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taxonomy.php

Timestamp:

08/26/2015 12:48:11 PM (11 years ago)

Author:

wonderboymusic

Message:

Taxonomy: move WP_Tax_Query into its own file. taxonomy.php loads the new files, so this is 100% BC if someone is loading taxonomy.php directly. New files created using svn cp.

Creates:
class-wp-tax-query.php
taxonomy-functions.php

taxonomy.php contains only top-level code. Class file only contains the class. Functions file only contains functions.

See #33413.

File:

: 1 edited

trunk/src/wp-includes/taxonomy.php (modified) (1 diff)

Legend:

: Unmodified
: Added
: Removed

trunk/src/wp-includes/taxonomy.php

-              r33727
+              r33760
  */
+//
+// Taxonomy Registration
+//
+/**
+ * Creates the initial taxonomies.
+ *
+ * This function fires twice: in wp-settings.php before plugins are loaded (for
+ * backwards compatibility reasons), and again on the {@see 'init'} action. We must
+ * avoid registering rewrite rules before the {@see 'init'} action.
+ *
+ * @since 2.8.0
+ *
+ * @global WP_Rewrite $wp_rewrite The WordPress rewrite class.
+ */
+function create_initial_taxonomies() {
+        global $wp_rewrite;
+        if ( ! did_action( 'init' ) ) {
+                $rewrite = array( 'category' => false, 'post_tag' => false, 'post_format' => false );
+        } else {
+                /**
+                 * Filter the post formats rewrite base.
+                 *
+                 * @since 3.1.0
+                 *
+                 * @param string $context Context of the rewrite base. Default 'type'.
+                 */
+                $post_format_base = apply_filters( 'post_format_rewrite_base', 'type' );
+                $rewrite = array(
+                        'category' => array(
+                                'hierarchical' => true,
+                                'slug' => get_option('category_base') ? get_option('category_base') : 'category',
+                                'with_front' => ! get_option('category_base') || $wp_rewrite->using_index_permalinks(),
+                                'ep_mask' => EP_CATEGORIES,
+                        ),
+                        'post_tag' => array(
+                                'hierarchical' => false,
+                                'slug' => get_option('tag_base') ? get_option('tag_base') : 'tag',
+                                'with_front' => ! get_option('tag_base') || $wp_rewrite->using_index_permalinks(),
+                                'ep_mask' => EP_TAGS,
+                        ),
+                        'post_format' => $post_format_base ? array( 'slug' => $post_format_base ) : false,
+                );
+        }
+        register_taxonomy( 'category', 'post', array(
+                'hierarchical' => true,
+                'query_var' => 'category_name',
+                'rewrite' => $rewrite['category'],
+                'public' => true,
+                'show_ui' => true,
+                'show_admin_column' => true,
+                '_builtin' => true,
+        ) );
+        register_taxonomy( 'post_tag', 'post', array(
+                'hierarchical' => false,
+                'query_var' => 'tag',
+                'rewrite' => $rewrite['post_tag'],
+                'public' => true,
+                'show_ui' => true,
+                'show_admin_column' => true,
+                '_builtin' => true,
+        ) );
+        register_taxonomy( 'nav_menu', 'nav_menu_item', array(
+                'public' => false,
+                'hierarchical' => false,
+                'labels' => array(
+                        'name' => __( 'Navigation Menus' ),
+                        'singular_name' => __( 'Navigation Menu' ),
+                ),
+                'query_var' => false,
+                'rewrite' => false,
+                'show_ui' => false,
+                '_builtin' => true,
+                'show_in_nav_menus' => false,
+        ) );
+        register_taxonomy( 'link_category', 'link', array(
+                'hierarchical' => false,
+                'labels' => array(
+                        'name' => __( 'Link Categories' ),
+                        'singular_name' => __( 'Link Category' ),
+                        'search_items' => __( 'Search Link Categories' ),
+                        'popular_items' => null,
+                        'all_items' => __( 'All Link Categories' ),
+                        'edit_item' => __( 'Edit Link Category' ),
+                        'update_item' => __( 'Update Link Category' ),
+                        'add_new_item' => __( 'Add New Link Category' ),
+                        'new_item_name' => __( 'New Link Category Name' ),
+                        'separate_items_with_commas' => null,
+                        'add_or_remove_items' => null,
+                        'choose_from_most_used' => null,
+                ),
+                'capabilities' => array(
+                        'manage_terms' => 'manage_links',
+                        'edit_terms'   => 'manage_links',
+                        'delete_terms' => 'manage_links',
+                        'assign_terms' => 'manage_links',
+                ),
+                'query_var' => false,
+                'rewrite' => false,
+                'public' => false,
+                'show_ui' => false,
+                '_builtin' => true,
+        ) );
+        register_taxonomy( 'post_format', 'post', array(
+                'public' => true,
+                'hierarchical' => false,
+                'labels' => array(
+                        'name' => _x( 'Format', 'post format' ),
+                        'singular_name' => _x( 'Format', 'post format' ),
+                ),
+                'query_var' => true,
+                'rewrite' => $rewrite['post_format'],
+                'show_ui' => false,
+                '_builtin' => true,
+                'show_in_nav_menus' => current_theme_supports( 'post-formats' ),
+        ) );
+}
+/**
+ * Retrieves a list of registered taxonomy names or objects.
+ *
+ * @since 3.0.0
+ *
+ * @global array $wp_taxonomies The registered taxonomies.
+ *
+ * @param array  $args     Optional. An array of `key => value` arguments to match against the taxonomy objects.
+ *                         Default empty array.
+ * @param string $output   Optional. The type of output to return in the array. Accepts either taxonomy 'names'
+ *                         or 'objects'. Default 'names'.
+ * @param string $operator Optional. The logical operation to perform. Accepts 'and' or 'or'. 'or' means only
+ *                         one element from the array needs to match; 'and' means all elements must match.
+ *                         Default 'and'.
+ * @return array A list of taxonomy names or objects.
+ */
+function get_taxonomies( $args = array(), $output = 'names', $operator = 'and' ) {
+        global $wp_taxonomies;
+        $field = ('names' == $output) ? 'name' : false;
+        return wp_filter_object_list($wp_taxonomies, $args, $operator, $field);
+}
+/**
+ * Return all of the taxonomy names that are of $object_type.
+ *
+ * It appears that this function can be used to find all of the names inside of
+ * $wp_taxonomies global variable.
+ *
+ * `<?php $taxonomies = get_object_taxonomies('post'); ?>` Should
+ * result in `Array( 'category', 'post_tag' )`
+ *
+ * @since 2.3.0
+ *
+ * @global array $wp_taxonomies The registered taxonomies.
+ *
+ * @param array|string|WP_Post $object Name of the type of taxonomy object, or an object (row from posts)
+ * @param string               $output Optional. The type of output to return in the array. Accepts either
+ *                                     taxonomy 'names' or 'objects'. Default 'names'.
+ * @return array The names of all taxonomy of $object_type.
+ */
+function get_object_taxonomies( $object, $output = 'names' ) {
+        global $wp_taxonomies;
+        if ( is_object($object) ) {
+                if ( $object->post_type == 'attachment' )
+                        return get_attachment_taxonomies($object);
+                $object = $object->post_type;
+        }
+        $object = (array) $object;
+        $taxonomies = array();
+        foreach ( (array) $wp_taxonomies as $tax_name => $tax_obj ) {
+                if ( array_intersect($object, (array) $tax_obj->object_type) ) {
+                        if ( 'names' == $output )
+                                $taxonomies[] = $tax_name;
+                        else
+                                $taxonomies[ $tax_name ] = $tax_obj;
+                }
+        }
+        return $taxonomies;
+}
+/**
+ * Retrieves the taxonomy object of $taxonomy.
+ *
+ * The get_taxonomy function will first check that the parameter string given
+ * is a taxonomy object and if it is, it will return it.
+ *
+ * @since 2.3.0
+ *
+ * @global array $wp_taxonomies The registered taxonomies.
+ *
+ * @param string $taxonomy Name of taxonomy object to return.
+ * @return object|false The Taxonomy Object or false if $taxonomy doesn't exist.
+ */
+function get_taxonomy( $taxonomy ) {
+        global $wp_taxonomies;
+        if ( ! taxonomy_exists( $taxonomy ) )
+                return false;
+        return $wp_taxonomies[$taxonomy];
+}
+/**
+ * Checks that the taxonomy name exists.
+ *
+ * Formerly is_taxonomy(), introduced in 2.3.0.
+ *
+ * @since 3.0.0
+ *
+ * @global array $wp_taxonomies The registered taxonomies.
+ *
+ * @param string $taxonomy Name of taxonomy object.
+ * @return bool Whether the taxonomy exists.
+ */
+function taxonomy_exists( $taxonomy ) {
+        global $wp_taxonomies;
+        return isset( $wp_taxonomies[$taxonomy] );
+}
+/**
+ * Whether the taxonomy object is hierarchical.
+ *
+ * Checks to make sure that the taxonomy is an object first. Then Gets the
+ * object, and finally returns the hierarchical value in the object.
+ *
+ * A false return value might also mean that the taxonomy does not exist.
+ *
+ * @since 2.3.0
+ *
+ * @param string $taxonomy Name of taxonomy object.
+ * @return bool Whether the taxonomy is hierarchical.
+ */
+function is_taxonomy_hierarchical($taxonomy) {
+        if ( ! taxonomy_exists($taxonomy) )
+                return false;
+        $taxonomy = get_taxonomy($taxonomy);
+        return $taxonomy->hierarchical;
+}
+/**
+ * Create or modify a taxonomy object. Do not use before init.
+ *
+ * A simple function for creating or modifying a taxonomy object based on the
+ * parameters given. The function will accept an array (third optional
+ * parameter), along with strings for the taxonomy name and another string for
+ * the object type.
+ *
+ * Nothing is returned, so expect error maybe or use taxonomy_exists() to check
+ * whether taxonomy exists.
+ *
+ * Optional $args contents:
+ *
+ * - label - Name of the taxonomy shown in the menu. Usually plural. If not set, labels['name'] will be used.
+ * - labels - An array of labels for this taxonomy.
+ *     * By default tag labels are used for non-hierarchical types and category labels for hierarchical ones.
+ *     * You can see accepted values in {@link get_taxonomy_labels()}.
+ * - description - A short descriptive summary of what the taxonomy is for. Defaults to blank.
+ * - public - If the taxonomy should be publicly queryable; //@TODO not implemented.
+ *     * Defaults to true.
+ * - hierarchical - Whether the taxonomy is hierarchical (e.g. category). Defaults to false.
+ * - show_ui - Whether to generate a default UI for managing this taxonomy in the admin.
+ *     * If not set, the default is inherited from public.
+ * - show_in_menu - Whether to show the taxonomy in the admin menu.
+ *     * If true, the taxonomy is shown as a submenu of the object type menu.
+ *     * If false, no menu is shown.
+ *     * show_ui must be true.
+ *     * If not set, the default is inherited from show_ui.
+ * - show_in_nav_menus - Makes this taxonomy available for selection in navigation menus.
+ *     * If not set, the default is inherited from public.
+ * - show_tagcloud - Whether to list the taxonomy in the Tag Cloud Widget.
+ *     * If not set, the default is inherited from show_ui.
+ * - show_in_quick_edit - Whether to show the taxonomy in the quick/bulk edit panel.
+ *     * It not set, the default is inherited from show_ui.
+ * - show_admin_column - Whether to display a column for the taxonomy on its post type listing screens.
+ *     * Defaults to false.
+ * - meta_box_cb - Provide a callback function for the meta box display.
+ *     * If not set, defaults to post_categories_meta_box for hierarchical taxonomies
+ *     and post_tags_meta_box for non-hierarchical.
+ *     * If false, no meta box is shown.
+ * - capabilities - Array of capabilities for this taxonomy.
+ *     * You can see accepted values in this function.
+ * - rewrite - Triggers the handling of rewrites for this taxonomy. Defaults to true, using $taxonomy as slug.
+ *     * To prevent rewrite, set to false.
+ *     * To specify rewrite rules, an array can be passed with any of these keys
+ *         * 'slug' => string Customize the permastruct slug. Defaults to $taxonomy key
+ *         * 'with_front' => bool Should the permastruct be prepended with WP_Rewrite::$front. Defaults to true.
+ *         * 'hierarchical' => bool Either hierarchical rewrite tag or not. Defaults to false.
+ *         * 'ep_mask' => const Assign an endpoint mask.
+ *             * If not specified, defaults to EP_NONE.
+ * - query_var - Sets the query_var key for this taxonomy. Defaults to $taxonomy key
+ *     * If false, a taxonomy cannot be loaded at ?{query_var}={term_slug}
+ *     * If specified as a string, the query ?{query_var_string}={term_slug} will be valid.
+ * - update_count_callback - Works much like a hook, in that it will be called when the count is updated.
+ *     * Defaults to _update_post_term_count() for taxonomies attached to post types, which then confirms
+ *       that the objects are published before counting them.
+ *     * Defaults to _update_generic_term_count() for taxonomies attached to other object types, such as links.
+ * - _builtin - true if this taxonomy is a native or "built-in" taxonomy. THIS IS FOR INTERNAL USE ONLY!
+ *
+ * @todo Document $args as a hash notation.
+ *
+ * @since 2.3.0
+ * @since 4.2.0 Introduced `show_in_quick_edit` argument.
+ *
+ * @global array $wp_taxonomies Registered taxonomies.
+ * @global WP    $wp            WP instance.
+ *
+ * @param string       $taxonomy    Taxonomy key, must not exceed 32 characters.
+ * @param array|string $object_type Name of the object type for the taxonomy object.
+ * @param array|string $args        See optional args description above.
+ * @return WP_Error|void WP_Error, if errors.
+ */
+function register_taxonomy( $taxonomy, $object_type, $args = array() ) {
+        global $wp_taxonomies, $wp;
+        if ( ! is_array( $wp_taxonomies ) )
+                $wp_taxonomies = array();
+        $defaults = array(
+                'labels'                => array(),
+                'description'           => '',
+                'public'                => true,
+                'hierarchical'          => false,
+                'show_ui'               => null,
+                'show_in_menu'          => null,
+                'show_in_nav_menus'     => null,
+                'show_tagcloud'         => null,
+                'show_in_quick_edit'    => null,
+                'show_admin_column'     => false,
+                'meta_box_cb'           => null,
+                'capabilities'          => array(),
+                'rewrite'               => true,
+                'query_var'             => $taxonomy,
+                'update_count_callback' => '',
+                '_builtin'              => false,
+        );
+        $args = wp_parse_args( $args, $defaults );
+        if ( empty( $taxonomy ) || strlen( $taxonomy ) > 32 ) {
+                _doing_it_wrong( __FUNCTION__, __( 'Taxonomy names must be between 1 and 32 characters in length.' ), '4.2' );
+                return new WP_Error( 'taxonomy_length_invalid', __( 'Taxonomy names must be between 1 and 32 characters in length.' ) );
+        }
+        if ( false !== $args['query_var'] && ! empty( $wp ) ) {
+                if ( true === $args['query_var'] )
+                        $args['query_var'] = $taxonomy;
+                else
+                        $args['query_var'] = sanitize_title_with_dashes( $args['query_var'] );
+                $wp->add_query_var( $args['query_var'] );
+        }
+        if ( false !== $args['rewrite'] && ( is_admin() || '' != get_option( 'permalink_structure' ) ) ) {
+                $args['rewrite'] = wp_parse_args( $args['rewrite'], array(
+                        'with_front' => true,
+                        'hierarchical' => false,
+                        'ep_mask' => EP_NONE,
+                ) );
+                if ( empty( $args['rewrite']['slug'] ) )
+                        $args['rewrite']['slug'] = sanitize_title_with_dashes( $taxonomy );
+                if ( $args['hierarchical'] && $args['rewrite']['hierarchical'] )
+                        $tag = '(.+?)';
+                else
+                        $tag = '([^/]+)';
+                add_rewrite_tag( "%$taxonomy%", $tag, $args['query_var'] ? "{$args['query_var']}=" : "taxonomy=$taxonomy&term=" );
+                add_permastruct( $taxonomy, "{$args['rewrite']['slug']}/%$taxonomy%", $args['rewrite'] );
+        }
+        // If not set, default to the setting for public.
+        if ( null === $args['show_ui'] )
+                $args['show_ui'] = $args['public'];
+        // If not set, default to the setting for show_ui.
+        if ( null === $args['show_in_menu' ] || ! $args['show_ui'] )
+                $args['show_in_menu' ] = $args['show_ui'];
+        // If not set, default to the setting for public.
+        if ( null === $args['show_in_nav_menus'] )
+                $args['show_in_nav_menus'] = $args['public'];
+        // If not set, default to the setting for show_ui.
+        if ( null === $args['show_tagcloud'] )
+                $args['show_tagcloud'] = $args['show_ui'];
+        // If not set, default to the setting for show_ui.
+        if ( null === $args['show_in_quick_edit'] ) {
+                $args['show_in_quick_edit'] = $args['show_ui'];
+        }
+        $default_caps = array(
+                'manage_terms' => 'manage_categories',
+                'edit_terms'   => 'manage_categories',
+                'delete_terms' => 'manage_categories',
+                'assign_terms' => 'edit_posts',
+        );
+        $args['cap'] = (object) array_merge( $default_caps, $args['capabilities'] );
+        unset( $args['capabilities'] );
+        $args['name'] = $taxonomy;
+        $args['object_type'] = array_unique( (array) $object_type );
+        $args['labels'] = get_taxonomy_labels( (object) $args );
+        $args['label'] = $args['labels']->name;
+        // If not set, use the default meta box
+        if ( null === $args['meta_box_cb'] ) {
+                if ( $args['hierarchical'] )
+                        $args['meta_box_cb'] = 'post_categories_meta_box';
+                else
+                        $args['meta_box_cb'] = 'post_tags_meta_box';
+        }
+        $wp_taxonomies[ $taxonomy ] = (object) $args;
+        // register callback handling for metabox
+        add_filter( 'wp_ajax_add-' . $taxonomy, '_wp_ajax_add_hierarchical_term' );
+        /**
+         * Fires after a taxonomy is registered.
+         *
+         * @since 3.3.0
+         *
+         * @param string       $taxonomy    Taxonomy slug.
+         * @param array|string $object_type Object type or array of object types.
+         * @param array        $args        Array of taxonomy registration arguments.
+         */
+        do_action( 'registered_taxonomy', $taxonomy, $object_type, $args );
+}
+/**
+ * Builds an object with all taxonomy labels out of a taxonomy object
+ *
+ * Accepted keys of the label array in the taxonomy object:
+ *
+ * - name - general name for the taxonomy, usually plural. The same as and overridden by $tax->label. Default is Tags/Categories
+ * - singular_name - name for one object of this taxonomy. Default is Tag/Category
+ * - search_items - Default is Search Tags/Search Categories
+ * - popular_items - This string isn't used on hierarchical taxonomies. Default is Popular Tags
+ * - all_items - Default is All Tags/All Categories
+ * - parent_item - This string isn't used on non-hierarchical taxonomies. In hierarchical ones the default is Parent Category
+ * - parent_item_colon - The same as `parent_item`, but with colon `:` in the end
+ * - edit_item - Default is Edit Tag/Edit Category
+ * - view_item - Default is View Tag/View Category
+ * - update_item - Default is Update Tag/Update Category
+ * - add_new_item - Default is Add New Tag/Add New Category
+ * - new_item_name - Default is New Tag Name/New Category Name
+ * - separate_items_with_commas - This string isn't used on hierarchical taxonomies. Default is "Separate tags with commas", used in the meta box.
+ * - add_or_remove_items - This string isn't used on hierarchical taxonomies. Default is "Add or remove tags", used in the meta box when JavaScript is disabled.
+ * - choose_from_most_used - This string isn't used on hierarchical taxonomies. Default is "Choose from the most used tags", used in the meta box.
+ * - not_found - Default is "No tags found"/"No categories found", used in the meta box and taxonomy list table.
+ * - no_terms - Default is "No tags"/"No categories", used in the posts and media list tables.
+ *
+ * Above, the first default value is for non-hierarchical taxonomies (like tags) and the second one is for hierarchical taxonomies (like categories).
+ *
+ * @todo Better documentation for the labels array.
+ *
+ * @since 3.0.0
+ * @since 4.3.0 Added the `no_terms` label.
+ *
+ * @param object $tax Taxonomy object.
+ * @return object object with all the labels as member variables.
+ */
+function get_taxonomy_labels( $tax ) {
+        $tax->labels = (array) $tax->labels;
+        if ( isset( $tax->helps ) && empty( $tax->labels['separate_items_with_commas'] ) )
+                $tax->labels['separate_items_with_commas'] = $tax->helps;
+        if ( isset( $tax->no_tagcloud ) && empty( $tax->labels['not_found'] ) )
+                $tax->labels['not_found'] = $tax->no_tagcloud;
+        $nohier_vs_hier_defaults = array(
+                'name' => array( _x( 'Tags', 'taxonomy general name' ), _x( 'Categories', 'taxonomy general name' ) ),
+                'singular_name' => array( _x( 'Tag', 'taxonomy singular name' ), _x( 'Category', 'taxonomy singular name' ) ),
+                'search_items' => array( __( 'Search Tags' ), __( 'Search Categories' ) ),
+                'popular_items' => array( __( 'Popular Tags' ), null ),
+                'all_items' => array( __( 'All Tags' ), __( 'All Categories' ) ),
+                'parent_item' => array( null, __( 'Parent Category' ) ),
+                'parent_item_colon' => array( null, __( 'Parent Category:' ) ),
+                'edit_item' => array( __( 'Edit Tag' ), __( 'Edit Category' ) ),
+                'view_item' => array( __( 'View Tag' ), __( 'View Category' ) ),
+                'update_item' => array( __( 'Update Tag' ), __( 'Update Category' ) ),
+                'add_new_item' => array( __( 'Add New Tag' ), __( 'Add New Category' ) ),
+                'new_item_name' => array( __( 'New Tag Name' ), __( 'New Category Name' ) ),
+                'separate_items_with_commas' => array( __( 'Separate tags with commas' ), null ),
+                'add_or_remove_items' => array( __( 'Add or remove tags' ), null ),
+                'choose_from_most_used' => array( __( 'Choose from the most used tags' ), null ),
+                'not_found' => array( __( 'No tags found.' ), __( 'No categories found.' ) ),
+                'no_terms' => array( __( 'No tags' ), __( 'No categories' ) ),
+        );
+        $nohier_vs_hier_defaults['menu_name'] = $nohier_vs_hier_defaults['name'];
+        return _get_custom_object_labels( $tax, $nohier_vs_hier_defaults );
+}
+/**
+ * Add an already registered taxonomy to an object type.
+ *
+ * @since 3.0.0
+ *
+ * @global array $wp_taxonomies The registered taxonomies.
+ *
+ * @param string $taxonomy    Name of taxonomy object.
+ * @param string $object_type Name of the object type.
+ * @return bool True if successful, false if not.
+ */
+function register_taxonomy_for_object_type( $taxonomy, $object_type) {
+        global $wp_taxonomies;
+        if ( !isset($wp_taxonomies[$taxonomy]) )
+                return false;
+        if ( ! get_post_type_object($object_type) )
+                return false;
+        if ( ! in_array( $object_type, $wp_taxonomies[$taxonomy]->object_type ) )
+                $wp_taxonomies[$taxonomy]->object_type[] = $object_type;
+        // Filter out empties.
