sort_key can has ą, fixes #673

[wolnelektury.git] / apps / catalogue / models.py

diff --git a/apps/catalogue/models.py b/apps/catalogue/models.py
index d63581f..eb55b98 100644 (file)
--- a/apps/catalogue/models.py
+++ b/apps/catalogue/models.py
@@ -13,11 +13,11 @@ from django.utils.translation import get_language
 from django.core.urlresolvers import reverse
 from datetime import datetime
 
 from django.core.urlresolvers import reverse
 from datetime import datetime
 

-from newtagging.models import TagBase
+from newtagging.models import TagBase, tags_updated

 from newtagging import managers
 from catalogue.fields import JSONField
 
 from newtagging import managers
 from catalogue.fields import JSONField
 

-from librarian import html, dcparser
+from librarian import dcparser, html, epub, NoDublinCore

 from mutagen import id3
 
 
 from mutagen import id3
 
 


@@ -44,18 +44,18 @@ class TagSubcategoryManager(models.Manager):
 class Tag(TagBase):
     name = models.CharField(_('name'), max_length=50, db_index=True)
     slug = models.SlugField(_('slug'), max_length=120, db_index=True)
 class Tag(TagBase):
     name = models.CharField(_('name'), max_length=50, db_index=True)
     slug = models.SlugField(_('slug'), max_length=120, db_index=True)

-    sort_key = models.SlugField(_('sort key'), max_length=120, db_index=True)
+    sort_key = models.CharField(_('sort key'), max_length=120, db_index=True)

     category = models.CharField(_('category'), max_length=50, blank=False, null=False,
         db_index=True, choices=TAG_CATEGORIES)
     description = models.TextField(_('description'), blank=True)
     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)
     category = models.CharField(_('category'), max_length=50, blank=False, null=False,
         db_index=True, choices=TAG_CATEGORIES)
     description = models.TextField(_('description'), blank=True)
     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'), default=0, blank=False, null=False)
+    book_count = models.IntegerField(_('book count'), blank=False, null=True)

     death = models.IntegerField(_(u'year of death'), blank=True, null=True)
     gazeta_link = models.CharField(blank=True, max_length=240)
     wiki_link = models.CharField(blank=True, max_length=240)
     death = models.IntegerField(_(u'year of death'), blank=True, null=True)
     gazeta_link = models.CharField(blank=True, max_length=240)
     wiki_link = models.CharField(blank=True, max_length=240)

-    
+

     categories_rev = {
         'autor': 'author',
         'epoka': 'epoch',
     categories_rev = {
         'autor': 'author',
         'epoka': 'epoch',


@@ -98,12 +98,35 @@ class Tag(TagBase):
         """ calculates the year of public domain entry for an author """
         return self.death + 71 if self.death is not None else None
 
         """ calculates the year of public domain entry for an author """
         return self.death + 71 if self.death is not None else None
 

+    def get_count(self):
+        """ returns global book count for book tags, fragment count for themes """
+
+        if self.book_count is None:
+            if self.category == 'book':
+                # never used
+                objects = Book.objects.none()
+            elif self.category == 'theme':
+                objects = Fragment.tagged.with_all((self,))
+            else:
+                objects = Book.tagged.with_all((self,)).order_by()
+                if self.category != 'set':
+                    # eliminate descendants
+                    l_tags = Tag.objects.filter(slug__in=[book.book_tag_slug() for book in objects])
+                    descendants_keys = [book.pk for book in Book.tagged.with_any(l_tags)]
+                    if descendants_keys:
+                        objects = objects.exclude(pk__in=descendants_keys)
+            self.book_count = objects.count()
+            self.save()
+        return self.book_count
+

     @staticmethod
     def get_tag_list(tags):
         if isinstance(tags, basestring):
             real_tags = []
     @staticmethod
     def get_tag_list(tags):
         if isinstance(tags, basestring):
             real_tags = []

+            ambiguous_slugs = []

             category = None
             category = None

-            for name in tags.split('/'):
+            tags_splitted = tags.split('/')
+            for index, name in enumerate(tags_splitted):

                 if name in Tag.categories_rev:
                     category = Tag.categories_rev[name]
                 else:
                 if name in Tag.categories_rev:
                     category = Tag.categories_rev[name]
                 else:


@@ -111,19 +134,31 @@ class Tag(TagBase):
                         real_tags.append(Tag.objects.get(slug=name, category=category))
                         category = None
                     else:
                         real_tags.append(Tag.objects.get(slug=name, category=category))
                         category = None
                     else:

