- Added librarian as a submodule.
[wolnelektury.git] / apps / catalogue / models.py
index db91190..367f382 100644 (file)
@@ -1,4 +1,7 @@
 # -*- coding: utf-8 -*-
 # -*- coding: utf-8 -*-
+# This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
+# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
+#
 from django.db import models
 from django.db.models import permalink, Q
 from django.utils.translation import ugettext_lazy as _
 from django.db import models
 from django.db.models import permalink, Q
 from django.utils.translation import ugettext_lazy as _
@@ -6,11 +9,16 @@ from django.contrib.auth.models import User
 from django.core.files import File
 from django.template.loader import render_to_string
 from django.utils.safestring import mark_safe
 from django.core.files import File
 from django.template.loader import render_to_string
 from django.utils.safestring import mark_safe
+from django.utils.translation import get_language
+from django.core.urlresolvers import reverse
+from datetime import datetime
 
 from newtagging.models import TagBase
 from newtagging import managers
 
 from newtagging.models import TagBase
 from newtagging import managers
+from catalogue.fields import JSONField
 
 from librarian import html, dcparser
 
 from librarian import html, dcparser
+from mutagen import id3
 
 
 TAG_CATEGORIES = (
 
 
 TAG_CATEGORIES = (
@@ -20,6 +28,7 @@ TAG_CATEGORIES = (
     ('genre', _('genre')),
     ('theme', _('theme')),
     ('set', _('set')),
     ('genre', _('genre')),
     ('theme', _('theme')),
     ('set', _('set')),
+    ('book', _('book')),
 )
 
 
 )
 
 
@@ -27,46 +36,113 @@ class TagSubcategoryManager(models.Manager):
     def __init__(self, subcategory):
         super(TagSubcategoryManager, self).__init__()
         self.subcategory = subcategory
     def __init__(self, subcategory):
         super(TagSubcategoryManager, self).__init__()
         self.subcategory = subcategory
-        
+
     def get_query_set(self):
         return super(TagSubcategoryManager, self).get_query_set().filter(category=self.subcategory)
 
 
 class Tag(TagBase):
     def get_query_set(self):
         return super(TagSubcategoryManager, self).get_query_set().filter(category=self.subcategory)
 
 
 class Tag(TagBase):
-    name = models.CharField(_('name'), max_length=50, unique=True, db_index=True)
-    slug = models.SlugField(_('slug'), max_length=120, unique=True, db_index=True)
+    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.SlugField(_('sort key'), max_length=120, db_index=True)
-    category = models.CharField(_('category'), max_length=50, blank=False, null=False, 
+    category = models.CharField(_('category'), max_length=50, blank=False, null=False,
         db_index=True, choices=TAG_CATEGORIES)
         db_index=True, choices=TAG_CATEGORIES)
-    description = models.TextField(blank=True)
-    
+    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)
     user = models.ForeignKey(User, blank=True, null=True)
-    
-    def has_description(self):
-        return len(self.description) > 0
-    has_description.short_description = _('description')
-    has_description.boolean = True
+    book_count = models.IntegerField(_('book count'), default=0, blank=False, null=False)
+    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',
+        'rodzaj': 'kind',
+        'gatunek': 'genre',
+        'motyw': 'theme',
+        'polka': 'set',
+    }
+    categories_dict = dict((item[::-1] for item in categories_rev.iteritems()))
 
 
-    @permalink
-    def get_absolute_url(self):
-        return ('catalogue.views.tagged_object_list', [self.slug])
-    
     class Meta:
         ordering = ('sort_key',)
         verbose_name = _('tag')
         verbose_name_plural = _('tags')
     class Meta:
         ordering = ('sort_key',)
         verbose_name = _('tag')
         verbose_name_plural = _('tags')
-    
+        unique_together = (("slug", "category"),)
+
     def __unicode__(self):
         return self.name
 
     def __unicode__(self):
         return self.name
 
+    def __repr__(self):
+        return "Tag(slug=%r)" % self.slug
+
+    @permalink
+    def get_absolute_url(self):
+        return ('catalogue.views.tagged_object_list', [self.url_chunk])
+
+    def has_description(self):
+        return len(self.description) > 0
+    has_description.short_description = _('description')
+    has_description.boolean = True
+
+    def alive(self):
+        return self.death is None
+
+    def in_pd(self):
+        """ tests whether an author is in public domain """
+        return self.death is not None and self.goes_to_pd() <= datetime.now().year
+
+    def goes_to_pd(self):
+        """ calculates the year of public domain entry for an author """
+        return self.death + 71 if self.death is not None else None
+
     @staticmethod
     def get_tag_list(tags):
         if isinstance(tags, basestring):
     @staticmethod
     def get_tag_list(tags):
         if isinstance(tags, basestring):
-            tag_slugs = tags.split('/')
-            return [Tag.objects.get(slug=slug) for slug in tag_slugs]
+            real_tags = []
+            ambiguous_slugs = []
+            category = None
+            tags_splitted = tags.split('/')
+            for index, name in enumerate(tags_splitted):
+                if 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)
+
+            if category:
+                # 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))
+
+
+# TODO: why is this hard-coded ?
+def book_upload_path(ext):
+    def get_dynamic_path(book, filename):
+        return 'lektura/%s.%s' % (book.slug, ext)
+    return get_dynamic_path
+
 
