add option to disable contact form after given datetime

[wolnelektury.git] / src / catalogue / models / book.py

diff --git a/src/catalogue/models/book.py b/src/catalogue/models/book.py
index 1524c34..69d71ae 100644 (file)
--- a/src/catalogue/models/book.py
+++ b/src/catalogue/models/book.py
@@ -4,14 +4,16 @@
 #
 from collections import OrderedDict
 from random import randint
 #
 from collections import OrderedDict
 from random import randint

+import os.path

 import re
 import re

+import urllib

 from django.conf import settings
 from django.db import connection, models, transaction
 from django.db.models import permalink
 import django.dispatch
 from django.contrib.contenttypes.fields import GenericRelation
 from django.core.urlresolvers import reverse
 from django.conf import settings
 from django.db import connection, models, transaction
 from django.db.models import permalink
 import django.dispatch
 from django.contrib.contenttypes.fields import GenericRelation
 from django.core.urlresolvers import reverse

-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import ugettext_lazy as _, get_language

 import jsonfield
 from fnpdjango.storage import BofhFileSystemStorage
 from ssify import flush_ssi_includes
 import jsonfield
 from fnpdjango.storage import BofhFileSystemStorage
 from ssify import flush_ssi_includes


@@ -19,64 +21,72 @@ from newtagging import managers
 from catalogue import constants
 from catalogue.fields import EbookField
 from catalogue.models import Tag, Fragment, BookMedia
 from catalogue import constants
 from catalogue.fields import EbookField
 from catalogue.models import Tag, Fragment, BookMedia

-from catalogue.utils import create_zip
+from catalogue.utils import create_zip, gallery_url, gallery_path
+from catalogue.models.tag import prefetched_relations

 from catalogue import app_settings
 from catalogue import tasks
 from catalogue import app_settings
 from catalogue import tasks

+from wolnelektury.utils import makedirs

 
 bofh_storage = BofhFileSystemStorage()
 
 
 
 bofh_storage = BofhFileSystemStorage()
 
 

-def _cover_upload_to(i, n):
-    return 'book/cover/%s.jpg' % i.slug
+def _make_upload_to(path):
+    def _upload_to(i, n):
+        return path % i.slug
+    return _upload_to
+
+
+_cover_upload_to = _make_upload_to('book/cover/%s.jpg')
+_cover_thumb_upload_to = _make_upload_to('book/cover_thumb/%s.jpg')

 
 

-def _cover_thumb_upload_to(i, n):
-    return 'book/cover_thumb/%s.jpg' % i.slug

 
 def _ebook_upload_to(upload_path):
 
 def _ebook_upload_to(upload_path):

-    def _upload_to(i, n):
-        return upload_path % i.slug
-    return _upload_to
+    return _make_upload_to(upload_path)

 
 
 class Book(models.Model):
     """Represents a book imported from WL-XML."""
 
 
 class Book(models.Model):
     """Represents a book imported from WL-XML."""

-    title         = models.CharField(_('title'), max_length=32767)
+    title = models.CharField(_('title'), max_length=32767)

     sort_key = models.CharField(_('sort key'), max_length=120, db_index=True, editable=False)
     sort_key = models.CharField(_('sort key'), max_length=120, db_index=True, editable=False)

-    sort_key_author = models.CharField(_('sort key by author'), max_length=120, db_index=True, editable=False, default=u'')
-    slug = models.SlugField(_('slug'), max_length=120, db_index=True,
-            unique=True)
+    sort_key_author = models.CharField(
+        _('sort key by author'), max_length=120, db_index=True, editable=False, default=u'')
+    slug = models.SlugField(_('slug'), max_length=120, db_index=True, unique=True)

     common_slug = models.SlugField(_('slug'), max_length=120, db_index=True)
     common_slug = models.SlugField(_('slug'), max_length=120, db_index=True)

-    language = models.CharField(_('language code'), max_length=3, db_index=True,
-                    default=app_settings.DEFAULT_LANGUAGE)
-    description   = models.TextField(_('description'), blank=True)
-    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)
+    language = models.CharField(_('language code'), max_length=3, db_index=True, default=app_settings.DEFAULT_LANGUAGE)
+    description = models.TextField(_('description'), blank=True)
+    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)
     parent_number = models.IntegerField(_('parent number'), default=0)

