``` /** * Original function written as mini-plugin (Featured image for Open Graph) * by @toscho (https://github.com/toscho) for MarketPress (http://marketpress.com/) * * The functions inserts the featured image as Open Graph image for social sharing. * More info on http://marketpress.com/2013/how-social-networks-find-the-featured-image/ * and/or https://github.com/inpsyde/mini-plugins * * Licence: GPL 2 * License URI: http://opensource.org/licenses/GPL-2.0 */ add_action( 'wp_head', 'so_ogp_image' ); /** * Create meta element for preview image. * * @wp-hook wp_head * @return void */ function so_ogp_image() { // restricted to singular pages only if ( ! is_singular() ) return; // there has to be a featured image set $thumb_id = get_post_thumbnail_id(); // no featured image. stop. if ( empty ( $thumb_id ) ) return; // FALSE or array $image = wp_get_attachment_image_src( $thumb_id ); // nothing found for unknown reasons if ( empty ( $image ) ) return; // make sure it is a real url $src = esc_url( $image[ 0 ] ); // esc_url() returns an empty string for some invalid URLs if ( '' !== $src ) print "<meta property='http://ogp.me/ns#image' content='$src' />"; } ```