 class Book(models.Model):
     title = models.CharField(_('title'), max_length=120)
 
 class Book(models.Model):
     title = models.CharField(_('title'), max_length=120)
@@ -74,160 +150,350 @@ class Book(models.Model):
     description = models.TextField(_('description'), blank=True)
     created_at = models.DateTimeField(_('creation date'), auto_now=True)
     _short_html = models.TextField(_('short HTML'), editable=False)
     description = models.TextField(_('description'), blank=True)
     created_at = models.DateTimeField(_('creation date'), auto_now=True)
     _short_html = models.TextField(_('short HTML'), editable=False)
-    
+    parent_number = models.IntegerField(_('parent number'), default=0)
+    extra_info = JSONField(_('extra information'))
+    gazeta_link = models.CharField(blank=True, max_length=240)
+    wiki_link = models.CharField(blank=True, max_length=240)
+
+
     # Formats
     # Formats
-    xml_file = models.FileField(_('XML file'), upload_to='books/xml', blank=True)
-    pdf_file = models.FileField(_('PDF file'), upload_to='books/pdf', blank=True)
-    odt_file = models.FileField(_('ODT file'), upload_to='books/odt', blank=True)
-    html_file = models.FileField(_('HTML file'), upload_to='books/html', blank=True)
-    
+    xml_file = models.FileField(_('XML file'), upload_to=book_upload_path('xml'), blank=True)
+    html_file = models.FileField(_('HTML file'), upload_to=book_upload_path('html'), blank=True)
+    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)
+    odt_file = models.FileField(_('ODT file'), upload_to=book_upload_path('odt'), 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)
+
     parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
     parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
-    
+
     objects = models.Manager()
     tagged = managers.ModelTaggedItemManager(Tag)
     tags = managers.TagDescriptor(Tag)
     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',)
+        verbose_name = _('book')
+        verbose_name_plural = _('books')
+
+    def __unicode__(self):
+        return self.title
+
+    def save(self, force_insert=False, force_update=False, reset_short_html=True, refresh_mp3=True):
+        if reset_short_html:
+            # Reset _short_html during save
+            for key in filter(lambda x: x.startswith('_short_html'), self.__dict__):
+                self.__setattr__(key, '')
+
+        book = super(Book, self).save(force_insert, force_update)
+
+        if refresh_mp3 and self.mp3_file:
+            print self.mp3_file, self.mp3_file.path
+            extra_info = self.get_extra_info_value()
+            extra_info.update(self.get_mp3_info())
+            self.set_extra_info_value(extra_info)
+            book = super(Book, self).save(force_insert, force_update)
+
+        return book
+
+    @permalink
+    def get_absolute_url(self):
+        return ('catalogue.views.book_detail', [self.slug])
+
+    @property
+    def name(self):
+        return self.title
+
+    def book_tag(self):
+        slug = ('l-' + self.slug)[:120]
+        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.save()
+        return book_tag
+
     def short_html(self):
     def short_html(self):
-        if len(self._short_html):
-            return mark_safe(self._short_html)
+        key = '_short_html_%s' % get_language()
+        short_html = getattr(self, key)
+
+        if short_html and len(short_html):
+            return mark_safe(short_html)
         else:
         else:
-            tags = self.tags.filter(~Q(category__in=('set', 'theme')))
-            tags = [u'<a href="%s">%s</a>' % (tag.get_absolute_url(), tag.name) for tag in tags]
+            tags = self.tags.filter(~Q(category__in=('set', 'theme', 'book')))
+            tags = [mark_safe(u'<a href="%s">%s</a>' % (tag.get_absolute_url(), tag.name)) for tag in tags]
 
             formats = []
             if self.html_file:
 
