + real_tags.append(Tag.objects.exclude(category='book').get(slug=name)) + deprecated = True + except Tag.MultipleObjectsReturned, e: + ambiguous_slugs.append(name) if category: # something strange left off @@ -144,8 +161,11 @@ class Tag(TagBase): e.tags = real_tags e.ambiguous_slugs = ambiguous_slugs raise e - else: - return real_tags + if deprecated: + e = Tag.UrlDeprecationWarning() + e.tags = real_tags + raise e + return real_tags else: return TagBase.get_tag_list(tags) @@ -155,25 +175,30 @@ class Tag(TagBase): # TODO: why is this hard-coded ? -def book_upload_path(ext=None): +def book_upload_path(ext=None, maxlen=100): def get_dynamic_path(media, filename, ext=ext): # how to put related book's slug here? if not ext: - ext = media.type + if media.type == 'daisy': + ext = 'daisy.zip' + else: + ext = media.type if not media.name: - name = slugify(filename.split(".")[0]) + name = slughifi(filename.split(".")[0]) else: - name = slugify(media.name) - return 'lektura/%s.%s' % (name, ext) + name = slughifi(media.name) + return 'book/%s/%s.%s' % (ext, name[:maxlen-len('book/%s/.%s' % (ext, ext))-4], ext) return get_dynamic_path class BookMedia(models.Model): type = models.CharField(_('type'), choices=MEDIA_FORMATS, max_length="100") - name = models.CharField(_('name'), max_length="100", blank=True) - file = models.FileField(_('file'), upload_to=book_upload_path(), blank=True) + name = models.CharField(_('name'), max_length="100") + file = OverwritingFileField(_('file'), upload_to=book_upload_path()) uploaded_at = models.DateTimeField(_('creation date'), auto_now_add=True, editable=False) - extra_info = JSONField(_('extra information'), default='{}') + extra_info = JSONField(_('extra information'), default='{}', editable=False) + book = models.ForeignKey('Book', related_name='media') + source_sha1 = models.CharField(null=True, blank=True, max_length=40, editable=False) def __unicode__(self): return "%s (%s)" % (self.name, self.file.name.split("/")[-1]) @@ -183,35 +208,86 @@ class BookMedia(models.Model): verbose_name = _('book media') verbose_name_plural = _('book media') - def save(self, force_insert=False, force_update=False): - media = super(BookMedia, self).save(force_insert, force_update) - if self.type == 'mp3': - file = self.file - extra_info = self.get_extra_info_value() - extra_info.update(self.get_mp3_info()) - self.set_extra_info_value(extra_info) - media = super(BookMedia, self).save(force_insert, force_update) - return media - - def get_mp3_info(self): - """Retrieves artist and director names from audio ID3 tags.""" + def save(self, *args, **kwargs): try: - audio = id3.ID3(self.file.path) - artist_name = ', '.join(', '.join(tag.text) for tag in audio.getall('TPE1')) - director_name = ', '.join(', '.join(tag.text) for tag in audio.getall('TPE3')) - except: - artist_name = director_name = '' - return {'artist_name': artist_name, 'director_name': director_name} + old = BookMedia.objects.get(pk=self.pk) + except BookMedia.DoesNotExist, e: + pass + else: + # if name changed, change the file name, too + if slughifi(self.name) != slughifi(old.name): + self.file.save(None, ExistingFile(self.file.path), save=False, leave=True) + + super(BookMedia, self).save(*args, **kwargs) + extra_info = self.get_extra_info_value() + extra_info.update(self.read_meta()) + self.set_extra_info_value(extra_info) + self.source_sha1 = self.read_source_sha1(self.file.path, self.type) + return super(BookMedia, self).save(*args, **kwargs) + + def read_meta(self): + """ + Reads some metadata from the audiobook. + """ + + artist_name = director_name = project = funded_by = '' + if self.type == 'mp3': + try: + audio = id3.ID3(self.file.path) + artist_name = ', '.join(', '.join(tag.text) for tag in audio.getall('TPE1')) + director_name = ', '.join(', '.join(tag.text) for tag in audio.getall('TPE3')) + project = ", ".join([t.data for t in audio.getall('PRIV') + if t.owner=='wolnelektury.pl?project']) + funded_by = ", ".join([t.data for t in audio.getall('PRIV') + if t.owner=='wolnelektury.pl?funded_by']) + except: + pass + elif self.type == 'ogg': + try: + audio = mutagen.File(self.file.path) + artist_name = ', '.join(audio.get('artist', [])) + director_name = ', '.join(audio.get('conductor', [])) + project = ", ".join(audio.get('project', [])) + funded_by = ", ".join(audio.get('funded_by', [])) + except: + pass + else: + return {} + return {'artist_name': artist_name, 'director_name': director_name, + 'project': project, 'funded_by': funded_by} + + @staticmethod + def read_source_sha1(filepath, filetype): + """ + Reads source file SHA1 from audiobok metadata. + """ + + if filetype == 'mp3': + try: + audio = id3.ID3(filepath) + return [t.data for t in audio.getall('PRIV') + if t.owner=='wolnelektury.pl?flac_sha1'][0] + except: + return None + elif filetype == 'ogg': + try: + audio = mutagen.File(filepath) + return audio.get('flac_sha1', [None])[0] + except: + return None + else: + return None class Book(models.Model): title = models.CharField(_('title'), max_length=120) + sort_key = models.CharField(_('sort_key'), max_length=120, db_index=True, editable=False) slug = models.SlugField(_('slug'), max_length=120, unique=True, db_index=True) description = models.TextField(_('description'), blank=True) - created_at = models.DateTimeField(_('creation date'), auto_now_add=True) - _short_html = models.TextField(_('short HTML'), editable=False) + created_at = models.DateTimeField(_('creation date'), auto_now_add=True, db_index=True) + changed_at = models.DateTimeField(_('creation date'), auto_now=True, db_index=True) parent_number = models.IntegerField(_('parent number'), default=0) - extra_info = JSONField(_('extra information')) + extra_info = JSONField(_('extra information'), default='{}') gazeta_link = models.CharField(blank=True, max_length=240) wiki_link = models.CharField(blank=True, max_length=240) # files generated during publication @@ -220,22 +296,17 @@ class Book(models.Model): pdf_file = models.FileField(_('PDF file'), upload_to=book_upload_path('pdf'), blank=True) epub_file = models.FileField(_('EPUB file'), upload_to=book_upload_path('epub'), blank=True) txt_file = models.FileField(_('TXT file'), upload_to=book_upload_path('txt'), blank=True) - # other files - medias = models.ManyToManyField(BookMedia, blank=True) - + parent = models.ForeignKey('self', blank=True, null=True, related_name='children') objects = models.Manager() tagged = managers.ModelTaggedItemManager(Tag) tags = managers.TagDescriptor(Tag) - _tag_counter = JSONField(null=True, editable=False) - _theme_counter = JSONField(null=True, editable=False) - class AlreadyExists(Exception): pass class Meta: - ordering = ('title',) + ordering = ('sort_key',) verbose_name = _('book') verbose_name_plural = _('books') @@ -243,16 +314,14 @@ class Book(models.Model): return self.title def save(self, force_insert=False, force_update=False, reset_short_html=True, **kwargs): + self.sort_key = sortify(self.title) + + ret = super(Book, self).save(force_insert, force_update) + if reset_short_html: - # Reset _short_html during save - update = {} - for key in filter(lambda x: x.startswith('_short_html'), self.__dict__): - update[key] = '' - self.__setattr__(key, '') - # Fragment.short_html relies on book's tags, so reset it here too - self.fragments.all().update(**update) + self.reset_short_html() - return super(Book, self).save(force_insert, force_update) + return ret @permalink def get_absolute_url(self): @@ -301,7 +370,7 @@ class Book(models.Model): else: return False else: - if self.medias.filter(book=self, type=type).count() > 0: + if self.media.filter(type=type).exists(): return True else: return False @@ -313,13 +382,13 @@ class Book(models.Model): elif type == "html": return self.html_file elif type == "epub": - return self.html_file + return self.epub_file elif type == "txt": return self.txt_file elif type == "pdf": return self.pdf_file else: - return self.medias.filter(book=self, type=type) + return self.media.filter(type=type) else: return None @@ -332,11 +401,25 @@ class Book(models.Model): def get_daisy(self): return self.get_media("daisy") + def reset_short_html(self): + if self.id is None: + return + + cache_key = "Book.short_html/%d/%s" + for lang, langname in settings.LANGUAGES: + cache.delete(cache_key % (self.id, lang)) + # Fragment.short_html relies on book's tags, so reset it here too + for fragm in self.fragments.all(): + fragm.reset_short_html() + def short_html(self): - key = '_short_html_%s' % get_language() - short_html = getattr(self, key) + if self.id: + cache_key = "Book.short_html/%d/%s" % (self.id, get_language()) + short_html = cache.get(cache_key) + else: + short_html = None - if short_html and len(short_html): + if short_html is not None: return mark_safe(short_html) else: tags = self.tags.filter(~Q(category__in=('set', 'theme', 'book'))) @@ -353,16 +436,17 @@ class Book(models.Model): if self.has_media("txt"): formats.append(u'TXT' % self.get_media('txt').url) # other files - for m in self.medias.order_by('type'): + for m in self.media.order_by('type'): formats.append(u'%s' % (m.file.url, m.type.upper())) formats = [mark_safe(format) for format in formats] - setattr(self, key, unicode(render_to_string('catalogue/book_short.html', - {'book': self, 'tags': tags, 'formats': formats}))) - self.save(reset_short_html=False) - return mark_safe(getattr(self, key)) + short_html = unicode(render_to_string('catalogue/book_short.html', + {'book': self, 'tags': tags, 'formats': formats})) + if self.id: + cache.set(cache_key, short_html, CACHE_FOREVER) + return mark_safe(short_html) @property def root_ancestor(self): @@ -452,8 +536,7 @@ class Book(models.Model): epub_file = StringIO() try: epub.transform(BookImportDocProvider(self), self.slug, output_file=epub_file) - self.epub_file.save('%s.epub' % self.slug, ContentFile(epub_file.getvalue()), save=False) - self.save() + self.epub_file.save('%s.epub' % self.slug, ContentFile(epub_file.getvalue())) FileRecord(slug=self.slug, type='epub', sha1=sha1(epub_file.getvalue()).hexdigest()).save() except NoDublinCore: pass @@ -467,9 +550,73 @@ class Book(models.Model): child_book.save() book_descendants += list(child_book.children.all()) + def build_txt(self): + from StringIO import StringIO + from django.core.files.base import ContentFile + from librarian import text + + out = StringIO() + text.transform(open(self.xml_file.path), out) + self.txt_file.save('%s.txt' % self.slug, ContentFile(out.getvalue())) + + + def build_html(self): + from tempfile import NamedTemporaryFile + from markupstring import MarkupString + + meta_tags = list(self.tags.filter( + category__in=('author', 'epoch', 'genre', 'kind'))) + book_tag = self.book_tag() + + html_file = NamedTemporaryFile() + if html.transform(self.xml_file.path, html_file, parse_dublincore=False): + self.html_file.save('%s.html' % self.slug, File(html_file)) + + # get ancestor l-tags for adding to new fragments + ancestor_tags = [] + p = self.parent + while p: + ancestor_tags.append(p.book_tag()) + p = p.parent + + # Delete old fragments and create them from scratch + self.fragments.all().delete() + # Extract fragments + closed_fragments, open_fragments = html.extract_fragments(self.html_file.path) + for fragment in closed_fragments.values(): + try: + theme_names = [s.strip() for s in fragment.themes.split(',')] + except AttributeError: + continue + themes = [] + for theme_name in theme_names: + if not theme_name: + continue + tag, created = Tag.objects.get_or_create(slug=slughifi(theme_name), category='theme') + if created: + tag.name = theme_name + tag.sort_key = theme_name.lower() + tag.save() + themes.append(tag) + if not themes: + continue + + text = fragment.to_string() + short_text = '' + if (len(MarkupString(text)) > 240): + short_text = unicode(MarkupString(text)[:160]) + new_fragment = Fragment.objects.create(anchor=fragment.id, book=self, + text=text, short_text=short_text) + + new_fragment.save() + new_fragment.tags = set(meta_tags + themes + [book_tag] + ancestor_tags) + self.save() + return True + return False + @classmethod - def from_xml_file(cls, xml_file, overwrite=False, build_epub=True): + def from_xml_file(cls, xml_file, **kwargs): # use librarian to parse meta-data book_info = dcparser.parse(xml_file) @@ -477,16 +624,13 @@ class Book(models.Model): xml_file = File(open(xml_file)) try: - return cls.from_text_and_meta(xml_file, book_info, overwrite, build_epub=build_epub) + return cls.from_text_and_meta(xml_file, book_info, **kwargs) finally: xml_file.close() @classmethod - def from_text_and_meta(cls, raw_file, book_info, overwrite=False, build_epub=True): - from tempfile import NamedTemporaryFile - from slughifi import slughifi - from markupstring import MarkupString - from django.core.files.storage import default_storage + def from_text_and_meta(cls, raw_file, book_info, overwrite=False, build_epub=True, build_txt=True): + import