Remove unnecessary queries from userbar

- This drops the number of queries from 9 to 5
- Add test for userbar with revisions
- The previous performance change dropped queries from 13 to 7

CHANGELOG.txt

@@ -9,6 +9,7 @@ Changelog
  * Add `PageQuerySet.private` method as an alias of `not_public` (Mehrdad Moradizadeh)
  * Most images in the admin will now only load once they are visible on screen (Jake Howard)
  * Allow setting default attributes on image tags (Jake Howard)
+ * Optimise the performance of the Wagtail userbar to remove duplicated queries, improving page loads when viewing live pages while signed in (Jake Howard)
  * Fix: Prevent `PageQuerySet.not_public` from returning all pages when no page restrictions exist (Mehrdad Moradizadeh)
 
 

docs/releases/4.1.md

@@ -17,6 +17,7 @@ Wagtail 4.1 is designated a Long Term Support (LTS) release. Long Term Support r
  * Add `PageQuerySet.private` method as an alias of `not_public` (Mehrdad Moradizadeh)
  * Most images in the admin will now only load once they are visible on screen (Jake Howard)
  * Allow setting default attributes on image tags [](adding_default_attributes_to_images) (Jake Howard)
+ * Optimise the performance of the Wagtail userbar to remove duplicated queries, improving page loads when viewing live pages while signed in (Jake Howard)
 
 ### Bug fixes
 

wagtail/admin/templatetags/wagtailuserbar.py

@@ -64,28 +64,21 @@ def wagtailuserbar(context, position="bottom-right"):
 
         if page and page.id:
             if revision_id:
+                revision = Revision.page_revisions.get(id=revision_id)
                 items = [
                     AdminItem(),
-                    ExplorePageItem(
-                        Revision.page_revisions.get(id=revision_id).content_object
-                    ),
-                    EditPageItem(
-                        Revision.page_revisions.get(id=revision_id).content_object
-                    ),
-                    ApproveModerationEditPageItem(
-                        Revision.page_revisions.get(id=revision_id)
-                    ),
-                    RejectModerationEditPageItem(
-                        Revision.page_revisions.get(id=revision_id)
-                    ),
+                    ExplorePageItem(revision.content_object),
+                    EditPageItem(revision.content_object),
+                    ApproveModerationEditPageItem(revision),
+                    RejectModerationEditPageItem(revision),
                 ]
             else:
                 # Not a revision
                 items = [
                     AdminItem(),
-                    ExplorePageItem(Page.objects.get(id=page.id)),
-                    EditPageItem(Page.objects.get(id=page.id)),
-                    AddPageItem(Page.objects.get(id=page.id)),
+                    ExplorePageItem(page),
+                    EditPageItem(page),
+                    AddPageItem(page),
                 ]
         else:
             # Not a page.

wagtail/admin/tests/test_userbar.py

@@ -16,26 +16,46 @@ class TestUserbarTag(TestCase, WagtailTestUtils):
         )
         self.homepage = Page.objects.get(id=2)
 
-    def dummy_request(self, user=None, is_preview=False, in_preview_panel=False):
+    def dummy_request(
+        self, user=None, *, is_preview=False, in_preview_panel=False, revision_id=None
+    ):
         request = RequestFactory().get("/")
         request.user = user or AnonymousUser()
         request.is_preview = is_preview
         request.in_preview_panel = in_preview_panel
+        if revision_id:
+            request.revision_id = revision_id
         return request
 
     def test_userbar_tag(self):
         template = Template("{% load wagtailuserbar %}{% wagtailuserbar %}")
-        content = template.render(
-            Context(
-                {
-                    PAGE_TEMPLATE_VAR: self.homepage,
-                    "request": self.dummy_request(self.user),
-                }
-            )
+        context = Context(
+            {
+                PAGE_TEMPLATE_VAR: self.homepage,
+                "request": self.dummy_request(self.user),
+            }
         )
+        with self.assertNumQueries(5):
+            content = template.render(context)
 
         self.assertIn("<!-- Wagtail user bar embed code -->", content)
 
+    def test_userbar_tag_revision(self):
+        self.homepage.save_revision(user=self.user, submitted_for_moderation=True)
+        revision = self.homepage.get_latest_revision()
+        template = Template("{% load wagtailuserbar %}{% wagtailuserbar %}")
+        context = Context(
+            {
+                PAGE_TEMPLATE_VAR: self.homepage,
+                "request": self.dummy_request(self.user, revision_id=revision.id),
+            }
+        )
+        with self.assertNumQueries(7):
+            content = template.render(context)
+
+        self.assertIn("<!-- Wagtail user bar embed code -->", content)
+        self.assertIn("Approve", content)
+
     def test_userbar_does_not_break_without_request(self):
         template = Template("{% load wagtailuserbar %}{% wagtailuserbar %}boom")
         content = template.render(Context({}))