+        $wp_taxonomies[ $taxonomy ]->object_type = array_filter( $wp_taxonomies[ $taxonomy ]->object_type );
+        return true;
+}
+/**
+ * Remove an already registered taxonomy from an object type.
+ *
+ * @since 3.7.0
+ *
+ * @global array $wp_taxonomies The registered taxonomies.
+ *
+ * @param string $taxonomy    Name of taxonomy object.
+ * @param string $object_type Name of the object type.
+ * @return bool True if successful, false if not.
+ */
+function unregister_taxonomy_for_object_type( $taxonomy, $object_type ) {
+        global $wp_taxonomies;
+        if ( ! isset( $wp_taxonomies[ $taxonomy ] ) )
+                return false;
+        if ( ! get_post_type_object( $object_type ) )
+                return false;
+        $key = array_search( $object_type, $wp_taxonomies[ $taxonomy ]->object_type, true );
+        if ( false === $key )
+                return false;
+        unset( $wp_taxonomies[ $taxonomy ]->object_type[ $key ] );
+        return true;
+}
+//
+// Term API
+//
+/**
+ * Retrieve object_ids of valid taxonomy and term.
+ *
+ * The strings of $taxonomies must exist before this function will continue. On
+ * failure of finding a valid taxonomy, it will return an WP_Error class, kind
+ * of like Exceptions in PHP 5, except you can't catch them. Even so, you can
+ * still test for the WP_Error class and get the error message.
+ *
+ * The $terms aren't checked the same as $taxonomies, but still need to exist
+ * for $object_ids to be returned.
+ *
+ * It is possible to change the order that object_ids is returned by either
+ * using PHP sort family functions or using the database by using $args with
+ * either ASC or DESC array. The value should be in the key named 'order'.
+ *
+ * @since 2.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param int|array    $term_ids   Term id or array of term ids of terms that will be used.
+ * @param string|array $taxonomies String of taxonomy name or Array of string values of taxonomy names.
+ * @param array|string $args       Change the order of the object_ids, either ASC or DESC.
+ * @return WP_Error|array If the taxonomy does not exist, then WP_Error will be returned. On success.
+ *      the array can be empty meaning that there are no $object_ids found or it will return the $object_ids found.
+ */
+function get_objects_in_term( $term_ids, $taxonomies, $args = array() ) {
+        global $wpdb;
+        if ( ! is_array( $term_ids ) ) {
+                $term_ids = array( $term_ids );
+        }
+        if ( ! is_array( $taxonomies ) ) {
+                $taxonomies = array( $taxonomies );
+        }
+        foreach ( (array) $taxonomies as $taxonomy ) {
+                if ( ! taxonomy_exists( $taxonomy ) ) {
+                        return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy' ) );
+                }
+        }
+        $defaults = array( 'order' => 'ASC' );
+        $args = wp_parse_args( $args, $defaults );
+        $order = ( 'desc' == strtolower( $args['order'] ) ) ? 'DESC' : 'ASC';
+        $term_ids = array_map('intval', $term_ids );
+        $taxonomies = "'" . implode( "', '", $taxonomies ) . "'";
+        $term_ids = "'" . implode( "', '", $term_ids ) . "'";
+        $object_ids = $wpdb->get_col("SELECT tr.object_id FROM $wpdb->term_relationships AS tr INNER JOIN $wpdb->term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy IN ($taxonomies) AND tt.term_id IN ($term_ids) ORDER BY tr.object_id $order");
+        if ( ! $object_ids ){
+                return array();
+        }
+        return $object_ids;
+}
+/**
+ * Given a taxonomy query, generates SQL to be appended to a main query.
+ *
+ * @since 3.1.0
+ *
+ * @see WP_Tax_Query
+ *
+ * @param array  $tax_query         A compact tax query
+ * @param string $primary_table
+ * @param string $primary_id_column
+ * @return array
+ */
+function get_tax_sql( $tax_query, $primary_table, $primary_id_column ) {
+        $tax_query_obj = new WP_Tax_Query( $tax_query );
+        return $tax_query_obj->get_sql( $primary_table, $primary_id_column );
+}
+/**
+ * Class for generating SQL clauses that filter a primary query according to object taxonomy terms.
+ *
+ * `WP_Tax_Query` is a helper that allows primary query classes, such as WP_Query, to filter
+ * their results by object metadata, by generating `JOIN` and `WHERE` subclauses to be attached
+ * to the primary SQL query string.
+ *
+ * @since 3.1.0
+ */
+class WP_Tax_Query {
+        /**
+         * Array of taxonomy queries.
+         *
+         * See {@see WP_Tax_Query::__construct()} for information on tax query arguments.
+         *
+         * @since 3.1.0
+         * @access public
+         * @var array
+         */
+        public $queries = array();
+        /**
+         * The relation between the queries. Can be one of 'AND' or 'OR'.
+         *
+         * @since 3.1.0
+         * @access public
+         * @var string
+         */
+        public $relation;
+        /**
+         * Standard response when the query should not return any rows.
+         *
+         * @since 3.2.0
+         *
+         * @static
+         * @access private
+         * @var string
+         */
+        private static $no_results = array( 'join' => array( '' ), 'where' => array( '0 = 1' ) );
+        /**
+         * A flat list of table aliases used in the JOIN clauses.
+         *
+         * @since 4.1.0
+         * @access protected
+         * @var array
+         */
+        protected $table_aliases = array();
+        /**
+         * Terms and taxonomies fetched by this query.
+         *
+         * We store this data in a flat array because they are referenced in a
+         * number of places by WP_Query.
+         *
+         * @since 4.1.0
+         * @access public
+         * @var array
+         */
+        public $queried_terms = array();
+        /**
+         * Database table that where the metadata's objects are stored (eg $wpdb->users).
+         *
+         * @since 4.1.0
+         * @access public
+         * @var string
+         */
+        public $primary_table;
+        /**
+         * Column in 'primary_table' that represents the ID of the object.
+         *
+         * @since 4.1.0
+         * @access public
+         * @var string
+         */
+        public $primary_id_column;
+        /**
+         * Constructor.
+         *
+         * @since 3.1.0
+         * @since 4.1.0 Added support for `$operator` 'NOT EXISTS' and 'EXISTS' values.
+         * @access public
+         *
+         * @param array $tax_query {
+         *     Array of taxonomy query clauses.
+         *
+         *     @type string $relation Optional. The MySQL keyword used to join
+         *                            the clauses of the query. Accepts 'AND', or 'OR'. Default 'AND'.
+         *     @type array {
+         *         Optional. An array of first-order clause parameters, or another fully-formed tax query.
+         *
+         *         @type string           $taxonomy         Taxonomy being queried. Optional when field=term_taxonomy_id.
+         *         @type string|int|array $terms            Term or terms to filter by.
+         *         @type string           $field            Field to match $terms against. Accepts 'term_id', 'slug',
+         *                                                 'name', or 'term_taxonomy_id'. Default: 'term_id'.
+         *         @type string           $operator         MySQL operator to be used with $terms in the WHERE clause.
+         *                                                  Accepts 'AND', 'IN', 'NOT IN', 'EXISTS', 'NOT EXISTS'.
+         *                                                  Default: 'IN'.
+         *         @type bool             $include_children Optional. Whether to include child terms.
+         *                                                  Requires a $taxonomy. Default: true.
+         *     }
+         * }
+         */
+        public function __construct( $tax_query ) {
+                if ( isset( $tax_query['relation'] ) ) {
+                        $this->relation = $this->sanitize_relation( $tax_query['relation'] );
+                } else {
+                        $this->relation = 'AND';
+                }
+                $this->queries = $this->sanitize_query( $tax_query );
+        }
+        /**
+         * Ensure the 'tax_query' argument passed to the class constructor is well-formed.
+         *
+         * Ensures that each query-level clause has a 'relation' key, and that
+         * each first-order clause contains all the necessary keys from `$defaults`.
+         *
+         * @since 4.1.0
+         * @access public
+         *
+         * @param array $queries Array of queries clauses.
+         * @return array Sanitized array of query clauses.
+         */
+        public function sanitize_query( $queries ) {
+                $cleaned_query = array();
+                $defaults = array(
+                        'taxonomy' => '',
+                        'terms' => array(),
+                        'field' => 'term_id',
+                        'operator' => 'IN',
+                        'include_children' => true,
+                );
+                foreach ( $queries as $key => $query ) {
+                        if ( 'relation' === $key ) {
+                                $cleaned_query['relation'] = $this->sanitize_relation( $query );
+                        // First-order clause.
+                        } elseif ( self::is_first_order_clause( $query ) ) {
+                                $cleaned_clause = array_merge( $defaults, $query );
+                                $cleaned_clause['terms'] = (array) $cleaned_clause['terms'];
+                                $cleaned_query[] = $cleaned_clause;
+                                /*
+                                 * Keep a copy of the clause in the flate
+                                 * $queried_terms array, for use in WP_Query.
+                                 */
+                                if ( ! empty( $cleaned_clause['taxonomy'] ) && 'NOT IN' !== $cleaned_clause['operator'] ) {
+                                        $taxonomy = $cleaned_clause['taxonomy'];
+                                        if ( ! isset( $this->queried_terms[ $taxonomy ] ) ) {
+                                                $this->queried_terms[ $taxonomy ] = array();
+                                        }
+                                        /*
+                                         * Backward compatibility: Only store the first
+                                         * 'terms' and 'field' found for a given taxonomy.
+                                         */
+                                        if ( ! empty( $cleaned_clause['terms'] ) && ! isset( $this->queried_terms[ $taxonomy ]['terms'] ) ) {
+                                                $this->queried_terms[ $taxonomy ]['terms'] = $cleaned_clause['terms'];
+                                        }
+                                        if ( ! empty( $cleaned_clause['field'] ) && ! isset( $this->queried_terms[ $taxonomy ]['field'] ) ) {
+                                                $this->queried_terms[ $taxonomy ]['field'] = $cleaned_clause['field'];
+                                        }
+                                }
+                        // Otherwise, it's a nested query, so we recurse.
+                        } elseif ( is_array( $query ) ) {
+                                $cleaned_subquery = $this->sanitize_query( $query );
+                                if ( ! empty( $cleaned_subquery ) ) {
+                                        // All queries with children must have a relation.
+                                        if ( ! isset( $cleaned_subquery['relation'] ) ) {
+                                                $cleaned_subquery['relation'] = 'AND';
+                                        }
+                                        $cleaned_query[] = $cleaned_subquery;
+                                }
+                        }
+                }
+                return $cleaned_query;
+        }
+        /**
+         * Sanitize a 'relation' operator.
+         *
+         * @since 4.1.0
+         * @access public
+         *
+         * @param string $relation Raw relation key from the query argument.
+         * @return string Sanitized relation ('AND' or 'OR').
+         */
+        public function sanitize_relation( $relation ) {
+                if ( 'OR' === strtoupper( $relation ) ) {
+                        return 'OR';
+                } else {
+                        return 'AND';
+                }
+        }
+        /**
+         * Determine whether a clause is first-order.
+         *
+         * A "first-order" clause is one that contains any of the first-order
+         * clause keys ('terms', 'taxonomy', 'include_children', 'field',
+         * 'operator'). An empty clause also counts as a first-order clause,
+         * for backward compatibility. Any clause that doesn't meet this is
+         * determined, by process of elimination, to be a higher-order query.
+         *
+         * @since 4.1.0
+         *
+         * @static
+         * @access protected
+         *
+         * @param array $query Tax query arguments.
+         * @return bool Whether the query clause is a first-order clause.
+         */
+        protected static function is_first_order_clause( $query ) {
+                return is_array( $query ) && ( empty( $query ) || array_key_exists( 'terms', $query ) || array_key_exists( 'taxonomy', $query ) || array_key_exists( 'include_children', $query ) || array_key_exists( 'field', $query ) || array_key_exists( 'operator', $query ) );
+        }
+        /**
+         * Generates SQL clauses to be appended to a main query.
+         *
+         * @since 3.1.0
+         *
+         * @static
+         * @access public
+         *
+         * @param string $primary_table     Database table where the object being filtered is stored (eg wp_users).
+         * @param string $primary_id_column ID column for the filtered object in $primary_table.
+         * @return array {
+         *     Array containing JOIN and WHERE SQL clauses to append to the main query.
+         *
+         *     @type string $join  SQL fragment to append to the main JOIN clause.
+         *     @type string $where SQL fragment to append to the main WHERE clause.
+         * }
+         */
+        public function get_sql( $primary_table, $primary_id_column ) {
+                $this->primary_table = $primary_table;
+                $this->primary_id_column = $primary_id_column;
+                return $this->get_sql_clauses();
+        }
+        /**
+         * Generate SQL clauses to be appended to a main query.
+         *
+         * Called by the public WP_Tax_Query::get_sql(), this method
+         * is abstracted out to maintain parity with the other Query classes.
+         *
+         * @since 4.1.0
+         * @access protected
+         *
+         * @return array {
+         *     Array containing JOIN and WHERE SQL clauses to append to the main query.
+         *
+         *     @type string $join  SQL fragment to append to the main JOIN clause.
+         *     @type string $where SQL fragment to append to the main WHERE clause.
+         * }
+         */
+        protected function get_sql_clauses() {
+                /*
+                 * $queries are passed by reference to get_sql_for_query() for recursion.
+                 * To keep $this->queries unaltered, pass a copy.
+                 */
+                $queries = $this->queries;
+                $sql = $this->get_sql_for_query( $queries );
+                if ( ! empty( $sql['where'] ) ) {
+                        $sql['where'] = ' AND ' . $sql['where'];
+                }
+                return $sql;
+        }
+        /**
+         * Generate SQL clauses for a single query array.
+         *
+         * If nested subqueries are found, this method recurses the tree to
+         * produce the properly nested SQL.
+         *
+         * @since 4.1.0
+         * @access protected
+         *
+         * @param array $query Query to parse, passed by reference.
+         * @param int   $depth Optional. Number of tree levels deep we currently are.
+         *                     Used to calculate indentation. Default 0.
+         * @return array {
+         *     Array containing JOIN and WHERE SQL clauses to append to a single query array.
+         *
+         *     @type string $join  SQL fragment to append to the main JOIN clause.
+         *     @type string $where SQL fragment to append to the main WHERE clause.
+         * }
+         */
+        protected function get_sql_for_query( &$query, $depth = 0 ) {
+                $sql_chunks = array(
+                        'join'  => array(),
+                        'where' => array(),
+                );
+                $sql = array(
+                        'join'  => '',
+                        'where' => '',
+                );
+                $indent = '';
+                for ( $i = 0; $i < $depth; $i++ ) {
+                        $indent .= "  ";
+                }
+                foreach ( $query as $key => &$clause ) {
+                        if ( 'relation' === $key ) {
+                                $relation = $query['relation'];
+                        } elseif ( is_array( $clause ) ) {
+                                // This is a first-order clause.
+                                if ( $this->is_first_order_clause( $clause ) ) {
+                                        $clause_sql = $this->get_sql_for_clause( $clause, $query );
+                                        $where_count = count( $clause_sql['where'] );
+                                        if ( ! $where_count ) {
+                                                $sql_chunks['where'][] = '';
+                                        } elseif ( 1 === $where_count ) {
+                                                $sql_chunks['where'][] = $clause_sql['where'][0];
+                                        } else {
+                                                $sql_chunks['where'][] = '( ' . implode( ' AND ', $clause_sql['where'] ) . ' )';
+                                        }
+                                        $sql_chunks['join'] = array_merge( $sql_chunks['join'], $clause_sql['join'] );
+                                // This is a subquery, so we recurse.
+                                } else {
+                                        $clause_sql = $this->get_sql_for_query( $clause, $depth + 1 );
+                                        $sql_chunks['where'][] = $clause_sql['where'];
+                                        $sql_chunks['join'][]  = $clause_sql['join'];
+                                }
+                        }
+                }
+                // Filter to remove empties.
+                $sql_chunks['join']  = array_filter( $sql_chunks['join'] );
+                $sql_chunks['where'] = array_filter( $sql_chunks['where'] );
+                if ( empty( $relation ) ) {
+                        $relation = 'AND';
+                }
+                // Filter duplicate JOIN clauses and combine into a single string.
+                if ( ! empty( $sql_chunks['join'] ) ) {
+                        $sql['join'] = implode( ' ', array_unique( $sql_chunks['join'] ) );
+                }
+                // Generate a single WHERE clause with proper brackets and indentation.
+                if ( ! empty( $sql_chunks['where'] ) ) {
+                        $sql['where'] = '( ' . "\n  " . $indent . implode( ' ' . "\n  " . $indent . $relation . ' ' . "\n  " . $indent, $sql_chunks['where'] ) . "\n" . $indent . ')';
+                }
+                return $sql;
+        }
+        /**
+         * Generate SQL JOIN and WHERE clauses for a "first-order" query clause.
+         *
+         * @since 4.1.0
+         * @access public
+         *
+         * @global wpdb $wpdb The WordPress database abstraction object.
+         *
+         * @param array $clause       Query clause, passed by reference.
+         * @param array $parent_query Parent query array.
+         * @return array {
+         *     Array containing JOIN and WHERE SQL clauses to append to a first-order query.
+         *
+         *     @type string $join  SQL fragment to append to the main JOIN clause.
+         *     @type string $where SQL fragment to append to the main WHERE clause.
+         * }
+         */
+        public function get_sql_for_clause( &$clause, $parent_query ) {
+                global $wpdb;
+                $sql = array(
+                        'where' => array(),
+                        'join'  => array(),
+                );
+                $join = $where = '';
+                $this->clean_query( $clause );
+                if ( is_wp_error( $clause ) ) {
+                        return self::$no_results;
+                }
+                $terms = $clause['terms'];
+                $operator = strtoupper( $clause['operator'] );
+                if ( 'IN' == $operator ) {
+                        if ( empty( $terms ) ) {
+                                return self::$no_results;
+                        }
+                        $terms = implode( ',', $terms );
+                        /*
+                         * Before creating another table join, see if this clause has a
+                         * sibling with an existing join that can be shared.
+                         */
+                        $alias = $this->find_compatible_table_alias( $clause, $parent_query );
+                        if ( false === $alias ) {
+                                $i = count( $this->table_aliases );
+                                $alias = $i ? 'tt' . $i : $wpdb->term_relationships;
+                                // Store the alias as part of a flat array to build future iterators.
+                                $this->table_aliases[] = $alias;
+                                // Store the alias with this clause, so later siblings can use it.
+                                $clause['alias'] = $alias;
+                                $join .= " INNER JOIN $wpdb->term_relationships";
+                                $join .= $i ? " AS $alias" : '';
+                                $join .= " ON ($this->primary_table.$this->primary_id_column = $alias.object_id)";
+                        }
+                        $where = "$alias.term_taxonomy_id $operator ($terms)";
+                } elseif ( 'NOT IN' == $operator ) {
+                        if ( empty( $terms ) ) {
+                                return $sql;
+                        }
+                        $terms = implode( ',', $terms );
+                        $where = "$this->primary_table.$this->primary_id_column NOT IN (
+                                SELECT object_id
+                                FROM $wpdb->term_relationships
+                                WHERE term_taxonomy_id IN ($terms)
+                        )";
+                } elseif ( 'AND' == $operator ) {
+                        if ( empty( $terms ) ) {
+                                return $sql;
+                        }
+                        $num_terms = count( $terms );
+                        $terms = implode( ',', $terms );
+                        $where = "(
+                                SELECT COUNT(1)
+                                FROM $wpdb->term_relationships
+                                WHERE term_taxonomy_id IN ($terms)
+                                AND object_id = $this->primary_table.$this->primary_id_column
+                        ) = $num_terms";
+                } elseif ( 'NOT EXISTS' === $operator || 'EXISTS' === $operator ) {
+                        $where = $wpdb->prepare( "$operator (
+                                SELECT 1
+                                FROM $wpdb->term_relationships
+                                INNER JOIN $wpdb->term_taxonomy
+                                ON $wpdb->term_taxonomy.term_taxonomy_id = $wpdb->term_relationships.term_taxonomy_id
+                                WHERE $wpdb->term_taxonomy.taxonomy = %s
+                                AND $wpdb->term_relationships.object_id = $this->primary_table.$this->primary_id_column
+                        )", $clause['taxonomy'] );
+                }
+                $sql['join'][]  = $join;
+                $sql['where'][] = $where;
+                return $sql;
+        }
+        /**
+         * Identify an existing table alias that is compatible with the current query clause.
+         *
+         * We avoid unnecessary table joins by allowing each clause to look for
+         * an existing table alias that is compatible with the query that it
+         * needs to perform.
+         *
+         * An existing alias is compatible if (a) it is a sibling of `$clause`
