protected function locateFile($file)
    {
        $this->locateFile && $file = call_user_func($this->locateFile, $file);

        return $file;
    }
protected function locateFile($file)
    {
        $this->locateFile && $file = call_user_func($this->locateFile, $file);

        return $file;
    }
protected function locateFile ( $ file ) { $ this -> locateFile && $ file = call_user_func ( $ this -> locateFile , $ file ) ; return $ file ; }
Convert file name by callback

@param string $file
@return mixed
Convert file name by callback