misc: add singleton accessor to site settings (#63223)

combo/data/models.py

@@ -2298,7 +2298,7 @@ class SiteSettings(models.Model):
 
     @classmethod
     def export_json(cls):
-        settings = SiteSettings.objects.get()
+        settings = cls.get_singleton()
         return {
             'initial_login_page_path': settings.initial_login_page_path,
             'welcome_page_path': settings.welcome_page_path,
@@ -2307,3 +2307,10 @@ class SiteSettings(models.Model):
     @classmethod
     def import_json(cls, data):
         SiteSettings.objects.update(**data)
+
+    @classmethod
+    def get_singleton(cls):
+        try:
+            return cls.objects.get()
+        except cls.DoesNotExist:
+            return cls()

combo/manager/views.py

@@ -1080,7 +1080,7 @@ class SiteSettingsView(UpdateView):
     success_url = reverse_lazy('combo-manager-homepage')
 
     def get_object(self):
-        return SiteSettings.objects.get()
+        return SiteSettings.get_singleton()
 
 
 site_settings = SiteSettingsView.as_view()

combo/public/views.py

@@ -464,7 +464,7 @@ def page(request):
     if not parts:
         parts = ['index']
 
-    site_settings = SiteSettings.objects.get()
+    site_settings = SiteSettings.get_singleton()
     if (
         parts == ['index']
         and (site_settings.initial_login_page or site_settings.initial_login_page_path)

tests/test_import_export.py

@@ -489,7 +489,7 @@ def test_import_export_payment(app):
 
 
 def test_import_export_settings(app):
-    site_settings = SiteSettings.objects.get()
+    site_settings = SiteSettings.get_singleton()
     site_settings.initial_login_page_path = '/test/'
     site_settings.welcome_page_path = '/hop/'
     site_settings.save()

tests/test_manager.py

@@ -2801,7 +2801,7 @@ def test_site_settings(app, admin_user):
     resp.form['initial_login_page_path'] = '/initial-login/'
     resp.form.submit()
 
-    site_settings = SiteSettings.objects.get()
+    site_settings = SiteSettings.get_singleton()
     assert site_settings.welcome_page_path == '/welcome/'
     assert site_settings.initial_login_page_path == '/initial-login/'
 

tests/test_public.py

@@ -651,7 +651,7 @@ def test_initial_login_page(app, admin_user):
     page = Page(title='Initial Login', slug='initial-login', template_name='standard', public=False)
     page.save()
 
-    site_settings = SiteSettings.objects.get()
+    site_settings = SiteSettings.get_singleton()
     site_settings.initial_login_page_path = '/initial-login/'
     site_settings.save()
 
@@ -721,7 +721,7 @@ def test_welcome_page(app, admin_user):
     page = Page(title='Welcome', slug='welcome', template_name='standard')
     page.save()
 
-    site_settings = SiteSettings.objects.get()
+    site_settings = SiteSettings.get_singleton()
     site_settings.welcome_page_path = '/welcome/'
     site_settings.save()