Pass the correct for_update value for get_form_class in SnippetViewSet's edit views (#10445)

Fixes #10438

CHANGELOG.txt

@@ -22,6 +22,7 @@ Changelog
  * 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)
+ * Fix: Pass the correct `for_update` value for `get_form_class` in `SnippetViewSet` edit views (Sage Abdullah)
  * Docs: Update documentation for `log_action` parameter on `RevisionMixin.save_revision` (Christer Jensen)
 
 

docs/releases/5.0.1.md

@@ -17,6 +17,7 @@ depth: 1
  * 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)
+ * Pass the correct `for_update` value for `get_form_class` in `SnippetViewSet` edit views (Sage Abdullah)
 
 ### Documentation
 

wagtail/snippets/tests/test_viewset.py

@@ -959,3 +959,20 @@ class TestMenuItemRegistration(BaseSnippetViewSetTests):
             menu_items = admin_menu.render_component(self.request)
             snippets = [item for item in menu_items if item.name == "snippets"]
             self.assertEqual(len(snippets), 0)
+
+
+class TestCustomFormClass(BaseSnippetViewSetTests):
+    model = DraftStateModel
+
+    def test_get_form_class(self):
+        add_view = self.client.get(self.get_url("add"))
+        self.assertNotContains(add_view, '<input type="text" name="text"')
+        self.assertContains(add_view, '<textarea name="text"')
+
+        obj = self.model.objects.create(text="Hello World")
+
+        # The get_form_class has been overridden to replace the widget for the
+        # text field with a TextInput, but only for the edit view
+        edit_view = self.client.get(self.get_url("edit", args=(quote(obj.pk),)))
+        self.assertContains(edit_view, '<input type="text" name="text"')
+        self.assertNotContains(edit_view, '<textarea name="text"')

wagtail/snippets/views/snippets.py

@@ -901,7 +901,7 @@ class SnippetViewSet(ModelViewSet):
             header_icon=self.icon,
             permission_policy=self.permission_policy,
             panel=self._edit_handler,
-            form_class=self.get_form_class(),
+            form_class=self.get_form_class(for_update=True),
             index_url_name=self.get_url_name("list"),
             edit_url_name=self.get_url_name("edit"),
             delete_url_name=self.get_url_name("delete"),
@@ -971,7 +971,7 @@ class SnippetViewSet(ModelViewSet):
             header_icon=self.icon,
             permission_policy=self.permission_policy,
             panel=self._edit_handler,
-            form_class=self.get_form_class(),
+            form_class=self.get_form_class(for_update=True),
             index_url_name=self.get_url_name("list"),
             edit_url_name=self.get_url_name("edit"),
             delete_url_name=self.get_url_name("delete"),
@@ -1044,7 +1044,7 @@ class SnippetViewSet(ModelViewSet):
     def preview_on_edit_view(self):
         return self.preview_on_edit_view_class.as_view(
             model=self.model,
-            form_class=self.get_form_class(),
+            form_class=self.get_form_class(for_update=True),
         )
 
     @property

wagtail/test/testapp/wagtail_hooks.py

@@ -1,3 +1,4 @@
+from django import forms
 from django.http import HttpResponse
 from django.utils.safestring import mark_safe
 
@@ -315,6 +316,12 @@ class DraftStateModelViewSet(SnippetViewSet):
         PublishingPanel(),
     ]
 
+    def get_form_class(self, for_update=False):
+        form_class = super().get_form_class(for_update)
+        if for_update:
+            form_class.base_fields["text"].widget = forms.TextInput()
+        return form_class
+
 
 class ModeratedModelViewSet(SnippetViewSet):
     model = ModeratedModel