             formats = []
             if self.html_file:
-                formats.append(u'<a href="%s">Czytaj online</a>' % self.html_file.url)
+                formats.append(u'<a href="%s">%s</a>' % (reverse('book_text', kwargs={'slug': self.slug}), _('Read online')))
             if self.pdf_file:
             if self.pdf_file:
-                formats.append(u'<a href="%s">Plik PDF</a>' % self.pdf_file.url)
+                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.odt_file:
             if self.odt_file:
-                formats.append(u'<a href="%s">Plik ODT</a>' % self.odt_file.url)
-            
-            self._short_html = unicode(render_to_string('catalogue/book_short.html',
-                {'book': self, 'tags': tags, 'formats': formats}))
-            self.save()
-            return mark_safe(self._short_html)
-    
+                formats.append(u'<a href="%s">ODT</a>' % self.odt_file.url)
+            if self.txt_file:
+                formats.append(u'<a href="%s">TXT</a>' % self.txt_file.url)
+            if self.mp3_file:
+                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 = [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))
+
+
+    def get_mp3_info(self):
+        """Retrieves artist and director names from audio ID3 tags."""
+        audio = id3.ID3(self.mp3_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'))
+        return {'artist_name': artist_name, 'director_name': director_name}
+
     def has_description(self):
         return len(self.description) > 0
     has_description.short_description = _('description')
     has_description.boolean = True
     def has_description(self):
         return len(self.description) > 0
     has_description.short_description = _('description')
     has_description.boolean = True
-    
+
     def has_pdf_file(self):
         return bool(self.pdf_file)
     has_pdf_file.short_description = 'PDF'
     has_pdf_file.boolean = True
     def has_pdf_file(self):
         return bool(self.pdf_file)
     has_pdf_file.short_description = 'PDF'
     has_pdf_file.boolean = True
-    
+
+    def has_epub_file(self):
+        return bool(self.epub_file)
+    has_epub_file.short_description = 'EPUB'
+    has_epub_file.boolean = True
+
     def has_odt_file(self):
         return bool(self.odt_file)
     has_odt_file.short_description = 'ODT'
     has_odt_file.boolean = True
     def has_odt_file(self):
         return bool(self.odt_file)
     has_odt_file.short_description = 'ODT'
     has_odt_file.boolean = True
-    
+
     def has_html_file(self):
         return bool(self.html_file)
     has_html_file.short_description = 'HTML'
     has_html_file.boolean = True
 
     def has_html_file(self):
         return bool(self.html_file)
     has_html_file.short_description = 'HTML'
     has_html_file.boolean = True
 
-    @staticmethod
-    def from_xml_file(xml_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)
+
+        try:
+            return cls.from_text_and_meta(xml_file, book_info, overwrite)
+        finally:
+            xml_file.close()
+
+    @classmethod
+    def from_text_and_meta(cls, raw_file, book_info, overwrite=False):
         from tempfile import NamedTemporaryFile
         from slughifi import slughifi
         from markupstring import MarkupString
         from tempfile import NamedTemporaryFile
         from slughifi import slughifi
         from markupstring import MarkupString
-        
+
         # Read book metadata
         # Read book metadata
-        book_info = dcparser.parse(xml_file)
-        book = Book(title=book_info.title, slug=slughifi(book_info.title))
+        book_base, book_slug = book_info.url.rsplit('/', 1)
+        book, created = Book.objects.get_or_create(slug=book_slug)
+
+        if created:
+            book_shelves = []
+        else:
+            if not overwrite:
+                raise Book.AlreadyExists(_('Book %s already exists') % book_slug)
+            # Save shelves for this book
+            book_shelves = list(book.tags.filter(category='set'))
+
+        book.title = book_info.title
+        book.set_extra_info_value(book_info.to_dict())
+        book._short_html = ''
         book.save()
         book.save()
-        
+
         book_tags = []
         book_tags = []
-        for category in ('kind', 'genre', 'author', 'epoch'):    
+        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_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(name=tag_name,
-                slug=slughifi(tag_name), sort_key=slughifi(tag_sort_key), category=category)
-            tag.save()
+            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.append(tag)
+
         book.tags = book_tags
         book.tags = book_tags
-        
+
+        book_tag = book.book_tag()
+
         if hasattr(book_info, 'parts'):
         if hasattr(book_info, 'parts'):
-            for part_url in book_info.parts:
+            for n, part_url in enumerate(book_info.parts):
                 base, slug = part_url.rsplit('/', 1)
                 base, slug = part_url.rsplit('/', 1)
-                child_book = Book.objects.get(slug=slug)
-                child_book.parent = book
-                child_book.save()
-        
+                try:
+                    child_book = Book.objects.get(slug=slug)
+                    child_book.parent = book
+                    child_book.parent_number = n
+                    child_book.save()
+                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
         # Save XML and HTML files
-        book.xml_file.save('%s.xml' % book.slug, File(file(xml_file)), save=False)
-        
+        book.xml_file.save('%s.xml' % book.slug, raw_file, save=False)
+
         html_file = NamedTemporaryFile()
         html_file = NamedTemporaryFile()
-        html.transform(book.xml_file.path, html_file)
-        book.html_file.save('%s.html' % book.slug, File(html_file), save=False)
-        
-        # Extract fragments
-        closed_fragments, open_fragments = html.extract_fragments(book.html_file.path)
-        book_themes = []
-        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 = Fragment(text=text, short_text=short_text, anchor=fragment.id, book=book)
-                
-            theme_names = [s.strip() for s in fragment.themes.split(',')]
-            themes = []
-            for theme_name in theme_names:
-                tag, created = Tag.objects.get_or_create(name=theme_name,
-                    slug=slughifi(theme_name), sort_key=slughifi(theme_name), category='theme')
-                tag.save()
-                themes.append(tag)
-            new_fragment.save()
-            new_fragment.tags = list(book.tags) + themes
-            book_themes += themes
-        
-        book_themes = set(book_themes)
-        book.tags = list(book.tags) + list(book_themes)
-        return book.save()
-    
-    @permalink
-    def get_absolute_url(self):
-        return ('catalogue.views.book_detail', [self.slug])
-        
-    class Meta:
-        ordering = ('title',)
-        verbose_name = _('book')
-        verbose_name_plural = _('books')
+        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)
+
+            # Extract fragments
+            closed_fragments, open_fragments = html.extract_fragments(book.html_file.path)
+            book_themes = []
+            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:
+                    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.save()
+                    themes.append(tag)
+                new_fragment.save()
+                new_fragment.tags = set(list(book.tags) + themes + [book_tag])
+                book_themes += themes
+
+            book_themes = set(book_themes)
+            book.tags = list(book.tags) + list(book_themes) + book_shelves
+
+        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, refresh_mp3=False)
+        return tags
+
+    @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, refresh_mp3=False)
+        return tags
+
+    @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())
 
