/wp-includes/taxonomy.php

<?php

/**

 * Taxonomy API

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 */



//

// Taxonomy Registration

//



/**

 * Creates the initial taxonomies when 'init' action is fired.

 */

function create_initial_taxonomies() {

	global $wp_rewrite;



	register_taxonomy( 'category', 'post', array(

		'hierarchical' => true,

	 	'update_count_callback' => '_update_post_term_count',

		'query_var' => 'category_name',

		'rewrite' => did_action( 'init' ) ? array(

					'hierarchical' => true,

					'slug' => get_option('category_base') ? get_option('category_base') : 'category',

					'with_front' => ( get_option('category_base') && ! $wp_rewrite->using_index_permalinks() ) ? false : true ) : false,

		'public' => true,

		'show_ui' => true,

		'_builtin' => true,

	) );



	register_taxonomy( 'post_tag', 'post', array(

	 	'hierarchical' => false,

		'update_count_callback' => '_update_post_term_count',

		'query_var' => 'tag',

		'rewrite' => did_action( 'init' ) ? array(

					'slug' => get_option('tag_base') ? get_option('tag_base') : 'tag',

					'with_front' => ( get_option('tag_base') && ! $wp_rewrite->using_index_permalinks() ) ? false : true ) : false,

		'public' => true,

		'show_ui' => 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,

		),

		'query_var' => false,

		'rewrite' => false,

		'public' => false,

		'show_ui' => false,

		'_builtin' => true,

	) );



	$rewrite = false;

	if ( did_action( 'init' ) ) {

		$rewrite = apply_filters( 'post_format_rewrite_base', 'type' );

		$rewrite = $rewrite ? array( 'slug' => $rewrite ) : false;

	}



	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,

		'show_ui' => false,

		'_builtin' => true,

		'show_in_nav_menus' => false,

	) );

}

add_action( 'init', 'create_initial_taxonomies', 0 ); // highest priority



/**

 * Get a list of registered taxonomy objects.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 3.0.0

 * @uses $wp_taxonomies

 * @see register_taxonomy

 *

 * @param array $args An array of key => value arguments to match against the taxonomy objects.

 * @param string $output The type of output to return, either taxonomy 'names' or 'objects'. 'names' is the default.

 * @param string $operator The logical operation to perform. 'or' means only one element

 *  from the array needs to match; 'and' means all elements must match. The default is '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.

 *

 * <code><?php $taxonomies = get_object_taxonomies('post'); ?></code> Should

 * result in <code>Array('category', 'post_tag')</code>

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses $wp_taxonomies

 *

 * @param array|string|object $object Name of the type of taxonomy object, or an object (row from posts)

 * @param string $output The type of output to return, either taxonomy 'names' or 'objects'. 'names' is the default.

 * @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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses $wp_taxonomies

 * @uses taxonomy_exists() Checks whether taxonomy exists

 *

 * @param string $taxonomy Name of taxonomy object to return

 * @return object|bool 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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 3.0.0

 *

 * @uses $wp_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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses taxonomy_exists() Checks whether taxonomy exists

 * @uses get_taxonomy() Used to get the taxonomy object

 *

 * @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.

 *

 * hierarchical - has some defined purpose at other parts of the API and is a

 * boolean value.

 *

 * update_count_callback - works much like a hook, in that it will be called

 * when the count is updated.

 *

 * rewrite - false to prevent rewrite, or array('slug'=>$slug) to customize

 * permastruct; default will use $taxonomy as slug.

 *

 * query_var - false to prevent queries, or string to customize query var

 * (?$query_var=$term); default will use $taxonomy as query var.

 *

 * public - If the taxonomy should be publically queryable; //@TODO not implemented.

 * defaults to true.

 *

 * show_ui - If the WordPress UI admin tags UI should apply to this taxonomy;

 * defaults to public.

 *

 * show_in_nav_menus - true makes this taxonomy available for selection in navigation menus.

 * Defaults to public.

 *

 * show_tagcloud - false to prevent the taxonomy being listed in the Tag Cloud Widget;

 * defaults to show_ui which defalts to public.

 *

 * labels - An array of labels for this taxonomy. You can see accepted values in {@link get_taxonomy_labels()}. By default tag labels are used for non-hierarchical types and category labels for hierarchical ones.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 * @uses $wp_taxonomies Inserts new taxonomy object into the list

 * @uses $wp_rewrite Adds rewrite tags and permastructs

 * @uses $wp Adds query vars

 *

 * @param string $taxonomy Name of taxonomy object

 * @param array|string $object_type Name of the object type for the taxonomy object.

 * @param array|string $args See above description for the two keys values.

