OpenGraph wp_head

gistfile1.txt

add_action('wp_head', 'opengraph_on_single');
function opengraph_on_single() {
	if ( is_single() ) {
        global $post;
        setup_postdata( $post );
        echo '<meta property="og:type" content="article" />
        <meta property="og:title" content="' . esc_attr( get_the_title() ) . '" />
        <meta property="og:url" content="' . get_permalink() . '" />
        <meta property="og:description" content="' . esc_attr( get_the_excerpt() ) . '" />';

        if ( has_post_thumbnail() ) {
        $imgsrc = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'medium' );
        echo '<meta property="og:image" content="' . $imgsrc[0] . '" />'
        }
    }
}