dpchen

All GFC comments display wordpress’s anonymous avatar. What happened?

Just noticed that %post_id% overlaps with the built-in permalink placeholders, so your normal post permalinks might be corrupted if you are using post id’s there as well. Simply change %post_id% to something original like %cpt_id% throughout your own functions and you’ll be fine.

I was having the same problem as well: couldn’t find a way to use post ID in the permalink of my custom post type. Here’s what I did.

Add the rewrite rule:

add_action('init', 'myposttype_rewrite');
function myposttype_rewrite() {
	global $wp_rewrite;
	$queryarg = 'post_type=myposttype&p=';
	$wp_rewrite->add_rewrite_tag('%post_id%', '([^/]+)', $queryarg);
	$wp_rewrite->add_permastruct('myposttype', '/myposttype/%post_id%', false);
	}

And hook the post_type_link filter:

add_filter('post_type_link', 'myposttype_permalink', 1, 3);
function myposttype_permalink($post_link, $id = 0, $leavename, $sample) {
	global $wp_rewrite;
	$post = &get_post($id);
	if ( is_wp_error( $post ) )
		return $post;
	$newlink = $wp_rewrite->get_extra_permastruct('myposttype');
	$newlink = str_replace("%post_id%", $post->ID, $newlink);
	$newlink = home_url(user_trailingslashit($newlink));
	return $newlink;
	}

Remember to flush your rewrite rules before you view your custom post type using the new permalink. Simply visit your Permalink settings page in the admin panel.

I still recommend WordPress – in the future versions – to have better UI for creating/managing custom post types, and allow a more flexible way of configuring custom post type permalinks.