+ def get_initial(self):
+ try:
+ return re.search(r'\w', self.title, re.U).group(0)
+ except AttributeError:
+ return ''
+
+ def get_next(self):
+ try:
+ return type(self).objects.filter(sort_key__gt=self.sort_key)[0]
+ except IndexError:
+ return None
+
+ def get_previous(self):
+ try:
+ return type(self).objects.filter(sort_key__lt=self.sort_key).order_by('-sort_key')[0]
+ except IndexError:
+ return None
+