-                        real_tags.append(Tag.objects.get(slug=name))
+                        try:
+                            real_tags.append(Tag.objects.exclude(category='book').get(slug=name))
+                        except Tag.MultipleObjectsReturned, e:
+                            ambiguous_slugs.append(name)
+

             if category:
             if category:

-                raise Http404
-            return real_tags
+                # something strange left off
+                raise Tag.DoesNotExist()
+            if ambiguous_slugs:
+                # some tags should be qualified
+                e = Tag.MultipleObjectsReturned()
+                e.tags = real_tags
+                e.ambiguous_slugs = ambiguous_slugs
+                raise e
+            else:
+                return real_tags

         else:
             return TagBase.get_tag_list(tags)
         else:
             return TagBase.get_tag_list(tags)

-    
+

     @property
     def url_chunk(self):
         return '/'.join((Tag.categories_dict[self.category], self.slug))
 
 
     @property
     def url_chunk(self):
         return '/'.join((Tag.categories_dict[self.category], self.slug))
 
 

-# TODO: why is this hard-coded ? 
+# TODO: why is this hard-coded ?

 def book_upload_path(ext):
     def get_dynamic_path(book, filename):
         return 'lektura/%s.%s' % (book.slug, ext)
 def book_upload_path(ext):
     def get_dynamic_path(book, filename):
         return 'lektura/%s.%s' % (book.slug, ext)


@@ -134,7 +169,7 @@ class Book(models.Model):
     title = models.CharField(_('title'), max_length=120)
     slug = models.SlugField(_('slug'), max_length=120, unique=True, db_index=True)
     description = models.TextField(_('description'), blank=True)
     title = models.CharField(_('title'), max_length=120)
     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=True)
+    created_at = models.DateTimeField(_('creation date'), auto_now_add=True)

     _short_html = models.TextField(_('short HTML'), editable=False)
     parent_number = models.IntegerField(_('parent number'), default=0)
     extra_info = JSONField(_('extra information'))
     _short_html = models.TextField(_('short HTML'), editable=False)
     parent_number = models.IntegerField(_('parent number'), default=0)
     extra_info = JSONField(_('extra information'))


@@ -151,13 +186,14 @@ class Book(models.Model):
     txt_file = models.FileField(_('TXT file'), upload_to=book_upload_path('txt'), blank=True)
     mp3_file = models.FileField(_('MP3 file'), upload_to=book_upload_path('mp3'), blank=True)
     ogg_file = models.FileField(_('OGG file'), upload_to=book_upload_path('ogg'), blank=True)
     txt_file = models.FileField(_('TXT file'), upload_to=book_upload_path('txt'), blank=True)
     mp3_file = models.FileField(_('MP3 file'), upload_to=book_upload_path('mp3'), blank=True)
     ogg_file = models.FileField(_('OGG file'), upload_to=book_upload_path('ogg'), blank=True)

+    daisy_file = models.FileField(_('DAISY file'), upload_to=book_upload_path('daisy.zip'), blank=True)

 
     parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
 
     objects = models.Manager()
     tagged = managers.ModelTaggedItemManager(Tag)
     tags = managers.TagDescriptor(Tag)
 
     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)
 
     _tag_counter = JSONField(null=True, editable=False)
     _theme_counter = JSONField(null=True, editable=False)
 


@@ -172,11 +208,15 @@ class Book(models.Model):
     def __unicode__(self):
         return self.title
 
     def __unicode__(self):
         return self.title
 

-    def save(self, force_insert=False, force_update=False, reset_short_html=True, refresh_mp3=True):
+    def save(self, force_insert=False, force_update=False, reset_short_html=True, refresh_mp3=True, **kwargs):

         if reset_short_html:
             # Reset _short_html during save
         if reset_short_html:
             # Reset _short_html during save

+            update = {}

             for key in filter(lambda x: x.startswith('_short_html'), self.__dict__):
             for key in filter(lambda x: x.startswith('_short_html'), self.__dict__):

+                update[key] = ''

                 self.__setattr__(key, '')
                 self.__setattr__(key, '')

+            # Fragment.short_html relies on book's tags, so reset it here too
+            self.fragments.all().update(**update)

 
         book = super(Book, self).save(force_insert, force_update)
 
 
         book = super(Book, self).save(force_insert, force_update)
 


@@ -196,13 +236,16 @@ class Book(models.Model):
     @property
     def name(self):
         return self.title
     @property
     def name(self):
         return self.title

-    
+
+    def book_tag_slug(self):
+        return ('l-' + self.slug)[:120]
+

     def book_tag(self):
     def book_tag(self):