+         * (ie, it's under the scope of the same relation), and (b) the combination
+         * of operator and relation between the clauses allows for a shared table
+         * join. In the case of WP_Tax_Query, this only applies to 'IN'
+         * clauses that are connected by the relation 'OR'.
+         *
+         * @since 4.1.0
+         * @access protected
+         *
+         * @param array       $clause       Query clause.
+         * @param array       $parent_query Parent query of $clause.
+         * @return string|false Table alias if found, otherwise false.
+         */
+        protected function find_compatible_table_alias( $clause, $parent_query ) {
+                $alias = false;
+                // Sanity check. Only IN queries use the JOIN syntax .
+                if ( ! isset( $clause['operator'] ) || 'IN' !== $clause['operator'] ) {
+                        return $alias;
+                }
+                // Since we're only checking IN queries, we're only concerned with OR relations.
+                if ( ! isset( $parent_query['relation'] ) || 'OR' !== $parent_query['relation'] ) {
+                        return $alias;
+                }
+                $compatible_operators = array( 'IN' );
+                foreach ( $parent_query as $sibling ) {
+                        if ( ! is_array( $sibling ) || ! $this->is_first_order_clause( $sibling ) ) {
+                                continue;
+                        }
+                        if ( empty( $sibling['alias'] ) || empty( $sibling['operator'] ) ) {
+                                continue;
+                        }
+                        // The sibling must both have compatible operator to share its alias.
+                        if ( in_array( strtoupper( $sibling['operator'] ), $compatible_operators ) ) {
+                                $alias = $sibling['alias'];
+                                break;
+                        }
+                }
+                return $alias;
+        }
+        /**
+         * Validates a single query.
+         *
+         * @since 3.2.0
+         * @access private
+         *
+         * @param array &$query The single query.
+         */
+        private function clean_query( &$query ) {
+                if ( empty( $query['taxonomy'] ) ) {
+                        if ( 'term_taxonomy_id' !== $query['field'] ) {
+                                $query = new WP_Error( 'Invalid taxonomy' );
+                                return;
+                        }
+                        // so long as there are shared terms, include_children requires that a taxonomy is set
+                        $query['include_children'] = false;
+                } elseif ( ! taxonomy_exists( $query['taxonomy'] ) ) {
+                        $query = new WP_Error( 'Invalid taxonomy' );
+                        return;
+                }
+                $query['terms'] = array_unique( (array) $query['terms'] );
+                if ( is_taxonomy_hierarchical( $query['taxonomy'] ) && $query['include_children'] ) {
+                        $this->transform_query( $query, 'term_id' );
+                        if ( is_wp_error( $query ) )
+                                return;
+                        $children = array();
+                        foreach ( $query['terms'] as $term ) {
+                                $children = array_merge( $children, get_term_children( $term, $query['taxonomy'] ) );
+                                $children[] = $term;
+                        }
+                        $query['terms'] = $children;
+                }
+                $this->transform_query( $query, 'term_taxonomy_id' );
+        }
+        /**
+         * Transforms a single query, from one field to another.
+         *
+         * @since 3.2.0
+         *
+         * @global wpdb $wpdb The WordPress database abstraction object.
+         *
+         * @param array  &$query          The single query.
+         * @param string $resulting_field The resulting field. Accepts 'slug', 'name', 'term_taxonomy_id',
+         *                                or 'term_id'. Default 'term_id'.
+         */
+        public function transform_query( &$query, $resulting_field ) {
+                global $wpdb;
+                if ( empty( $query['terms'] ) )
+                        return;
+                if ( $query['field'] == $resulting_field )
+                        return;
+                $resulting_field = sanitize_key( $resulting_field );
+                switch ( $query['field'] ) {
+                        case 'slug':
+                        case 'name':
+                                foreach ( $query['terms'] as &$term ) {
+                                        /*
+                                         * 0 is the $term_id parameter. We don't have a term ID yet, but it doesn't
+                                         * matter because `sanitize_term_field()` ignores the $term_id param when the
+                                         * context is 'db'.
+                                         */
+                                        $term = "'" . esc_sql( sanitize_term_field( $query['field'], $term, 0, $query['taxonomy'], 'db' ) ) . "'";
+                                }
+                                $terms = implode( ",", $query['terms'] );
+                                $terms = $wpdb->get_col( "
+                                        SELECT $wpdb->term_taxonomy.$resulting_field
+                                        FROM $wpdb->term_taxonomy
+                                        INNER JOIN $wpdb->terms USING (term_id)
+                                        WHERE taxonomy = '{$query['taxonomy']}'
+                                        AND $wpdb->terms.{$query['field']} IN ($terms)
+                                " );
+                                break;
+                        case 'term_taxonomy_id':
+                                $terms = implode( ',', array_map( 'intval', $query['terms'] ) );
+                                $terms = $wpdb->get_col( "
+                                        SELECT $resulting_field
+                                        FROM $wpdb->term_taxonomy
+                                        WHERE term_taxonomy_id IN ($terms)
+                                " );
+                                break;
+                        default:
+                                $terms = implode( ',', array_map( 'intval', $query['terms'] ) );
+                                $terms = $wpdb->get_col( "
+                                        SELECT $resulting_field
+                                        FROM $wpdb->term_taxonomy
+                                        WHERE taxonomy = '{$query['taxonomy']}'
+                                        AND term_id IN ($terms)
+                                " );
+                }
+                if ( 'AND' == $query['operator'] && count( $terms ) < count( $query['terms'] ) ) {
+                        $query = new WP_Error( 'Inexistent terms' );
+                        return;
+                }
+                $query['terms'] = $terms;
+                $query['field'] = $resulting_field;
+        }
+}
+/**
+ * Get all Term data from database by Term ID.
+ *
+ * The usage of the get_term function is to apply filters to a term object. It
+ * is possible to get a term object from the database before applying the
+ * filters.
+ *
+ * $term ID must be part of $taxonomy, to get from the database. Failure, might
+ * be able to be captured by the hooks. Failure would be the same value as $wpdb
+ * returns for the get_row method.
+ *
+ * There are two hooks, one is specifically for each term, named 'get_term', and
+ * the second is for the taxonomy name, 'term_$taxonomy'. Both hooks gets the
+ * term object, and the taxonomy name as parameters. Both hooks are expected to
+ * return a Term object.
+ *
+ * {@see 'get_term'} hook - Takes two parameters the term Object and the taxonomy name.
+ * Must return term object. Used in get_term() as a catch-all filter for every
+ * $term.
+ *
+ * {@see 'get_$taxonomy'} hook - Takes two parameters the term Object and the taxonomy
+ * name. Must return term object. $taxonomy will be the taxonomy name, so for
+ * example, if 'category', it would be 'get_category' as the filter name. Useful
+ * for custom taxonomies or plugging into default taxonomies.
+ *
+ * @todo Better formatting for DocBlock
+ *
+ * @since 2.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ * @see sanitize_term_field() The $context param lists the available values for get_term_by() $filter param.
+ *
+ * @param int|object $term     If integer, will get from database. If object will apply filters and return $term.
+ * @param string     $taxonomy Taxonomy name that $term is part of.
+ * @param string     $output   Constant OBJECT, ARRAY_A, or ARRAY_N
+ * @param string     $filter   Optional, default is raw or no WordPress defined filter will applied.
+ * @return object|array|null|WP_Error Term Row from database. Will return null if $term is empty. If taxonomy does not
+ * exist then WP_Error will be returned.
+ */
+function get_term($term, $taxonomy, $output = OBJECT, $filter = 'raw') {
+        global $wpdb;
+        if ( empty( $term ) ) {
+                return new WP_Error( 'invalid_term', __( 'Empty Term' ) );
+        }
+        if ( ! taxonomy_exists( $taxonomy ) ) {
+                return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy' ) );
+        }
+        if ( is_object($term) && empty($term->filter) ) {
+                wp_cache_add( $term->term_id, $term, $taxonomy );
+                $_term = $term;
+        } else {
+                if ( is_object($term) )
+                        $term = $term->term_id;
+                if ( !$term = (int) $term )
+                        return null;
+                if ( ! $_term = wp_cache_get( $term, $taxonomy ) ) {
+                        $_term = $wpdb->get_row( $wpdb->prepare( "SELECT t.*, tt.* FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id WHERE tt.taxonomy = %s AND t.term_id = %d LIMIT 1", $taxonomy, $term) );
+                        if ( ! $_term )
+                                return null;
+                        wp_cache_add( $term, $_term, $taxonomy );
+                }
+        }
+        /**
+         * Filter a term.
+         *
+         * @since 2.3.0
+         *
+         * @param int|object $_term    Term object or ID.
+         * @param string     $taxonomy The taxonomy slug.
+         */
+        $_term = apply_filters( 'get_term', $_term, $taxonomy );
+        /**
+         * Filter a taxonomy.
+         *
+         * The dynamic portion of the filter name, `$taxonomy`, refers
+         * to the taxonomy slug.
+         *
+         * @since 2.3.0
+         *
+         * @param int|object $_term    Term object or ID.
+         * @param string     $taxonomy The taxonomy slug.
+         */
+        $_term = apply_filters( "get_$taxonomy", $_term, $taxonomy );
+        $_term = sanitize_term($_term, $taxonomy, $filter);
+        if ( $output == OBJECT ) {
+                return $_term;
+        } elseif ( $output == ARRAY_A ) {
+                $__term = get_object_vars($_term);
+                return $__term;
+        } elseif ( $output == ARRAY_N ) {
+                $__term = array_values(get_object_vars($_term));
+                return $__term;
+        } else {
+                return $_term;
+        }
+}
+/**
+ * Get all Term data from database by Term field and data.
+ *
+ * Warning: $value is not escaped for 'name' $field. You must do it yourself, if
+ * required.
+ *
+ * The default $field is 'id', therefore it is possible to also use null for
+ * field, but not recommended that you do so.
+ *
+ * If $value does not exist, the return value will be false. If $taxonomy exists
+ * and $field and $value combinations exist, the Term will be returned.
+ *
+ * @todo Better formatting for DocBlock.
+ *
+ * @since 2.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ * @see sanitize_term_field() The $context param lists the available values for get_term_by() $filter param.
+ *
+ * @param string     $field    Either 'slug', 'name', 'id' (term_id), or 'term_taxonomy_id'
+ * @param string|int $value    Search for this term value
+ * @param string     $taxonomy Taxonomy Name
+ * @param string     $output   Constant OBJECT, ARRAY_A, or ARRAY_N
+ * @param string     $filter   Optional, default is raw or no WordPress defined filter will applied.
+ * @return object|array|null|WP_Error|false Term Row from database.
+ *                                          Will return false if $taxonomy does not exist or $term was not found.
+ */
+function get_term_by($field, $value, $taxonomy, $output = OBJECT, $filter = 'raw') {
+        global $wpdb;
+        if ( ! taxonomy_exists($taxonomy) )
+                return false;
+        if ( 'slug' == $field ) {
+                $field = 't.slug';
+                $value = sanitize_title($value);
+                if ( empty($value) )
+                        return false;
+        } elseif ( 'name' == $field ) {
+                // Assume already escaped
+                $value = wp_unslash($value);
+                $field = 't.name';
+        } elseif ( 'term_taxonomy_id' == $field ) {
+                $value = (int) $value;
+                $field = 'tt.term_taxonomy_id';
+        } else {
+                $term = get_term( (int) $value, $taxonomy, $output, $filter );
+                if ( is_wp_error( $term ) )
+                        $term = false;
+                return $term;
+        }
+        $term = $wpdb->get_row( $wpdb->prepare( "SELECT t.*, tt.* FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id WHERE tt.taxonomy = %s AND $field = %s LIMIT 1", $taxonomy, $value ) );
+        if ( ! $term )
+                return false;
+        wp_cache_add( $term->term_id, $term, $taxonomy );
+        /** This filter is documented in wp-includes/taxonomy.php */
+        $term = apply_filters( 'get_term', $term, $taxonomy );
+        /** This filter is documented in wp-includes/taxonomy.php */
+        $term = apply_filters( "get_$taxonomy", $term, $taxonomy );
+        $term = sanitize_term($term, $taxonomy, $filter);
+        if ( $output == OBJECT ) {
+                return $term;
+        } elseif ( $output == ARRAY_A ) {
+                return get_object_vars($term);
+        } elseif ( $output == ARRAY_N ) {
+                return array_values(get_object_vars($term));
+        } else {
+                return $term;
+        }
+}
+/**
+ * Merge all term children into a single array of their IDs.
+ *
+ * This recursive function will merge all of the children of $term into the same
+ * array of term IDs. Only useful for taxonomies which are hierarchical.
+ *
+ * Will return an empty array if $term does not exist in $taxonomy.
+ *
+ * @since 2.3.0
+ *
+ * @param string $term_id  ID of Term to get children.
+ * @param string $taxonomy Taxonomy Name.
+ * @return array|WP_Error List of Term IDs. WP_Error returned if `$taxonomy` does not exist.
+ */
+function get_term_children( $term_id, $taxonomy ) {
+        if ( ! taxonomy_exists($taxonomy) )
+                return new WP_Error('invalid_taxonomy', __('Invalid taxonomy'));
+        $term_id = intval( $term_id );
+        $terms = _get_term_hierarchy($taxonomy);
+        if ( ! isset($terms[$term_id]) )
+                return array();
+        $children = $terms[$term_id];
+        foreach ( (array) $terms[$term_id] as $child ) {
+                if ( $term_id == $child ) {
+                        continue;
+                }
+                if ( isset($terms[$child]) )
+                        $children = array_merge($children, get_term_children($child, $taxonomy));
+        }
+        return $children;
+}
+/**
+ * Get sanitized Term field.
+ *
+ * Does checks for $term, based on the $taxonomy. The function is for contextual
+ * reasons and for simplicity of usage. See sanitize_term_field() for more
+ * information.
+ *
+ * @since 2.3.0
+ *
+ * @param string $field    Term field to fetch.
+ * @param int    $term     Term ID.
+ * @param string $taxonomy Taxonomy Name.
+ * @param string $context  Optional, default is display. Look at sanitize_term_field() for available options.
+ * @return string|int|null|WP_Error Will return an empty string if $term is not an object or if $field is not set in $term.
+ */
+function get_term_field( $field, $term, $taxonomy, $context = 'display' ) {
+        $term = (int) $term;
+        $term = get_term( $term, $taxonomy );
+        if ( is_wp_error($term) )
+                return $term;
+        if ( !is_object($term) )
+                return '';
+        if ( !isset($term->$field) )
+                return '';
+        return sanitize_term_field($field, $term->$field, $term->term_id, $taxonomy, $context);
+}
+/**
+ * Sanitizes Term for editing.
+ *
+ * Return value is sanitize_term() and usage is for sanitizing the term for
+ * editing. Function is for contextual and simplicity.
+ *
+ * @since 2.3.0
+ *
+ * @param int|object $id       Term ID or object.
+ * @param string     $taxonomy Taxonomy name.
+ * @return string|int|null|WP_Error Will return empty string if $term is not an object.
+ */
+function get_term_to_edit( $id, $taxonomy ) {
+        $term = get_term( $id, $taxonomy );
+        if ( is_wp_error($term) )
+                return $term;
+        if ( !is_object($term) )
+                return '';
+        return sanitize_term($term, $taxonomy, 'edit');
+}
+/**
+ * Retrieve the terms in a given taxonomy or list of taxonomies.
+ *
+ * You can fully inject any customizations to the query before it is sent, as
+ * well as control the output with a filter.
+ *
+ * The {@see 'get_terms'} filter will be called when the cache has the term and will
+ * pass the found term along with the array of $taxonomies and array of $args.
+ * This filter is also called before the array of terms is passed and will pass
+ * the array of terms, along with the $taxonomies and $args.
+ *
+ * The {@see 'list_terms_exclusions'} filter passes the compiled exclusions along with
+ * the $args.
+ *
+ * The {@see 'get_terms_orderby'} filter passes the `ORDER BY` clause for the query
+ * along with the $args array.
+ *
+ * @since 2.3.0
+ * @since 4.2.0 Introduced 'name' and 'childless' parameters.
+ *
+ * @global wpdb  $wpdb WordPress database abstraction object.
+ * @global array $wp_filter
+ *
+ * @param string|array $taxonomies Taxonomy name or list of Taxonomy names.
+ * @param array|string $args {
+ *     Optional. Array or string of arguments to get terms.
+ *
+ *     @type string       $orderby           Field(s) to order terms by. Accepts term fields ('name', 'slug',
+ *                                           'term_group', 'term_id', 'id', 'description'), 'count' for term
+ *                                           taxonomy count, 'include' to match the 'order' of the $include param,
+ *                                           or 'none' to skip ORDER BY. Defaults to 'name'.
+ *     @type string       $order             Whether to order terms in ascending or descending order.
+ *                                           Accepts 'ASC' (ascending) or 'DESC' (descending).
+ *                                           Default 'ASC'.
+ *     @type bool|int     $hide_empty        Whether to hide terms not assigned to any posts. Accepts
+ *                                           1|true or 0|false. Default 1|true.
+ *     @type array|string $include           Array or comma/space-separated string of term ids to include.
+ *                                           Default empty array.
+ *     @type array|string $exclude           Array or comma/space-separated string of term ids to exclude.
+ *                                           If $include is non-empty, $exclude is ignored.
+ *                                           Default empty array.
+ *     @type array|string $exclude_tree      Array or comma/space-separated string of term ids to exclude
+ *                                           along with all of their descendant terms. If $include is
+ *                                           non-empty, $exclude_tree is ignored. Default empty array.
+ *     @type int|string   $number            Maximum number of terms to return. Accepts ''|0 (all) or any
+ *                                           positive number. Default ''|0 (all).
+ *     @type int          $offset            The number by which to offset the terms query. Default empty.
+ *     @type string       $fields            Term fields to query for. Accepts 'all' (returns an array of complete
+ *                                           term objects), 'ids' (returns an array of ids), 'id=>parent' (returns
+ *                                           an associative array with ids as keys, parent term IDs as values),
+ *                                           'names' (returns an array of term names), 'count' (returns the number
+ *                                           of matching terms), 'id=>name' (returns an associative array with ids
+ *                                           as keys, term names as values), or 'id=>slug' (returns an associative
+ *                                           array with ids as keys, term slugs as values). Default 'all'.
+ *     @type string|array $name              Optional. Name or array of names to return term(s) for. Default empty.
+ *     @type string|array $slug              Optional. Slug or array of slugs to return term(s) for. Default empty.
+ *     @type bool         $hierarchical      Whether to include terms that have non-empty descendants (even
+ *                                           if $hide_empty is set to true). Default true.
+ *     @type string       $search            Search criteria to match terms. Will be SQL-formatted with
+ *                                           wildcards before and after. Default empty.
+ *     @type string       $name__like        Retrieve terms with criteria by which a term is LIKE $name__like.
+ *                                           Default empty.
+ *     @type string       $description__like Retrieve terms where the description is LIKE $description__like.
+ *                                           Default empty.
+ *     @type bool         $pad_counts        Whether to pad the quantity of a term's children in the quantity
+ *                                           of each term's "count" object variable. Default false.
+ *     @type string       $get               Whether to return terms regardless of ancestry or whether the terms
+ *                                           are empty. Accepts 'all' or empty (disabled). Default empty.
+ *     @type int          $child_of          Term ID to retrieve child terms of. If multiple taxonomies
+ *                                           are passed, $child_of is ignored. Default 0.
+ *     @type int|string   $parent            Parent term ID to retrieve direct-child terms of. Default empty.
+ *     @type bool         $childless         True to limit results to terms that have no children. This parameter has
+ *                                           no effect on non-hierarchical taxonomies. Default false.
+ *     @type string       $cache_domain      Unique cache key to be produced when this query is stored in an
+ *                                           object cache. Default is 'core'.
+ * }
+ * @return array|int|WP_Error List of Term Objects and their children. Will return WP_Error, if any of $taxonomies
+ *                        do not exist.
+ */
+function get_terms( $taxonomies, $args = '' ) {
+        global $wpdb;
+        $empty_array = array();
+        $single_taxonomy = ! is_array( $taxonomies ) || 1 === count( $taxonomies );
+        if ( ! is_array( $taxonomies ) ) {
+                $taxonomies = array( $taxonomies );
+        }
+        foreach ( $taxonomies as $taxonomy ) {
+                if ( ! taxonomy_exists($taxonomy) ) {
+                        return new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy' ) );
+                }
+        }
+        $defaults = array('orderby' => 'name', 'order' => 'ASC',
+                'hide_empty' => true, 'exclude' => array(), 'exclude_tree' => array(), 'include' => array(),
+                'number' => '', 'fields' => 'all', 'name' => '', 'slug' => '', 'parent' => '', 'childless' => false,
+                'hierarchical' => true, 'child_of' => 0, 'get' => '', 'name__like' => '', 'description__like' => '',
+                'pad_counts' => false, 'offset' => '', 'search' => '', 'cache_domain' => 'core' );
+        $args = wp_parse_args( $args, $defaults );
+        $args['number'] = absint( $args['number'] );
+        $args['offset'] = absint( $args['offset'] );
+        // Save queries by not crawling the tree in the case of multiple taxes or a flat tax.
+        $has_hierarchical_tax = false;
