Change data model to versioned tables

src/tixlbase/forms.py

@@ -0,0 +1,15 @@
+from django.forms.models import ModelFormMetaclass, BaseModelForm
+from django.utils import six
+from versions.models import Versionable
+
+
+class VersionedBaseModelForm(BaseModelForm):
+    def save(self, commit=True):
+        if self.instance.pk is not None and isinstance(self.instance, Versionable):
+            if self.has_changed():
+                self.instance = self.instance.clone()
+        super().save(commit)
+
+
+class VersionedModelForm(six.with_metaclass(ModelFormMetaclass, VersionedBaseModelForm)):
+    pass