+
+
+@register.filter
+def class_name(obj):
+ return obj.__class__.__name__
+
+
+@register.simple_tag
+def source_name(url):
+ url = url.lstrip()
+ netloc = urlparse(url).netloc
+ if not netloc:
+ netloc = urlparse('http://' + url).netloc
+ if not netloc:
+ return ''
+ source, created = Source.objects.get_or_create(netloc=netloc)
+ return source.name or netloc
+
+
+@ssi_variable(register, patch_response=[add_never_cache_headers])
+def catalogue_random_book(request, exclude_ids):
+ from .. import app_settings
+ if random() < app_settings.RELATED_RANDOM_PICTURE_CHANCE:
+ return None
+ queryset = Book.objects.exclude(pk__in=exclude_ids)
+ count = queryset.count()
+ if count:
+ return queryset[randint(0, count - 1)].pk
+ else:
+ return None
+
+
+@ssi_variable(register, patch_response=[add_never_cache_headers])
+def choose_fragment(request, book_id=None, tag_ids=None, unless=False):
+ if unless:
+ return None
+
+ if book_id is not None:
+ fragment = Book.objects.get(pk=book_id).choose_fragment()
+ else:
+ if tag_ids is not None:
+ tags = Tag.objects.filter(pk__in=tag_ids)
+ fragments = Fragment.tagged.with_all(tags).order_by().only('id')
+ else:
+ fragments = Fragment.objects.all().order_by().only('id')
+ fragment_count = fragments.count()
+ fragment = fragments[randint(0, fragment_count - 1)] if fragment_count else None
+ return fragment.pk if fragment is not None else None