re # check for parts before we do anything children = [] @@ -501,6 +645,8 @@ class Book(models.Model): # Read book metadata book_base, book_slug = book_info.url.rsplit('/', 1) + if re.search(r'[^a-zA-Z0-9-]', book_slug): + raise ValueError('Invalid characters in slug') book, created = Book.objects.get_or_create(slug=book_slug) if created: @@ -513,10 +659,9 @@ class Book(models.Model): book.title = book_info.title book.set_extra_info_value(book_info.to_dict()) - book._short_html = '' book.save() - book_tags = [] + meta_tags = [] categories = (('kinds', 'kind'), ('genres', 'genre'), ('authors', 'author'), ('epochs', 'epoch')) for field_name, category in categories: try: @@ -531,11 +676,11 @@ class Book(models.Model): tag, created = Tag.objects.get_or_create(slug=slughifi(tag_name), category=category) if created: tag.name = tag_name - tag.sort_key = tag_sort_key.lower() + tag.sort_key = sortify(tag_sort_key.lower()) tag.save() - book_tags.append(tag) + meta_tags.append(tag) - book.tags = book_tags + book_shelves + book.tags = set(meta_tags + book_shelves) book_tag = book.book_tag() @@ -550,46 +695,9 @@ class Book(models.Model): # delete old fragments when overwriting book.fragments.all().delete() - html_file = NamedTemporaryFile() - if html.transform(book.xml_file.path, html_file, parse_dublincore=False): - book.html_file.save('%s.html' % book.slug, File(html_file), save=False) - - # get ancestor l-tags for adding to new fragments - ancestor_tags = [] - p = book.parent - while p: - ancestor_tags.append(p.book_tag()) - p = p.parent - - # Extract fragments - closed_fragments, open_fragments = html.extract_fragments(book.html_file.path) - for fragment in closed_fragments.values(): - try: - theme_names = [s.strip() for s in fragment.themes.split(',')] - except AttributeError: - continue - themes = [] - for theme_name in theme_names: - if not theme_name: - continue - tag, created = Tag.objects.get_or_create(slug=slughifi(theme_name), category='theme') - if created: - tag.name = theme_name - tag.sort_key = theme_name.lower() - tag.save() - themes.append(tag) - if not themes: - continue - - text = fragment.to_string() - short_text = '' - if (len(MarkupString(text)) > 240): - short_text = unicode(MarkupString(text)[:160]) - new_fragment, created = Fragment.objects.get_or_create(anchor=fragment.id, book=book, - defaults={'text': text, 'short_text': short_text}) - - new_fragment.save() - new_fragment.tags = set(book_tags + themes + [book_tag] + ancestor_tags) + if book.build_html(): + if not settings.NO_BUILD_TXT and build_txt: + book.build_txt() if not settings.NO_BUILD_EPUB and build_epub: book.root_ancestor.build_epub() @@ -605,57 +713,69 @@ class Book(models.Model): fragment.tags = set(list(fragment.tags) + [book_tag]) book_descendants += list(child_book.children.all()) + book.save() + # refresh cache book.reset_tag_counter() book.reset_theme_counter() - book.save() return book - - def refresh_tag_counter(self): - tags = {} - for child in self.children.all().order_by(): - for tag_pk, value in child.tag_counter.iteritems(): - tags[tag_pk] = tags.get(tag_pk, 0) + value - for tag in self.tags.exclude(category__in=('book', 'theme', 'set')).order_by(): - tags[tag.pk] = 1 - self.set__tag_counter_value(tags) - self.save(reset_short_html=False) - return tags - def reset_tag_counter(self): - self._tag_counter = None - self.save(reset_short_html=False) + if self.id is None: + return + + cache_key = "Book.tag_counter/%d" % self.id + cache.delete(cache_key) if self.parent: self.parent.reset_tag_counter() @property def tag_counter(self): - if self._tag_counter is None: - return self.refresh_tag_counter() - return dict((int(k), v) for k, v in self.get__tag_counter_value().iteritems()) - - def refresh_theme_counter(self): - tags = {} - for fragment in Fragment.tagged.with_any([self.book_tag()]).order_by(): - for tag in fragment.tags.filter(category='theme').order_by(): - tags[tag.pk] = tags.get(tag.pk, 0) + 1 - self.set__theme_counter_value(tags) - self.save(reset_short_html=False) + if self.id: + cache_key = "Book.tag_counter/%d" % self.id + tags = cache.get(cache_key) + else: + tags = None + + if tags is None: + tags = {} + for child in self.children.all().order_by(): + for tag_pk, value in