compatible with django 2.2

Author: Dmitriy Kosolapov

singleton_models/admin.py

@@ -1,6 +1,12 @@
+import django
 from django.contrib import admin
 from django.utils.translation import ugettext as _
-from django.utils.encoding import force_unicode
+
+if django.VERSION >= (1, 8):
+    from django.utils.encoding import force_text
+else:
+    from django.utils.encoding import force_unicode as force_text
+
 from django.http import HttpResponseRedirect
 from functools import update_wrapper
 
@@ -18,28 +24,31 @@ def has_delete_permission(self, request, obj=None):
         return False
 
     def get_urls(self):
-        try:
-            from django.conf.urls.defaults import patterns, url
-        except ImportError:
-            from django.conf.urls import patterns, url
-
         def wrap(view):
             def wrapper(*args, **kwargs):
                 return self.admin_site.admin_view(view)(*args, **kwargs)
             return update_wrapper(wrapper, view)
 
-        info = self.model._meta.app_label, self.model._meta.module_name
+        info = self.model._meta.app_label, self.model._meta.model_name
 
-        urlpatterns = patterns('',
-            url(r'^history/$',
-                wrap(self.history_view),
-                {'object_id': '1'},
-                name='%s_%s_history' % info),
-            url(r'^$',
-                wrap(self.change_view),
-                {'object_id': '1'},
-                name='%s_%s_changelist' % info),
-        )
+        if django.VERSION >= (1, 8):
+            from django.urls import path
+            urlpatterns = [
+                path(r'history/', wrap(self.history_view), {'object_id': '1'}, name='%s_%s_history' % info),
+                path(r'', wrap(self.change_view), {'object_id': '1'}, name='%s_%s_changelist' % info),
+           ]
+        else:
+            try:
+                from django.conf.urls.defaults import patterns, url
+            except ImportError:
+                from django.conf.urls import patterns, url
+            info = self.model._meta.app_label, self.model._meta.module_name
+
+            urlpatterns = patterns(
+                '',
+                url(r'^history/$', wrap(self.history_view), {'object_id': '1'}, name='%s_%s_history' % info),
+                url(r'^$', wrap(self.change_view), {'object_id': '1'}, name='%s_%s_changelist' % info),
+            )
         return urlpatterns
 
     def response_change(self, request, obj):
@@ -48,8 +57,8 @@ def response_change(self, request, obj):
         """
         opts = obj._meta
 
-        msg = _('%(obj)s was changed successfully.') % {'obj': force_unicode(obj)}
-        if request.POST.has_key("_continue"):
+        msg = _('%(obj)s was changed successfully.') % {'obj': force_text(obj)}
+        if request.POST.get("_continue"):
             self.message_user(request, msg + ' ' + _("You may edit it again below."))
             return HttpResponseRedirect(request.path)
         else:

singleton_models/templates/admin/singleton_models/change_form.html

@@ -4,7 +4,7 @@
 {% block breadcrumbs %}
 <div class="breadcrumbs">
     <a href="../../">{% trans 'Home' %}</a> &rsaquo; 
-    <a href="../">{{ app_label|capfirst|escape }}</a> &rsaquo; 
+    <a href="../">{{ opts.app_config.verbose_name|default:app_label|capfirst|escape }}</a> &rsaquo;
     {{ opts.verbose_name|capfirst }}
 </div>
 {% endblock %}