yii\filters\Cors::beforeAction PHP Метод

    public function beforeAction($action)
    {
        $this->request = $this->request ?: Yii::$app->getRequest();
        $this->response = $this->response ?: Yii::$app->getResponse();
        $this->overrideDefaultSettings($action);
        $requestCorsHeaders = $this->extractHeaders();
        $responseCorsHeaders = $this->prepareHeaders($requestCorsHeaders);
        $this->addCorsHeaders($this->response, $responseCorsHeaders);
        return true;
    }