framework/rest/OptionsAction.php
public function run($id = null)
    {
        if (Yii::$app->getRequest()->getMethod() !== 'OPTIONS') {
            Yii::$app->getResponse()->setStatusCode(405);
        }
        $options = $id === null ? $this->collectionOptions : $this->resourceOptions;
        $headers = Yii::$app->getResponse()->getHeaders();
        $headers->set('Allow', implode(', ', $options));
        $headers->set('Access-Control-Allow-Methods', implode(', ', $options));
    }
public function run($id = null)
    {
        if (Yii::$app->getRequest()->getMethod() !== 'OPTIONS') {
            Yii::$app->getResponse()->setStatusCode(405);
        }
        $options = $id === null ? $this->collectionOptions : $this->resourceOptions;
        $headers = Yii::$app->getResponse()->getHeaders();
        $headers->set('Allow', implode(', ', $options));
        $headers->set('Access-Control-Allow-Methods', implode(', ', $options));
    }
Responds to the OPTIONS request.
@param string $id