+        foreach ( $taxonomies as $_tax ) {
+                if ( is_taxonomy_hierarchical( $_tax ) ) {
+                        $has_hierarchical_tax = true;
+                }
+        }
+        if ( ! $has_hierarchical_tax ) {
+                $args['hierarchical'] = false;
+                $args['pad_counts'] = false;
+        }
+        // 'parent' overrides 'child_of'.
+        if ( 0 < intval( $args['parent'] ) ) {
+                $args['child_of'] = false;
+        }
+        if ( 'all' == $args['get'] ) {
+                $args['childless'] = false;
+                $args['child_of'] = 0;
+                $args['hide_empty'] = 0;
+                $args['hierarchical'] = false;
+                $args['pad_counts'] = false;
+        }
+        /**
+         * Filter the terms query arguments.
+         *
+         * @since 3.1.0
+         *
+         * @param array $args       An array of get_term() arguments.
+         * @param array $taxonomies An array of taxonomies.
+         */
+        $args = apply_filters( 'get_terms_args', $args, $taxonomies );
+        // Avoid the query if the queried parent/child_of term has no descendants.
+        $child_of = $args['child_of'];
+        $parent   = $args['parent'];
+        if ( $child_of ) {
+                $_parent = $child_of;
+        } elseif ( $parent ) {
+                $_parent = $parent;
+        } else {
+                $_parent = false;
+        }
+        if ( $_parent ) {
+                $in_hierarchy = false;
+                foreach ( $taxonomies as $_tax ) {
+                        $hierarchy = _get_term_hierarchy( $_tax );
+                        if ( isset( $hierarchy[ $_parent ] ) ) {
+                                $in_hierarchy = true;
+                        }
+                }
+                if ( ! $in_hierarchy ) {
+                        return $empty_array;
+                }
+        }
+        // $args can be whatever, only use the args defined in defaults to compute the key.
+        $filter_key = ( has_filter('list_terms_exclusions') ) ? serialize($GLOBALS['wp_filter']['list_terms_exclusions']) : '';
+        $key = md5( serialize( wp_array_slice_assoc( $args, array_keys( $defaults ) ) ) . serialize( $taxonomies ) . $filter_key );
+        $last_changed = wp_cache_get( 'last_changed', 'terms' );
+        if ( ! $last_changed ) {
+                $last_changed = microtime();
+                wp_cache_set( 'last_changed', $last_changed, 'terms' );
+        }
+        $cache_key = "get_terms:$key:$last_changed";
+        $cache = wp_cache_get( $cache_key, 'terms' );
+        if ( false !== $cache ) {
+                /**
+                 * Filter the given taxonomy's terms cache.
+                 *
+                 * @since 2.3.0
+                 *
+                 * @param array $cache      Cached array of terms for the given taxonomy.
+                 * @param array $taxonomies An array of taxonomies.
+                 * @param array $args       An array of get_terms() arguments.
+                 */
+                return apply_filters( 'get_terms', $cache, $taxonomies, $args );
+        }
+        $_orderby = strtolower( $args['orderby'] );
+        if ( 'count' == $_orderby ) {
+                $orderby = 'tt.count';
+        } elseif ( 'name' == $_orderby ) {
+                $orderby = 't.name';
+        } elseif ( 'slug' == $_orderby ) {
+                $orderby = 't.slug';
+        } elseif ( 'include' == $_orderby && ! empty( $args['include'] ) ) {
+                $include = implode( ',', array_map( 'absint', $args['include'] ) );
+                $orderby = "FIELD( t.term_id, $include )";
+        } elseif ( 'term_group' == $_orderby ) {
+                $orderby = 't.term_group';
+        } elseif ( 'description' == $_orderby ) {
+                $orderby = 'tt.description';
+        } elseif ( 'none' == $_orderby ) {
+                $orderby = '';
+        } elseif ( empty($_orderby) || 'id' == $_orderby ) {
+                $orderby = 't.term_id';
+        } else {
+                $orderby = 't.name';
+        }
+        /**
+         * Filter the ORDERBY clause of the terms query.
+         *
+         * @since 2.8.0
+         *
+         * @param string $orderby    `ORDERBY` clause of the terms query.
+         * @param array  $args       An array of terms query arguments.
+         * @param array  $taxonomies An array of taxonomies.
+         */
+        $orderby = apply_filters( 'get_terms_orderby', $orderby, $args, $taxonomies );
+        $order = strtoupper( $args['order'] );
+        if ( ! empty( $orderby ) ) {
+                $orderby = "ORDER BY $orderby";
+        } else {
+                $order = '';
+        }
+        if ( '' !== $order && ! in_array( $order, array( 'ASC', 'DESC' ) ) ) {
+                $order = 'ASC';
+        }
+        $where = "tt.taxonomy IN ('" . implode("', '", $taxonomies) . "')";
+        $exclude = $args['exclude'];
+        $exclude_tree = $args['exclude_tree'];
+        $include = $args['include'];
+        $inclusions = '';
+        if ( ! empty( $include ) ) {
+                $exclude = '';
+                $exclude_tree = '';
+                $inclusions = implode( ',', wp_parse_id_list( $include ) );
+        }
+        if ( ! empty( $inclusions ) ) {
+                $inclusions = ' AND t.term_id IN ( ' . $inclusions . ' )';
+                $where .= $inclusions;
+        }
+        $exclusions = array();
+        if ( ! empty( $exclude_tree ) ) {
+                $exclude_tree = wp_parse_id_list( $exclude_tree );
+                $excluded_children = $exclude_tree;
+                foreach ( $exclude_tree as $extrunk ) {
+                        $excluded_children = array_merge(
+                                $excluded_children,
+                                (array) get_terms( $taxonomies[0], array( 'child_of' => intval( $extrunk ), 'fields' => 'ids', 'hide_empty' => 0 ) )
+                        );
+                }
+                $exclusions = array_merge( $excluded_children, $exclusions );
+        }
+        if ( ! empty( $exclude ) ) {
+                $exclusions = array_merge( wp_parse_id_list( $exclude ), $exclusions );
+        }
+        // 'childless' terms are those without an entry in the flattened term hierarchy.
+        $childless = (bool) $args['childless'];
+        if ( $childless ) {
+                foreach ( $taxonomies as $_tax ) {
+                        $term_hierarchy = _get_term_hierarchy( $_tax );
+                        $exclusions = array_merge( array_keys( $term_hierarchy ), $exclusions );
+                }
+        }
+        if ( ! empty( $exclusions ) ) {
+                $exclusions = ' AND t.term_id NOT IN (' . implode( ',', array_map( 'intval', $exclusions ) ) . ')';
+        } else {
+                $exclusions = '';
+        }
+        /**
+         * Filter the terms to exclude from the terms query.
+         *
+         * @since 2.3.0
+         *
+         * @param string $exclusions `NOT IN` clause of the terms query.
+         * @param array  $args       An array of terms query arguments.
+         * @param array  $taxonomies An array of taxonomies.
+         */
+        $exclusions = apply_filters( 'list_terms_exclusions', $exclusions, $args, $taxonomies );
+        if ( ! empty( $exclusions ) ) {
+                $where .= $exclusions;
+        }
+        if ( ! empty( $args['name'] ) ) {
+                $names = (array) $args['name'];
+                foreach ( $names as &$_name ) {
+                        $_name = sanitize_term_field( 'name', $_name, 0, reset( $taxonomies ), 'db' );
+                }
+                $where .= " AND t.name IN ('" . implode( "', '", array_map( 'esc_sql', $names ) ) . "')";
+        }
+        if ( ! empty( $args['slug'] ) ) {
+                if ( is_array( $args['slug'] ) ) {
+                        $slug = array_map( 'sanitize_title', $args['slug'] );
+                        $where .= " AND t.slug IN ('" . implode( "', '", $slug ) . "')";
+                } else {
+                        $slug = sanitize_title( $args['slug'] );
+                        $where .= " AND t.slug = '$slug'";
+                }
+        }
+        if ( ! empty( $args['name__like'] ) ) {
+                $where .= $wpdb->prepare( " AND t.name LIKE %s", '%' . $wpdb->esc_like( $args['name__like'] ) . '%' );
+        }
+        if ( ! empty( $args['description__like'] ) ) {
+                $where .= $wpdb->prepare( " AND tt.description LIKE %s", '%' . $wpdb->esc_like( $args['description__like'] ) . '%' );
+        }
+        if ( '' !== $parent ) {
+                $parent = (int) $parent;
+                $where .= " AND tt.parent = '$parent'";
+        }
+        $hierarchical = $args['hierarchical'];
+        if ( 'count' == $args['fields'] ) {
+                $hierarchical = false;
+        }
+        if ( $args['hide_empty'] && !$hierarchical ) {
+                $where .= ' AND tt.count > 0';
+        }
+        $number = $args['number'];
+        $offset = $args['offset'];
+        // Don't limit the query results when we have to descend the family tree.
+        if ( $number && ! $hierarchical && ! $child_of && '' === $parent ) {
+                if ( $offset ) {
+                        $limits = 'LIMIT ' . $offset . ',' . $number;
+                } else {
+                        $limits = 'LIMIT ' . $number;
+                }
+        } else {
+                $limits = '';
+        }
+        if ( ! empty( $args['search'] ) ) {
+                $like = '%' . $wpdb->esc_like( $args['search'] ) . '%';
+                $where .= $wpdb->prepare( ' AND ((t.name LIKE %s) OR (t.slug LIKE %s))', $like, $like );
+        }
+        $selects = array();
+        switch ( $args['fields'] ) {
+                case 'all':
+                        $selects = array( 't.*', 'tt.*' );
+                        break;
+                case 'ids':
+                case 'id=>parent':
+                        $selects = array( 't.term_id', 'tt.parent', 'tt.count', 'tt.taxonomy' );
+                        break;
+                case 'names':
+                        $selects = array( 't.term_id', 'tt.parent', 'tt.count', 't.name', 'tt.taxonomy' );
+                        break;
+                case 'count':
+                        $orderby = '';
+                        $order = '';
+                        $selects = array( 'COUNT(*)' );
+                        break;
+                case 'id=>name':
+                        $selects = array( 't.term_id', 't.name', 'tt.count', 'tt.taxonomy' );
+                        break;
+                case 'id=>slug':
+                        $selects = array( 't.term_id', 't.slug', 'tt.count', 'tt.taxonomy' );
+                        break;
+        }
+        $_fields = $args['fields'];
+        /**
+         * Filter the fields to select in the terms query.
+         *
+         * Field lists modified using this filter will only modify the term fields returned
+         * by the function when the `$fields` parameter set to 'count' or 'all'. In all other
+         * cases, the term fields in the results array will be determined by the `$fields`
+         * parameter alone.
+         *
+         * Use of this filter can result in unpredictable behavior, and is not recommended.
+         *
+         * @since 2.8.0
+         *
+         * @param array $selects    An array of fields to select for the terms query.
+         * @param array $args       An array of term query arguments.
+         * @param array $taxonomies An array of taxonomies.
+         */
+        $fields = implode( ', ', apply_filters( 'get_terms_fields', $selects, $args, $taxonomies ) );
+        $join = "INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id";
+        $pieces = array( 'fields', 'join', 'where', 'orderby', 'order', 'limits' );
+        /**
+         * Filter the terms query SQL clauses.
+         *
+         * @since 3.1.0
+         *
+         * @param array $pieces     Terms query SQL clauses.
+         * @param array $taxonomies An array of taxonomies.
+         * @param array $args       An array of terms query arguments.
+         */
+        $clauses = apply_filters( 'terms_clauses', compact( $pieces ), $taxonomies, $args );
+        $fields = isset( $clauses[ 'fields' ] ) ? $clauses[ 'fields' ] : '';
+        $join = isset( $clauses[ 'join' ] ) ? $clauses[ 'join' ] : '';
+        $where = isset( $clauses[ 'where' ] ) ? $clauses[ 'where' ] : '';
+        $orderby = isset( $clauses[ 'orderby' ] ) ? $clauses[ 'orderby' ] : '';
+        $order = isset( $clauses[ 'order' ] ) ? $clauses[ 'order' ] : '';
+        $limits = isset( $clauses[ 'limits' ] ) ? $clauses[ 'limits' ] : '';
+        $query = "SELECT $fields FROM $wpdb->terms AS t $join WHERE $where $orderby $order $limits";
+        if ( 'count' == $_fields ) {
+                return $wpdb->get_var( $query );
+        }
+        $terms = $wpdb->get_results($query);
+        if ( 'all' == $_fields ) {
+                update_term_cache( $terms );
+        }
+        if ( empty($terms) ) {
+                wp_cache_add( $cache_key, array(), 'terms', DAY_IN_SECONDS );
+                /** This filter is documented in wp-includes/taxonomy.php */
+                return apply_filters( 'get_terms', array(), $taxonomies, $args );
+        }
+        if ( $child_of ) {
+                foreach ( $taxonomies as $_tax ) {
+                        $children = _get_term_hierarchy( $_tax );
+                        if ( ! empty( $children ) ) {
+                                $terms = _get_term_children( $child_of, $terms, $_tax );
+                        }
+                }
+        }
+        // Update term counts to include children.
+        if ( $args['pad_counts'] && 'all' == $_fields ) {
+                foreach ( $taxonomies as $_tax ) {
+                        _pad_term_counts( $terms, $_tax );
+                }
+        }
+        // Make sure we show empty categories that have children.
+        if ( $hierarchical && $args['hide_empty'] && is_array( $terms ) ) {
+                foreach ( $terms as $k => $term ) {
+                        if ( ! $term->count ) {
+                                $children = get_term_children( $term->term_id, $term->taxonomy );
+                                if ( is_array( $children ) ) {
+                                        foreach ( $children as $child_id ) {
+                                                $child = get_term( $child_id, $term->taxonomy );
+                                                if ( $child->count ) {
+                                                        continue 2;
+                                                }
+                                        }
+                                }
+                                // It really is empty.
+                                unset($terms[$k]);
+                        }
+                }
+        }
+        $_terms = array();
+        if ( 'id=>parent' == $_fields ) {
+                foreach ( $terms as $term ) {
+                        $_terms[ $term->term_id ] = $term->parent;
+                }
+        } elseif ( 'ids' == $_fields ) {
+                foreach ( $terms as $term ) {
+                        $_terms[] = $term->term_id;
+                }
+        } elseif ( 'names' == $_fields ) {
+                foreach ( $terms as $term ) {
+                        $_terms[] = $term->name;
+                }
+        } elseif ( 'id=>name' == $_fields ) {
+                foreach ( $terms as $term ) {
+                        $_terms[ $term->term_id ] = $term->name;
+                }
+        } elseif ( 'id=>slug' == $_fields ) {
+                foreach ( $terms as $term ) {
+                        $_terms[ $term->term_id ] = $term->slug;
+                }
+        }
+        if ( ! empty( $_terms ) ) {
+                $terms = $_terms;
+        }
+        if ( $number && is_array( $terms ) && count( $terms ) > $number ) {
+                $terms = array_slice( $terms, $offset, $number );
+        }
+        wp_cache_add( $cache_key, $terms, 'terms', DAY_IN_SECONDS );
+        /** This filter is documented in wp-includes/taxonomy */
+        return apply_filters( 'get_terms', $terms, $taxonomies, $args );
+}
+/**
+ * Check if Term exists.
+ *
+ * Formerly is_term(), introduced in 2.3.0.
+ *
+ * @since 3.0.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param int|string $term     The term to check
+ * @param string     $taxonomy The taxonomy name to use
+ * @param int        $parent   Optional. ID of parent term under which to confine the exists search.
+ * @return mixed Returns null if the term does not exist. Returns the term ID
+ *               if no taxonomy is specified and the term ID exists. Returns
+ *               an array of the term ID and the term taxonomy ID the taxonomy
+ *               is specified and the pairing exists.
+ */
+function term_exists( $term, $taxonomy = '', $parent = null ) {
+        global $wpdb;
+        $select = "SELECT term_id FROM $wpdb->terms as t WHERE ";
+        $tax_select = "SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE ";
+        if ( is_int($term) ) {
+                if ( 0 == $term )
+                        return 0;
+                $where = 't.term_id = %d';
+                if ( !empty($taxonomy) )
+                        return $wpdb->get_row( $wpdb->prepare( $tax_select . $where . " AND tt.taxonomy = %s", $term, $taxonomy ), ARRAY_A );
+                else
+                        return $wpdb->get_var( $wpdb->prepare( $select . $where, $term ) );
+        }
+        $term = trim( wp_unslash( $term ) );
+        $slug = sanitize_title( $term );
+        $where = 't.slug = %s';
+        $else_where = 't.name = %s';
+        $where_fields = array($slug);
+        $else_where_fields = array($term);
+        $orderby = 'ORDER BY t.term_id ASC';
+        $limit = 'LIMIT 1';
+        if ( !empty($taxonomy) ) {
+                if ( is_numeric( $parent ) ) {
+                        $parent = (int) $parent;
+                        $where_fields[] = $parent;
+                        $else_where_fields[] = $parent;
+                        $where .= ' AND tt.parent = %d';
+                        $else_where .= ' AND tt.parent = %d';
+                }
+                $where_fields[] = $taxonomy;
+                $else_where_fields[] = $taxonomy;
+                if ( $result = $wpdb->get_row( $wpdb->prepare("SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE $where AND tt.taxonomy = %s $orderby $limit", $where_fields), ARRAY_A) )
+                        return $result;
+                return $wpdb->get_row( $wpdb->prepare("SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE $else_where AND tt.taxonomy = %s $orderby $limit", $else_where_fields), ARRAY_A);
+        }
+        if ( $result = $wpdb->get_var( $wpdb->prepare("SELECT term_id FROM $wpdb->terms as t WHERE $where $orderby $limit", $where_fields) ) )
+                return $result;
+        return $wpdb->get_var( $wpdb->prepare("SELECT term_id FROM $wpdb->terms as t WHERE $else_where $orderby $limit", $else_where_fields) );
+}
+/**
+ * Check if a term is an ancestor of another term.
+ *
+ * You can use either an id or the term object for both parameters.
+ *
+ * @since 3.4.0
+ *
+ * @param int|object $term1    ID or object to check if this is the parent term.
+ * @param int|object $term2    The child term.
+ * @param string     $taxonomy Taxonomy name that $term1 and `$term2` belong to.
+ * @return bool Whether `$term2` is a child of `$term1`.
+ */
+function term_is_ancestor_of( $term1, $term2, $taxonomy ) {
+        if ( ! isset( $term1->term_id ) )
+                $term1 = get_term( $term1, $taxonomy );
+        if ( ! isset( $term2->parent ) )
+                $term2 = get_term( $term2, $taxonomy );
+        if ( empty( $term1->term_id ) || empty( $term2->parent ) )
+                return false;
+        if ( $term2->parent == $term1->term_id )
+                return true;
+        return term_is_ancestor_of( $term1, get_term( $term2->parent, $taxonomy ), $taxonomy );
+}
+/**
+ * Sanitize Term all fields.
+ *
+ * Relies on sanitize_term_field() to sanitize the term. The difference is that
+ * this function will sanitize <strong>all</strong> fields. The context is based
+ * on sanitize_term_field().
+ *
+ * The $term is expected to be either an array or an object.
+ *
+ * @since 2.3.0
+ *
+ * @param array|object $term     The term to check.
+ * @param string       $taxonomy The taxonomy name to use.
+ * @param string       $context  Optional. Context in which to sanitize the term. Accepts 'edit', 'db',
+ *                               'display', 'attribute', or 'js'. Default 'display'.
+ * @return array|object Term with all fields sanitized.
+ */
+function sanitize_term($term, $taxonomy, $context = 'display') {
+        $fields = array( 'term_id', 'name', 'description', 'slug', 'count', 'parent', 'term_group', 'term_taxonomy_id', 'object_id' );
+        $do_object = is_object( $term );
+        $term_id = $do_object ? $term->term_id : (isset($term['term_id']) ? $term['term_id'] : 0);
+        foreach ( (array) $fields as $field ) {
+                if ( $do_object ) {
+                        if ( isset($term->$field) )
+                                $term->$field = sanitize_term_field($field, $term->$field, $term_id, $taxonomy, $context);
+                } else {
+                        if ( isset($term[$field]) )
+                                $term[$field] = sanitize_term_field($field, $term[$field], $term_id, $taxonomy, $context);
+                }
+        }
+        if ( $do_object )
+                $term->filter = $context;
+        else
+                $term['filter'] = $context;
+        return $term;
+}
+/**
+ * Cleanse the field value in the term based on the context.
+ *
+ * Passing a term field value through the function should be assumed to have
+ * cleansed the value for whatever context the term field is going to be used.
+ *
+ * If no context or an unsupported context is given, then default filters will
+ * be applied.
+ *
+ * There are enough filters for each context to support a custom filtering
+ * without creating your own filter function. Simply create a function that
+ * hooks into the filter you need.
+ *
+ * @since 2.3.0
+ *
+ * @param string $field    Term field to sanitize.
+ * @param string $value    Search for this term value.
+ * @param int    $term_id  Term ID.
+ * @param string $taxonomy Taxonomy Name.
+ * @param string $context  Context in which to sanitize the term field. Accepts 'edit', 'db', 'display',
+ *                         'attribute', or 'js'.
+ * @return mixed Sanitized field.
+ */
+function sanitize_term_field($field, $value, $term_id, $taxonomy, $context) {
+        $int_fields = array( 'parent', 'term_id', 'count', 'term_group', 'term_taxonomy_id', 'object_id' );
+        if ( in_array( $field, $int_fields ) ) {
+                $value = (int) $value;
+                if ( $value < 0 )
+                        $value = 0;
+        }
+        if ( 'raw' == $context )
+                return $value;
+        if ( 'edit' == $context ) {
+                /**
+                 * Filter a term field to edit before it is sanitized.
+                 *
+                 * The dynamic portion of the filter name, `$field`, refers to the term field.
+                 *
+                 * @since 2.3.0
+                 *
+                 * @param mixed $value     Value of the term field.
+                 * @param int   $term_id   Term ID.
+                 * @param string $taxonomy Taxonomy slug.
+                 */
+                $value = apply_filters( "edit_term_{$field}", $value, $term_id, $taxonomy );
+                /**
+                 * Filter the taxonomy field to edit before it is sanitized.
+                 *
+                 * The dynamic portions of the filter name, `$taxonomy` and `$field`, refer
+                 * to the taxonomy slug and taxonomy field, respectively.
+                 *
+                 * @since 2.3.0
+                 *
+                 * @param mixed $value   Value of the taxonomy field to edit.
+                 * @param int   $term_id Term ID.
+                 */
+                $value = apply_filters( "edit_{$taxonomy}_{$field}", $value, $term_id );
+                if ( 'description' == $field )
+                        $value = esc_html($value); // textarea_escaped
+                else
+                        $value = esc_attr($value);
+        } elseif ( 'db' == $context ) {
+                /**
+                 * Filter a term field value before it is sanitized.
+                 *
+                 * The dynamic portion of the filter name, `$field`, refers to the term field.
+                 *
+                 * @since 2.3.0
+                 *
