/**
* Output the OpenGraphProtocol object as HTML elements string
*
* @return string
*/
private function toHTML()
{
$allowed = array_flip(['type', 'title', 'site_name', 'description', 'url', 'determiner', 'locale', 'images', 'videos', 'audios']);
$attributes = array_intersect_key(get_object_vars($this), $allowed);
return OGMetaBuilder::html($attributes);
}
/**
* Output the object as HTML <meta> elements
* @return string HTML meta element string
*/
public function toHTML()
{
return rtrim(OGMetaBuilder::html(get_object_vars($this), static::PREFIX), PHP_EOL);
}