Get Information About Top-Level Pages in WordPress

by Curtiss   |   last updated October 2, 2010   |   PHP Tutorials ·

About a week ago, someone commented on my post about styling top-level pages differently in WordPress, asking how to get the slug for a top-level page while one of its descendant pages is being viewed.

It just so happened that I was in the process of working on a WordPress theme that needed to display the title of the top-level page on all of its descendants. As part of that process, I wrote a quick function that retrieves the top-level parent of any page on a WordPress site as a WordPress post object.

The function is written like:

function get_topLevel($current_post=NULL) {
	if(empty($current_post)) { global $post; $current_post = clone $post; }
	if(empty($current_post->post_parent)) { return $current_post; }
	while(!empty($current_post->post_parent)) {
		$current_post = get_post($current_post->post_parent);
	}
	return $current_post;
}

To use the function in your theme, simply copy the code above and paste it into your functions.php file. Then, you would call the function like:

$topLevel = get_topLevel(clone $post);

Then, if you need to get the slug of that page, you can do one of two things:

1. Use the post_name property of the $topLevel object you just accessed. The post_name property is supposed to be an alias of the post slug, according to the quick reference for the WordPress post object on RazorLight Media’s website.
2. Use a custom function to retrieve the slug from the permalink (example below).

Getting a Post’s Slug from Its Permalink

To get a post or page slug from its permalink in WordPress, you would normally use code similar to the following.

$permalink = get_permalink( $post->ID ); /* Retrieve the permalink */
$slug = basename( $permalink ); /* Get the slug from the permalink */

Of course, to make things more efficient, you could simply combine the basename() function and the get_permalink() function into one action like the following.

$slug = basename( get_permalink( $post->ID ) );

The basename() function is a native PHP function that strips all information except for the file or directory name from a URI. If you combine it with the WordPress get_permalink() function, it will, in effect, return the post or page slug.