wp_update_term() WordPress Function

function wp_update_term( $term_id, $taxonomy, $args = array() ) {
	global $wpdb;

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

	$term_id = (int) $term_id;

	// First, get all of the original args.
	$term = get_term( $term_id, $taxonomy );

	if ( is_wp_error( $term ) ) {
		return $term;
	}

	if ( ! $term ) {
		return new WP_Error( 'invalid_term', __( 'Empty Term.' ) );
	}

	$term = (array) $term->data;

	// Escape data pulled from DB.
	$term = wp_slash( $term );

	// Merge old and new args with new args overwriting old ones.
	$args = array_merge( $term, $args );

	$defaults    = array(
		'alias_of'    => '',
		'description' => '',
		'parent'      => 0,
		'slug'        => '',
	);
	$args        = wp_parse_args( $args, $defaults );
	$args        = sanitize_term( $args, $taxonomy, 'db' );
	$parsed_args = $args;

	// expected_slashed ($name)
	$name        = wp_unslash( $args['name'] );
	$description = wp_unslash( $args['description'] );

	$parsed_args['name']        = $name;
	$parsed_args['description'] = $description;

	if ( '' === trim( $name ) ) {
		return new WP_Error( 'empty_term_name', __( 'A name is required for this term.' ) );
	}

	if ( (int) $parsed_args['parent'] > 0 && ! term_exists( (int) $parsed_args['parent'] ) ) {
		return new WP_Error( 'missing_parent', __( 'Parent term does not exist.' ) );
	}

	$empty_slug = false;
	if ( empty( $args['slug'] ) ) {
		$empty_slug = true;
		$slug       = sanitize_title( $name );
	} else {
		$slug = $args['slug'];
	}

	$parsed_args['slug'] = $slug;

	$term_group = isset( $parsed_args['term_group'] ) ? $parsed_args['term_group'] : 0;
	if ( $args['alias_of'] ) {
		$alias = get_term_by( 'slug', $args['alias_of'], $taxonomy );
		if ( ! empty( $alias->term_group ) ) {
			// The alias we want is already in a group, so let's use that one.
			$term_group = $alias->term_group;
		} elseif ( ! empty( $alias->term_id ) ) {
			/*
			 * The alias is not in a group, so we create a new one
			 * and add the alias to it.
			 */
			$term_group = $wpdb->get_var( "SELECT MAX(term_group) FROM $wpdb->terms" ) + 1;

			wp_update_term(
				$alias->term_id,
				$taxonomy,
				array(
					'term_group' => $term_group,
				)
			);
		}

		$parsed_args['term_group'] = $term_group;
	}

	/**
	 * Filters the term parent.
	 *
	 * Hook to this filter to see if it will cause a hierarchy loop.
	 *
	 * @since 3.1.0
	 *
	 * @param int    $parent      ID of the parent term.
	 * @param int    $term_id     Term ID.
	 * @param string $taxonomy    Taxonomy slug.
	 * @param array  $parsed_args An array of potentially altered update arguments for the given term.
	 * @param array  $args        An array of update arguments for the given term.
	 */
	$parent = (int) apply_filters( 'wp_update_term_parent', $args['parent'], $term_id, $taxonomy, $parsed_args, $args );

	// Check for duplicate slug.
	$duplicate = get_term_by( 'slug', $slug, $taxonomy );
	if ( $duplicate && $duplicate->term_id !== $term_id ) {
		// If an empty slug was passed or the parent changed, reset the slug to something unique.
		// Otherwise, bail.
		if ( $empty_slug || ( $parent !== (int) $term['parent'] ) ) {
			$slug = wp_unique_term_slug( $slug, (object) $args );
		} else {
			/* translators: %s: Taxonomy term slug. */
			return new WP_Error( 'duplicate_term_slug', sprintf( __( 'The slug “%s” is already in use by another term.' ), $slug ) );
		}
	}

	$tt_id = (int) $wpdb->get_var( $wpdb->prepare( "SELECT tt.term_taxonomy_id FROM $wpdb->term_taxonomy AS tt INNER JOIN $wpdb->terms AS t ON tt.term_id = t.term_id WHERE tt.taxonomy = %s AND t.term_id = %d", $taxonomy, $term_id ) );

	// Check whether this is a shared term that needs splitting.
	$_term_id = _split_shared_term( $term_id, $tt_id );
	if ( ! is_wp_error( $_term_id ) ) {
		$term_id = $_term_id;
	}

