(Fix Included) Support Date Permalinks With Custom Post Types

One weakness in the new custom post type feature is the inability to support custom permalink structures. I modified the file wp-includes/link-template.php to support it, and it’d be great to see this get into a future release.

Right now, when setting a custom permalink structure for a custom post type (using add_permastruct()), if the structure contains date tags like %year% it is broken. Routing tables (in $wp_rewrite) are set properly, but the permalinks returned by get_permalink() are busted.

This code fixes that problem to support the permalink tags %year%, %monthnum%, %day%, %hour%, %minute%, and %second%. Now all of those tags can be used in the permastructs for custom post types.

To use them you need to call:
add_permastruct('<post-type>', "<permastruct>", true, EP_NONE);
after you call register_post_type, using %<post-type>% for the post’s slug. (For example, the permastruct for my custom ‘news’ type is ‘news/%year%/%monthnum%/%news%’)

Here’s the code with my addition commented out:

function get_post_permalink( $id = 0, $leavename = false, $sample = false ) {
	global $wp_rewrite;

	$post = &get_post($id);

	if ( is_wp_error( $post ) )
		return $post;

	$post_link = $wp_rewrite->get_extra_permastruct($post->post_type);

	$slug = $post->post_name;

	$draft_or_pending = in_array( $post->post_status, array( 'draft', 'pending', 'auto-draft' ) );

	$post_type = get_post_type_object($post->post_type);

	if ( !empty($post_link) && ( ( isset($post->post_status) && !$draft_or_pending ) || $sample ) ) {
		if ( ! $leavename ) {
			if ( $post_type->hierarchical )
				$slug = get_page_uri($id);
			$post_link = str_replace("%$post->post_type%", $slug, $post_link);
		}
		$post_link = home_url( user_trailingslashit($post_link) );
	} else {
		if ( $post_type->query_var && ( isset($post->post_status) && !$draft_or_pending ) )
			$post_link = add_query_arg($post_type->query_var, $slug, '');
		else
			$post_link = add_query_arg(array('post_type' => $post->post_type, 'p' => $post->ID), '');
		$post_link = home_url($post_link);
	}

	/******** Support more permalink structures (Richard Connamacher) ********/
	$rewritecode = array(
		'%year%',
		'%monthnum%',
		'%day%',
		'%hour%',
		'%minute%',
		'%second%',
	);
	$unixtime = strtotime($post->post_date);
	$date = explode(" ",date('Y m d H i s', $unixtime));
	$rewritereplace = array(
		$date[0],
		$date[1],
		$date[2],
		$date[3],
		$date[4],
		$date[5],
	);

	$post_link = str_replace($rewritecode, $rewritereplace, $post_link);
	/******** End addition ********/

	return apply_filters('post_type_link', $post_link, $post, $leavename, $sample);
}