+                 * @param mixed  $value    Value of the term field.
+                 * @param string $taxonomy Taxonomy slug.
+                 */
+                $value = apply_filters( "pre_term_{$field}", $value, $taxonomy );
+                /**
+                 * Filter a taxonomy field before it is sanitized.
+                 *
+                 * The dynamic portions of the filter name, `$taxonomy` and `$field`, refer
+                 * to the taxonomy slug and field name, respectively.
+                 *
+                 * @since 2.3.0
+                 *
+                 * @param mixed $value Value of the taxonomy field.
+                 */
+                $value = apply_filters( "pre_{$taxonomy}_{$field}", $value );
+                // Back compat filters
+                if ( 'slug' == $field ) {
+                        /**
+                         * Filter the category nicename before it is sanitized.
+                         *
+                         * Use the pre_{$taxonomy}_{$field} hook instead.
+                         *
+                         * @since 2.0.3
+                         *
+                         * @param string $value The category nicename.
+                         */
+                        $value = apply_filters( 'pre_category_nicename', $value );
+                }
+        } elseif ( 'rss' == $context ) {
+                /**
+                 * Filter the term field for use in RSS.
+                 *
+                 * The dynamic portion of the filter name, `$field`, refers to the term field.
+                 *
+                 * @since 2.3.0
+                 *
+                 * @param mixed  $value    Value of the term field.
+                 * @param string $taxonomy Taxonomy slug.
+                 */
+                $value = apply_filters( "term_{$field}_rss", $value, $taxonomy );
+                /**
+                 * Filter the taxonomy field for use in RSS.
+                 *
+                 * The dynamic portions of the hook name, `$taxonomy`, and `$field`, refer
+                 * to the taxonomy slug and field name, respectively.
+                 *
+                 * @since 2.3.0
+                 *
+                 * @param mixed $value Value of the taxonomy field.
+                 */
+                $value = apply_filters( "{$taxonomy}_{$field}_rss", $value );
+        } else {
+                // Use display filters by default.
+                /**
+                 * Filter the term field sanitized for display.
+                 *
+                 * The dynamic portion of the filter name, `$field`, refers to the term field name.
+                 *
+                 * @since 2.3.0
+                 *
+                 * @param mixed  $value    Value of the term field.
+                 * @param int    $term_id  Term ID.
+                 * @param string $taxonomy Taxonomy slug.
+                 * @param string $context  Context to retrieve the term field value.
+                 */
+                $value = apply_filters( "term_{$field}", $value, $term_id, $taxonomy, $context );
+                /**
+                 * Filter the taxonomy field sanitized for display.
+                 *
+                 * The dynamic portions of the filter name, `$taxonomy`, and `$field`, refer
+                 * to the taxonomy slug and taxonomy field, respectively.
+                 *
+                 * @since 2.3.0
+                 *
+                 * @param mixed  $value   Value of the taxonomy field.
+                 * @param int    $term_id Term ID.
+                 * @param string $context Context to retrieve the taxonomy field value.
+                 */
+                $value = apply_filters( "{$taxonomy}_{$field}", $value, $term_id, $context );
+        }
+        if ( 'attribute' == $context ) {
+                $value = esc_attr($value);
+        } elseif ( 'js' == $context ) {
+                $value = esc_js($value);
+        }
+        return $value;
+}
+/**
+ * Count how many terms are in Taxonomy.
+ *
+ * Default $args is 'hide_empty' which can be 'hide_empty=true' or array('hide_empty' => true).
+ *
+ * @todo Document $args as a hash notation.
+ *
+ * @since 2.3.0
+ *
+ * @param string       $taxonomy Taxonomy name
+ * @param array|string $args     Overwrite defaults. See get_terms()
+ * @return array|int|WP_Error How many terms are in $taxonomy. WP_Error if $taxonomy does not exist.
+ */
+function wp_count_terms( $taxonomy, $args = array() ) {
+        $defaults = array('hide_empty' => false);
+        $args = wp_parse_args($args, $defaults);
+        // backwards compatibility
+        if ( isset($args['ignore_empty']) ) {
+                $args['hide_empty'] = $args['ignore_empty'];
+                unset($args['ignore_empty']);
+        }
+        $args['fields'] = 'count';
+        return get_terms($taxonomy, $args);
+}
+/**
+ * Will unlink the object from the taxonomy or taxonomies.
+ *
+ * Will remove all relationships between the object and any terms in
+ * a particular taxonomy or taxonomies. Does not remove the term or
+ * taxonomy itself.
+ *
+ * @since 2.3.0
+ *
+ * @param int          $object_id  The term Object Id that refers to the term.
+ * @param string|array $taxonomies List of Taxonomy Names or single Taxonomy name.
+ */
+function wp_delete_object_term_relationships( $object_id, $taxonomies ) {
+        $object_id = (int) $object_id;
+        if ( !is_array($taxonomies) )
+                $taxonomies = array($taxonomies);
+        foreach ( (array) $taxonomies as $taxonomy ) {
+                $term_ids = wp_get_object_terms( $object_id, $taxonomy, array( 'fields' => 'ids' ) );
+                $term_ids = array_map( 'intval', $term_ids );
+                wp_remove_object_terms( $object_id, $term_ids, $taxonomy );
+        }
+}
+/**
+ * Removes a term from the database.
+ *
+ * If the term is a parent of other terms, then the children will be updated to
+ * that term's parent.
+ *
+ * The `$args` 'default' will only override the terms found, if there is only one
+ * term found. Any other and the found terms are used.
+ *
+ * The $args 'force_default' will force the term supplied as default to be
+ * assigned even if the object was not going to be termless
+ *
+ * @todo Document $args as a hash notation.
+ *
+ * @since 2.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param int          $term     Term ID.
+ * @param string       $taxonomy Taxonomy Name.
+ * @param array|string $args     Optional. Change 'default' term id and override found term ids.
+ * @return bool|int|WP_Error Returns false if not term; true if completes delete action.
+ */
+function wp_delete_term( $term, $taxonomy, $args = array() ) {
+        global $wpdb;
+        $term = (int) $term;
+        if ( ! $ids = term_exists($term, $taxonomy) )
+                return false;
+        if ( is_wp_error( $ids ) )
+                return $ids;
+        $tt_id = $ids['term_taxonomy_id'];
+        $defaults = array();
+        if ( 'category' == $taxonomy ) {
+                $defaults['default'] = get_option( 'default_category' );
+                if ( $defaults['default'] == $term )
+                        return 0; // Don't delete the default category
+        }
+        $args = wp_parse_args($args, $defaults);
+        if ( isset( $args['default'] ) ) {
+                $default = (int) $args['default'];
+                if ( ! term_exists( $default, $taxonomy ) ) {
+                        unset( $default );
+                }
+        }
+        if ( isset( $args['force_default'] ) ) {
+                $force_default = $args['force_default'];
+        }
+        /**
+         * Fires when deleting a term, before any modifications are made to posts or terms.
+         *
+         * @since 4.1.0
+         *
+         * @param int    $term     Term ID.
+         * @param string $taxonomy Taxonomy Name.
+         */
+        do_action( 'pre_delete_term', $term, $taxonomy );
+        // Update children to point to new parent
+        if ( is_taxonomy_hierarchical($taxonomy) ) {
+                $term_obj = get_term($term, $taxonomy);
+                if ( is_wp_error( $term_obj ) )
+                        return $term_obj;
+                $parent = $term_obj->parent;
+                $edit_ids = $wpdb->get_results( "SELECT term_id, term_taxonomy_id FROM $wpdb->term_taxonomy WHERE `parent` = " . (int)$term_obj->term_id );
+                $edit_tt_ids = wp_list_pluck( $edit_ids, 'term_taxonomy_id' );
+                /**
+                 * Fires immediately before a term to delete's children are reassigned a parent.
+                 *
+                 * @since 2.9.0
+                 *
+                 * @param array $edit_tt_ids An array of term taxonomy IDs for the given term.
+                 */
+                do_action( 'edit_term_taxonomies', $edit_tt_ids );
+                $wpdb->update( $wpdb->term_taxonomy, compact( 'parent' ), array( 'parent' => $term_obj->term_id) + compact( 'taxonomy' ) );
+                // Clean the cache for all child terms.
+                $edit_term_ids = wp_list_pluck( $edit_ids, 'term_id' );
+                clean_term_cache( $edit_term_ids, $taxonomy );
+                /**
+                 * Fires immediately after a term to delete's children are reassigned a parent.
+                 *
+                 * @since 2.9.0
+                 *
+                 * @param array $edit_tt_ids An array of term taxonomy IDs for the given term.
+                 */
+                do_action( 'edited_term_taxonomies', $edit_tt_ids );
+        }
+        // Get the term before deleting it or its term relationships so we can pass to actions below.
+        $deleted_term = get_term( $term, $taxonomy );
+        $objects = $wpdb->get_col( $wpdb->prepare( "SELECT object_id FROM $wpdb->term_relationships WHERE term_taxonomy_id = %d", $tt_id ) );
+        foreach ( (array) $objects as $object ) {
+                $terms = wp_get_object_terms($object, $taxonomy, array('fields' => 'ids', 'orderby' => 'none'));
+                if ( 1 == count($terms) && isset($default) ) {
+                        $terms = array($default);
+                } else {
+                        $terms = array_diff($terms, array($term));
+                        if (isset($default) && isset($force_default) && $force_default)
+                                $terms = array_merge($terms, array($default));
+                }
+                $terms = array_map('intval', $terms);
+                wp_set_object_terms($object, $terms, $taxonomy);
+        }
+        // Clean the relationship caches for all object types using this term.
+        $tax_object = get_taxonomy( $taxonomy );
+        foreach ( $tax_object->object_type as $object_type )
+                clean_object_term_cache( $objects, $object_type );
+        /**
+         * Fires immediately before a term taxonomy ID is deleted.
+         *
+         * @since 2.9.0
+         *
+         * @param int $tt_id Term taxonomy ID.
+         */
+        do_action( 'delete_term_taxonomy', $tt_id );
+        $wpdb->delete( $wpdb->term_taxonomy, array( 'term_taxonomy_id' => $tt_id ) );
+        /**
+         * Fires immediately after a term taxonomy ID is deleted.
+         *
+         * @since 2.9.0
+         *
+         * @param int $tt_id Term taxonomy ID.
+         */
+        do_action( 'deleted_term_taxonomy', $tt_id );
+        // Delete the term if no taxonomies use it.
+        if ( !$wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_taxonomy WHERE term_id = %d", $term) ) )
+                $wpdb->delete( $wpdb->terms, array( 'term_id' => $term ) );
+        clean_term_cache($term, $taxonomy);
+        /**
+         * Fires after a term is deleted from the database and the cache is cleaned.
+         *
+         * @since 2.5.0
+         *
+         * @param int     $term         Term ID.
+         * @param int     $tt_id        Term taxonomy ID.
+         * @param string  $taxonomy     Taxonomy slug.
+         * @param mixed   $deleted_term Copy of the already-deleted term, in the form specified
+         *                              by the parent function. WP_Error otherwise.
+         */
+        do_action( 'delete_term', $term, $tt_id, $taxonomy, $deleted_term );
+        /**
+         * Fires after a term in a specific taxonomy is deleted.
+         *
+         * The dynamic portion of the hook name, `$taxonomy`, refers to the specific
+         * taxonomy the term belonged to.
+         *
+         * @since 2.3.0
+         *
+         * @param int     $term         Term ID.
+         * @param int     $tt_id        Term taxonomy ID.
+         * @param mixed   $deleted_term Copy of the already-deleted term, in the form specified
+         *                              by the parent function. WP_Error otherwise.
+         */
+        do_action( "delete_$taxonomy", $term, $tt_id, $deleted_term );
+        return true;
+}
+/**
+ * Deletes one existing category.
+ *
+ * @since 2.0.0
+ *
+ * @param int $cat_ID
+ * @return bool|int|WP_Error Returns true if completes delete action; false if term doesn't exist;
+ *      Zero on attempted deletion of default Category; WP_Error object is also a possibility.
+ */
+function wp_delete_category( $cat_ID ) {
+        return wp_delete_term( $cat_ID, 'category' );
+}
+/**
+ * Retrieves the terms associated with the given object(s), in the supplied taxonomies.
+ *
+ * @since 2.3.0
+ * @since 4.2.0 Added support for 'taxonomy', 'parent', and 'term_taxonomy_id' values of `$orderby`.
+ *              Introduced `$parent` argument.
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param int|array    $object_ids The ID(s) of the object(s) to retrieve.
+ * @param string|array $taxonomies The taxonomies to retrieve terms from.
+ * @param array|string $args {
+ *     Array of arguments.
+ *     @type string $orderby Field by which results should be sorted. Accepts 'name', 'count', 'slug', 'term_group',
+ *                           'term_order', 'taxonomy', 'parent', or 'term_taxonomy_id'. Default 'name'.
+ *     @type string $order   Sort order. Accepts 'ASC' or 'DESC'. Default 'ASC'.
+ *     @type string $fields  Fields to return for matched terms. Accepts 'all', 'ids', 'names', and
+ *                           'all_with_object_id'. Note that 'all' or 'all_with_object_id' will result in an array of
+ *                           term objects being returned, 'ids' will return an array of integers, and 'names' an array
+ *                           of strings.
+ *     @type int    $parent  Optional. Limit results to the direct children of a given term ID.
+ * }
+ * @return array|WP_Error The requested term data or empty array if no terms found.
+ *                        WP_Error if any of the $taxonomies don't exist.
+ */
+function wp_get_object_terms($object_ids, $taxonomies, $args = array()) {
+        global $wpdb;
+        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(
+                'orderby' => 'name',
+                'order'   => 'ASC',
+                'fields'  => 'all',
+                'parent'  => '',
+        );
+        $args = wp_parse_args( $args, $defaults );
+        $terms = array();
+        if ( count($taxonomies) > 1 ) {
+                foreach ( $taxonomies as $index => $taxonomy ) {
+                        $t = get_taxonomy($taxonomy);
+                        if ( isset($t->args) && is_array($t->args) && $args != array_merge($args, $t->args) ) {
+                                unset($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);
+        }
+        $orderby = $args['orderby'];
+        $order = $args['order'];
+        $fields = $args['fields'];
+        if ( in_array( $orderby, array( 'term_id', 'name', 'slug', 'term_group' ) ) ) {
+                $orderby = "t.$orderby";
+        } elseif ( in_array( $orderby, array( 'count', 'parent', 'taxonomy', 'term_taxonomy_id' ) ) ) {
+                $orderby = "tt.$orderby";
+        } elseif ( 'term_order' === $orderby ) {
+                $orderby = 'tr.term_order';
+        } elseif ( 'none' === $orderby ) {
+                $orderby = '';
+                $order = '';
+        } else {
+                $orderby = 't.term_id';
+        }
+        // tt_ids queries can only be none or tr.term_taxonomy_id
+        if ( ('tt_ids' == $fields) && !empty($orderby) )
+                $orderby = 'tr.term_taxonomy_id';
+        if ( !empty($orderby) )
+                $orderby = "ORDER BY $orderby";
+        $order = strtoupper( $order );
+        if ( '' !== $order && ! in_array( $order, array( 'ASC', 'DESC' ) ) )
+                $order = 'ASC';
+        $taxonomy_array = $taxonomies;
+        $object_id_array = $object_ids;
+        $taxonomies = "'" . implode("', '", $taxonomies) . "'";
+        $object_ids = implode(', ', $object_ids);
+        $select_this = '';
+        if ( 'all' == $fields ) {
+                $select_this = 't.*, tt.*';
+        } elseif ( 'ids' == $fields ) {
+                $select_this = 't.term_id';
+        } elseif ( 'names' == $fields ) {
+                $select_this = 't.name';
+        } elseif ( 'slugs' == $fields ) {
+                $select_this = 't.slug';
+        } elseif ( 'all_with_object_id' == $fields ) {
+                $select_this = 't.*, tt.*, tr.object_id';
+        }
+        $where = array(
+                "tt.taxonomy IN ($taxonomies)",
+                "tr.object_id IN ($object_ids)",
+        );
+        if ( '' !== $args['parent'] ) {
+                $where[] = $wpdb->prepare( 'tt.parent = %d', $args['parent'] );
+        }
+        $where = implode( ' AND ', $where );
+        $query = "SELECT $select_this FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON tt.term_id = t.term_id INNER JOIN $wpdb->term_relationships AS tr ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE $where $orderby $order";
+        $objects = false;
+        if ( 'all' == $fields || 'all_with_object_id' == $fields ) {
+                $_terms = $wpdb->get_results( $query );
+                foreach ( $_terms as $key => $term ) {
+                        $_terms[$key] = sanitize_term( $term, $taxonomy, 'raw' );
+                }
+                $terms = array_merge( $terms, $_terms );
+                update_term_cache( $terms );
+                $objects = true;
+        } elseif ( 'ids' == $fields || 'names' == $fields || 'slugs' == $fields ) {
+                $_terms = $wpdb->get_col( $query );
+                $_field = ( 'ids' == $fields ) ? 'term_id' : 'name';
+                foreach ( $_terms as $key => $term ) {
+                        $_terms[$key] = sanitize_term_field( $_field, $term, $term, $taxonomy, 'raw' );
+                }
+                $terms = array_merge( $terms, $_terms );
+        } elseif ( 'tt_ids' == $fields ) {
+                $terms = $wpdb->get_col("SELECT tr.term_taxonomy_id FROM $wpdb->term_relationships AS tr INNER JOIN $wpdb->term_taxonomy AS tt ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tr.object_id IN ($object_ids) AND tt.taxonomy IN ($taxonomies) $orderby $order");
+                foreach ( $terms as $key => $tt_id ) {
+                        $terms[$key] = sanitize_term_field( 'term_taxonomy_id', $tt_id, 0, $taxonomy, 'raw' ); // 0 should be the term id, however is not needed when using raw context.
+                }
+        }
+        if ( ! $terms ) {
+                $terms = array();
+        } elseif ( $objects && 'all_with_object_id' !== $fields ) {
+                $_tt_ids = array();
+                $_terms = array();
+                foreach ( $terms as $term ) {
+                        if ( in_array( $term->term_taxonomy_id, $_tt_ids ) ) {
+                                continue;
+                        }
+                        $_tt_ids[] = $term->term_taxonomy_id;
+                        $_terms[] = $term;
+                }
+                $terms = $_terms;
+        } elseif ( ! $objects ) {
+                $terms = array_values( array_unique( $terms ) );
+        }
+        /**
+         * Filter the terms for a given object or objects.
+         *
+         * @since 4.2.0
+         *
+         * @param array $terms           An array of terms for the given object or objects.
+         * @param array $object_id_array Array of object IDs for which `$terms` were retrieved.
+         * @param array $taxonomy_array  Array of taxonomies from which `$terms` were retrieved.
+         * @param array $args            An 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_id_array, $taxonomy_array, $args );
+        /**
+         * Filter the terms for a given object or objects.
+         *
+         * The `$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 array     $terms      An array of terms for the given object or objects.
+         * @param int|array $object_ids Object ID or array of IDs.
+         * @param string    $taxonomies SQL-formatted (comma-separated and quoted) list of taxonomy names.
+         * @param array     $args       An array of arguments for retrieving terms for the given object(s).
+         *                              See {@see wp_get_object_terms()} for details.
+         */
+        return apply_filters( 'wp_get_object_terms', $terms, $object_ids, $taxonomies, $args );
+}
+/**
+ * Add a new term to the database.
+ *
+ * A non-existent term is inserted in the following sequence:
+ * 1. The term is added to the term table, then related to the taxonomy.
+ * 2. If everything is correct, several actions are fired.
+ * 3. The 'term_id_filter' is evaluated.
+ * 4. The term cache is cleaned.
+ * 5. Several more actions are fired.
+ * 6. An array is returned containing the term_id and term_taxonomy_id.
+ *
+ * If the 'slug' argument is not empty, then it is checked to see if the term
+ * is invalid. If it is not a valid, existing term, it is added and the term_id
+ * is given.
+ *
+ * If the taxonomy is hierarchical, and the 'parent' argument is not empty,
+ * the term is inserted and the term_id will be given.
+ * Error handling:
+ * If $taxonomy does not exist or $term is empty,
+ * a WP_Error object will be returned.
+ *
+ * If the term already exists on the same hierarchical level,
+ * or the term slug and name are not unique, a WP_Error object will be returned.
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ * @since 2.3.0
+ *
+ * @param string       $term     The term to add or update.
+ * @param string       $taxonomy The taxonomy to which to add the term.
+ * @param array|string $args {
+ *     Optional. Array or string of arguments for inserting a term.
+ *
+ *     @type string $alias_of    Slug of the term to make this term an alias of.
+ *                               Default empty string. Accepts a term slug.
+ *     @type string $description The term description. Default empty string.
+ *     @type int    $parent      The id of the parent term. Default 0.
+ *     @type string $slug        The term slug to use. Default empty string.
+ * }
+ * @return array|WP_Error An array containing the `term_id` and `term_taxonomy_id`,
+ *                        {@see WP_Error} otherwise.
+ */
+function wp_insert_term( $term, $taxonomy, $args = array() ) {
+        global $wpdb;
+        if ( ! taxonomy_exists($taxonomy) ) {
+                return new WP_Error('invalid_taxonomy', __('Invalid taxonomy'));
+        }
+        /**
+         * Filter a term before it is sanitized and inserted into the database.
+         *
+         * @since 3.0.0
+         *
+         * @param string $term     The term to add or update.
+         * @param string $taxonomy Taxonomy slug.
+         */
+        $term = apply_filters( 'pre_insert_term', $term, $taxonomy );
+        if ( is_wp_error( $term ) ) {
+                return $term;
+        }
+        if ( is_int($term) && 0 == $term ) {
+                return new WP_Error('invalid_term_id', __('Invalid term ID'));
+        }
+        if ( '' == trim($term) ) {
+                return new WP_Error('empty_term_name', __('A name is required for this term'));
+        }
+        $defaults = array( 'alias_of' => '', 'description' => '', 'parent' => 0, 'slug' => '');
+        $args = wp_parse_args( $args, $defaults );
+        if ( $args['parent'] > 0 && ! term_exists( (int) $args['parent'] ) ) {
+                return new WP_Error( 'missing_parent', __( 'Parent term does not exist.' ) );
+        }
+        $args['name'] = $term;
+        $args['taxonomy'] = $taxonomy;
+        $args = sanitize_term($args, $taxonomy, 'db');
+        // expected_slashed ($name)
+        $name = wp_unslash( $args['name'] );
+        $description = wp_unslash( $args['description'] );
+        $parent = (int) $args['parent'];
+        $slug_provided = ! empty( $args['slug'] );
+        if ( ! $slug_provided ) {
+                $slug = sanitize_title( $name );
+        } else {
+                $slug = $args['slug'];
+        }
+        $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,
