ENH: Add failHandler to template_data

src/formhandler.js

@@ -123,7 +123,8 @@ export function formhandler(js_options) {
         col_defaults: col_defaults,
         isEdit: false,
         isAdd: false,
-        templates: default_templates
+        templates: default_templates,
+        _failHandler: failHandler.bind(this, $this, template)
       }
       // Store template_data in $this
       $this.data('formhandler', template_data)