 
-    def __unicode__(self):
-        return self.title
 
 
 class Fragment(models.Model):
     text = models.TextField()
     short_text = models.TextField(editable=False)
     _short_html = models.TextField(editable=False)
 
 
 class Fragment(models.Model):
     text = models.TextField()
     short_text = models.TextField(editable=False)
     _short_html = models.TextField(editable=False)
-    anchor = models.IntegerField()
+    anchor = models.CharField(max_length=120)
     book = models.ForeignKey(Book, related_name='fragments')
 
     objects = models.Manager()
     tagged = managers.ModelTaggedItemManager(Tag)
     tags = managers.TagDescriptor(Tag)
     book = models.ForeignKey(Book, related_name='fragments')
 
     objects = models.Manager()
     tagged = managers.ModelTaggedItemManager(Tag)
     tags = managers.TagDescriptor(Tag)
-    
+
+    class Meta:
+        ordering = ('book', 'anchor',)
+        verbose_name = _('fragment')
+        verbose_name_plural = _('fragments')
+
+    def get_absolute_url(self):
+        return '%s#m%s' % (reverse('book_text', kwargs={'slug': self.book.slug}), self.anchor)
+
     def short_html(self):
     def short_html(self):
-        if len(self._short_html):
-            return mark_safe(self._short_html)
+        key = '_short_html_%s' % get_language()
+        short_html = getattr(self, key)
+        if short_html and len(short_html):
+            return mark_safe(short_html)
         else:
         else:
-            book_authors = [u'<a href="%s">%s</a>' % (tag.get_absolute_url(), tag.name) 
+            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']
                 for tag in self.book.tags if tag.category == 'author']
-            
-            self._short_html = unicode(render_to_string('catalogue/fragment_short.html',
-                {'fragment': self, 'book': self.book, 'book_authors': book_authors}))
+
+            setattr(self, key, unicode(render_to_string('catalogue/fragment_short.html',
+                {'fragment': self, 'book': self.book, 'book_authors': book_authors})))
             self.save()
             self.save()
-            return mark_safe(self._short_html)
-        
+            return mark_safe(getattr(self, key))
+
+
+class BookStub(models.Model):
+    title = models.CharField(_('title'), max_length=120)
+    author = models.CharField(_('author'), max_length=120)
+    pd = models.IntegerField(_('goes to public domain'), null=True, blank=True)
+    slug = models.SlugField(_('slug'), max_length=120, unique=True, db_index=True)
+    translator = models.TextField(_('translator'), blank=True)
+    translator_death = models.TextField(_('year of translator\'s death'), blank=True)
+
     class Meta:
     class Meta:
-        ordering = ('book', 'anchor',)
-        verbose_name = _('fragment')
-        verbose_name_plural = _('fragments')
+        ordering = ('title',)
+        verbose_name = _('book stub')
+        verbose_name_plural = _('book stubs')
+
+    def __unicode__(self):
+        return self.title
+
+    @permalink
+    def get_absolute_url(self):
+        return ('catalogue.views.book_detail', [self.slug])
+
+    def in_pd(self):
+        return self.pd is not None and self.pd <= datetime.now().year
+
+    @property
+    def name(self):
+        return self.title
+