Fixed #20133 -- Added summary to admin deletion confirmation pages.

Thanks jonash for the suggestion and initial patch.

django/contrib/admin/actions.py

@@ -33,7 +33,7 @@ def delete_selected(modeladmin, request, queryset):
 
     # Populate deletable_objects, a data structure of all related objects that
     # will also be deleted.
-    deletable_objects, perms_needed, protected = get_deleted_objects(
+    deletable_objects, model_count, perms_needed, protected = get_deleted_objects(
         queryset, opts, request.user, modeladmin.admin_site, using)
 
     # The user has already confirmed the deletion.
@@ -67,6 +67,7 @@ def delete_selected(modeladmin, request, queryset):
         "title": title,
         "objects_name": objects_name,
         "deletable_objects": [deletable_objects],
+        "model_count": dict(model_count),
         'queryset': queryset,
         "perms_lacking": perms_needed,
         "protected": protected,

django/contrib/admin/options.py

@@ -1606,7 +1606,7 @@ class ModelAdmin(BaseModelAdmin):
 
         # Populate deleted_objects, a data structure of all related objects that
         # will also be deleted.
-        (deleted_objects, perms_needed, protected) = get_deleted_objects(
+        (deleted_objects, model_count, perms_needed, protected) = get_deleted_objects(
             [obj], opts, request.user, self.admin_site, using)
 
         if request.POST:  # The user has already confirmed the deletion.
@@ -1631,6 +1631,7 @@ class ModelAdmin(BaseModelAdmin):
             object_name=object_name,
             object=obj,
             deleted_objects=deleted_objects,
+            model_count=dict(model_count),
             perms_lacking=perms_needed,
             protected=protected,
             opts=opts,

django/contrib/admin/templates/admin/delete_confirmation.html

@@ -30,6 +30,8 @@
     </ul>
 {% else %}
     <p>{% blocktrans with escaped_object=object %}Are you sure you want to delete the {{ object_name }} "{{ escaped_object }}"? All of the following related items will be deleted:{% endblocktrans %}</p>
+    {% include "admin/includes/object_delete_summary.html" %}
+    <h2>{% trans "Objects" %}</h2>
     <ul>{{ deleted_objects|unordered_list }}</ul>
     <form action="" method="post">{% csrf_token %}
     <div>

django/contrib/admin/templates/admin/delete_selected_confirmation.html

@@ -29,6 +29,8 @@
     </ul>
 {% else %}
     <p>{% blocktrans %}Are you sure you want to delete the selected {{ objects_name }}? All of the following objects and their related items will be deleted:{% endblocktrans %}</p>
+    {% include "admin/includes/object_delete_summary.html" %}
+    <h2>{% trans "Objects" %}</h2>
     {% for deletable_object in deletable_objects %}
         <ul>{{ deletable_object|unordered_list }}</ul>
     {% endfor %}

django/contrib/admin/templates/admin/includes/object_delete_summary.html

@@ -0,0 +1,7 @@
+{% load i18n %}
+<h2>{% trans "Summary" %}</h2>
+<ul>
+    {% for model_name, object_count in model_count.items %}
+    <li>{{ model_name|capfirst }}: {{ object_count }}</li>
+    {% endfor %}
+</ul>

django/contrib/admin/utils.py

@@ -1,5 +1,6 @@
 from __future__ import unicode_literals
 
+from collections import defaultdict
 import datetime
 import decimal
 
@@ -154,7 +155,7 @@ def get_deleted_objects(objs, opts, user, admin_site, using):
 
     protected = [format_callback(obj) for obj in collector.protected]
 
-    return to_delete, perms_needed, protected
+    return to_delete, collector.model_count, perms_needed, protected
 
 
 class NestedObjects(Collector):
@@ -162,6 +163,7 @@ class NestedObjects(Collector):
         super(NestedObjects, self).__init__(*args, **kwargs)
         self.edges = {}  # {from_instance: [to_instances]}
         self.protected = set()
+        self.model_count = defaultdict(int)
 
     def add_edge(self, source, target):
         self.edges.setdefault(source, []).append(target)
@@ -176,6 +178,7 @@ class NestedObjects(Collector):
                 self.add_edge(getattr(obj, related_name), obj)
             else:
                 self.add_edge(None, obj)
+            self.model_count[obj._meta.verbose_name_plural] += 1
         try:
             return super(NestedObjects, self).collect(objs, source_attr=source_attr, **kwargs)
         except models.ProtectedError as e:

docs/releases/1.8.txt

@@ -44,6 +44,10 @@ Minor features
   to limit the ``list_filter`` choices to foreign objects which are attached to
   those from the ``ModelAdmin``.
 
+* The :meth:`ModelAdmin.delete_view()
+  <django.contrib.admin.ModelAdmin.delete_view>` displays a summary of objects
+  to be deleted on the deletion confirmation page.
+
 :mod:`django.contrib.auth`
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 

tests/admin_views/tests.py

@@ -1425,10 +1425,15 @@ class AdminViewPermissionsTest(TestCase):
         self.client.get('/test_admin/admin/')
         self.client.post(login_url, self.deleteuser_login)
         response = self.client.get('/test_admin/admin/admin_views/section/1/delete/')
+        self.assertContains(response, "<h2>Summary</h2>")
+        self.assertContains(response, "<li>Articles: 3</li>")
         # test response contains link to related Article
         self.assertContains(response, "admin_views/article/1/")
 
         response = self.client.get('/test_admin/admin/admin_views/article/1/delete/')
+        self.assertContains(response, "admin_views/article/1/")
+        self.assertContains(response, "<h2>Summary</h2>")
+        self.assertContains(response, "<li>Articles: 1</li>")
         self.assertEqual(response.status_code, 200)
         post = self.client.post('/test_admin/admin/admin_views/article/1/delete/', delete_dict)
         self.assertRedirects(post, '/test_admin/admin/')
@@ -2547,6 +2552,9 @@ class AdminActionsTest(TestCase):
         confirmation = self.client.post('/test_admin/admin/admin_views/subscriber/', action_data)
         self.assertIsInstance(confirmation, TemplateResponse)
         self.assertContains(confirmation, "Are you sure you want to delete the selected subscribers?")
+        self.assertContains(confirmation, "<h2>Summary</h2>")
+        self.assertContains(confirmation, "<li>Subscribers: 3</li>")
+        self.assertContains(confirmation, "<li>External subscribers: 1</li>")
         self.assertContains(confirmation, ACTION_CHECKBOX_NAME, count=2)
         self.client.post('/test_admin/admin/admin_views/subscriber/', delete_confirmation_data)
         self.assertEqual(Subscriber.objects.count(), 0)