Give ability to override missing fields warning

flask_admin/model/base.py

@@ -1017,6 +1017,9 @@ class BaseModelView(BaseView, ActionsMixin):
                     missing_fields.append(field.name)
 
         return missing_fields
+        
+    def _show_missing_fields_warning(self, text):
+        warnings.warn(text)
 
     def _validate_form_class(self, ruleset, form_class, remove_missing=True):
         form_fields = []
@@ -1032,14 +1035,14 @@ class BaseModelView(BaseView, ActionsMixin):
                     missing_fields.append(field_name)
 
         if missing_fields:
-            warnings.warn('Fields missing from ruleset: %s' % (','.join(missing_fields)))
+            self._show_missing_fields_warning('Fields missing from ruleset: %s' % (','.join(missing_fields)))
         if remove_missing:
             self._remove_fields_from_form_class(missing_fields, form_class)
 
     def _validate_form_instance(self, ruleset, form, remove_missing=True):
         missing_fields = self._get_ruleset_missing_fields(ruleset=ruleset, form=form)
         if missing_fields:
-            warnings.warn('Fields missing from ruleset: %s' % (','.join(missing_fields)))
+            self._show_missing_fields_warning('Fields missing from ruleset: %s' % (','.join(missing_fields)))
         if remove_missing:
             self._remove_fields_from_form_instance(missing_fields, form)