Fix crash when deleting a single snippet using the bulk actions interface (#10447)

Fixes #10441

CHANGELOG.txt

@@ -21,6 +21,7 @@ Changelog
  * Fix: Rectify previous fix for TableBlock becoming uneditable after save (Sage Abdullah)
  * Fix: Ensure that copying page correctly picks up the latest revision (Matt Westcott)
  * Fix: Ensure comment buttons always respect `WAGTAILADMIN_COMMENTS_ENABLED` (Thibaud Colas)
+ * Fix: Fix error when deleting a single snippet through the bulk actions interface (Sage Abdullah)
  * Docs: Update documentation for `log_action` parameter on `RevisionMixin.save_revision` (Christer Jensen)
 
 

docs/releases/5.0.1.md

@@ -16,6 +16,7 @@ depth: 1
  * Rectify previous fix for TableBlock becoming uneditable after save (Sage Abdullah)
  * Ensure that copying page correctly picks up the latest revision (Matt Westcott)
  * Ensure comment buttons always respect `WAGTAILADMIN_COMMENTS_ENABLED` (Thibaud Colas)
+ * Fix error when deleting a single snippet through the bulk actions interface (Sage Abdullah)
 
 ### Documentation
 

wagtail/snippets/bulk_actions/delete.py

@@ -1,9 +1,12 @@
+from django.contrib.admin.utils import quote
+from django.urls import reverse
 from django.utils.functional import cached_property
 from django.utils.text import capfirst
 from django.utils.translation import gettext_lazy as _
 from django.utils.translation import ngettext
 
 from wagtail.admin.views.generic import BeforeAfterHookMixin
+from wagtail.models import ReferenceIndex
 from wagtail.snippets.bulk_actions.snippet_bulk_action import SnippetBulkAction
 from wagtail.snippets.permissions import get_permission_name
 
@@ -61,6 +64,25 @@ class DeleteBulkAction(BeforeAfterHookMixin, SnippetBulkAction):
         ).delete()
         return len(objects), 0
 
+    def get_context_data(self, **kwargs):
+        context = super().get_context_data(**kwargs)
+        # Add usage information to the context only if there is a single item
+        if len(context["items"]) == 1:
+            item_context = context["items"][0]
+            item = item_context["item"]
+            item_context.update(
+                {
+                    "usage_count": (
+                        ReferenceIndex.get_grouped_references_to(item).count()
+                    ),
+                    "usage_url": reverse(
+                        item.snippet_viewset.get_url_name("usage"),
+                        args=(quote(item.pk),),
+                    ),
+                }
+            )
+        return context
+
     def get_success_message(self, num_parent_objects, num_child_objects):
         if num_parent_objects == 1:
             return _("%(model_name)s '%(object)s' deleted.") % {

wagtail/snippets/templates/wagtailsnippets/bulk_actions/confirm_bulk_delete.html

@@ -3,7 +3,7 @@
 
 {% block titletag %}
     {% if items|length == 1 %}
-        {% blocktrans trimmed with snippet_type_name=model_opts.verbose_name %}Delete {{ snippet_type_name }}{% endblocktrans %} - {{ items|first }}
+        {% blocktrans trimmed with snippet_type_name=model_opts.verbose_name %}Delete {{ snippet_type_name }}{% endblocktrans %} - {{ items.0.item }}
     {% else %}
         {{ items|length }} {{ model_opts.verbose_name_plural|capfirst }}
     {% endif %}
@@ -22,7 +22,7 @@
     {% if items %}
         {% if items|length == 1 %}
             <div class="usagecount">
-                <a href="{{ items.0.item.usage_url }}">{% blocktrans trimmed count usage_count=items.0.item.get_usage.count %}Used {{ usage_count }} time{% plural %}Used {{ usage_count }} times{% endblocktrans %}</a>
+                <a href="{{ items.0.usage_url }}">{% blocktrans trimmed count usage_count=items.0.usage_count %}Used {{ usage_count }} time{% plural %}Used {{ usage_count }} times{% endblocktrans %}</a>
             </div>
             <p>{% blocktrans trimmed with snippet_type_name=model_opts.verbose_name %}Are you sure you want to delete this {{ snippet_type_name }}?{% endblocktrans %}</p>
         {% else %}

wagtail/snippets/tests/test_bulk_actions/test_bulk_delete.py

@@ -1,3 +1,4 @@
+from django.contrib.admin.utils import quote
 from django.contrib.auth.models import Permission
 from django.http import HttpRequest, HttpResponse
 from django.test import TestCase
@@ -32,11 +33,13 @@ class TestSnippetDeleteView(WagtailTestUtils, TestCase):
             )
             + "?"
         )
-        for snippet in self.test_snippets:
-            self.url += f"id={snippet.pk}&"
+
+    def get_url(self, items=()):
+        items = items or self.test_snippets
+        return self.url + "&".join(f"id={item.pk}" for item in items)
 