-        slug = ('l-' + self.slug)[:120]
+        slug = self.book_tag_slug()

         book_tag, created = Tag.objects.get_or_create(slug=slug, category='book')
         if created:
             book_tag.name = self.title[:50]
         book_tag, created = Tag.objects.get_or_create(slug=slug, category='book')
         if created:
             book_tag.name = self.title[:50]

-            book_tag.sort_key = slug
+            book_tag.sort_key = self.title.lower()

             book_tag.save()
         return book_tag
 
             book_tag.save()
         return book_tag
 


@@ -221,8 +264,8 @@ class Book(models.Model):
                 formats.append(u'<a href="%s">%s</a>' % (reverse('book_text', kwargs={'slug': self.slug}), _('Read online')))
             if self.pdf_file:
                 formats.append(u'<a href="%s">PDF</a>' % self.pdf_file.url)
                 formats.append(u'<a href="%s">%s</a>' % (reverse('book_text', kwargs={'slug': self.slug}), _('Read online')))
             if self.pdf_file:
                 formats.append(u'<a href="%s">PDF</a>' % self.pdf_file.url)

-            if self.epub_file:
-                formats.append(u'<a href="%s">EPUB</a>' % self.epub_file.url)
+            if self.root_ancestor.epub_file:
+                formats.append(u'<a href="%s">EPUB</a>' % self.root_ancestor.epub_file.url)

             if self.odt_file:
                 formats.append(u'<a href="%s">ODT</a>' % self.odt_file.url)
             if self.txt_file:
             if self.odt_file:
                 formats.append(u'<a href="%s">ODT</a>' % self.odt_file.url)
             if self.txt_file:


@@ -231,6 +274,8 @@ class Book(models.Model):
                 formats.append(u'<a href="%s">MP3</a>' % self.mp3_file.url)
             if self.ogg_file:
                 formats.append(u'<a href="%s">OGG</a>' % self.ogg_file.url)
                 formats.append(u'<a href="%s">MP3</a>' % self.mp3_file.url)
             if self.ogg_file:
                 formats.append(u'<a href="%s">OGG</a>' % self.ogg_file.url)

+            if self.daisy_file:
+                formats.append(u'<a href="%s">DAISY</a>' % self.daisy_file.url)

 
             formats = [mark_safe(format) for format in formats]
 
 
             formats = [mark_safe(format) for format in formats]
 


@@ -240,6 +285,18 @@ class Book(models.Model):
             return mark_safe(getattr(self, key))
 
 
             return mark_safe(getattr(self, key))
 
 

+    @property
+    def root_ancestor(self):
+        """ returns the oldest ancestor """
+
+        if not hasattr(self, '_root_ancestor'):
+            book = self
+            while book.parent:
+                book = book.parent
+            self._root_ancestor = book
+        return self._root_ancestor
+
+

     def get_mp3_info(self):
         """Retrieves artist and director names from audio ID3 tags."""
         audio = id3.ID3(self.mp3_file.path)
     def get_mp3_info(self):
         """Retrieves artist and director names from audio ID3 tags."""
         audio = id3.ID3(self.mp3_file.path)


@@ -272,13 +329,59 @@ class Book(models.Model):
     has_html_file.short_description = 'HTML'
     has_html_file.boolean = True
 
     has_html_file.short_description = 'HTML'
     has_html_file.boolean = True
 

+    def build_epub(self, remove_descendants=True):
+        """ (Re)builds the epub file.
+            If book has a parent, does nothing.
+            Unless remove_descendants is False, descendants' epubs are removed.
+        """
+    
+        from StringIO import StringIO
+        from hashlib import sha1
+        from django.core.files.base import ContentFile
+        from librarian import DocProvider
+
+        class BookImportDocProvider(DocProvider):
+            """ used for joined EPUBs """
+
+            def __init__(self, book):
+                self.book = book
+
+            def by_slug(self, slug):
+                if slug == self.book.slug:
+                    return self.book.xml_file
+                else:
+                    return Book.objects.get(slug=slug).xml_file
+
+        if self.parent:
+            # don't need an epub
+            return
+
+        epub_file = StringIO()
+        try:
+            epub.transform(BookImportDocProvider(self), self.slug, epub_file)
+            self.epub_file.save('%s.epub' % self.slug, ContentFile(epub_file.getvalue()), save=False)
+            self.save()
+            FileRecord(slug=self.slug, type='epub', sha1=sha1(epub_file.getvalue()).hexdigest()).save()
+        except NoDublinCore:
+            pass
+
+        book_descendants = list(self.children.all())
+        while len(book_descendants) > 0:
+            child_book = book_descendants.pop(0)
+            if remove_descendants and child_book.has_epub_file():
+                child_book.epub_file.delete()
+            # save anyway, to refresh short_html
+            child_book.save()
+            book_descendants += list(child_book.children.all())
+
+

