get_boundary_post() – Function | Developer.WordPress.org

Retrieves the boundary post.

Description

Boundary being either the first or last post by publish date within the constraints specified by $in_same_term or $excluded_terms.

Parameters

$in_same_termbooloptional: Whether returned post should be in the same taxonomy term.

Default:false
$excluded_termsint[]|stringoptional: Array or comma-separated list of excluded term IDs.

Default:''
$startbooloptional: Whether to retrieve first or last post.

Default:true
$taxonomystringoptional: Taxonomy, if $in_same_term is true. Default 'category'.
Default:'category'

Return

array|null Array containing the boundary post object if successful, null otherwise.

More Information

get_boundary_post() will set the post pointer to the first post.

Source

function get_boundary_post( $in_same_term = false, $excluded_terms = '', $start = true, $taxonomy = 'category' ) {
	$post = get_post();

	if ( ! $post || ! is_single() || is_attachment() || ! taxonomy_exists( $taxonomy ) ) {
		return null;
	}

	$query_args = array(
		'posts_per_page'         => 1,
		'order'                  => $start ? 'ASC' : 'DESC',
		'update_post_term_cache' => false,
		'update_post_meta_cache' => false,
	);

	$term_array = array();

	if ( ! is_array( $excluded_terms ) ) {
		if ( ! empty( $excluded_terms ) ) {
			$excluded_terms = explode( ',', $excluded_terms );
		} else {
			$excluded_terms = array();
		}
	}

	if ( $in_same_term || ! empty( $excluded_terms ) ) {
		if ( $in_same_term ) {
			$term_array = wp_get_object_terms( $post->ID, $taxonomy, array( 'fields' => 'ids' ) );
		}

		if ( ! empty( $excluded_terms ) ) {
			$excluded_terms = array_map( 'intval', $excluded_terms );
			$excluded_terms = array_diff( $excluded_terms, $term_array );

			$inverse_terms = array();
			foreach ( $excluded_terms as $excluded_term ) {
				$inverse_terms[] = $excluded_term * -1;
			}
			$excluded_terms = $inverse_terms;
		}

		$query_args['tax_query'] = array(
			array(
				'taxonomy' => $taxonomy,
				'terms'    => array_merge( $term_array, $excluded_terms ),
			),
		);
	}

	return get_posts( $query_args );
}

View all references View on Trac View on GitHub

Uses	Description
is_single()`wp-includes/query.php`	Determines whether the query is for an existing single post.
is_attachment()`wp-includes/query.php`	Determines whether the query is for an existing attachment page.
wp_get_object_terms()`wp-includes/taxonomy.php`	Retrieves the terms associated with the given object(s), in the supplied taxonomies.
taxonomy_exists()`wp-includes/taxonomy.php`	Determines whether the taxonomy name exists.
get_posts()`wp-includes/post.php`	Retrieves an array of the latest posts, or posts matching the given criteria.
get_post()`wp-includes/post.php`	Retrieves post data given a post ID or post object.

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Used by	Description
get_boundary_post_rel_link()`wp-includes/deprecated.php`	Get boundary post relational link.

Changelog

Version	Description
2.8.0	Introduced.

User Contributed Notes

Steven Lin 5 years ago

Migrate from Codex:

Link with title of first post in current post’s category:

<?php
   $first= get_boundary_post(true, , true, 'category');
   if (!empty($first)) { foreach ($first as $post) { ?>
   <a href="<?php echo the_permalink($post->ID); ?>"><?php echo $post->post_title; ?></a>
<?php }} ?>

Link with title of latest post in current post’s category:

<?php
   $latest= get_boundary_post(true, , false, 'category');
   if (!empty($latest)) { foreach ($latest as $post) { ?>
   <a href="<?php echo the_permalink($post->ID); ?>"><?php echo $post->post_title; ?></a>
<?php }} ?>

Skip to note 4 content

captainusman 2 years ago

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This function Not working in WordPress 6+

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get_boundary_post( bool $in_same_term = false, int[]|string $excluded_terms = '', bool $start = true, string $taxonomy = 'category' ): array|null

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