-    extra_info    = jsonfield.JSONField(_('extra information'), default={})
-    gazeta_link   = models.CharField(blank=True, max_length=240)
-    wiki_link     = models.CharField(blank=True, max_length=240)
+    extra_info = jsonfield.JSONField(_('extra information'), default={})
+    gazeta_link = models.CharField(blank=True, max_length=240)
+    wiki_link = models.CharField(blank=True, max_length=240)
+    print_on_demand = models.BooleanField(_('print on demand'), default=False)
+    recommended = models.BooleanField(_('recommended'), default=False)

 
     # files generated during publication
 
     # files generated during publication

-    cover = EbookField('cover', _('cover'),
-            null=True, blank=True,
-            upload_to=_cover_upload_to,
-            storage=bofh_storage, max_length=255)
+    cover = EbookField(
+        'cover', _('cover'),
+        null=True, blank=True,
+        upload_to=_cover_upload_to,
+        storage=bofh_storage, max_length=255)

     # Cleaner version of cover for thumbs
     # Cleaner version of cover for thumbs

-    cover_thumb = EbookField('cover_thumb', _('cover thumbnail'),
-            null=True, blank=True,
-            upload_to=_cover_thumb_upload_to,
-            max_length=255)
+    cover_thumb = EbookField(
+        'cover_thumb', _('cover thumbnail'),
+        null=True, blank=True,
+        upload_to=_cover_thumb_upload_to,
+        max_length=255)

     ebook_formats = constants.EBOOK_FORMATS
     formats = ebook_formats + ['html', 'xml']
 
     ebook_formats = constants.EBOOK_FORMATS
     formats = ebook_formats + ['html', 'xml']
 

-    parent = models.ForeignKey('self', blank=True, null=True,
-        related_name='children')
-    ancestor = models.ManyToManyField('self', blank=True,
-        editable=False, related_name='descendant', symmetrical=False)
+    parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
+    ancestor = models.ManyToManyField('self', blank=True, editable=False, related_name='descendant', symmetrical=False)

 
 

-    objects  = models.Manager()
-    tagged   = managers.ModelTaggedItemManager(Tag)
-    tags     = managers.TagDescriptor(Tag)
+    cached_author = models.CharField(blank=True, max_length=240, db_index=True)
+    has_audience = models.BooleanField(default=False)
+
+    objects = models.Manager()
+    tagged = managers.ModelTaggedItemManager(Tag)
+    tags = managers.TagDescriptor(Tag)

     tag_relations = GenericRelation(Tag.intermediary_table_model)
 
     html_built = django.dispatch.Signal()
     tag_relations = GenericRelation(Tag.intermediary_table_model)
 
     html_built = django.dispatch.Signal()


@@ -88,7 +98,7 @@ class Book(models.Model):
         pass
 
     class Meta:
         pass
 
     class Meta:

-        ordering = ('sort_key',)
+        ordering = ('sort_key_author', 'sort_key')

         verbose_name = _('book')
         verbose_name_plural = _('books')
         app_label = 'catalogue'
         verbose_name = _('book')
         verbose_name_plural = _('books')
         app_label = 'catalogue'


@@ -100,35 +110,65 @@ class Book(models.Model):
         try:
             return re.search(r'\w', self.title, re.U).group(0)
         except AttributeError:
         try:
             return re.search(r'\w', self.title, re.U).group(0)
         except AttributeError:

-            return None
+            return ''

 
 

-    def author_str(self):
-        return ", ".join(str(t) for t in self.tags.filter(category='author'))
+    def authors(self):
+        return self.tags.filter(category='author')
+
+    def tag_unicode(self, category):
+        relations = prefetched_relations(self, category)
+        if relations:
+            return ', '.join(rel.tag.name for rel in relations)
+        else:
+            return ', '.join(self.tags.filter(category=category).values_list('name', flat=True))
+
+    def author_unicode(self):
+        return self.cached_author
+
+    def translator(self):
+        translators = self.extra_info.get('translators')
+        if not translators:
+            return None
+        if len(translators) > 3:
+            translators = translators[:2]
+            others = ' i inni'
+        else:
+            others = ''
+        return ', '.join(u'\xa0'.join(reversed(translator.split(', ', 1))) for translator in translators) + others

 
     def save(self, force_insert=False, force_update=False, **kwargs):
         from sortify import sortify
 
         self.sort_key = sortify(self.title)[:120]
 
     def save(self, force_insert=False, force_update=False, **kwargs):
         from sortify import sortify
 
         self.sort_key = sortify(self.title)[:120]