     @classmethod
     def from_xml_file(cls, xml_file, overwrite=False):
         # use librarian to parse meta-data
         book_info = dcparser.parse(xml_file)
 
         if not isinstance(xml_file, File):
     @classmethod
     def from_xml_file(cls, xml_file, overwrite=False):
         # use librarian to parse meta-data
         book_info = dcparser.parse(xml_file)
 
         if not isinstance(xml_file, File):

-            xml_file = File(xml_file)
+            xml_file = File(open(xml_file))

 
         try:
             return cls.from_text_and_meta(xml_file, book_info, overwrite)
 
         try:
             return cls.from_text_and_meta(xml_file, book_info, overwrite)


@@ -290,6 +393,7 @@ class Book(models.Model):
         from tempfile import NamedTemporaryFile
         from slughifi import slughifi
         from markupstring import MarkupString
         from tempfile import NamedTemporaryFile
         from slughifi import slughifi
         from markupstring import MarkupString

+        from django.core.files.storage import default_storage

 
         # Read book metadata
         book_base, book_slug = book_info.url.rsplit('/', 1)
 
         # Read book metadata
         book_base, book_slug = book_info.url.rsplit('/', 1)


@@ -309,20 +413,25 @@ class Book(models.Model):
         book.save()
 
         book_tags = []
         book.save()
 
         book_tags = []

-        for category in ('kind', 'genre', 'author', 'epoch'):
-            tag_name = getattr(book_info, category)
-            tag_sort_key = tag_name
-            if category == 'author':
-                tag_sort_key = tag_name.last_name
-                tag_name = ' '.join(tag_name.first_names) + ' ' + tag_name.last_name
-            tag, created = Tag.objects.get_or_create(slug=slughifi(tag_name), category=category)
-            if created:
-                tag.name = tag_name
-                tag.sort_key = slughifi(tag_sort_key)
-                tag.save()
-            book_tags.append(tag)
-
-        book.tags = book_tags
+        categories = (('kinds', 'kind'), ('genres', 'genre'), ('authors', 'author'), ('epochs', 'epoch'))
+        for field_name, category in categories:
+            try:
+                tag_names = getattr(book_info, field_name)
+            except:
+                tag_names = [getattr(book_info, category)]
+            for tag_name in tag_names:
+                tag_sort_key = tag_name
+                if category == 'author':
+                    tag_sort_key = tag_name.last_name
+                    tag_name = ' '.join(tag_name.first_names) + ' ' + tag_name.last_name
+                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.save()
+                book_tags.append(tag)
+
+        book.tags = book_tags + book_shelves

 
         book_tag = book.book_tag()
 
 
         book_tag = book.book_tag()
 


@@ -337,56 +446,77 @@ class Book(models.Model):
                 except Book.DoesNotExist, e:
                     raise Book.DoesNotExist(_('Book with slug = "%s" does not exist.') % slug)
 
                 except Book.DoesNotExist, e:
                     raise Book.DoesNotExist(_('Book with slug = "%s" does not exist.') % slug)
 

-        book_descendants = list(book.children.all())
-        while len(book_descendants) > 0:
-            child_book = book_descendants.pop(0)
-            child_book.tags = list(child_book.tags) + [book_tag]
-            child_book.save()
-            for fragment in child_book.fragments.all():
-                fragment.tags = set(list(fragment.tags) + [book_tag])
-            book_descendants += list(child_book.children.all())
-

         # Save XML and HTML files
         book.xml_file.save('%s.xml' % book.slug, raw_file, save=False)
 
         # Save XML and HTML files
         book.xml_file.save('%s.xml' % book.slug, raw_file, save=False)
 

+        # 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)
 
         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)
             # Extract fragments
             closed_fragments, open_fragments = html.extract_fragments(book.html_file.path)

-            book_themes = []

             for fragment in closed_fragments.values():
             for fragment in closed_fragments.values():

-                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})
-

                 try:
                     theme_names = [s.strip() for s in fragment.themes.split(',')]
                 except AttributeError:
                     continue
                 themes = []
                 for theme_name in theme_names:
                 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, created = Tag.objects.get_or_create(slug=slughifi(theme_name), category='theme')
                     if created:
                         tag.name = theme_name

-                        tag.sort_key = slughifi(theme_name)
+                        tag.sort_key = theme_name.lower()

                         tag.save()
                     themes.append(tag)
                         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.save()