child.tag_counter.iteritems(): + tags[tag_pk] = tags.get(tag_pk, 0) + value + for tag in self.tags.exclude(category__in=('book', 'theme', 'set')).order_by(): + tags[tag.pk] = 1 + + if self.id: + cache.set(cache_key, tags, CACHE_FOREVER) return tags def reset_theme_counter(self): - self._theme_counter = None - self.save(reset_short_html=False) + if self.id is None: + return + + cache_key = "Book.theme_counter/%d" % self.id + cache.delete(cache_key) if self.parent: self.parent.reset_theme_counter() @property def theme_counter(self): - if self._theme_counter is None: - return self.refresh_theme_counter() - return dict((int(k), v) for k, v in self.get__theme_counter_value().iteritems()) + if self.id: + cache_key = "Book.theme_counter/%d" % self.id + tags = cache.get(cache_key) + else: + tags = None + + if tags is None: + tags = {} + for fragment in Fragment.tagged.with_any([self.book_tag()]).order_by(): + for tag in fragment.tags.filter(category='theme').order_by(): + tags[tag.pk] = tags.get(tag.pk, 0) + 1 + + if self.id: + cache.set(cache_key, tags, CACHE_FOREVER) + return tags def pretty_title(self, html_links=False): book = self @@ -674,11 +794,28 @@ class Book(models.Model): return ', '.join(names) + @classmethod + def tagged_top_level(cls, tags): + """ Returns top-level books tagged with `tags'. + + It only returns those books which don't have ancestors which are + also tagged with those tags. + + """ + # get relevant books and their tags + objects = cls.tagged.with_all(tags) + # eliminate descendants + l_tags = Tag.objects.filter(category='book', slug__in=[book.book_tag_slug() for book in objects]) + descendants_keys = [book.pk for book in cls.tagged.with_any(l_tags)] + if descendants_keys: + objects = objects.exclude(pk__in=descendants_keys) + + return objects + class Fragment(models.Model): text = models.TextField() short_text = models.TextField(editable=False) - _short_html = models.TextField(editable=False) anchor = models.CharField(max_length=120) book = models.ForeignKey(Book, related_name='fragments') @@ -694,16 +831,29 @@ class Fragment(models.Model): def get_absolute_url(self): return '%s#m%s' % (reverse('book_text', kwargs={'slug': self.book.slug}), self.anchor) + def reset_short_html(self): + if self.id is None: + return + + cache_key = "Fragment.short_html/%d/%s" + for lang, langname in settings.LANGUAGES: + cache.delete(cache_key % (self.id, lang)) + def short_html(self): - key = '_short_html_%s' % get_language() - short_html = getattr(self, key) - if short_html and len(short_html): + if self.id: + cache_key = "Fragment.short_html/%d/%s" % (self.id, get_language()) + short_html = cache.get(cache_key) + else: + short_html = None + + if short_html is not None: return mark_safe(short_html) else: - setattr(self, key, unicode(render_to_string('catalogue/fragment_short.html', - {'fragment': self}))) - self.save() - return mark_safe(getattr(self, key)) + short_html = unicode(render_to_string('catalogue/fragment_short.html', + {'fragment': self})) + if self.id: + cache.set(cache_key, short_html, CACHE_FOREVER) + return mark_safe(short_html) class FileRecord(models.Model): @@ -720,10 +870,17 @@ class FileRecord(models.Model): def __unicode__(self): return "%s %s.%s" % (self.sha1, self.slug, self.type) +########### +# +# SIGNALS +# +########### + def _tags_updated_handler(sender, affected_tags, **kwargs): # reset tag global counter - Tag.objects.filter(pk__in=[tag.pk for tag in affected_tags]).update(book_count=None) + # we want Tag.changed_at updated for API to know the tag was touched + Tag.objects.filter(pk__in=[tag.pk for tag in affected_tags]).update(book_count=None, changed_at=datetime.now()) # if book tags changed, reset book tag counter if isinstance(sender, Book) and \ @@ -737,3 +894,15 @@ def _tags_updated_handler(sender, affected_tags, **kwargs): sender.book.reset_theme_counter() tags_updated.connect(_tags_updated_handler) + +def _pre_delete_handler(sender, instance, **kwargs): + """ refresh Book on BookMedia delete """ + if sender == BookMedia: + instance.book.save() +pre_delete.connect(_pre_delete_handler) + +def _post_save_handler(sender, instance, **kwargs): + """ refresh all the short_html stuff on BookMedia update """ + if sender == BookMedia: + instance.book.save() +post_save.connect(_post_save_handler)