 */

function register_taxonomy( $taxonomy, $object_type, $args = array() ) {

	global $wp_taxonomies, $wp_rewrite, $wp;



	if ( ! is_array($wp_taxonomies) )

		$wp_taxonomies = array();



	$defaults = array(	'hierarchical' => false,

						'update_count_callback' => '',

						'rewrite' => true,

						'query_var' => $taxonomy,

						'public' => true,

						'show_ui' => null,

						'show_tagcloud' => null,

						'_builtin' => false,

						'labels' => array(),

						'capabilities' => array(),

						'show_in_nav_menus' => null,

					);

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



	if ( false !== $args['query_var'] && !empty($wp) ) {

		if ( true === $args['query_var'] )

			$args['query_var'] = $taxonomy;

		$args['query_var'] = sanitize_title_with_dashes($args['query_var']);

		$wp->add_query_var($args['query_var']);

	}



	if ( false !== $args['rewrite'] && '' != get_option('permalink_structure') ) {

		$args['rewrite'] = wp_parse_args($args['rewrite'], array(

			'slug' => sanitize_title_with_dashes($taxonomy),

			'with_front' => true,

			'hierarchical' => false

		));



		if ( $args['hierarchical'] && $args['rewrite']['hierarchical'] )

			$tag = '(.+?)';

		else

			$tag = '([^/]+)';



		$wp_rewrite->add_rewrite_tag("%$taxonomy%", $tag, $args['query_var'] ? "{$args['query_var']}=" : "taxonomy=$taxonomy&term=");

		$wp_rewrite->add_permastruct($taxonomy, "{$args['rewrite']['slug']}/%$taxonomy%", $args['rewrite']['with_front']);

	}



	if ( is_null($args['show_ui']) )

		$args['show_ui'] = $args['public'];



	// Whether to show this type in nav-menus.php. Defaults to the setting for public.

	if ( null === $args['show_in_nav_menus'] )

		$args['show_in_nav_menus'] = $args['public'];



	if ( is_null($args['show_tagcloud']) )

		$args['show_tagcloud'] = $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;



	$wp_taxonomies[$taxonomy] = (object) $args;



	// register callback handling for metabox

 	add_filter('wp_ajax_add-' . $taxonomy, '_wp_ajax_add_hierarchical_term');

}



/**

 * 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 overriden by $tax->label. Default is Post Tags/Categories

 * - singular_name - name for one object of this taxonomy. Default is Post 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 <code>parent_item</code>, but with colon <code>:</code> in the end

 * - edit_item - Default is Edit Tag/Edit 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.

 *

 * Above, the first default value is for non-hierarchical taxonomies (like tags) and the second one is for hierarchical taxonomies (like categories.)

 *

 * @since 3.0.0

 * @param object $tax Taxonomy object

 * @return object object with all the labels as member variables

 */



function get_taxonomy_labels( $tax ) {

	if ( isset( $tax->helps ) && empty( $tax->labels['separate_items_with_commas'] ) )

		$tax->labels['separate_items_with_commas'] = $tax->helps;



	$nohier_vs_hier_defaults = array(

		'name' => array( _x( 'Post Tags', 'taxonomy general name' ), _x( 'Categories', 'taxonomy general name' ) ),

		'singular_name' => array( _x( 'Post 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 ),

	);

	$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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 3.0.0

 * @uses $wp_taxonomies Modifies taxonomy object

 *

 * @param string $taxonomy Name of taxonomy object

 * @param array|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;



	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'.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses $wpdb

 * @uses wp_parse_args() Creates an array from string $args.

 *

 * @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 );

	extract( $args, EXTR_SKIP );



	$order = ( 'desc' == strtolower( $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 );

}



/**

 * Container class for a multiple taxonomy query.

 *

 * @since 3.1.0

 */

class WP_Tax_Query {



	/**

	 * List of taxonomy queries. A single taxonomy query is an associative array:

	 * - 'taxonomy' string The taxonomy being queried

	 * - 'terms' string|array The list of terms

	 * - 'field' string (optional) Which term field is being used.

	 *		Possible values: 'term_id', 'slug' or 'name'

	 *		Default: 'term_id'

	 * - 'operator' string (optional)

	 *		Possible values: 'AND', 'IN' or 'NOT IN'.

	 *		Default: 'IN'

	 * - 'include_children' bool (optional) Whether to include child terms.

	 *		Default: true

	 *

	 * @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

	 * @access private

	 * @var string

	 */

	private static $no_results = array( 'join' => '', 'where' => ' AND 0 = 1' );



	/**

	 * Constructor.

	 *

	 * Parses a compact tax query and sets defaults.

