Add Route.level property

conman/routes/models.py

@@ -136,6 +136,16 @@ def handle(self, request, path):
         # Deal with the request
         return handler.handle(request, path)
 
+    @property
+    def level(self):
+        """Fetch the one-indexed 'level' of this item in the URL tree."""
+        return self.url.count('/')
+
+    @level.setter
+    def level(self, new_value):
+        """Silently fails to allow queryset annotation to work."""
+        pass
+
     def move_to(self, new_url, *, move_children):
         """
         Move this Route to a new url.

tests/routes/test_models.py

@@ -47,6 +47,18 @@ def test_url_form_widget(self):
         widget = Route._meta.get_field('url').formfield().widget
         self.assertIsInstance(widget, forms.TextInput)
 
+    def test_level(self):
+        """Route.level is based on the url field."""
+        urls = (
+            (1, '/'),
+            (2, '/branch/'),
+            (3, '/branch/leaf/'),
+        )
+        for level, url in urls:
+            with self.subTest(url=url):
+                route = RouteFactory.build(url=url)
+                self.assertEqual(route.level, level)
+
 
 class RouteUniquenessTest(TestCase):
     """Check uniqueness conditions on Route are enforced in the DB."""