WordPress.org

Ready to get started?Download WordPress

Codex

Function Reference/get post ancestors

Contents

Description

Retrieve the parents of the post based on the post ID.

Usage

<?php get_post_ancestors$post ?>

Parameters

$post
(mixed) (required) Post ID or post object.
Default: None

Return Values

(array) 
Array of IDs or empty if no ancestors are found. The direct parent is returned as the first value in the array. The highest level ancestor is returned as the last value in the array.

Examples

Get Ancestors Page Slug

This example returns the highest page {slug} in a tree and uses it as a Body_Class, so the parent and all children will have the same Body Class!

This example for a twenty eleven child theme in the header.php file

</head>

<?php
/* Get the Page Slug to Use as a Body Class, this will only return a value on pages! */
$class = '';
/* is it a page */
if( is_page() ) { 
	global $post;
        /* Get an array of Ancestors and Parents if they exist */
	$parents = get_post_ancestors( $post->ID );
        /* Get the top Level page->ID count base 1, array base 0 so -1 */ 
	$id = ($parents) ? $parents[count($parents)-1]: $post->ID;
	/* Get the parent and set the $class with the page slug (post_name) */
        $parent = get_page( $id );
	$class = $parent->post_name;
}
?>

<body <?php body_class( $class ); ?>>

Get Ancestors Post Meta

If we did not want to use the page slug, we could use a custom field eg: 'body_class', on the top level page and set the class in the post meta.

</head>

<?php
$class = '';
if( is_page() ) {
	global $post;
	$parents = get_post_ancestors( $post->ID );
	$id = ($parents) ? $parents[count($parents)-1]: $post->ID;
	$class = get_post_meta( $id, 'body_class', true );
}
?>

<body <?php body_class( $class ); ?>>

Get Ancestors Page Thumbnail

Get the top level page thumbnail and display it!

<?php
global $post;
$parents = get_post_ancestors( $post->ID );
/* Get the ID of the 'top most' Page if not return current page ID */
$id = ($parents) ? $parents[count($parents)-1]: $post->ID;
if(has_post_thumbnail( $id )) {
	get_the_post_thumbnail( $id, 'thumbnail');
}
?>

Adeptris

Notes

Change Log

Since: 2.5.0

Source File

get_post_ancestors() is located in wp-includes/post.php.

Related

See also index of Function Reference and index of Template Tags.