Fix #2046 (#2047)

* Fix #2046

* Add requirements

requirements/requirements.txt

@@ -36,3 +36,4 @@ django-reversion==2.0.8
 WeasyPrint==0.42
 whoosh==2.7.4
 django-speedinfo==1.3.5
+django-reversion-compare==0.8.4

sapl/settings.py

@@ -87,6 +87,7 @@ INSTALLED_APPS = (
     'sass_processor',
     'rest_framework',
     'reversion',
+    'reversion_compare',
     'whoosh',
     'speedinfo',
 

sapl/utils.py

@@ -25,6 +25,7 @@ from django_filters.filterset import STRICTNESS
 from easy_thumbnails import source_generators
 from floppyforms import ClearableFileInput
 from reversion.admin import VersionAdmin
+from reversion_compare.admin import CompareVersionAdmin
 from unipath.path import Path
 
 from sapl.crispy_layout_mixin import SaplFormLayout, form_actions, to_row
@@ -228,7 +229,7 @@ def register_all_models_in_admin(module_name):
     appname = appname[1] if appname[0] == 'sapl' else appname[0]
     app = apps.get_app_config(appname)
     for model in app.get_models():
-        class CustomModelAdmin(VersionAdmin):
+        class CustomModelAdmin(CompareVersionAdmin):
             list_display = [f.name for f in model._meta.fields
                             if f.name != 'id']