-        self.title = unicode(self.title) # ???
+        self.title = unicode(self.title)  # ???

 
         try:
 
         try:

-            author = self.tags.filter(category='author')[0].sort_key
-        except IndexError:
+            author = self.authors().first().sort_key
+        except AttributeError:

             author = u''
         self.sort_key_author = author
 
             author = u''
         self.sort_key_author = author
 

+        self.cached_author = self.tag_unicode('author')
+        self.has_audience = 'audience' in self.extra_info
+

         ret = super(Book, self).save(force_insert, force_update, **kwargs)
 
         return ret
 
     @permalink
     def get_absolute_url(self):
         ret = super(Book, self).save(force_insert, force_update, **kwargs)
 
         return ret
 
     @permalink
     def get_absolute_url(self):

-        return ('catalogue.views.book_detail', [self.slug])
+        return 'catalogue.views.book_detail', [self.slug]

 
     @staticmethod
     @permalink
     def create_url(slug):
 
     @staticmethod
     @permalink
     def create_url(slug):

-        return ('catalogue.views.book_detail', [slug])
+        return 'catalogue.views.book_detail', [slug]
+
+    def gallery_path(self):
+        return gallery_path(self.slug)
+
+    def gallery_url(self):
+        return gallery_url(self.slug)

 
     @property
     def name(self):
 
     @property
     def name(self):


@@ -140,6 +180,9 @@ class Book(models.Model):
     def language_name(self):
         return dict(settings.LANGUAGES).get(self.language_code(), "")
 
     def language_name(self):
         return dict(settings.LANGUAGES).get(self.language_code(), "")
 

+    def is_foreign(self):
+        return self.language_code() != settings.LANGUAGE_CODE
+

     def has_media(self, type_):
         if type_ in Book.formats:
             return bool(getattr(self, "%s_file" % type_))
     def has_media(self, type_):
         if type_ in Book.formats:
             return bool(getattr(self, "%s_file" % type_))


@@ -157,10 +200,13 @@ class Book(models.Model):
 
     def get_mp3(self):
         return self.get_media("mp3")
 
     def get_mp3(self):
         return self.get_media("mp3")

+

     def get_odt(self):
         return self.get_media("odt")
     def get_odt(self):
         return self.get_media("odt")

+

     def get_ogg(self):
         return self.get_media("ogg")
     def get_ogg(self):
         return self.get_media("ogg")

+

     def get_daisy(self):
         return self.get_media("daisy")
 
     def get_daisy(self):
         return self.get_media("daisy")
 


@@ -194,10 +240,11 @@ class Book(models.Model):
         else:
             meta_fallbacks = None
 
         else:
             meta_fallbacks = None
 

-        return WLDocument.from_file(self.xml_file.path,
-                provider=ORMDocProvider(self),
-                parse_dublincore=parse_dublincore,
-                meta_fallbacks=meta_fallbacks)
+        return WLDocument.from_file(
+            self.xml_file.path,
+            provider=ORMDocProvider(self),
+            parse_dublincore=parse_dublincore,
+            meta_fallbacks=meta_fallbacks)

 
     @staticmethod
     def zip_format(format_):
 
     @staticmethod
     def zip_format(format_):


@@ -209,8 +256,7 @@ class Book(models.Model):
 
         field_name = "%s_file" % format_
         books = Book.objects.filter(parent=None).exclude(**{field_name: ""})
 
         field_name = "%s_file" % format_
         books = Book.objects.filter(parent=None).exclude(**{field_name: ""})

-        paths = [(pretty_file_name(b), getattr(b, field_name).path)
-                    for b in books.iterator()]
+        paths = [(pretty_file_name(b), getattr(b, field_name).path) for b in books.iterator()]

         return create_zip(paths, app_settings.FORMAT_ZIPS[format_])
 
     def zip_audiobooks(self, format_):
         return create_zip(paths, app_settings.FORMAT_ZIPS[format_])
 
     def zip_audiobooks(self, format_):


