WordPress Version: 5.5
/**
* Returns the canonical URL for a post.
*
* When the post is the same as the current requested page the function will handle the
* pagination arguments too.
*
* @since 4.6.0
*
* @param int|WP_Post $post Optional. Post ID or object. Default is global `$post`.
* @return string|false The canonical URL, or false if the post does not exist or has not
* been published yet.
*/
function wp_get_canonical_url($post = null)
{
$post = get_post($post);
if (!$post) {
return false;
}
if ('publish' !== $post->post_status) {
return false;
}
$canonical_url = get_permalink($post);
// If a canonical is being generated for the current page, make sure it has pagination if needed.
if (get_queried_object_id() === $post->ID) {
$page = get_query_var('page', 0);
if ($page >= 2) {
if (!get_option('permalink_structure')) {
$canonical_url = add_query_arg('page', $page, $canonical_url);
} else {
$canonical_url = trailingslashit($canonical_url) . user_trailingslashit($page, 'single_paged');
}
}
$cpage = get_query_var('cpage', 0);
if ($cpage) {
$canonical_url = get_comments_pagenum_link($cpage);
}
}
/**
* Filters the canonical URL for a post.
*
* @since 4.6.0
*
* @param string $canonical_url The post's canonical URL.
* @param WP_Post $post Post object.
*/
return apply_filters('get_canonical_url', $canonical_url, $post);
}