X-Git-Url: https://git.mdrn.pl/wolnelektury.git/blobdiff_plain/33af401eb4abe15a37d0147807d06a9b19eaa802..0eedef1eafceaaa3f4f78b014236bf642be2807b:/src/catalogue/models/book.py

diff --git a/src/catalogue/models/book.py b/src/catalogue/models/book.py
index 01f02816a..97677bdee 100644
--- a/src/catalogue/models/book.py
+++ b/src/catalogue/models/book.py
@@ -226,6 +226,11 @@ class Book(models.Model):
     def isbn_mobi(self):
         return self.get_extra_info_json().get('isbn_mobi')
 
+    def is_accessible_to(self, user):
+        if not self.preview:
+            return True
+        Membership = apps.get_model('club', 'Membership')
+        return Membership.is_active_for(user)
 
     def save(self, force_insert=False, force_update=False, **kwargs):
         from sortify import sortify
@@ -738,6 +743,8 @@ class Book(models.Model):
     def update_references(self):
         from references.models import Entity, Reference
         master = self.get_master()
+        if master is None:
+            master = []
         found = set()
         for i, sec in enumerate(master):
             for ref in sec.findall('.//ref'):