@@ -232,6 +278,20 @@ class Book(models.Model):
             index.index.rollback()
             raise e
 
             index.index.rollback()
             raise e
 

+    def download_pictures(self, remote_gallery_url):
+        gallery_path = self.gallery_path()
+        # delete previous files, so we don't include old files in ebooks
+        if os.path.isdir(gallery_path):
+            for filename in os.listdir(gallery_path):
+                file_path = os.path.join(gallery_path, filename)
+                os.unlink(file_path)
+        ilustr_elements = list(self.wldocument().edoc.findall('//ilustr'))
+        if ilustr_elements:
+            makedirs(gallery_path)
+            for ilustr in ilustr_elements:
+                ilustr_src = ilustr.get('src')
+                ilustr_path = os.path.join(gallery_path, ilustr_src)
+                urllib.urlretrieve('%s/%s' % (remote_gallery_url, ilustr_src), ilustr_path)

 
     @classmethod
     def from_xml_file(cls, xml_file, **kwargs):
 
     @classmethod
     def from_xml_file(cls, xml_file, **kwargs):


@@ -250,9 +310,8 @@ class Book(models.Model):
             xml_file.close()
 
     @classmethod
             xml_file.close()
 
     @classmethod

-    def from_text_and_meta(cls, raw_file, book_info, overwrite=False,
-            dont_build=None, search_index=True,
-            search_index_tags=True):
+    def from_text_and_meta(cls, raw_file, book_info, overwrite=False, dont_build=None, search_index=True,
+                           search_index_tags=True, remote_gallery_url=None):

         if dont_build is None:
             dont_build = set()
         dont_build = set.union(set(dont_build), set(app_settings.DONT_BUILD))
         if dont_build is None:
             dont_build = set()
         dont_build = set.union(set(dont_build), set(app_settings.DONT_BUILD))


@@ -264,8 +323,7 @@ class Book(models.Model):
                 try:
                     children.append(Book.objects.get(slug=part_url.slug))
                 except Book.DoesNotExist:
                 try:
                     children.append(Book.objects.get(slug=part_url.slug))
                 except Book.DoesNotExist:

-                    raise Book.DoesNotExist(_('Book "%s" does not exist.') %
-                            part_url.slug)
+                    raise Book.DoesNotExist(_('Book "%s" does not exist.') % part_url.slug)

 
         # Read book metadata
         book_slug = book_info.url.slug
 
         # Read book metadata
         book_slug = book_info.url.slug


@@ -278,8 +336,7 @@ class Book(models.Model):
             old_cover = None
         else:
             if not overwrite:
             old_cover = None
         else:
             if not overwrite:

-                raise Book.AlreadyExists(_('Book %s already exists') % (
-                        book_slug))
+                raise Book.AlreadyExists(_('Book %s already exists') % book_slug)

             # Save shelves for this book
             book_shelves = list(book.tags.filter(category='set'))
             old_cover = book.cover_info()
             # Save shelves for this book
             book_shelves = list(book.tags.filter(category='set'))
             old_cover = book.cover_info()


@@ -322,6 +379,9 @@ class Book(models.Model):
         cls.repopulate_ancestors()
         tasks.update_counters.delay()
 
         cls.repopulate_ancestors()
         tasks.update_counters.delay()
 

+        if remote_gallery_url:
+            book.download_pictures(remote_gallery_url)
+

         # No saves beyond this point.
 
         # Build cover.
         # No saves beyond this point.
 
         # Build cover.


@@ -345,41 +405,42 @@ class Book(models.Model):
         for child in notify_cover_changed:
             child.parent_cover_changed()
 
         for child in notify_cover_changed:
             child.parent_cover_changed()
 

+        book.save()  # update sort_key_author

         cls.published.send(sender=cls, instance=book)
         return book
 
     @classmethod
         cls.published.send(sender=cls, instance=book)
         return book
 
     @classmethod

+    @transaction.atomic

     def repopulate_ancestors(cls):
         """Fixes the ancestry cache."""
         # TODO: table names
     def repopulate_ancestors(cls):
         """Fixes the ancestry cache."""
         # TODO: table names