	/**
	 * Fires immediately before the given terms are edited.
	 *
	 * @since 2.9.0
	 *
	 * @param int    $term_id  Term ID.
	 * @param string $taxonomy Taxonomy slug.
	 */
	do_action( 'edit_terms', $term_id, $taxonomy );

	$data = compact( 'name', 'slug', 'term_group' );

	/**
	 * Filters term data before it is updated in the database.
	 *
	 * @since 4.7.0
	 *
	 * @param array  $data     Term data to be updated.
	 * @param int    $term_id  Term ID.
	 * @param string $taxonomy Taxonomy slug.
	 * @param array  $args     Arguments passed to wp_update_term().
	 */
	$data = apply_filters( 'wp_update_term_data', $data, $term_id, $taxonomy, $args );

	$wpdb->update( $wpdb->terms, $data, compact( 'term_id' ) );

	if ( empty( $slug ) ) {
		$slug = sanitize_title( $name, $term_id );
		$wpdb->update( $wpdb->terms, compact( 'slug' ), compact( 'term_id' ) );
	}

	/**
	 * Fires immediately after a term is updated in the database, but before its
	 * term-taxonomy relationship is updated.
	 *
	 * @since 2.9.0
	 *
	 * @param int    $term_id  Term ID.
	 * @param string $taxonomy Taxonomy slug.
	 */
	do_action( 'edited_terms', $term_id, $taxonomy );

	/**
	 * Fires immediate before a term-taxonomy relationship is updated.
	 *
	 * @since 2.9.0
	 *
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 */
	do_action( 'edit_term_taxonomy', $tt_id, $taxonomy );

	$wpdb->update( $wpdb->term_taxonomy, compact( 'term_id', 'taxonomy', 'description', 'parent' ), array( 'term_taxonomy_id' => $tt_id ) );

	/**
	 * Fires immediately after a term-taxonomy relationship is updated.
	 *
	 * @since 2.9.0
	 *
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 */
	do_action( 'edited_term_taxonomy', $tt_id, $taxonomy );

	/**
	 * Fires after a term has been updated, but before the term cache has been cleaned.
	 *
	 * The {@see 'edit_$taxonomy'} hook is also available for targeting a specific
	 * taxonomy.
	 *
	 * @since 2.3.0
	 *
	 * @param int    $term_id  Term ID.
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 */
	do_action( 'edit_term', $term_id, $tt_id, $taxonomy );

	/**
	 * Fires after a term in a specific taxonomy has been updated, but before the term
	 * cache has been cleaned.
	 *
	 * The dynamic portion of the hook name, `$taxonomy`, refers to the taxonomy slug.
	 *
	 * Possible hook names include:
	 *
	 *  - `edit_category`
	 *  - `edit_post_tag`
	 *
	 * @since 2.3.0
	 *
	 * @param int $term_id Term ID.
	 * @param int $tt_id   Term taxonomy ID.
	 */
	do_action( "edit_{$taxonomy}", $term_id, $tt_id );

	/** This filter is documented in wp-includes/taxonomy.php */
	$term_id = apply_filters( 'term_id_filter', $term_id, $tt_id );

	clean_term_cache( $term_id, $taxonomy );

	/**
	 * Fires after a term has been updated, and the term cache has been cleaned.
	 *
	 * The {@see 'edited_$taxonomy'} hook is also available for targeting a specific
	 * taxonomy.
	 *
	 * @since 2.3.0
	 *
	 * @param int    $term_id  Term ID.
	 * @param int    $tt_id    Term taxonomy ID.
	 * @param string $taxonomy Taxonomy slug.
	 */
	do_action( 'edited_term', $term_id, $tt_id, $taxonomy );

	/**
	 * Fires after a term for a specific taxonomy has been updated, and the term
	 * cache has been cleaned.
	 *
	 * The dynamic portion of the hook name, `$taxonomy`, refers to the taxonomy slug.
	 *
	 * Possible hook names include:
	 *
	 *  - `edited_category`
	 *  - `edited_post_tag`
	 *
	 * @since 2.3.0
	 *
	 * @param int $term_id Term ID.
	 * @param int $tt_id   Term taxonomy ID.
	 */
	do_action( "edited_{$taxonomy}", $term_id, $tt_id );

	/** This action is documented in wp-includes/taxonomy.php */
	do_action( 'saved_term', $term_id, $tt_id, $taxonomy, true );

	/** This action is documented in wp-includes/taxonomy.php */
	do_action( "saved_{$taxonomy}", $term_id, $tt_id, true );

	return array(
		'term_id'          => $term_id,
		'term_taxonomy_id' => $tt_id,
	);
}