     def test_simple(self):
-        response = self.client.get(self.url)
+        response = self.client.get(self.get_url())
         self.assertEqual(response.status_code, 200)
         self.assertTemplateUsed(
             response, "wagtailsnippets/bulk_actions/confirm_bulk_delete.html"
@@ -45,8 +48,32 @@ class TestSnippetDeleteView(WagtailTestUtils, TestCase):
         self.assertEqual(response.context["header_icon"], "cog")
         self.assertContains(response, "icon icon-cog", count=1)
 
+    def test_get_single_delete(self):
+        item = self.test_snippets[0]
+        response = self.client.get(self.get_url(items=(item,)))
+        self.assertEqual(response.status_code, 200)
+        self.assertTemplateUsed(
+            response, "wagtailsnippets/bulk_actions/confirm_bulk_delete.html"
+        )
+        self.assertTemplateUsed(response, "wagtailadmin/shared/header.html")
+        self.assertEqual(response.context["header_icon"], "cog")
+        self.assertContains(response, "icon icon-cog", count=1)
+        self.assertContains(
+            response,
+            "<title>Delete full-featured snippet - Title-1 - Wagtail</title>",
+            html=True,
+        )
+        self.assertContains(
+            response,
+            reverse(
+                self.snippet_model.snippet_viewset.get_url_name("usage"),
+                args=(quote(item.pk),),
+            ),
+        )
+        self.assertContains(response, "Used 0 times")
+
     def test_bulk_delete(self):
-        response = self.client.post(self.url)
+        response = self.client.post(self.get_url())
 
         # Should redirect back to index
         self.assertEqual(response.status_code, 302)
@@ -64,7 +91,7 @@ class TestSnippetDeleteView(WagtailTestUtils, TestCase):
         )
         self.user.save()
 
-        response = self.client.get(self.url)
+        response = self.client.get(self.get_url())
         self.assertEqual(response.status_code, 200)
 
         html = response.content.decode()
@@ -76,7 +103,7 @@ class TestSnippetDeleteView(WagtailTestUtils, TestCase):
         for snippet in self.test_snippets:
             self.assertInHTML(f"<li>{snippet.text}</li>", html)
 
-        response = self.client.post(self.url)
+        response = self.client.post(self.get_url())
         # User should be redirected back to the index
         self.assertEqual(response.status_code, 302)
 
@@ -88,7 +115,7 @@ class TestSnippetDeleteView(WagtailTestUtils, TestCase):
         with self.register_hook(
             "before_bulk_action", lambda *args: HttpResponse("Overridden!")
         ):
-            response = self.client.get(self.url)
+            response = self.client.get(self.get_url())
 
         self.assertEqual(response.status_code, 200)
 
@@ -113,7 +140,7 @@ class TestSnippetDeleteView(WagtailTestUtils, TestCase):
             return HttpResponse("Overridden!")
 
         with self.register_hook("before_bulk_action", hook_func):
-            response = self.client.post(self.url)
+            response = self.client.post(self.get_url())
 
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.content, b"Overridden!")
@@ -136,7 +163,7 @@ class TestSnippetDeleteView(WagtailTestUtils, TestCase):
             return HttpResponse("Overridden!")
 
         with self.register_hook("after_bulk_action", hook_func):
-            response = self.client.post(self.url)
+            response = self.client.post(self.get_url())
 
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.content, b"Overridden!")
@@ -159,7 +186,7 @@ class TestSnippetDeleteView(WagtailTestUtils, TestCase):
             return HttpResponse("Overridden!")
 
         with self.register_hook("before_delete_snippet", hook_func):
-            response = self.client.get(self.url)
+            response = self.client.get(self.get_url())
 
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.content, b"Overridden!")
@@ -180,7 +207,7 @@ class TestSnippetDeleteView(WagtailTestUtils, TestCase):
             return HttpResponse("Overridden!")
 
         with self.register_hook("before_delete_snippet", hook_func):
-            response = self.client.post(self.url)
+            response = self.client.post(self.get_url())
 
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.content, b"Overridden!")
@@ -201,7 +228,7 @@ class TestSnippetDeleteView(WagtailTestUtils, TestCase):
             return HttpResponse("Overridden!")
 
         with self.register_hook("after_delete_snippet", hook_func):
-            response = self.client.post(self.url)
+            response = self.client.post(self.get_url())
 
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.content, b"Overridden!")