public function actionCreate()
    {
        if (!\Yii::$app->user->can('create'))
            return $this->alert(Module::t('core', 'Access denied.'));

        $model = new Rubric();
        $request = \Yii::$app->getRequest();
        $loaded = $model->load($request->post());
        
        // prependTo() call validate() and save()
        if ($loaded && $model->prependTo($this->findModel($model->parent_node))) {
            return $this->redirect(['index']);
        } else {
            return $this->renderAjax('create', [
                'model' => $model,
            ]);
        }
    }