+                        ) );
+                }
+        }
+        /*
+         * Prevent the creation of terms with duplicate names at the same level of a taxonomy hierarchy,
+         * unless a unique slug has been explicitly provided.
+         */
+        if ( $name_match = get_term_by( 'name', $name, $taxonomy ) ) {
+                $slug_match = get_term_by( 'slug', $slug, $taxonomy );
+                if ( ! $slug_provided || $name_match->slug === $slug || $slug_match ) {
+                        if ( is_taxonomy_hierarchical( $taxonomy ) ) {
+                                $siblings = get_terms( $taxonomy, array( 'get' => 'all', 'parent' => $parent ) );
+                                $existing_term = null;
+                                if ( $name_match->slug === $slug && in_array( $name, wp_list_pluck( $siblings, 'name' ) ) ) {
+                                        $existing_term = $name_match;
+                                } elseif ( $slug_match && in_array( $slug, wp_list_pluck( $siblings, 'slug' ) ) ) {
+                                        $existing_term = $slug_match;
+                                }
+                                if ( $existing_term ) {
+                                        return new WP_Error( 'term_exists', __( 'A term with the name provided already exists with this parent.' ), $existing_term->term_id );
+                                }
+                        } else {
+                                return new WP_Error( 'term_exists', __( 'A term with the name provided already exists in this taxonomy.' ), $name_match->term_id );
+                        }
+                }
+        }
+        $slug = wp_unique_term_slug( $slug, (object) $args );
+        if ( false === $wpdb->insert( $wpdb->terms, compact( 'name', 'slug', 'term_group' ) ) ) {
+                return new WP_Error( 'db_insert_error', __( 'Could not insert term into the database' ), $wpdb->last_error );
+        }
+        $term_id = (int) $wpdb->insert_id;
+        // Seems unreachable, However, Is used in the case that a term name is provided, which sanitizes to an empty string.
+        if ( empty($slug) ) {
+                $slug = sanitize_title($slug, $term_id);
+                /** This action is documented in wp-includes/taxonomy.php */
+                do_action( 'edit_terms', $term_id, $taxonomy );
+                $wpdb->update( $wpdb->terms, compact( 'slug' ), compact( 'term_id' ) );
+                /** This action is documented in wp-includes/taxonomy.php */
+                do_action( 'edited_terms', $term_id, $taxonomy );
+        }
+        $tt_id = $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, $term_id ) );
+        if ( !empty($tt_id) ) {
+                return array('term_id' => $term_id, 'term_taxonomy_id' => $tt_id);
+        }
+        $wpdb->insert( $wpdb->term_taxonomy, compact( 'term_id', 'taxonomy', 'description', 'parent') + array( 'count' => 0 ) );
+        $tt_id = (int) $wpdb->insert_id;
+        /*
+         * Sanity check: if we just created a term with the same parent + taxonomy + slug but a higher term_id than
+         * an existing term, then we have unwittingly created a duplicate term. Delete the dupe, and use the term_id
+         * and term_taxonomy_id of the older term instead. Then return out of the function so that the "create" hooks
+         * are not fired.
+         */
+        $duplicate_term = $wpdb->get_row( $wpdb->prepare( "SELECT t.term_id, tt.term_taxonomy_id FROM $wpdb->terms t INNER JOIN $wpdb->term_taxonomy tt ON ( tt.term_id = t.term_id ) WHERE t.slug = %s AND tt.parent = %d AND tt.taxonomy = %s AND t.term_id < %d AND tt.term_taxonomy_id != %d", $slug, $parent, $taxonomy, $term_id, $tt_id ) );
+        if ( $duplicate_term ) {
+                $wpdb->delete( $wpdb->terms, array( 'term_id' => $term_id ) );
+                $wpdb->delete( $wpdb->term_taxonomy, array( 'term_taxonomy_id' => $tt_id ) );
+                $term_id = (int) $duplicate_term->term_id;
+                $tt_id   = (int) $duplicate_term->term_taxonomy_id;
+                clean_term_cache( $term_id, $taxonomy );
+                return array( 'term_id' => $term_id, 'term_taxonomy_id' => $tt_id );
+        }
+        /**
+         * Fires immediately after a new term is created, before the term cache is cleaned.
+         *
+         * @since 2.3.0
+         *
+         * @param int    $term_id  Term ID.
+         * @param int    $tt_id    Term taxonomy ID.
+         * @param string $taxonomy Taxonomy slug.
+         */
+        do_action( "create_term", $term_id, $tt_id, $taxonomy );
+        /**
+         * Fires after a new term is created for a specific taxonomy.
+         *
+         * The dynamic portion of the hook name, `$taxonomy`, refers
+         * to the slug of the taxonomy the term was created for.
+         *
+         * @since 2.3.0
+         *
+         * @param int $term_id Term ID.
+         * @param int $tt_id   Term taxonomy ID.
+         */
+        do_action( "create_$taxonomy", $term_id, $tt_id );
+        /**
+         * Filter the term ID after a new term is created.
+         *
+         * @since 2.3.0
+         *
+         * @param int $term_id Term ID.
+         * @param int $tt_id   Taxonomy term ID.
+         */
+        $term_id = apply_filters( 'term_id_filter', $term_id, $tt_id );
+        clean_term_cache($term_id, $taxonomy);
+        /**
+         * Fires after a new term is created, and after the term cache has been cleaned.
+         *
+         * @since 2.3.0
+         *
+         * @param int    $term_id  Term ID.
+         * @param int    $tt_id    Term taxonomy ID.
+         * @param string $taxonomy Taxonomy slug.
+         */
+        do_action( 'created_term', $term_id, $tt_id, $taxonomy );
+        /**
+         * Fires after a new term in a specific taxonomy is created, and after the term
+         * cache has been cleaned.
+         *
+         * The dynamic portion of the hook name, `$taxonomy`, refers to the taxonomy slug.
+         *
+         * @since 2.3.0
+         *
+         * @param int $term_id Term ID.
+         * @param int $tt_id   Term taxonomy ID.
+         */
+        do_action( "created_$taxonomy", $term_id, $tt_id );
+        return array('term_id' => $term_id, 'term_taxonomy_id' => $tt_id);
+}
+/**
+ * Create Term and Taxonomy Relationships.
+ *
+ * Relates an object (post, link etc) to a term and taxonomy type. Creates the
+ * term and taxonomy relationship if it doesn't already exist. Creates a term if
+ * it doesn't exist (using the slug).
+ *
+ * A relationship means that the term is grouped in or belongs to the taxonomy.
+ * A term has no meaning until it is given context by defining which taxonomy it
+ * exists under.
+ *
+ * @since 2.3.0
+ *
+ * @global wpdb $wpdb The WordPress database abstraction object.
+ *
+ * @param int              $object_id The object to relate to.
+ * @param array|int|string $terms     A single term slug, single term id, or array of either term slugs or ids.
+ *                                    Will replace all existing related terms in this taxonomy.
+ * @param string           $taxonomy  The context in which to relate the term to the object.
+ * @param bool             $append    Optional. If false will delete difference of terms. Default false.
+ * @return array|WP_Error Affected Term IDs.
+ */
+function wp_set_object_terms( $object_id, $terms, $taxonomy, $append = false ) {
+        global $wpdb;
+        $object_id = (int) $object_id;
+        if ( ! taxonomy_exists($taxonomy) )
+                return new WP_Error('invalid_taxonomy', __('Invalid taxonomy'));
+        if ( !is_array($terms) )
+                $terms = array($terms);
+        if ( ! $append )
+                $old_tt_ids =  wp_get_object_terms($object_id, $taxonomy, array('fields' => 'tt_ids', 'orderby' => 'none'));
+        else
+                $old_tt_ids = array();
+        $tt_ids = array();
+        $term_ids = array();
+        $new_tt_ids = array();
+        foreach ( (array) $terms as $term) {
+                if ( !strlen(trim($term)) )
+                        continue;
+                if ( !$term_info = term_exists($term, $taxonomy) ) {
+                        // Skip if a non-existent term ID is passed.
+                        if ( is_int($term) )
+                                continue;
+                        $term_info = wp_insert_term($term, $taxonomy);
+                }
+                if ( is_wp_error($term_info) )
+                        return $term_info;
+                $term_ids[] = $term_info['term_id'];
+                $tt_id = $term_info['term_taxonomy_id'];
+                $tt_ids[] = $tt_id;
+                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 ) ) )
+                        continue;
+                /**
+                 * Fires immediately before an object-term relationship is added.
+                 *
+                 * @since 2.9.0
+                 *
+                 * @param int $object_id Object ID.
+                 * @param int $tt_id     Term taxonomy ID.
+                 */
+                do_action( 'add_term_relationship', $object_id, $tt_id );
+                $wpdb->insert( $wpdb->term_relationships, array( 'object_id' => $object_id, 'term_taxonomy_id' => $tt_id ) );
+                /**
+                 * Fires immediately after an object-term relationship is added.
+                 *
+                 * @since 2.9.0
+                 *
+                 * @param int $object_id Object ID.
+                 * @param int $tt_id     Term taxonomy ID.
+                 */
+                do_action( 'added_term_relationship', $object_id, $tt_id );
+                $new_tt_ids[] = $tt_id;
+        }
+        if ( $new_tt_ids )
+                wp_update_term_count( $new_tt_ids, $taxonomy );
+        if ( ! $append ) {
+                $delete_tt_ids = array_diff( $old_tt_ids, $tt_ids );
+                if ( $delete_tt_ids ) {
+                        $in_delete_tt_ids = "'" . implode( "', '", $delete_tt_ids ) . "'";
+                        $delete_term_ids = $wpdb->get_col( $wpdb->prepare( "SELECT tt.term_id FROM $wpdb->term_taxonomy AS tt WHERE tt.taxonomy = %s AND tt.term_taxonomy_id IN ($in_delete_tt_ids)", $taxonomy ) );
+                        $delete_term_ids = array_map( 'intval', $delete_term_ids );
+                        $remove = wp_remove_object_terms( $object_id, $delete_term_ids, $taxonomy );
+                        if ( is_wp_error( $remove ) ) {
+                                return $remove;
+                        }
+                }
+        }
+        $t = get_taxonomy($taxonomy);
+        if ( ! $append && isset($t->sort) && $t->sort ) {
+                $values = array();
+                $term_order = 0;
+                $final_tt_ids = wp_get_object_terms($object_id, $taxonomy, array('fields' => 'tt_ids'));
+                foreach ( $tt_ids as $tt_id )
+                        if ( in_array($tt_id, $final_tt_ids) )
+                                $values[] = $wpdb->prepare( "(%d, %d, %d)", $object_id, $tt_id, ++$term_order);
+                if ( $values )
+                        if ( false === $wpdb->query( "INSERT INTO $wpdb->term_relationships (object_id, term_taxonomy_id, term_order) VALUES " . join( ',', $values ) . " ON DUPLICATE KEY UPDATE term_order = VALUES(term_order)" ) )
+                                return new WP_Error( 'db_insert_error', __( 'Could not insert term relationship into the database' ), $wpdb->last_error );
+        }
+        wp_cache_delete( $object_id, $taxonomy . '_relationships' );
+        /**
+         * Fires after an object's terms have been set.
+         *
+         * @since 2.8.0
+         *
+         * @param int    $object_id  Object ID.
+         * @param array  $terms      An array of object terms.
+         * @param array  $tt_ids     An array of term taxonomy IDs.
+         * @param string $taxonomy   Taxonomy slug.
+         * @param bool   $append     Whether to append new terms to the old terms.
+         * @param array  $old_tt_ids Old array of term taxonomy IDs.
+         */
+        do_action( 'set_object_terms', $object_id, $terms, $tt_ids, $taxonomy, $append, $old_tt_ids );
+        return $tt_ids;
+}
+/**
+ * Add term(s) associated with a given object.
+ *
+ * @since 3.6.0
+ *
+ * @param int              $object_id The ID of the object to which the terms will be added.
+ * @param array|int|string $terms     The slug(s) or ID(s) of the term(s) to add.
+ * @param array|string     $taxonomy  Taxonomy name.
+ * @return array|WP_Error Affected Term IDs
+ */
+function wp_add_object_terms( $object_id, $terms, $taxonomy ) {
+        return wp_set_object_terms( $object_id, $terms, $taxonomy, true );
+}
+/**
+ * Remove term(s) associated with a given object.
+ *
+ * @since 3.6.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param int              $object_id The ID of the object from which the terms will be removed.
+ * @param array|int|string $terms     The slug(s) or ID(s) of the term(s) to remove.
+ * @param array|string     $taxonomy  Taxonomy name.
+ * @return bool|WP_Error True on success, false or WP_Error on failure.
+ */
+function wp_remove_object_terms( $object_id, $terms, $taxonomy ) {
+        global $wpdb;
+        $object_id = (int) $object_id;
+        if ( ! taxonomy_exists( $taxonomy ) ) {
+                return new WP_Error( 'invalid_taxonomy', __( 'Invalid Taxonomy' ) );
+        }
+        if ( ! is_array( $terms ) ) {
+                $terms = array( $terms );
+        }
+        $tt_ids = array();
+        foreach ( (array) $terms as $term ) {
+                if ( ! strlen( trim( $term ) ) ) {
+                        continue;
+                }
+                if ( ! $term_info = term_exists( $term, $taxonomy ) ) {
+                        // Skip if a non-existent term ID is passed.
+                        if ( is_int( $term ) ) {
+                                continue;
+                        }
+                }
+                if ( is_wp_error( $term_info ) ) {
+                        return $term_info;
+                }
+                $tt_ids[] = $term_info['term_taxonomy_id'];
+        }
+        if ( $tt_ids ) {
+                $in_tt_ids = "'" . implode( "', '", $tt_ids ) . "'";
+                /**
+                 * Fires immediately before an object-term relationship is deleted.
+                 *
+                 * @since 2.9.0
+                 *
+                 * @param int   $object_id Object ID.
+                 * @param array $tt_ids    An array of term taxonomy IDs.
+                 */
+                do_action( 'delete_term_relationships', $object_id, $tt_ids );
+                $deleted = $wpdb->query( $wpdb->prepare( "DELETE FROM $wpdb->term_relationships WHERE object_id = %d AND term_taxonomy_id IN ($in_tt_ids)", $object_id ) );
+                /**
+                 * Fires immediately after an object-term relationship is deleted.
+                 *
+                 * @since 2.9.0
+                 *
+                 * @param int   $object_id Object ID.
+                 * @param array $tt_ids    An array of term taxonomy IDs.
+                 */
+                do_action( 'deleted_term_relationships', $object_id, $tt_ids );
+                wp_update_term_count( $tt_ids, $taxonomy );
+                return (bool) $deleted;
+        }
+        return false;
+}
+/**
+ * Will make slug unique, if it isn't already.
+ *
+ * The `$slug` has to be unique global to every taxonomy, meaning that one
+ * taxonomy term can't have a matching slug with another taxonomy term. Each
+ * slug has to be globally unique for every taxonomy.
+ *
+ * The way this works is that if the taxonomy that the term belongs to is
+ * hierarchical and has a parent, it will append that parent to the $slug.
+ *
+ * If that still doesn't return an unique slug, then it try to append a number
+ * until it finds a number that is truly unique.
+ *
+ * The only purpose for `$term` is for appending a parent, if one exists.
+ *
+ * @since 2.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param string $slug The string that will be tried for a unique slug.
+ * @param object $term The term object that the `$slug` will belong to.
+ * @return string Will return a true unique slug.
+ */
+function wp_unique_term_slug( $slug, $term ) {
+        global $wpdb;
+        $needs_suffix = true;
+        $original_slug = $slug;
+        // As of 4.1, duplicate slugs are allowed as long as they're in different taxonomies.
+        if ( ! term_exists( $slug ) || get_option( 'db_version' ) >= 30133 && ! get_term_by( 'slug', $slug, $term->taxonomy ) ) {
+                $needs_suffix = false;
+        }
+        /*
+         * If the taxonomy supports hierarchy and the term has a parent, make the slug unique
+         * by incorporating parent slugs.
+         */
+        $parent_suffix = '';
+        if ( $needs_suffix && is_taxonomy_hierarchical( $term->taxonomy ) && ! empty( $term->parent ) ) {
+                $the_parent = $term->parent;
+                while ( ! empty($the_parent) ) {
+                        $parent_term = get_term($the_parent, $term->taxonomy);
+                        if ( is_wp_error($parent_term) || empty($parent_term) )
+                                break;
+                        $parent_suffix .= '-' . $parent_term->slug;
+                        if ( ! term_exists( $slug . $parent_suffix ) ) {
+                                break;
+                        }
+                        if ( empty($parent_term->parent) )
+                                break;
+                        $the_parent = $parent_term->parent;
+                }
+        }
+        // If we didn't get a unique slug, try appending a number to make it unique.
+        /**
+         * Filter whether the proposed unique term slug is bad.
+         *
+         * @since 4.3.0
+         *
+         * @param bool   $needs_suffix Whether the slug needs to be made unique with a suffix.
+         * @param string $slug         The slug.
+         * @param object $term         Term object.
+         */
+        if ( apply_filters( 'wp_unique_term_slug_is_bad_slug', $needs_suffix, $slug, $term ) ) {
+                if ( $parent_suffix ) {
+                        $slug .= $parent_suffix;
+                } else {
+                        if ( ! empty( $term->term_id ) )
+                                $query = $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s AND term_id != %d", $slug, $term->term_id );
+                        else
+                                $query = $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s", $slug );
+                        if ( $wpdb->get_var( $query ) ) {
+                                $num = 2;
+                                do {
+                                        $alt_slug = $slug . "-$num";
+                                        $num++;
+                                        $slug_check = $wpdb->get_var( $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s", $alt_slug ) );
+                                } while ( $slug_check );
+                                $slug = $alt_slug;
+                        }
+                }
+        }
+        /**
+         * Filter the unique term slug.
+         *
+         * @since 4.3.0
+         *
+         * @param string $slug          Unique term slug.
+         * @param object $term          Term object.
+         * @param string $original_slug Slug originally passed to the function for testing.
+         */
+        return apply_filters( 'wp_unique_term_slug', $slug, $term, $original_slug );
+}
+/**
+ * Update term based on arguments provided.
+ *
+ * The $args will indiscriminately override all values with the same field name.
+ * Care must be taken to not override important information need to update or
+ * update will fail (or perhaps create a new term, neither would be acceptable).
+ *
+ * Defaults will set 'alias_of', 'description', 'parent', and 'slug' if not
+ * defined in $args already.
+ *
+ * 'alias_of' will create a term group, if it doesn't already exist, and update
+ * it for the $term.
+ *
+ * If the 'slug' argument in $args is missing, then the 'name' in $args will be
+ * used. It should also be noted that if you set 'slug' and it isn't unique then
+ * a WP_Error will be passed back. If you don't pass any slug, then a unique one
+ * will be created for you.
+ *
+ * For what can be overrode in `$args`, check the term scheme can contain and stay
+ * away from the term keys.
+ *
+ * @since 2.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param int          $term_id  The ID of the term
+ * @param string       $taxonomy The context in which to relate the term to the object.
+ * @param array|string $args     Optional. Array of get_terms() arguments. Default empty array.
+ * @return array|WP_Error Returns Term ID and Taxonomy Term ID
+ */
+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, ARRAY_A );
+        if ( is_wp_error( $term ) ) {
+                return $term;
+        }
+        if ( ! $term ) {
+                return new WP_Error( 'invalid_term', __( 'Empty Term' ) );
+        }
+        // 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 ( $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;
+        }
+        /**
+         * Filter 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 = 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 != $term['parent']) )
+                        $slug = wp_unique_term_slug($slug, (object) $args);
+                else
+                        return new WP_Error('duplicate_term_slug', sprintf(__('The slug &#8220;%s&#8221; 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 );
+        $wpdb->update($wpdb->terms, compact( 'name', 'slug', 'term_group' ), compact( 'term_id' ) );
+        if ( empty($slug) ) {
+                $slug = sanitize_title($name, $term_id);
+                $wpdb->update( $wpdb->terms, compact( 'slug' ), compact( 'term_id' ) );
+        }
+        /**
+         * Fires immediately after the given terms are edited.
+         *
+         * @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 );
+        // Clean the relationship caches for all object types using this term.
+        $objects = $wpdb->get_col( $wpdb->prepare( "SELECT object_id FROM $wpdb->term_relationships WHERE term_taxonomy_id = %d", $tt_id ) );
+        $tax_object = get_taxonomy( $taxonomy );
+        foreach ( $tax_object->object_type as $object_type ) {
+                clean_object_term_cache( $objects, $object_type );
+        }
+        /**
+         * Fires after a term has been updated, but before the term cache has been cleaned.
+         *
+         * @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.
+         *
+         * @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.
+         *
+         * @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.
+         *
+         * @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 );
+        return array('term_id' => $term_id, 'term_taxonomy_id' => $tt_id);
+}
+/**
+ * Enable or disable term counting.
+ *
+ * @since 2.5.0
+ *
+ * @staticvar bool $_defer
+ *
+ * @param bool $defer Optional. Enable if true, disable if false.
+ * @return bool Whether term counting is enabled or disabled.
+ */
+function wp_defer_term_counting($defer=null) {
+        static $_defer = false;
+        if ( is_bool($defer) ) {
+                $_defer = $defer;
+                // flush any deferred counts
+                if ( !$defer )
+                        wp_update_term_count( null, null, true );
+        }
+        return $_defer;
+}
+/**
+ * Updates the amount of terms in taxonomy.
+ *
+ * If there is a taxonomy callback applied, then it will be called for updating
+ * the count.
+ *
+ * The default action is to count what the amount of terms have the relationship
+ * of term ID. Once that is done, then update the database.
+ *
+ * @since 2.3.0
+ *
+ * @staticvar array $_deferred
+ *
+ * @param int|array $terms    The term_taxonomy_id of the terms.
+ * @param string    $taxonomy The context of the term.
+ * @return bool If no terms will return false, and if successful will return true.
+ */
+function wp_update_term_count( $terms, $taxonomy, $do_deferred=false ) {
+        static $_deferred = array();
+        if ( $do_deferred ) {
+                foreach ( (array) array_keys($_deferred) as $tax ) {
+                        wp_update_term_count_now( $_deferred[$tax], $tax );
+                        unset( $_deferred[$tax] );
+                }
+        }
+        if ( empty($terms) )
+                return false;
+        if ( !is_array($terms) )
+                $terms = array($terms);
+        if ( wp_defer_term_counting() ) {
+                if ( !isset($_deferred[$taxonomy]) )
+                        $_deferred[$taxonomy] = array();