-        with transaction.atomic():
-            cursor = connection.cursor()
-            if connection.vendor == 'postgres':
-                cursor.execute("TRUNCATE catalogue_book_ancestor")
-                cursor.execute("""
-                    WITH RECURSIVE ancestry AS (
-                        SELECT book.id, book.parent_id
-                        FROM catalogue_book AS book
-                        WHERE book.parent_id IS NOT NULL
-                        UNION
-                        SELECT ancestor.id, book.parent_id
-                        FROM ancestry AS ancestor, catalogue_book AS book
-                        WHERE ancestor.parent_id = book.id
-                            AND book.parent_id IS NOT NULL
-                        )
-                    INSERT INTO catalogue_book_ancestor
-                        (from_book_id, to_book_id)
-                        SELECT id, parent_id
-                        FROM ancestry
-                        ORDER BY id;
-                    """)
-            else:
-                cursor.execute("DELETE FROM catalogue_book_ancestor")
-                for b in cls.objects.exclude(parent=None):
-                    parent = b.parent
-                    while parent is not None:
-                        b.ancestor.add(parent)
-                        parent = parent.parent
+        cursor = connection.cursor()
+        if connection.vendor == 'postgres':
+            cursor.execute("TRUNCATE catalogue_book_ancestor")
+            cursor.execute("""
+                WITH RECURSIVE ancestry AS (
+                    SELECT book.id, book.parent_id
+                    FROM catalogue_book AS book
+                    WHERE book.parent_id IS NOT NULL
+                    UNION
+                    SELECT ancestor.id, book.parent_id
+                    FROM ancestry AS ancestor, catalogue_book AS book
+                    WHERE ancestor.parent_id = book.id
+                        AND book.parent_id IS NOT NULL
+                    )
+                INSERT INTO catalogue_book_ancestor
+                    (from_book_id, to_book_id)
+                    SELECT id, parent_id
+                    FROM ancestry
+                    ORDER BY id;
+                """)
+        else:
+            cursor.execute("DELETE FROM catalogue_book_ancestor")
+            for b in cls.objects.exclude(parent=None):
+                parent = b.parent
+                while parent is not None:
+                    b.ancestor.add(parent)
+                    parent = parent.parent

 
     def flush_includes(self, languages=True):
         if not languages:
 
     def flush_includes(self, languages=True):
         if not languages:


@@ -448,8 +509,7 @@ class Book(models.Model):
         return books
 
     def pretty_title(self, html_links=False):
         return books
 
     def pretty_title(self, html_links=False):

-        names = [(tag.name, tag.get_absolute_url())
-            for tag in self.tags.filter(category='author')]
+        names = [(tag.name, tag.get_absolute_url()) for tag in self.authors().only('name', 'category', 'slug')]

         books = self.parents() + [self]
         names.extend([(b.title, b.get_absolute_url()) for b in books])
 
         books = self.parents() + [self]
         names.extend([(b.title, b.get_absolute_url()) for b in books])
 


@@ -459,6 +519,13 @@ class Book(models.Model):
             names = [tag[0] for tag in names]
         return ', '.join(names)
 
             names = [tag[0] for tag in names]
         return ', '.join(names)
 

+    def publisher(self):
+        publisher = self.extra_info['publisher']
+        if isinstance(publisher, basestring):
+            return publisher
+        elif isinstance(publisher, list):
+            return ', '.join(publisher)
+

     @classmethod
     def tagged_top_level(cls, tags):
         """ Returns top-level books tagged with `tags`.
     @classmethod
     def tagged_top_level(cls, tags):
         """ Returns top-level books tagged with `tags`.


@@ -471,7 +538,7 @@ class Book(models.Model):
         return objects.exclude(ancestor__in=objects)
 
     @classmethod
         return objects.exclude(ancestor__in=objects)
 
     @classmethod

-    def book_list(cls, filter=None):
+    def book_list(cls, book_filter=None):

         """Generates a hierarchical listing of all books.
 
         Books are optionally filtered with a test function.
         """Generates a hierarchical listing of all books.
 
         Books are optionally filtered with a test function.


