yii\web\Request::getBaseUrl PHP Method

    public function getBaseUrl()
    {
        if ($this->_baseUrl === null) {
            $this->_baseUrl = rtrim(dirname($this->getScriptUrl()), '\\/');
        }
        return $this->_baseUrl;
    }

 /**
  * @param \yii\web\Request $request
  * @return \yii\web\Response|null
  */
 protected function handleRedirectRequest($request)
 {
     $key = ltrim(str_replace($request->getBaseUrl(), '', $request->getUrl()), '/');
     if (array_key_exists($key, $this->redirectRoutes)) {
         return $this->getResponse()->redirect(Url::to($this->redirectRoutes[$key]));
     } else {
         return null;
     }
 }