wp_set_object_terms( int $object_id, string|int|array $terms, string $taxonomy, bool $append = false ): array|WP_Error

Description

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$object_idint

The object to relate to.

$termsstring|int|array

A single term slug, single term ID, or array of either term slugs or IDs.
Will replace all existing related terms in this taxonomy. Passing an empty array will remove all related terms.

$taxonomystring

The context in which to relate the term to the object.

$appendbooloptional

If false will delete difference of terms. Default false.Default: false

Return value

array|WP_Error

Term taxonomy IDs of the affected terms or WP_Error on failure.

Performance profile

How much work a call to wp_set_object_terms() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Heavy

Reaches the database via ->get_col().

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

19–125

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 224.

Plugin surface

3 hooks

Third-party callbacks on 'add_term_relationship', 'added_term_relationship', 'set_object_terms' run inside this call, and their cost is not bounded by anything here.

Called by

8

8 places in core call this, so the cost is paid more often than your own code shows.

What it touches

• querycontent querywp_get_object_terms()called directly
• hookthird-party callbacksdo_action()called directly
• cacheobject cachewp_cache_delete()called directly
• sqldatabase query->get_col()called directly

Further down the call graph this can also reach option, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 57 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost wp_set_object_terms() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 3

3 hooks fire while wp_set_object_terms() runs, in this order:

1. 1
   do_action( add_term_relationship )actionline 2879 (+69 into the body)

   Fires immediately before an object-term relationship is added.

2. 2
   do_action( added_term_relationship )actionline 2899 (+89 into the body)

   Fires immediately after an object-term relationship is added.

3. 3
   do_action( set_object_terms )actionline 2966 (+156 into the body)

   Fires after an object's terms have been set.

Uses · 13

• taxonomy_exists()Determines whether the taxonomy name exists.
• __()Retrieves the translation of $text.
• wp_get_object_terms()Retrieves the terms associated with the given object(s), in the supplied taxonomies.
• term_exists()Determines whether a taxonomy term exists.
• wp_insert_term()Adds a new term to the database.
• is_wp_error()Checks whether the given variable is a WordPress Error.
• do_action()Calls the callback functions that have been added to an action hook.
• wp_update_term_count()Updates the amount of terms in taxonomy.
• wp_remove_object_terms()Removes term(s) associated with a given object.
• get_taxonomy()Retrieves the taxonomy object of $taxonomy.
• wp_cache_delete()Removes the cache contents matching key and group.
• wp_cache_set_terms_last_changed()Sets the last changed time for the 'terms' cache group.

Used by · 8

• WP_REST_Posts_Controller::handle_terms()Updates the post's terms from a REST request.
• media_upload_form_handler()Handles form submissions for the legacy media uploader.
• wp_add_object_terms()Adds term(s) associated with a given object.
• wp_ajax_save_attachment_compat()Handles saving backward compatible attachment attributes via AJAX.
• wp_delete_term()Removes a term from the database.
• wp_set_link_cats()Updates link with the specified link categories.
• wp_set_post_terms()Sets the terms for a post.
• wp_update_nav_menu_item()Saves the properties of a menu item or create a new one.

Source code

View on Trac ↗View on GitHub ↗

2810function wp_set_object_terms( $object_id, $terms, $taxonomy, $append = false ) {2811	global $wpdb;2812 2813	$object_id = (int) $object_id;2814 2815	if ( ! taxonomy_exists( $taxonomy ) ) {2816		return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );2817	}2818 2819	if ( empty( $terms ) ) {2820		$terms = array();2821	} elseif ( ! is_array( $terms ) ) {2822		$terms = array( $terms );2823	}2824 2825	if ( ! $append ) {2826		$old_tt_ids = wp_get_object_terms(2827			$object_id,2828			$taxonomy,2829			array(2830				'fields'                 => 'tt_ids',2831				'orderby'                => 'none',2832				'update_term_meta_cache' => false,2833			)2834		);2835	} else {2836		$old_tt_ids = array();2837	}2838 2839	$tt_ids     = array();2840	$new_tt_ids = array();2841 2842	foreach ( (array) $terms as $term ) {2843		if ( '' === trim( $term ) ) {2844			continue;2845		}2846 2847		$term_info = term_exists( $term, $taxonomy );2848 2849		if ( ! $term_info ) {2850			// Skip if a non-existent term ID is passed.2851			if ( is_int( $term ) ) {2852				continue;2853			}2854 2855			$term_info = wp_insert_term( $term, $taxonomy );2856		}2857 2858		if ( is_wp_error( $term_info ) ) {2859			return $term_info;2860		}2861 2862		$tt_id    = $term_info['term_taxonomy_id'];2863		$tt_ids[] = $tt_id;2864 2865		if ( $wpdb->get_var( $wpdb->prepare( "SELECT term_taxonomy_id FROM $wpdb->term_relationships WHERE object_id = %d AND term_taxonomy_id = %d", $object_id, $tt_id ) ) ) {2866			continue;2867		}2868 2869		/**2870		 * Fires immediately before an object-term relationship is added.2871		 *2872		 * @since 2.9.02873		 * @since 4.7.0 Added the `$taxonomy` parameter.2874		 *2875		 * @param int    $object_id Object ID.2876		 * @param int    $tt_id     Term taxonomy ID.2877		 * @param string $taxonomy  Taxonomy slug.2878		 */2879		do_action( 'add_term_relationship', $object_id, $tt_id, $taxonomy );2880 2881		$wpdb->insert(2882			$wpdb->term_relationships,2883			array(2884				'object_id'        => $object_id,2885				'term_taxonomy_id' => $tt_id,2886			)2887		);2888 2889		/**

Changelog

Introduced in 2.3.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 6.8.8 tag, from src/wp-includes/taxonomy.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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