yii\web\Request::getMethod PHP Method

    public function getMethod()
    {
        if (isset($_POST[$this->methodParam])) {
            return strtoupper($_POST[$this->methodParam]);
        }
        if (isset($_SERVER['HTTP_X_HTTP_METHOD_OVERRIDE'])) {
            return strtoupper($_SERVER['HTTP_X_HTTP_METHOD_OVERRIDE']);
        }
        if (isset($_SERVER['REQUEST_METHOD'])) {
            return strtoupper($_SERVER['REQUEST_METHOD']);
        }
        return 'GET';
    }

 /**
  * @param \yii\web\UrlManager $manager
  * @param \yii\web\Request $request
  * @return array|bool
  */
 public function parseRequest($manager, $request)
 {
     if ($this->mode === self::CREATION_ONLY) {
         return false;
     }
     if (!empty($this->verb) && !in_array($request->getMethod(), $this->verb, true)) {
         return false;
     }
     $pathInfo = $request->getPathInfo();
     if ($this->host !== null) {
         $pathInfo = strtolower($request->getHostInfo()) . ($pathInfo === '' ? '' : '/' . $pathInfo);
     }
     $params = $request->getQueryParams();
     $suffix = (string) ($this->suffix === null ? $manager->suffix : $this->suffix);
     $treeNode = null;
     $originalDir = $pathInfo;
     if ($suffix) {
         $originalDir = substr($pathInfo, 0, strlen($pathInfo) - strlen($suffix));
     }
     $dependency = new TagDependency(['tags' => [(new Tree())->getTableCacheTag()]]);
     if (!$pathInfo) {
         $treeNode = Tree::getDb()->cache(function ($db) {
             return Tree::find()->where(["site_code" => \Yii::$app->cms->site->code, "level" => 0])->one();
         }, null, $dependency);
     } else {
         $treeNode = Tree::find()->where(["dir" => $originalDir, "site_code" => \Yii::$app->cms->site->code])->one();
     }
     if ($treeNode) {
         \Yii::$app->cms->setCurrentTree($treeNode);
         $params['id'] = $treeNode->id;
         return ['cms/tree/view', $params];
     } else {
         return false;
     }
 }