code: public function getViewPath()
      {
          if ($this->_viewPath === null) {
              $this->_viewPath = $this->module->getViewPath() . DIRECTORY_SEPARATOR . $this->id;
          }
  
          return $this->_viewPath;
      }
docs: Returns the directory containing view files for this controller.
  The default implementation returns the directory named as controller [[id]] under the [[module]]'s
  [[viewPath]] directory.
  @return string the directory containing the view files for this controller.