Possible fix to get django-faq working with Haystack 1.X-2.0

search_indexes.diff

diff --git a/faq/search_indexes.py b/faq/search_indexes.py
index 1515984..8032937 100644
--- a/faq/search_indexes.py
+++ b/faq/search_indexes.py
@@ -1,29 +1,59 @@
 # -*- coding: utf-8 -*-
 
 from haystack import indexes
-from haystack.sites import site
 
 from faq.settings import SEARCH_INDEX
 from faq.models import Topic, Question
 
 
+# Haystack 2.0 (commit 070d46d72f92) requires that concrete SearchIndex classes
+# use the indexes.Indexable mixin. Here we workaround that so our SearchIndex
+# classes also work for Haystack 1.X.
+try:
+    mixin = indexes.Indexable
+except AttributeError:
+    mixin = object
+
+
 class FAQIndexBase(SEARCH_INDEX):
 
     text = indexes.CharField(document=True, use_template=True)
     url = indexes.CharField(model_attr='get_absolute_url', indexed=False)
 
 
-class TopicIndex(FAQIndexBase):
+class TopicIndex(FAQIndexBase, mixin):
 
+    # Required method for Haystack 2.0, but harmless on 1.X.
+    def get_model(self):
+        return Topic
+
+    # ``get_queryset`` is deprecated in Haystack v2, and ``index_queryset``
+    # ought to be used instead. But we must use the former to support
+    # Haystack < 1.2.4. Support for such older version is likely to be dropped
+    # in the near future.
     def get_queryset(self):
         return Topic.objects.published()
 
 
-class QuestionIndex(FAQIndexBase):
+class QuestionIndex(FAQIndexBase, mixin):
+
+    # Required method for Haystack 2.0, but harmless on 1.X.
+    def get_model(self):
+        return Question
 
+    # ``get_queryset`` is deprecated in Haystack v2, and ``index_queryset``
+    # ought to be used instead. But we must use the former to support
+    # Haystack < 1.2.4. Support for such older version is likely to be dropped
+    # in the near future.
     def get_queryset(self):
         return Question.objects.published()
 
 
-site.register(Topic, TopicIndex)
-site.register(Question, QuestionIndex)
+# try/except in order to register search indexes with site for Haystack 1.X
+# without throwing exceptions with Haystack 2.0.
+try:
+    from haystack.sites import site
+    site.register(Topic, TopicIndex)
+    site.register(Question, QuestionIndex)
+except ImportError:
+    pass