From 18f764b3aeb2f696fe1837074b3b2ca2515ebeae Mon Sep 17 00:00:00 2001
From: abhisgithub <abhijitbonik@hotmail.com>
Date: Tue, 12 Jun 2018 18:22:29 +0530
Subject: [PATCH] revision compare for course articles

---
 Course/admin.py | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/Course/admin.py b/Course/admin.py
index 9d6634ae..ac05c775 100644
--- a/Course/admin.py
+++ b/Course/admin.py
@@ -1,12 +1,31 @@
 from django.contrib import admin
 from mptt.admin import DraggableMPTTAdmin
 from .models import Course, Topics, Links, TopicArticle
+from reversion_compare.admin import CompareVersionAdmin
+from reversion_compare.mixins import CompareMixin
+from django.db.models import Manager
 # Register your models here.
 
+_old_compare = CompareMixin.compare
+
+
+def compare(self, obj, version1, version2):
+    def replace_taggit_field(version_ins):
+        for fieldname in version_ins.field_dict:
+            if isinstance(version_ins.field_dict[fieldname], Manager):
+                version_ins.field_dict[fieldname] = []
+    replace_taggit_field(version1)
+    replace_taggit_field(version2)
+    return _old_compare(self, obj, version1, version2)
+
+CompareMixin.compare = compare
+
+class TopicArticleAdmin(CompareVersionAdmin):
+    pass
 
 admin.site.register(Course)
 admin.site.register(Links)
-admin.site.register(TopicArticle)
+admin.site.register(TopicArticle, TopicArticleAdmin)