+                $_deferred[$taxonomy] = array_unique( array_merge($_deferred[$taxonomy], $terms) );
+                return true;
+        }
+        return wp_update_term_count_now( $terms, $taxonomy );
+}
+/**
+ * Perform term count update immediately.
+ *
+ * @since 2.5.0
+ *
+ * @param array  $terms    The term_taxonomy_id of terms to update.
+ * @param string $taxonomy The context of the term.
+ * @return true Always true when complete.
+ */
+function wp_update_term_count_now( $terms, $taxonomy ) {
+        $terms = array_map('intval', $terms);
+        $taxonomy = get_taxonomy($taxonomy);
+        if ( !empty($taxonomy->update_count_callback) ) {
+                call_user_func($taxonomy->update_count_callback, $terms, $taxonomy);
+        } else {
+                $object_types = (array) $taxonomy->object_type;
+                foreach ( $object_types as &$object_type ) {
+                        if ( 0 === strpos( $object_type, 'attachment:' ) )
+                                list( $object_type ) = explode( ':', $object_type );
+                }
+                if ( $object_types == array_filter( $object_types, 'post_type_exists' ) ) {
+                        // Only post types are attached to this taxonomy
+                        _update_post_term_count( $terms, $taxonomy );
+                } else {
+                        // Default count updater
+                        _update_generic_term_count( $terms, $taxonomy );
+                }
+        }
+        clean_term_cache($terms, '', false);
+        return true;
+}
+//
+// Cache
+//
+/**
+ * Removes the taxonomy relationship to terms from the cache.
+ *
+ * Will remove the entire taxonomy relationship containing term `$object_id`. The
+ * term IDs have to exist within the taxonomy `$object_type` for the deletion to
+ * take place.
+ *
+ * @since 2.3.0
+ *
+ * @see get_object_taxonomies() for more on $object_type.
+ *
+ * @param int|array    $object_ids  Single or list of term object ID(s).
+ * @param array|string $object_type The taxonomy object type.
+ */
+function clean_object_term_cache($object_ids, $object_type) {
+        if ( !is_array($object_ids) )
+                $object_ids = array($object_ids);
+        $taxonomies = get_object_taxonomies( $object_type );
+        foreach ( $object_ids as $id ) {
+                foreach ( $taxonomies as $taxonomy ) {
+                        wp_cache_delete($id, "{$taxonomy}_relationships");
+                }
+        }
+        /**
+         * Fires after the object term cache has been cleaned.
+         *
+         * @since 2.5.0
+         *
+         * @param array  $object_ids An array of object IDs.
+         * @param string $objet_type Object type.
+         */
+        do_action( 'clean_object_term_cache', $object_ids, $object_type );
+}
+/**
+ * Will remove all of the term ids from the cache.
+ *
+ * @since 2.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ * @global bool $_wp_suspend_cache_invalidation
+ *
+ * @param int|array $ids            Single or list of Term IDs.
+ * @param string    $taxonomy       Optional. Can be empty and will assume `tt_ids`, else will use for context.
+ *                                  Default empty.
+ * @param bool      $clean_taxonomy Optional. Whether to clean taxonomy wide caches (true), or just individual
+ *                                  term object caches (false). Default true.
+ */
+function clean_term_cache($ids, $taxonomy = '', $clean_taxonomy = true) {
+        global $wpdb, $_wp_suspend_cache_invalidation;
+        if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
+                return;
+        }
+        if ( !is_array($ids) )
+                $ids = array($ids);
+        $taxonomies = array();
+        // If no taxonomy, assume tt_ids.
+        if ( empty($taxonomy) ) {
+                $tt_ids = array_map('intval', $ids);
+                $tt_ids = implode(', ', $tt_ids);
+                $terms = $wpdb->get_results("SELECT term_id, taxonomy FROM $wpdb->term_taxonomy WHERE term_taxonomy_id IN ($tt_ids)");
+                $ids = array();
+                foreach ( (array) $terms as $term ) {
+                        $taxonomies[] = $term->taxonomy;
+                        $ids[] = $term->term_id;
+                        wp_cache_delete($term->term_id, $term->taxonomy);
+                }
+                $taxonomies = array_unique($taxonomies);
+        } else {
+                $taxonomies = array($taxonomy);
+                foreach ( $taxonomies as $taxonomy ) {
+                        foreach ( $ids as $id ) {
+                                wp_cache_delete($id, $taxonomy);
+                        }
+                }
+        }
+        foreach ( $taxonomies as $taxonomy ) {
+                if ( $clean_taxonomy ) {
+                        wp_cache_delete('all_ids', $taxonomy);
+                        wp_cache_delete('get', $taxonomy);
+                        delete_option("{$taxonomy}_children");
+                        // Regenerate {$taxonomy}_children
+                        _get_term_hierarchy($taxonomy);
+                }
+                /**
+                 * Fires once after each taxonomy's term cache has been cleaned.
+                 *
+                 * @since 2.5.0
+                 *
+                 * @param array  $ids      An array of term IDs.
+                 * @param string $taxonomy Taxonomy slug.
+                 */
+                do_action( 'clean_term_cache', $ids, $taxonomy );
+        }
+        wp_cache_set( 'last_changed', microtime(), 'terms' );
+}
+/**
+ * Retrieves the taxonomy relationship to the term object id.
+ *
+ * @since 2.3.0
+ *
+ * @param int    $id       Term object ID.
+ * @param string $taxonomy Taxonomy name.
+ * @return bool|mixed Empty array if $terms found, but not `$taxonomy`. False if nothing is in cache
+ *                    for `$taxonomy` and `$id`.
+ */
+function get_object_term_cache( $id, $taxonomy ) {
+        return wp_cache_get( $id, "{$taxonomy}_relationships" );
+}
+/**
+ * Updates the cache for the given term object ID(s).
+ *
+ * Note: Due to performance concerns, great care should be taken to only update
+ * term caches when necessary. Processing time can increase exponentially depending
+ * on both the number of passed term IDs and the number of taxonomies those terms
+ * belong to.
+ *
+ * Caches will only be updated for terms not already cached.
+ *
+ * @since 2.3.0
+ *
+ * @param string|array $object_ids  Comma-separated list or array of term object IDs.
+ * @param array|string $object_type The taxonomy object type.
+ * @return void|false False if all of the terms in `$object_ids` are already cached.
+ */
+function update_object_term_cache($object_ids, $object_type) {
+        if ( empty($object_ids) )
+                return;
+        if ( !is_array($object_ids) )
+                $object_ids = explode(',', $object_ids);
+        $object_ids = array_map('intval', $object_ids);
+        $taxonomies = get_object_taxonomies($object_type);
+        $ids = array();
+        foreach ( (array) $object_ids as $id ) {
+                foreach ( $taxonomies as $taxonomy ) {
+                        if ( false === wp_cache_get($id, "{$taxonomy}_relationships") ) {
+                                $ids[] = $id;
+                                break;
+                        }
+                }
+        }
+        if ( empty( $ids ) )
+                return false;
+        $terms = wp_get_object_terms($ids, $taxonomies, array('fields' => 'all_with_object_id'));
+        $object_terms = array();
+        foreach ( (array) $terms as $term )
+                $object_terms[$term->object_id][$term->taxonomy][] = $term;
+        foreach ( $ids as $id ) {
+                foreach ( $taxonomies as $taxonomy ) {
+                        if ( ! isset($object_terms[$id][$taxonomy]) ) {
+                                if ( !isset($object_terms[$id]) )
+                                        $object_terms[$id] = array();
+                                $object_terms[$id][$taxonomy] = array();
+                        }
+                }
+        }
+        foreach ( $object_terms as $id => $value ) {
+                foreach ( $value as $taxonomy => $terms ) {
+                        wp_cache_add( $id, $terms, "{$taxonomy}_relationships" );
+                }
+        }
+}
+/**
+ * Updates Terms to Taxonomy in cache.
+ *
+ * @since 2.3.0
+ *
+ * @param array  $terms    List of term objects to change.
+ * @param string $taxonomy Optional. Update Term to this taxonomy in cache. Default empty.
+ */
+function update_term_cache( $terms, $taxonomy = '' ) {
+        foreach ( (array) $terms as $term ) {
+                $term_taxonomy = $taxonomy;
+                if ( empty($term_taxonomy) )
+                        $term_taxonomy = $term->taxonomy;
+                wp_cache_add( $term->term_id, $term, $term_taxonomy );
+        }
+}
+//
+// Private
+//
+/**
+ * Retrieves children of taxonomy as Term IDs.
+ *
+ * @ignore
+ * @since 2.3.0
+ *
+ * @param string $taxonomy Taxonomy name.
+ * @return array Empty if $taxonomy isn't hierarchical or returns children as Term IDs.
+ */
+function _get_term_hierarchy( $taxonomy ) {
+        if ( !is_taxonomy_hierarchical($taxonomy) )
+                return array();
+        $children = get_option("{$taxonomy}_children");
+        if ( is_array($children) )
+                return $children;
+        $children = array();
+        $terms = get_terms($taxonomy, array('get' => 'all', 'orderby' => 'id', 'fields' => 'id=>parent'));
+        foreach ( $terms as $term_id => $parent ) {
+                if ( $parent > 0 )
+                        $children[$parent][] = $term_id;
+        }
+        update_option("{$taxonomy}_children", $children);
+        return $children;
+}
+/**
+ * Get the subset of $terms that are descendants of $term_id.
+ *
+ * If `$terms` is an array of objects, then _get_term_children() returns an array of objects.
+ * If `$terms` is an array of IDs, then _get_term_children() returns an array of IDs.
+ *
+ * @access private
+ * @since 2.3.0
+ *
+ * @param int    $term_id   The ancestor term: all returned terms should be descendants of `$term_id`.
+ * @param array  $terms     The set of terms - either an array of term objects or term IDs - from which those that
+ *                          are descendants of $term_id will be chosen.
+ * @param string $taxonomy  The taxonomy which determines the hierarchy of the terms.
+ * @param array  $ancestors Optional. Term ancestors that have already been identified. Passed by reference, to keep
+ *                          track of found terms when recursing the hierarchy. The array of located ancestors is used
+ *                          to prevent infinite recursion loops. For performance, `term_ids` are used as array keys,
+ *                          with 1 as value. Default empty array.
+ * @return array|WP_Error The subset of $terms that are descendants of $term_id.
+ */
+function _get_term_children( $term_id, $terms, $taxonomy, &$ancestors = array() ) {
+        $empty_array = array();
+        if ( empty($terms) )
+                return $empty_array;
+        $term_list = array();
+        $has_children = _get_term_hierarchy($taxonomy);
+        if  ( ( 0 != $term_id ) && ! isset($has_children[$term_id]) )
+                return $empty_array;
+        // Include the term itself in the ancestors array, so we can properly detect when a loop has occurred.
+        if ( empty( $ancestors ) ) {
+                $ancestors[ $term_id ] = 1;
+        }
+        foreach ( (array) $terms as $term ) {
+                $use_id = false;
+                if ( !is_object($term) ) {
+                        $term = get_term($term, $taxonomy);
+                        if ( is_wp_error( $term ) )
+                                return $term;
+                        $use_id = true;
+                }
+                // Don't recurse if we've already identified the term as a child - this indicates a loop.
+                if ( isset( $ancestors[ $term->term_id ] ) ) {
+                        continue;
+                }
+                if ( $term->parent == $term_id ) {
+                        if ( $use_id )
+                                $term_list[] = $term->term_id;
+                        else
+                                $term_list[] = $term;
+                        if ( !isset($has_children[$term->term_id]) )
+                                continue;
+                        $ancestors[ $term->term_id ] = 1;
+                        if ( $children = _get_term_children( $term->term_id, $terms, $taxonomy, $ancestors) )
+                                $term_list = array_merge($term_list, $children);
+                }
+        }
+        return $term_list;
+}
+/**
+ * Add count of children to parent count.
+ *
+ * Recalculates term counts by including items from child terms. Assumes all
+ * relevant children are already in the $terms argument.
+ *
+ * @access private
+ * @since 2.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param array  $terms    List of term IDs, passed by reference.
+ * @param string $taxonomy Term context.
+ */
+function _pad_term_counts( &$terms, $taxonomy ) {
+        global $wpdb;
+        // This function only works for hierarchical taxonomies like post categories.
+        if ( !is_taxonomy_hierarchical( $taxonomy ) )
+                return;
+        $term_hier = _get_term_hierarchy($taxonomy);
+        if ( empty($term_hier) )
+                return;
+        $term_items = array();
+        $terms_by_id = array();
+        $term_ids = array();
+        foreach ( (array) $terms as $key => $term ) {
+                $terms_by_id[$term->term_id] = & $terms[$key];
+                $term_ids[$term->term_taxonomy_id] = $term->term_id;
+        }
+        // Get the object and term ids and stick them in a lookup table.
+        $tax_obj = get_taxonomy($taxonomy);
+        $object_types = esc_sql($tax_obj->object_type);
+        $results = $wpdb->get_results("SELECT object_id, term_taxonomy_id FROM $wpdb->term_relationships INNER JOIN $wpdb->posts ON object_id = ID WHERE term_taxonomy_id IN (" . implode(',', array_keys($term_ids)) . ") AND post_type IN ('" . implode("', '", $object_types) . "') AND post_status = 'publish'");
+        foreach ( $results as $row ) {
+                $id = $term_ids[$row->term_taxonomy_id];
+                $term_items[$id][$row->object_id] = isset($term_items[$id][$row->object_id]) ? ++$term_items[$id][$row->object_id] : 1;
+        }
+        // Touch every ancestor's lookup row for each post in each term.
+        foreach ( $term_ids as $term_id ) {
+                $child = $term_id;
+                $ancestors = array();
+                while ( !empty( $terms_by_id[$child] ) && $parent = $terms_by_id[$child]->parent ) {
+                        $ancestors[] = $child;
+                        if ( !empty( $term_items[$term_id] ) )
+                                foreach ( $term_items[$term_id] as $item_id => $touches ) {
+                                        $term_items[$parent][$item_id] = isset($term_items[$parent][$item_id]) ? ++$term_items[$parent][$item_id]: 1;
+                                }
+                        $child = $parent;
+                        if ( in_array( $parent, $ancestors ) ) {
+                                break;
+                        }
+                }
+        }
+        // Transfer the touched cells.
+        foreach ( (array) $term_items as $id => $items )
+                if ( isset($terms_by_id[$id]) )
+                        $terms_by_id[$id]->count = count($items);
+}
+//
+// Default callbacks
+//
+/**
+ * Will update term count based on object types of the current taxonomy.
+ *
+ * Private function for the default callback for post_tag and category
+ * taxonomies.
+ *
+ * @access private
+ * @since 2.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param array  $terms    List of Term taxonomy IDs.
+ * @param object $taxonomy Current taxonomy object of terms.
+ */
+function _update_post_term_count( $terms, $taxonomy ) {
+        global $wpdb;
+        $object_types = (array) $taxonomy->object_type;
+        foreach ( $object_types as &$object_type )
+                list( $object_type ) = explode( ':', $object_type );
+        $object_types = array_unique( $object_types );
+        if ( false !== ( $check_attachments = array_search( 'attachment', $object_types ) ) ) {
+                unset( $object_types[ $check_attachments ] );
+                $check_attachments = true;
+        }
+        if ( $object_types )
+                $object_types = esc_sql( array_filter( $object_types, 'post_type_exists' ) );
+        foreach ( (array) $terms as $term ) {
+                $count = 0;
+                // Attachments can be 'inherit' status, we need to base count off the parent's status if so.
+                if ( $check_attachments )
+                        $count += (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_relationships, $wpdb->posts p1 WHERE p1.ID = $wpdb->term_relationships.object_id AND ( post_status = 'publish' OR ( post_status = 'inherit' AND post_parent > 0 AND ( SELECT post_status FROM $wpdb->posts WHERE ID = p1.post_parent ) = 'publish' ) ) AND post_type = 'attachment' AND term_taxonomy_id = %d", $term ) );
+                if ( $object_types )
+                        $count += (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_relationships, $wpdb->posts WHERE $wpdb->posts.ID = $wpdb->term_relationships.object_id AND post_status = 'publish' AND post_type IN ('" . implode("', '", $object_types ) . "') AND term_taxonomy_id = %d", $term ) );
+                /** This action is documented in wp-includes/taxonomy.php */
+                do_action( 'edit_term_taxonomy', $term, $taxonomy->name );
+                $wpdb->update( $wpdb->term_taxonomy, compact( 'count' ), array( 'term_taxonomy_id' => $term ) );
+                /** This action is documented in wp-includes/taxonomy.php */
+                do_action( 'edited_term_taxonomy', $term, $taxonomy->name );
+        }
+}
+/**
+ * Will update term count based on number of objects.
+ *
+ * Default callback for the 'link_category' taxonomy.
+ *
+ * @since 3.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param array  $terms    List of term taxonomy IDs.
+ * @param object $taxonomy Current taxonomy object of terms.
+ */
+function _update_generic_term_count( $terms, $taxonomy ) {
+        global $wpdb;
+        foreach ( (array) $terms as $term ) {
+                $count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_relationships WHERE term_taxonomy_id = %d", $term ) );
+                /** This action is documented in wp-includes/taxonomy.php */
+                do_action( 'edit_term_taxonomy', $term, $taxonomy->name );
+                $wpdb->update( $wpdb->term_taxonomy, compact( 'count' ), array( 'term_taxonomy_id' => $term ) );
+                /** This action is documented in wp-includes/taxonomy.php */
+                do_action( 'edited_term_taxonomy', $term, $taxonomy->name );
+        }
+}
+/**
+ * Create a new term for a term_taxonomy item that currently shares its term
+ * with another term_taxonomy.
+ *
+ * @ignore
+ * @since 4.2.0
+ * @since 4.3.0 Introduced `$record` parameter. Also, `$term_id` and
+ *              `$term_taxonomy_id` can now accept objects.
+ *
+ * @global wpdb $wpdb
+ *
+ * @param int|object $term_id          ID of the shared term, or the shared term object.
+ * @param int|object $term_taxonomy_id ID of the term_taxonomy item to receive a new term, or the term_taxonomy object
+ *                                     (corresponding to a row from the term_taxonomy table).
+ * @param bool       $record           Whether to record data about the split term in the options table. The recording
+ *                                     process has the potential to be resource-intensive, so during batch operations
+ *                                     it can be beneficial to skip inline recording and do it just once, after the
+ *                                     batch is processed. Only set this to `false` if you know what you are doing.
+ *                                     Default: true.
+ * @return int|WP_Error When the current term does not need to be split (or cannot be split on the current
+ *                      database schema), `$term_id` is returned. When the term is successfully split, the
+ *                      new term_id is returned. A WP_Error is returned for miscellaneous errors.
+ */
+function _split_shared_term( $term_id, $term_taxonomy_id, $record = true ) {
+        global $wpdb;
+        if ( is_object( $term_id ) ) {
+                $shared_term = $term_id;
+                $term_id = intval( $shared_term->term_id );
+        }
+        if ( is_object( $term_taxonomy_id ) ) {
+                $term_taxonomy = $term_taxonomy_id;
+                $term_taxonomy_id = intval( $term_taxonomy->term_taxonomy_id );
+        }
+        // If there are no shared term_taxonomy rows, there's nothing to do here.
+        $shared_tt_count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_taxonomy tt WHERE tt.term_id = %d AND tt.term_taxonomy_id != %d", $term_id, $term_taxonomy_id ) );
+        if ( ! $shared_tt_count ) {
+                return $term_id;
+        }
+        /*
+         * Verify that the term_taxonomy_id passed to the function is actually associated with the term_id.
+         * If there's a mismatch, it may mean that the term is already split. Return the actual term_id from the db.
+         */
+        $check_term_id = $wpdb->get_var( $wpdb->prepare( "SELECT term_id FROM $wpdb->term_taxonomy WHERE term_taxonomy_id = %d", $term_taxonomy_id ) );
+        if ( $check_term_id != $term_id ) {
+                return $check_term_id;
+        }
+        // Pull up data about the currently shared slug, which we'll use to populate the new one.
+        if ( empty( $shared_term ) ) {
+                $shared_term = $wpdb->get_row( $wpdb->prepare( "SELECT t.* FROM $wpdb->terms t WHERE t.term_id = %d", $term_id ) );
+        }
+        $new_term_data = array(
+                'name' => $shared_term->name,
+                'slug' => $shared_term->slug,
+                'term_group' => $shared_term->term_group,
+        );
+        if ( false === $wpdb->insert( $wpdb->terms, $new_term_data ) ) {
+                return new WP_Error( 'db_insert_error', __( 'Could not split shared term.' ), $wpdb->last_error );
+        }
+        $new_term_id = (int) $wpdb->insert_id;
+        // Update the existing term_taxonomy to point to the newly created term.
+        $wpdb->update( $wpdb->term_taxonomy,
+                array( 'term_id' => $new_term_id ),
+                array( 'term_taxonomy_id' => $term_taxonomy_id )
+        );
+        // Reassign child terms to the new parent.
+        if ( empty( $term_taxonomy ) ) {
+                $term_taxonomy = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->term_taxonomy WHERE term_taxonomy_id = %d", $term_taxonomy_id ) );
+        }
+        $children_tt_ids = $wpdb->get_col( $wpdb->prepare( "SELECT term_taxonomy_id FROM $wpdb->term_taxonomy WHERE parent = %d AND taxonomy = %s", $term_id, $term_taxonomy->taxonomy ) );
+        if ( ! empty( $children_tt_ids ) ) {
+                foreach ( $children_tt_ids as $child_tt_id ) {
+                        $wpdb->update( $wpdb->term_taxonomy,
+                                array( 'parent' => $new_term_id ),
+                                array( 'term_taxonomy_id' => $child_tt_id )
+                        );
+                        clean_term_cache( $term_id, $term_taxonomy->taxonomy );
+                }
+        } else {
+                // If the term has no children, we must force its taxonomy cache to be rebuilt separately.
+                clean_term_cache( $new_term_id, $term_taxonomy->taxonomy );
+        }
+        // Clean the cache for term taxonomies formerly shared with the current term.
+        $shared_term_taxonomies = $wpdb->get_row( $wpdb->prepare( "SELECT taxonomy FROM $wpdb->term_taxonomy WHERE term_id = %d", $term_id ) );
+        if ( $shared_term_taxonomies ) {
+                foreach ( $shared_term_taxonomies as $shared_term_taxonomy ) {
+                        clean_term_cache( $term_id, $shared_term_taxonomy );
+                }
+        }
+        // Keep a record of term_ids that have been split, keyed by old term_id. See {@see wp_get_split_term()}.
+        if ( $record ) {
+                $split_term_data = get_option( '_split_terms', array() );
+                if ( ! isset( $split_term_data[ $term_id ] ) ) {
+                        $split_term_data[ $term_id ] = array();
+                }
+                $split_term_data[ $term_id ][ $term_taxonomy->taxonomy ] = $new_term_id;
+                update_option( '_split_terms', $split_term_data );
+        }
+        /**
