protected function setupCallbackUrl() { //Create and setup callback URL $this->callback_url = new Url(); $this->callback_url->setScheme('http'); $this->callback_url->setHost('ws.audioscrobbler.com'); $this->callback_url->setPath('/2.0/'); //2.0 - API version $this->callback_url->appendQuery("api_key={$this->key}"); if ($this->data_format == self::DATA_JSON) { $this->callback_url->appendQuery('format=json'); } //JSON result }