-                new_fragment.tags = set(list(book.tags) + themes + [book_tag])
-                book_themes += themes
+                new_fragment.tags = set(book_tags + themes + [book_tag] + ancestor_tags)
+
+        if not book.parent:
+            book.build_epub(remove_descendants=False)

 
 

-            book_themes = set(book_themes)
-            book.tags = list(book.tags) + list(book_themes) + book_shelves
+        book_descendants = list(book.children.all())
+        # add l-tag to descendants and their fragments
+        # delete unnecessary EPUB files
+        while len(book_descendants) > 0:
+            child_book = book_descendants.pop(0)
+            child_book.tags = list(child_book.tags) + [book_tag]
+            if child_book.has_epub_file():
+                child_book.epub_file.delete()
+            child_book.save()
+            for fragment in child_book.fragments.all():
+                fragment.tags = set(list(fragment.tags) + [book_tag])
+            book_descendants += list(child_book.children.all())
+
+        # refresh cache
+        book.reset_tag_counter()
+        book.reset_theme_counter()

 
         book.save()
         return book
 
         book.save()
         return book

-    
-    
+
+

     def refresh_tag_counter(self):
         tags = {}
         for child in self.children.all().order_by():
     def refresh_tag_counter(self):
         tags = {}
         for child in self.children.all().order_by():


@@ -397,7 +527,13 @@ class Book(models.Model):
         self.set__tag_counter_value(tags)
         self.save(reset_short_html=False, refresh_mp3=False)
         return tags
         self.set__tag_counter_value(tags)
         self.save(reset_short_html=False, refresh_mp3=False)
         return tags

-    
+
+    def reset_tag_counter(self):
+        self._tag_counter = None
+        self.save(reset_short_html=False, refresh_mp3=False)
+        if self.parent:
+            self.parent.reset_tag_counter()
+

     @property
     def tag_counter(self):
         if self._tag_counter is None:
     @property
     def tag_counter(self):
         if self._tag_counter is None:


@@ -412,13 +548,19 @@ class Book(models.Model):
         self.set__theme_counter_value(tags)
         self.save(reset_short_html=False, refresh_mp3=False)
         return tags
         self.set__theme_counter_value(tags)
         self.save(reset_short_html=False, refresh_mp3=False)
         return tags

-    
+
+    def reset_theme_counter(self):
+        self._theme_counter = None
+        self.save(reset_short_html=False, refresh_mp3=False)
+        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())
     @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())

-    
+

 
 
 class Fragment(models.Model):
 
 
 class Fragment(models.Model):


@@ -446,11 +588,8 @@ class Fragment(models.Model):
         if short_html and len(short_html):
             return mark_safe(short_html)
         else:
         if short_html and len(short_html):
             return mark_safe(short_html)
         else:

-            book_authors = [mark_safe(u'<a href="%s">%s</a>' % (tag.get_absolute_url(), tag.name))
-                for tag in self.book.tags if tag.category == 'author']
-

             setattr(self, key, unicode(render_to_string('catalogue/fragment_short.html',
             setattr(self, key, unicode(render_to_string('catalogue/fragment_short.html',

-                {'fragment': self, 'book': self.book, 'book_authors': book_authors})))
+                {'fragment': self})))

             self.save()
             return mark_safe(getattr(self, key))
 
             self.save()
             return mark_safe(getattr(self, key))
 


@@ -483,3 +622,34 @@ class BookStub(models.Model):
         return self.title
 
 
         return self.title
 
 

+class FileRecord(models.Model):
+    slug = models.SlugField(_('slug'), max_length=120, db_index=True)
+    type = models.CharField(_('type'), max_length=20, db_index=True)
+    sha1 = models.CharField(_('sha-1 hash'), max_length=40)
+    time = models.DateTimeField(_('time'), auto_now_add=True)
+
+    class Meta:
+        ordering = ('-time','-slug', '-type')
+        verbose_name = _('file record')
+        verbose_name_plural = _('file records')
+
+    def __unicode__(self):
+        return "%s %s.%s" % (self.sha1,  self.slug, self.type)
+
+
+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)
+
+    # if book tags changed, reset book tag counter
+    if isinstance(sender, Book) and \
+                Tag.objects.filter(pk__in=(tag.pk for tag in affected_tags)).\
+                    exclude(category__in=('book', 'theme', 'set')).count():
+        sender.reset_tag_counter()
+    # if fragment theme changed, reset book theme counter
+    elif isinstance(sender, Fragment) and \
+                Tag.objects.filter(pk__in=(tag.pk for tag in affected_tags)).\
+                    filter(category='theme').count():
+        sender.book.reset_theme_counter()
+tags_updated.connect(_tags_updated_handler)
+