+         * Fires after a previously shared taxonomy term is split into two separate terms.
+         *
+         * @since 4.2.0
+         *
+         * @param int    $term_id          ID of the formerly shared term.
+         * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
+         * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
+         * @param string $taxonomy         Taxonomy for the split term.
+         */
+        do_action( 'split_shared_term', $term_id, $new_term_id, $term_taxonomy_id, $term_taxonomy->taxonomy );
+        return $new_term_id;
+}
+/**
+ * Splits a batch of shared taxonomy terms.
+ *
+ * @since 4.3.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ */
+function _wp_batch_split_terms() {
+        global $wpdb;
+        $lock_name = 'term_split.lock';
+        // Try to lock.
+        $lock_result = $wpdb->query( $wpdb->prepare( "INSERT IGNORE INTO `$wpdb->options` ( `option_name`, `option_value`, `autoload` ) VALUES (%s, %s, 'no') /* LOCK */", $lock_name, time() ) );
+        if ( ! $lock_result ) {
+                $lock_result = get_option( $lock_name );
+                // Bail if we were unable to create a lock, or if the existing lock is still valid.
+                if ( ! $lock_result || ( $lock_result > ( time() - HOUR_IN_SECONDS ) ) ) {
+                        wp_schedule_single_event( time() + ( 5 * MINUTE_IN_SECONDS ), 'wp_split_shared_term_batch' );
+                        return;
+                }
+        }
+        // Update the lock, as by this point we've definitely got a lock, just need to fire the actions.
+        update_option( $lock_name, time() );
+        // Get a list of shared terms (those with more than one associated row in term_taxonomy).
+        $shared_terms = $wpdb->get_results(
+                "SELECT tt.term_id, t.*, count(*) as term_tt_count FROM {$wpdb->term_taxonomy} tt
+                 LEFT JOIN {$wpdb->terms} t ON t.term_id = tt.term_id
+                 GROUP BY t.term_id
+                 HAVING term_tt_count > 1
+                 LIMIT 10"
+        );
+        // No more terms, we're done here.
+        if ( ! $shared_terms ) {
+                update_option( 'finished_splitting_shared_terms', true );
+                delete_option( $lock_name );
+                return;
+        }
+        // Shared terms found? We'll need to run this script again.
+        wp_schedule_single_event( time() + ( 2 * MINUTE_IN_SECONDS ), 'wp_split_shared_term_batch' );
+        // Rekey shared term array for faster lookups.
+        $_shared_terms = array();
+        foreach ( $shared_terms as $shared_term ) {
+                $term_id = intval( $shared_term->term_id );
+                $_shared_terms[ $term_id ] = $shared_term;
+        }
+        $shared_terms = $_shared_terms;
+        // Get term taxonomy data for all shared terms.
+        $shared_term_ids = implode( ',', array_keys( $shared_terms ) );
+        $shared_tts = $wpdb->get_results( "SELECT * FROM {$wpdb->term_taxonomy} WHERE `term_id` IN ({$shared_term_ids})" );
+        // Split term data recording is slow, so we do it just once, outside the loop.
+        $split_term_data = get_option( '_split_terms', array() );
+        $skipped_first_term = $taxonomies = array();
+        foreach ( $shared_tts as $shared_tt ) {
+                $term_id = intval( $shared_tt->term_id );
+                // Don't split the first tt belonging to a given term_id.
+                if ( ! isset( $skipped_first_term[ $term_id ] ) ) {
+                        $skipped_first_term[ $term_id ] = 1;
+                        continue;
+                }
+                if ( ! isset( $split_term_data[ $term_id ] ) ) {
+                        $split_term_data[ $term_id ] = array();
+                }
+                // Keep track of taxonomies whose hierarchies need flushing.
+                if ( ! isset( $taxonomies[ $shared_tt->taxonomy ] ) ) {
+                        $taxonomies[ $shared_tt->taxonomy ] = 1;
+                }
+                // Split the term.
+                $split_term_data[ $term_id ][ $shared_tt->taxonomy ] = _split_shared_term( $shared_terms[ $term_id ], $shared_tt, false );
+        }
+        // Rebuild the cached hierarchy for each affected taxonomy.
+        foreach ( array_keys( $taxonomies ) as $tax ) {
+                delete_option( "{$tax}_children" );
+                _get_term_hierarchy( $tax );
+        }
+        update_option( '_split_terms', $split_term_data );
+        delete_option( $lock_name );
+}
+/**
+ * In order to avoid the _wp_batch_split_terms() job being accidentally removed,
+ * check that it's still scheduled while we haven't finished splitting terms.
+ *
+ * @ignore
+ * @since 4.3.0
+ */
+function _wp_check_for_scheduled_split_terms() {
+        if ( ! get_option( 'finished_splitting_shared_terms' ) && ! wp_next_scheduled( 'wp_split_shared_term_batch' ) ) {
+                wp_schedule_single_event( time() + MINUTE_IN_SECONDS, 'wp_split_shared_term_batch' );
+        }
+}
+/**
+ * Check default categories when a term gets split to see if any of them need to be updated.
+ *
+ * @ignore
+ * @since 4.2.0
+ *
+ * @param int    $term_id          ID of the formerly shared term.
+ * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
+ * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
+ * @param string $taxonomy         Taxonomy for the split term.
+ */
+function _wp_check_split_default_terms( $term_id, $new_term_id, $term_taxonomy_id, $taxonomy ) {
+        if ( 'category' != $taxonomy ) {
+                return;
+        }
+        foreach ( array( 'default_category', 'default_link_category', 'default_email_category' ) as $option ) {
+                if ( $term_id == get_option( $option, -1 ) ) {
+                        update_option( $option, $new_term_id );
+                }
+        }
+}
+/**
+ * Check menu items when a term gets split to see if any of them need to be updated.
+ *
+ * @ignore
+ * @since 4.2.0
+ *
+ * @global wpdb $wpdb
+ *
+ * @param int    $term_id          ID of the formerly shared term.
+ * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
+ * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
+ * @param string $taxonomy         Taxonomy for the split term.
+ */
+function _wp_check_split_terms_in_menus( $term_id, $new_term_id, $term_taxonomy_id, $taxonomy ) {
+        global $wpdb;
+        $post_ids = $wpdb->get_col( $wpdb->prepare(
+                "SELECT m1.post_id
+                FROM {$wpdb->postmeta} AS m1
+                        INNER JOIN {$wpdb->postmeta} AS m2 ON ( m2.post_id = m1.post_id )
+                        INNER JOIN {$wpdb->postmeta} AS m3 ON ( m3.post_id = m1.post_id )
+                WHERE ( m1.meta_key = '_menu_item_type' AND m1.meta_value = 'taxonomy' )
+                        AND ( m2.meta_key = '_menu_item_object' AND m2.meta_value = '%s' )
+                        AND ( m3.meta_key = '_menu_item_object_id' AND m3.meta_value = %d )",
+                $taxonomy,
+                $term_id
+        ) );
+        if ( $post_ids ) {
+                foreach ( $post_ids as $post_id ) {
+                        update_post_meta( $post_id, '_menu_item_object_id', $new_term_id, $term_id );
+                }
+        }
+}
+/**
+ * If the term being split is a nav_menu, change associations.
+ *
+ * @ignore
+ * @since 4.3.0
+ *
+ * @global wpdb $wpdb
+ *
+ * @param int    $term_id          ID of the formerly shared term.
+ * @param int    $new_term_id      ID of the new term created for the $term_taxonomy_id.
+ * @param int    $term_taxonomy_id ID for the term_taxonomy row affected by the split.
+ * @param string $taxonomy         Taxonomy for the split term.
+ */
+function _wp_check_split_nav_menu_terms( $term_id, $new_term_id, $term_taxonomy_id, $taxonomy ) {
+        if ( 'nav_menu' !== $taxonomy ) {
+                return;
+        }
+        // Update menu locations.
+        $locations = get_nav_menu_locations();
+        foreach ( $locations as $location => $menu_id ) {
+                if ( $term_id == $menu_id ) {
+                        $locations[ $location ] = $new_term_id;
+                }
+        }
+        set_theme_mod( 'nav_menu_locations', $locations );
+}
+/**
+ * Get data about terms that previously shared a single term_id, but have since been split.
+ *
+ * @since 4.2.0
+ *
+ * @param int $old_term_id Term ID. This is the old, pre-split term ID.
+ * @return array Array of new term IDs, keyed by taxonomy.
+ */
+function wp_get_split_terms( $old_term_id ) {
+        $split_terms = get_option( '_split_terms', array() );
+        $terms = array();
+        if ( isset( $split_terms[ $old_term_id ] ) ) {
+                $terms = $split_terms[ $old_term_id ];
+        }
+        return $terms;
+}
+/**
+ * Get the new term ID corresponding to a previously split term.
+ *
+ * @since 4.2.0
+ *
+ * @param int    $old_term_id Term ID. This is the old, pre-split term ID.
+ * @param string $taxonomy    Taxonomy that the term belongs to.
+ * @return int|false If a previously split term is found corresponding to the old term_id and taxonomy,
+ *                   the new term_id will be returned. If no previously split term is found matching
+ *                   the parameters, returns false.
+ */
+function wp_get_split_term( $old_term_id, $taxonomy ) {
+        $split_terms = wp_get_split_terms( $old_term_id );
+        $term_id = false;
+        if ( isset( $split_terms[ $taxonomy ] ) ) {
+                $term_id = (int) $split_terms[ $taxonomy ];
+        }
+        return $term_id;
+}
+/**
+ * Generate a permalink for a taxonomy term archive.
+ *
+ * @since 2.5.0
+ *
+ * @global WP_Rewrite $wp_rewrite
+ *
+ * @param object|int|string $term     The term object, ID, or slug whose link will be retrieved.
+ * @param string            $taxonomy Optional. Taxonomy. Default empty.
+ * @return string|WP_Error HTML link to taxonomy term archive on success, WP_Error if term does not exist.
+ */
+function get_term_link( $term, $taxonomy = '' ) {
+        global $wp_rewrite;
+        if ( !is_object($term) ) {
+                if ( is_int( $term ) ) {
+                        $term = get_term( $term, $taxonomy );
+                } else {
+                        $term = get_term_by( 'slug', $term, $taxonomy );
+                }
+        }
+        if ( !is_object($term) )
+                $term = new WP_Error('invalid_term', __('Empty Term'));
+        if ( is_wp_error( $term ) )
+                return $term;
+        $taxonomy = $term->taxonomy;
+        $termlink = $wp_rewrite->get_extra_permastruct($taxonomy);
+        $slug = $term->slug;
+        $t = get_taxonomy($taxonomy);
+        if ( empty($termlink) ) {
+                if ( 'category' == $taxonomy )
+                        $termlink = '?cat=' . $term->term_id;
+                elseif ( $t->query_var )
+                        $termlink = "?$t->query_var=$slug";
+                else
+                        $termlink = "?taxonomy=$taxonomy&term=$slug";
+                $termlink = home_url($termlink);
+        } else {
+                if ( $t->rewrite['hierarchical'] ) {
+                        $hierarchical_slugs = array();
+                        $ancestors = get_ancestors( $term->term_id, $taxonomy, 'taxonomy' );
+                        foreach ( (array)$ancestors as $ancestor ) {
+                                $ancestor_term = get_term($ancestor, $taxonomy);
+                                $hierarchical_slugs[] = $ancestor_term->slug;
+                        }
+                        $hierarchical_slugs = array_reverse($hierarchical_slugs);
+                        $hierarchical_slugs[] = $slug;
+                        $termlink = str_replace("%$taxonomy%", implode('/', $hierarchical_slugs), $termlink);
+                } else {
+                        $termlink = str_replace("%$taxonomy%", $slug, $termlink);
+                }
+                $termlink = home_url( user_trailingslashit($termlink, 'category') );
+        }
+        // Back Compat filters.
+        if ( 'post_tag' == $taxonomy ) {
+                /**
+                 * Filter the tag link.
+                 *
+                 * @since 2.3.0
+                 * @deprecated 2.5.0 Use 'term_link' instead.
+                 *
+                 * @param string $termlink Tag link URL.
+                 * @param int    $term_id  Term ID.
+                 */
+                $termlink = apply_filters( 'tag_link', $termlink, $term->term_id );
+        } elseif ( 'category' == $taxonomy ) {
+                /**
+                 * Filter the category link.
+                 *
+                 * @since 1.5.0
+                 * @deprecated 2.5.0 Use 'term_link' instead.
+                 *
+                 * @param string $termlink Category link URL.
+                 * @param int    $term_id  Term ID.
+                 */
+                $termlink = apply_filters( 'category_link', $termlink, $term->term_id );
+        }
+        /**
+         * Filter the term link.
+         *
+         * @since 2.5.0
+         *
+         * @param string $termlink Term link URL.
+         * @param object $term     Term object.
+         * @param string $taxonomy Taxonomy slug.
+         */
+        return apply_filters( 'term_link', $termlink, $term, $taxonomy );
+}
+/**
+ * Display the taxonomies of a post with available options.
+ *
+ * This function can be used within the loop to display the taxonomies for a
+ * post without specifying the Post ID. You can also use it outside the Loop to
+ * display the taxonomies for a specific post.
+ *
+ * @since 2.5.0
+ *
+ * @param array $args {
+ *     Arguments about which post to use and how to format the output. Shares all of the arguments
+ *     supported by get_the_taxonomies(), in addition to the following.
+ *
+ *     @type  int|WP_Post $post   Post ID or object to get taxonomies of. Default current post.
+ *     @type  string      $before Displays before the taxonomies. Default empty string.
+ *     @type  string      $sep    Separates each taxonomy. Default is a space.
+ *     @type  string      $after  Displays after the taxonomies. Default empty string.
+ * }
+ * @param array $args See {@link get_the_taxonomies()} for a description of arguments and their defaults.
+ */
+function the_taxonomies( $args = array() ) {
+        $defaults = array(
+                'post' => 0,
+                'before' => '',
+                'sep' => ' ',
+                'after' => '',
+        );
+        $r = wp_parse_args( $args, $defaults );
+        echo $r['before'] . join( $r['sep'], get_the_taxonomies( $r['post'], $r ) ) . $r['after'];
+}
+/**
+ * Retrieve all taxonomies associated with a post.
+ *
+ * This function can be used within the loop. It will also return an array of
+ * the taxonomies with links to the taxonomy and name.
+ *
+ * @since 2.5.0
+ *
+ * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
+ * @param array $args {
+ *     Optional. Arguments about how to format the list of taxonomies. Default empty array.
+ *
+ *     @type string $template      Template for displaying a taxonomy label and list of terms.
+ *                                 Default is "Label: Terms."
+ *     @type string $term_template Template for displaying a single term in the list. Default is the term name
+ *                                 linked to its archive.
+ * }
+ * @return array List of taxonomies.
+ */
+function get_the_taxonomies( $post = 0, $args = array() ) {
+        $post = get_post( $post );
+        $args = wp_parse_args( $args, array(
+                /* translators: %s: taxonomy label, %l: list of terms formatted as per $term_template */
+                'template' => __( '%s: %l.' ),
+                'term_template' => '<a href="%1$s">%2$s</a>',
+        ) );
+        $taxonomies = array();
+        if ( ! $post ) {
+                return $taxonomies;
+        }
+        foreach ( get_object_taxonomies( $post ) as $taxonomy ) {
+                $t = (array) get_taxonomy( $taxonomy );
+                if ( empty( $t['label'] ) ) {
+                        $t['label'] = $taxonomy;
+                }
+                if ( empty( $t['args'] ) ) {
+                        $t['args'] = array();
+                }
+                if ( empty( $t['template'] ) ) {
+                        $t['template'] = $args['template'];
+                }
+                if ( empty( $t['term_template'] ) ) {
+                        $t['term_template'] = $args['term_template'];
+                }
+                $terms = get_object_term_cache( $post->ID, $taxonomy );
+                if ( false === $terms ) {
+                        $terms = wp_get_object_terms( $post->ID, $taxonomy, $t['args'] );
+                }
+                $links = array();
+                foreach ( $terms as $term ) {
+                        $links[] = wp_sprintf( $t['term_template'], esc_attr( get_term_link( $term ) ), $term->name );
+                }
+                if ( $links ) {
+                        $taxonomies[$taxonomy] = wp_sprintf( $t['template'], $t['label'], $links, $terms );
+                }
+        }
+        return $taxonomies;
+}
+/**
+ * Retrieve all taxonomies of a post with just the names.
+ *
+ * @since 2.5.0
+ *
+ * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
+ * @return array
+ */
+function get_post_taxonomies( $post = 0 ) {
+        $post = get_post( $post );
+        return get_object_taxonomies($post);
+}
+/**
+ * Determine if the given object is associated with any of the given terms.
+ *
+ * The given terms are checked against the object's terms' term_ids, names and slugs.
+ * Terms given as integers will only be checked against the object's terms' term_ids.
+ * If no terms are given, determines if object is associated with any terms in the given taxonomy.
+ *
+ * @since 2.7.0
+ *
+ * @param int              $object_id ID of the object (post ID, link ID, ...).
+ * @param string           $taxonomy  Single taxonomy name.
+ * @param int|string|array $terms     Optional. Term term_id, name, slug or array of said. Default null.
+ * @return bool|WP_Error WP_Error on input error.
+ */
+function is_object_in_term( $object_id, $taxonomy, $terms = null ) {
+        if ( !$object_id = (int) $object_id )
+                return new WP_Error( 'invalid_object', __( 'Invalid object ID' ) );
+        $object_terms = get_object_term_cache( $object_id, $taxonomy );
+        if ( false === $object_terms )
+                 $object_terms = wp_get_object_terms( $object_id, $taxonomy );
+        if ( is_wp_error( $object_terms ) )
+                return $object_terms;
+        if ( empty( $object_terms ) )
+                return false;
+        if ( empty( $terms ) )
+                return ( !empty( $object_terms ) );
+        $terms = (array) $terms;
+        if ( $ints = array_filter( $terms, 'is_int' ) )
+                $strs = array_diff( $terms, $ints );
+        else
+                $strs =& $terms;
+        foreach ( $object_terms as $object_term ) {
+                // If term is an int, check against term_ids only.
+                if ( $ints && in_array( $object_term->term_id, $ints ) ) {
+                        return true;
+                }
+                if ( $strs ) {
+                        // Only check numeric strings against term_id, to avoid false matches due to type juggling.
+                        $numeric_strs = array_map( 'intval', array_filter( $strs, 'is_numeric' ) );
+                        if ( in_array( $object_term->term_id, $numeric_strs, true ) ) {
+                                return true;
+                        }
+                        if ( in_array( $object_term->name, $strs ) ) return true;
+                        if ( in_array( $object_term->slug, $strs ) ) return true;
+                }
+        }
+        return false;
+}
+/**
+ * Determine if the given object type is associated with the given taxonomy.
+ *
+ * @since 3.0.0
+ *
+ * @param string $object_type Object type string.
+ * @param string $taxonomy    Single taxonomy name.
+ * @return bool True if object is associated with the taxonomy, otherwise false.
+ */
+function is_object_in_taxonomy( $object_type, $taxonomy ) {
+        $taxonomies = get_object_taxonomies( $object_type );
+        if ( empty( $taxonomies ) ) {
+                return false;
+        }
+        return in_array( $taxonomy, $taxonomies );
+}
+/**
+ * Get an array of ancestor IDs for a given object.
+ *
+ * @since 3.1.0
+ * @since 4.1.0 Introduced the `$resource_type` argument.
+ *
+ * @param int    $object_id     Optional. The ID of the object. Default 0.
+ * @param string $object_type   Optional. The type of object for which we'll be retrieving
+ *                              ancestors. Accepts a post type or a taxonomy name. Default empty.
+ * @param string $resource_type Optional. Type of resource $object_type is. Accepts 'post_type'
+ *                              or 'taxonomy'. Default empty.
+ * @return array An array of ancestors from lowest to highest in the hierarchy.
+ */
+function get_ancestors( $object_id = 0, $object_type = '', $resource_type = '' ) {
+        $object_id = (int) $object_id;
+        $ancestors = array();
+        if ( empty( $object_id ) ) {
+                /** This filter is documented in wp-includes/taxonomy.php */
+                return apply_filters( 'get_ancestors', $ancestors, $object_id, $object_type, $resource_type );
+        }
+        if ( ! $resource_type ) {
+                if ( is_taxonomy_hierarchical( $object_type ) ) {
+                        $resource_type = 'taxonomy';
+                } elseif ( post_type_exists( $object_type ) ) {
+                        $resource_type = 'post_type';
+                }
+        }
+        if ( 'taxonomy' === $resource_type ) {
+                $term = get_term($object_id, $object_type);
+                while ( ! is_wp_error($term) && ! empty( $term->parent ) && ! in_array( $term->parent, $ancestors ) ) {
+                        $ancestors[] = (int) $term->parent;
+                        $term = get_term($term->parent, $object_type);
+                }
+        } elseif ( 'post_type' === $resource_type ) {
+                $ancestors = get_post_ancestors($object_id);
+        }
+        /**
+         * Filter a given object's ancestors.
+         *
+         * @since 3.1.0
+         * @since 4.1.1 Introduced the `$resource_type` parameter.
+         *
+         * @param array  $ancestors     An array of object ancestors.
+         * @param int    $object_id     Object ID.
+         * @param string $object_type   Type of object.
+         * @param string $resource_type Type of resource $object_type is.
+         */
+        return apply_filters( 'get_ancestors', $ancestors, $object_id, $object_type, $resource_type );
+}
+/**
+ * Returns the term's parent's term_ID.
+ *
+ * @since 3.1.0
+ *
+ * @param int    $term_id  Term ID.
+ * @param string $taxonomy Taxonomy name.
+ * @return int|false False on error.
+ */
+function wp_get_term_taxonomy_parent_id( $term_id, $taxonomy ) {
+        $term = get_term( $term_id, $taxonomy );
+        if ( ! $term || is_wp_error( $term ) ) {
+                return false;
+        }
+        return (int) $term->parent;
+}
+/**
+ * Checks the given subset of the term hierarchy for hierarchy loops.
+ * Prevents loops from forming and breaks those that it finds.
+ *
+ * Attached to the {@see 'wp_update_term_parent'} filter.
+ *
+ * @since 3.1.0
+ *
+ * @param int    $parent   `term_id` of the parent for the term we're checking.
+ * @param int    $term_id  The term we're checking.
+ * @param string $taxonomy The taxonomy of the term we're checking.
+ *
+ * @return int The new parent for the term.
+ */
+function wp_check_term_hierarchy_for_loops( $parent, $term_id, $taxonomy ) {
+        // Nothing fancy here - bail
+        if ( !$parent )
+                return 0;
+        // Can't be its own parent.
+        if ( $parent == $term_id )
+                return 0;
+        // Now look for larger loops.
+        if ( !$loop = wp_find_hierarchy_loop( 'wp_get_term_taxonomy_parent_id', $term_id, $parent, array( $taxonomy ) ) )
+                return $parent; // No loop
+        // Setting $parent to the given value causes a loop.
+        if ( isset( $loop[$term_id] ) )
+                return 0;
+        // There's a loop, but it doesn't contain $term_id. Break the loop.
+        foreach ( array_keys( $loop ) as $loop_member )
+                wp_update_term( $loop_member, $taxonomy, array( 'parent' => 0 ) );
+        return $parent;
+}
+require_once( ABSPATH . WPINC . '/taxonomy-functions.php' );
+require_once( ABSPATH . WPINC . '/class-wp-tax-query.php' );

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Changeset 33760 for trunk/src/wp-includes/taxonomy.php

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trunk/src/wp-includes/taxonomy.php

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