	 *

	 * @since 3.1.0

	 * @access public

	 *

	 * @param array $tax_query A compact tax query:

	 *  array(

	 *    'relation' => 'OR',

	 *    array(

	 *      'taxonomy' => 'tax1',

	 *      'terms' => array( 'term1', 'term2' ),

	 *      'field' => 'slug',

	 *    ),

	 *    array(

	 *      'taxonomy' => 'tax2',

	 *      'terms' => array( 'term-a', 'term-b' ),

	 *      'field' => 'slug',

	 *    ),

	 *  )

	 */

	public function __construct( $tax_query ) {

		if ( isset( $tax_query['relation'] ) && strtoupper( $tax_query['relation'] ) == 'OR' ) {

			$this->relation = 'OR';

		} else {

			$this->relation = 'AND';

		}



		$defaults = array(

			'taxonomy' => '',

			'terms' => array(),

			'include_children' => true,

			'field' => 'term_id',

			'operator' => 'IN',

		);



		foreach ( $tax_query as $query ) {

			if ( ! is_array( $query ) )

				continue;



			$query = array_merge( $defaults, $query );



			$query['terms'] = (array) $query['terms'];



			$this->queries[] = $query;

		}

	}



	/**

	 * Generates SQL clauses to be appended to a main query.

	 *

	 * @since 3.1.0

	 * @access public

	 *

	 * @param string $primary_table

	 * @param string $primary_id_column

	 * @return array

	 */

	public function get_sql( $primary_table, $primary_id_column ) {

		global $wpdb;



		$join = '';

		$where = array();

		$i = 0;



		foreach ( $this->queries as $query ) {

			$this->clean_query( $query );



			if ( is_wp_error( $query ) ) {

				return self::$no_results;

			}



			extract( $query );



			if ( 'IN' == $operator ) {



				if ( empty( $terms ) ) {

					if ( 'OR' == $this->relation )

						continue;

					else

						return self::$no_results;

				}



				$terms = implode( ',', $terms );



				$alias = $i ? 'tt' . $i : $wpdb->term_relationships;



				$join .= " INNER JOIN $wpdb->term_relationships";

				$join .= $i ? " AS $alias" : '';

				$join .= " ON ($primary_table.$primary_id_column = $alias.object_id)";



				$where[] = "$alias.term_taxonomy_id $operator ($terms)";

			} elseif ( 'NOT IN' == $operator ) {



				if ( empty( $terms ) )

					continue;



				$terms = implode( ',', $terms );



				$where[] = "$primary_table.$primary_id_column NOT IN (

					SELECT object_id

					FROM $wpdb->term_relationships

					WHERE term_taxonomy_id IN ($terms)

				)";

			} elseif ( 'AND' == $operator ) {



				if ( empty( $terms ) )

					continue;



				$num_terms = count( $terms );



				$terms = implode( ',', $terms );



				$where[] = "(

					SELECT COUNT(1)

					FROM $wpdb->term_relationships

					WHERE term_taxonomy_id IN ($terms)

					AND object_id = $primary_table.$primary_id_column

				) = $num_terms";

			}



			$i++;

		}



		if ( !empty( $where ) )

			$where = ' AND ( ' . implode( " $this->relation ", $where ) . ' )';

		else

			$where = '';



		return compact( 'join', 'where' );

	}



	/**

	 * Validates a single query.

	 *

	 * @since 3.2.0

	 * @access private

	 *

	 * @param array &$query The single query

	 */

	private function clean_query( &$query ) {

		if ( ! 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

	 * @access private

	 *

	 * @param array &$query The single query

	 * @param string $resulting_field The resulting field

	 */

	private function transform_query( &$query, $resulting_field ) {

		global $wpdb;



		if ( empty( $query['terms'] ) )

			return;



		if ( $query['field'] == $resulting_field )

			return;



		$resulting_field = esc_sql( $resulting_field );



		switch ( $query['field'] ) {

			case 'slug':

			case 'name':

				$terms = "'" . implode( "','", array_map( 'sanitize_title_for_query', $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;



			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.

 *

 * '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.

 *

 * '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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses $wpdb

 * @uses sanitize_term() Cleanses the term based on $filter context before returning.

 * @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 mixed|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;

	$null = null;



	if ( empty($term) ) {

		$error = new WP_Error('invalid_term', __('Empty Term'));

		return $error;

	}



	if ( ! taxonomy_exists($taxonomy) ) {

		$error = new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));

		return $error;

	}



	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;

		$term = (int) $term;

		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 = %s LIMIT 1", $taxonomy, $term) );

			if ( ! $_term )

				return $null;

			wp_cache_add($term, $_term, $taxonomy);

		}

	}



	$_term = apply_filters('get_term', $_term, $taxonomy);

	$_term = apply_filters("get_$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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses $wpdb

 * @uses sanitize_term() Cleanses the term based on $filter context before returning.

