wp_get_object_terms()WP 2.3.0

Retrieves the terms associated with the given object(s), in the supplied taxonomies.

1 time — 0.003926 sec (very slow) | 50000 times — 8.64 sec (fast) | PHP 7.1.2, WP 4.8

Return

WP_Term[]|Int[]|String[]|String|WP_Error. Array of terms, a count thereof as a numeric string, or WP_Error if any of the taxonomies do not exist. See WP_Term_Query::get_terms() for more information.

Usage

wp_get_object_terms( $object_ids, $taxonomies, $args );
$object_ids(int|int[]) (required)
The ID(s) of the object(s) to retrieve.
$taxonomies(string|string[]) (required)
The taxonomy names to retrieve terms from.
$args(array|string)
See WP_Term_Query::__construct() for supported arguments.
Default: array()

Examples

0

#1 All elements of the 'product_categories' taxonomy post

Get the terms of the product_categories taxonomy of the current post ($post->ID):

$product_cats = wp_get_object_terms( $post->ID, 'product_categories' );
0

#2 Returns the list of elements of the "product" taxonomy that are set for the posts:

$product_terms = wp_get_object_terms( $post->ID, 'product' );

if( $product_terms && ! is_wp_error( $product_terms ) ){

	$lis = [];
	foreach( $product_terms as $term ){
		$lis[] = '<li><a href="'. get_term_link( $term ) .'">'. esc_html( $term->name ) .'</a></li>';
	}

	echo '<ul>'. implode( "\n", $lis ) .'</ul>';
}
0

#3 Gets the topmost taxonomy element for the specified or current post in the loop

See the example in the get_the_terms() description.

Changelog

Since 2.3.0 Introduced.
Since 4.2.0 Added support for 'taxonomy', 'parent', and 'term_taxonomy_id' values of $orderby. Introduced $parent argument.
Since 4.4.0 Introduced $meta_query and $update_term_meta_cache arguments. When $fields is 'all' or 'all_with_object_id', an array of WP_Term objects will be returned.
Since 4.7.0 Refactored to use WP_Term_Query, and to support any WP_Term_Query arguments.
Since 6.3.0 Passing update_term_meta_cache argument value false by default resulting in get_terms() to not prime the term meta cache.

wp_get_object_terms() code WP 6.5.2

function wp_get_object_terms( $object_ids, $taxonomies, $args = array() ) {
	if ( empty( $object_ids ) || empty( $taxonomies ) ) {
		return array();
	}

	if ( ! is_array( $taxonomies ) ) {
		$taxonomies = array( $taxonomies );
	}

	foreach ( $taxonomies as $taxonomy ) {
		if ( ! taxonomy_exists( $taxonomy ) ) {
			return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
		}
	}

	if ( ! is_array( $object_ids ) ) {
		$object_ids = array( $object_ids );
	}
	$object_ids = array_map( 'intval', $object_ids );

	$defaults = array(
		'update_term_meta_cache' => false,
	);

	$args = wp_parse_args( $args, $defaults );

	/**
	 * Filters arguments for retrieving object terms.
	 *
	 * @since 4.9.0
	 *
	 * @param array    $args       An array of arguments for retrieving terms for the given object(s).
	 *                             See {@see wp_get_object_terms()} for details.
	 * @param int[]    $object_ids Array of object IDs.
	 * @param string[] $taxonomies Array of taxonomy names to retrieve terms from.
	 */
	$args = apply_filters( 'wp_get_object_terms_args', $args, $object_ids, $taxonomies );

	/*
	 * When one or more queried taxonomies is registered with an 'args' array,
	 * those params override the `$args` passed to this function.
	 */
	$terms = array();
	if ( count( $taxonomies ) > 1 ) {
		foreach ( $taxonomies as $index => $taxonomy ) {
			$t = get_taxonomy( $taxonomy );
			if ( isset( $t->args ) && is_array( $t->args ) && array_merge( $args, $t->args ) != $args ) {
				unset( $taxonomies[ $index ] );
				$terms = array_merge( $terms, wp_get_object_terms( $object_ids, $taxonomy, array_merge( $args, $t->args ) ) );
			}
		}
	} else {
		$t = get_taxonomy( $taxonomies[0] );
		if ( isset( $t->args ) && is_array( $t->args ) ) {
			$args = array_merge( $args, $t->args );
		}
	}

	$args['taxonomy']   = $taxonomies;
	$args['object_ids'] = $object_ids;

	// Taxonomies registered without an 'args' param are handled here.
	if ( ! empty( $taxonomies ) ) {
		$terms_from_remaining_taxonomies = get_terms( $args );

		// Array keys should be preserved for values of $fields that use term_id for keys.
		if ( ! empty( $args['fields'] ) && str_starts_with( $args['fields'], 'id=>' ) ) {
			$terms = $terms + $terms_from_remaining_taxonomies;
		} else {
			$terms = array_merge( $terms, $terms_from_remaining_taxonomies );
		}
	}

	/**
	 * Filters the terms for a given object or objects.
	 *
	 * @since 4.2.0
	 *
	 * @param WP_Term[]|int[]|string[]|string $terms      Array of terms or a count thereof as a numeric string.
	 * @param int[]                           $object_ids Array of object IDs for which terms were retrieved.
	 * @param string[]                        $taxonomies Array of taxonomy names from which terms were retrieved.
	 * @param array                           $args       Array of arguments for retrieving terms for the given
	 *                                                    object(s). See wp_get_object_terms() for details.
	 */
	$terms = apply_filters( 'get_object_terms', $terms, $object_ids, $taxonomies, $args );

	$object_ids = implode( ',', $object_ids );
	$taxonomies = "'" . implode( "', '", array_map( 'esc_sql', $taxonomies ) ) . "'";

	/**
	 * Filters the terms for a given object or objects.
	 *
	 * The `$taxonomies` parameter passed to this filter is formatted as a SQL fragment. The
	 * {@see 'get_object_terms'} filter is recommended as an alternative.
	 *
	 * @since 2.8.0
	 *
	 * @param WP_Term[]|int[]|string[]|string $terms      Array of terms or a count thereof as a numeric string.
	 * @param string                          $object_ids Comma separated list of object IDs for which terms were retrieved.
	 * @param string                          $taxonomies SQL fragment of taxonomy names from which terms were retrieved.
	 * @param array                           $args       Array of arguments for retrieving terms for the given
	 *                                                    object(s). See wp_get_object_terms() for details.
	 */
	return apply_filters( 'wp_get_object_terms', $terms, $object_ids, $taxonomies, $args );
}