+ categories = all_categories
+
+ updated = []
+ deleted = []
+
+ for tag in Tag.objects.filter(category__in=categories, changed_at__gte=since):
+ tag_d = cls.tag_dict(tag, fields)
+ updated.append(tag_d)
+
+ for tag in Deleted.objects.filter(category__in=categories,
+ content_type=Tag, deleted_at__gte=since, created_at__lt=since):
+ deleted.append(tag.id)
+ return {'updated': updated, 'deleted': deleted}
+
+ @classmethod
+ def changes(cls, since=0, request=None, book_fields=None,
+ tag_fields=None, tag_categories=None):
+ changes = {
+ 'time_checked': timestamp(datetime.now())
+ }
+
+ changes_by_type = {
+ 'books': cls.book_changes(since, request, book_fields),
+ 'tags': cls.tag_changes(since, request, tag_fields, tag_categories),
+ }
+
+ for model in changes_by_type:
+ for field in changes_by_type[model]:
+ changes.setdefault(field, {})[model] = changes_by_type[model][field]
+ return changes
+
+
+class BookChangesHandler(CatalogueHandler):
+ allowed_methods = ('GET',)
+
+ def read(self, request, since):
+ return self.book_changes(since, request)
+
+
+class TagChangesHandler(CatalogueHandler):
+ allowed_methods = ('GET',)
+
+ def read(self, request, since):
+ return self.tag_changes(since, request)
+
+
+class ChangesHandler(CatalogueHandler):
+ allowed_methods = ('GET',)