Introduce is_taggable utility function for identifying taggable models

netbox/extras/utils.py

@@ -0,0 +1,15 @@
+from taggit.managers import _TaggableManager
+from utilities.querysets import DummyQuerySet
+
+
+def is_taggable(obj):
+    """
+    Return True if the instance can have Tags assigned to it; False otherwise.
+    """
+    if hasattr(obj, 'tags'):
+        if issubclass(obj.tags.__class__, _TaggableManager):
+            return True
+        # TaggableManager has been replaced with a DummyQuerySet prior to object deletion
+        if isinstance(obj.tags, DummyQuerySet):
+            return True
+    return False