If your CI version is below 3, you have to use like that:
$this->router->fetch_class();
$this->router->fetch_method();
and if your CI version is 3 or above. These methods are deprecated.
$this->router->fetch_class();
$this->router->fetch_method();
You can access the properties instead.
$this->router->class;
$this->router->method;
See codeigniter user guide
URI Routing methods fetch_directory(), fetch_class(), fetch_method()
With properties CI_Router::$directory, CI_Router::$class and CI_Router::$method being public and their respective fetch_*() no longer doing anything else to just return the properties - it doesn’t make sense to keep them.
Those are all internal, undocumented methods, but we’ve opted to deprecate them for now in order to maintain backwards-compatibility just in case. If some of you have utilized them, then you can now just access the properties instead:
$this->router->directory;
$this->router->class;
$this->router->method;