public function getQrCodeUri($uri = 'https://chart.googleapis.com/chart?chs=200x200&chld=M|0&cht=qr&chl={PROVISIONING_URI}', $placeholder = '{PROVISIONING_URI}') { $provisioning_uri = urlencode($this->getProvisioningUri()); return str_replace($placeholder, $provisioning_uri, $uri); }