@@ -479,10 +546,9 @@ class Book(models.Model):
         """
 
         books_by_parent = {}
         """
 
         books_by_parent = {}

-        books = cls.objects.all().order_by('parent_number', 'sort_key').only(
-                'title', 'parent', 'slug')
-        if filter:
-            books = books.filter(filter).distinct()
+        books = cls.objects.order_by('parent_number', 'sort_key').only('title', 'parent', 'slug')
+        if book_filter:
+            books = books.filter(book_filter).distinct()

 
             book_ids = set(b['pk'] for b in books.values("pk").iterator())
             for book in books.iterator():
 
             book_ids = set(b['pk'] for b in books.values("pk").iterator())
             for book in books.iterator():


@@ -500,7 +566,7 @@ class Book(models.Model):
             books_by_author[tag] = []
 
         for book in books_by_parent.get(None, ()):
             books_by_author[tag] = []
 
         for book in books_by_parent.get(None, ()):

-            authors = list(book.tags.filter(category='author'))
+            authors = list(book.authors().only('pk'))

             if authors:
                 for author in authors:
                     books_by_author[author].append(book)
             if authors:
                 for author in authors:
                     books_by_author[author].append(book)


@@ -513,11 +579,13 @@ class Book(models.Model):
         "SP": (1, u"szkoła podstawowa"),
         "SP1": (1, u"szkoła podstawowa"),
         "SP2": (1, u"szkoła podstawowa"),
         "SP": (1, u"szkoła podstawowa"),
         "SP1": (1, u"szkoła podstawowa"),
         "SP2": (1, u"szkoła podstawowa"),

+        "SP3": (1, u"szkoła podstawowa"),

         "P": (1, u"szkoła podstawowa"),
         "G": (2, u"gimnazjum"),
         "L": (3, u"liceum"),
         "LP": (3, u"liceum"),
     }
         "P": (1, u"szkoła podstawowa"),
         "G": (2, u"gimnazjum"),
         "L": (3, u"liceum"),
         "LP": (3, u"liceum"),
     }

+

     def audiences_pl(self):
         audiences = self.extra_info.get('audiences', [])
         audiences = sorted(set([self._audiences_pl.get(a, (99, a)) for a in audiences]))
     def audiences_pl(self):
         audiences = self.extra_info.get('audiences', [])
         audiences = sorted(set([self._audiences_pl.get(a, (99, a)) for a in audiences]))


@@ -544,19 +612,39 @@ class Book(models.Model):
         else:
             return None
 
         else:
             return None
 

+    def update_popularity(self):
+        count = self.tags.filter(category='set').values('user').order_by('user').distinct().count()
+        try:
+            pop = self.popularity
+            pop.count = count
+            pop.save()
+        except BookPopularity.DoesNotExist:
+            BookPopularity.objects.create(book=self, count=count)

 
 

-# add the file fields
-for format_ in Book.formats:
-    field_name = "%s_file" % format_
-    # This weird globals() assignment makes Django migrations comfortable.
-    _upload_to = _ebook_upload_to('book/%s/%%s.%s' % (format_, format_))
-    _upload_to.__name__ = '_%s_upload_to' % format_
-    globals()[_upload_to.__name__] = _upload_to
-
-    EbookField(format_, _("%s file" % format_.upper()),
-        upload_to=_upload_to,
-        storage=bofh_storage,
-        max_length=255,
-        blank=True,
-        default=''
-    ).contribute_to_class(Book, field_name)
+    def ridero_link(self):
+        return 'https://ridero.eu/%s/books/wl_%s/' % (get_language(), self.slug.replace('-', '_'))
+
+
+def add_file_fields():
+    for format_ in Book.formats:
+        field_name = "%s_file" % format_
+        # This weird globals() assignment makes Django migrations comfortable.
+        _upload_to = _ebook_upload_to('book/%s/%%s.%s' % (format_, format_))
+        _upload_to.__name__ = '_%s_upload_to' % format_
+        globals()[_upload_to.__name__] = _upload_to
+
+        EbookField(
+            format_, _("%s file" % format_.upper()),
+            upload_to=_upload_to,
+            storage=bofh_storage,
+            max_length=255,
+            blank=True,
+            default=''
+        ).contribute_to_class(Book, field_name)
+
+add_file_fields()
+
+
+class BookPopularity(models.Model):
+    book = models.OneToOneField(Book, related_name='popularity')
+    count = models.IntegerField(default=0)