 * @see sanitize_term_field() The $context param lists the available values for get_term_by() $filter param.

 *

 * @param string $field Either 'slug', 'name', or '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 mixed 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;

	} else if ( 'name' == $field ) {

		// Assume already escaped

		$value = stripslashes($value);

		$field = 't.name';

	} 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);



	$term = apply_filters('get_term', $term, $taxonomy);

	$term = apply_filters("get_$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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses $wpdb

 * @uses _get_term_hierarchy()

 * @uses get_term_children() Used to get the children of both $taxonomy and the parent $term

 *

 * @param string $term_id ID of Term to get children

 * @param string $taxonomy Taxonomy Name

 * @return array|WP_Error List of Term Objects. 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 ( 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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses sanitize_term_field() Passes the return value in sanitize_term_field on success.

 *

 * @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 mixed 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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses sanitize_term() Passes the return value on success

 *

 * @param int|object $id Term ID or Object

 * @param string $taxonomy Taxonomy Name

 * @return mixed|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 '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 'list_terms_exclusions' filter passes the compiled exclusions along with

 * the $args.

 *

 * The 'get_terms_orderby' filter passes the ORDER BY clause for the query

 * along with the $args array.

 *

 * The 'get_terms_fields' filter passes the fields for the SELECT query

 * along with the $args array.

 *

 * The list of arguments that $args can contain, which will overwrite the defaults:

 *

 * orderby - Default is 'name'. Can be name, count, term_group, slug or nothing

 * (will use term_id), Passing a custom value other than these will cause it to

 * order based on the custom value.

 *

 * order - Default is ASC. Can use DESC.

 *

 * hide_empty - Default is true. Will not return empty terms, which means

 * terms whose count is 0 according to the given taxonomy.

 *

 * exclude - Default is an empty array.  An array, comma- or space-delimited string

 * of term ids to exclude from the return array.  If 'include' is non-empty,

 * 'exclude' is ignored.

 *

 * exclude_tree - Default is an empty array.  An array, comma- or space-delimited

 * string of term ids to exclude from the return array, along with all of their

 * descendant terms according to the primary taxonomy.  If 'include' is non-empty,

 * 'exclude_tree' is ignored.

 *

 * include - Default is an empty array.  An array, comma- or space-delimited string

 * of term ids to include in the return array.

 *

 * number - The maximum number of terms to return.  Default is to return them all.

 *

 * offset - The number by which to offset the terms query.

 *

 * fields - Default is 'all', which returns an array of term objects.

 * If 'fields' is 'ids' or 'names', returns an array of

 * integers or strings, respectively.

 *

 * slug - Returns terms whose "slug" matches this value. Default is empty string.

 *

 * hierarchical - Whether to include terms that have non-empty descendants

 * (even if 'hide_empty' is set to true).

 *

 * search - Returned terms' names will contain the value of 'search',

 * case-insensitive.  Default is an empty string.

 *

 * name__like - Returned terms' names will begin with the value of 'name__like',

 * case-insensitive. Default is empty string.

 *

 * The argument 'pad_counts', if set to true will include the quantity of a term's

 * children in the quantity of each term's "count" object variable.

 *

 * The 'get' argument, if set to 'all' instead of its default empty string,

 * returns terms regardless of ancestry or whether the terms are empty.

 *

 * The 'child_of' argument, when used, should be set to the integer of a term ID.  Its default

 * is 0.  If set to a non-zero value, all returned terms will be descendants

 * of that term according to the given taxonomy.  Hence 'child_of' is set to 0

 * if more than one taxonomy is passed in $taxonomies, because multiple taxonomies

 * make term ancestry ambiguous.

 *

 * The 'parent' argument, when used, should be set to the integer of a term ID.  Its default is

 * the empty string '', which has a different meaning from the integer 0.

 * If set to an integer value, all returned terms will have as an immediate

 * ancestor the term whose ID is specified by that integer according to the given taxonomy.

 * The 'parent' argument is different from 'child_of' in that a term X is considered a 'parent'

 * of term Y only if term X is the father of term Y, not its grandfather or great-grandfather, etc.

 *

 * The 'cache_domain' argument enables a unique cache key to be produced when this query is stored

 * in object cache. For instance, if you are using one of this function's filters to modify the

 * query (such as 'terms_clauses'), setting 'cache_domain' to a unique value will not overwrite

 * the cache for similar queries. Default value is 'core'.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses $wpdb

 * @uses wp_parse_args() Merges the defaults with those defined by $args and allows for strings.

 *

 * @param string|array $taxonomies Taxonomy name or list of Taxonomy names

 * @param string|array $args The values of what to search for when returning terms

 * @return array|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 = false;

	if ( !is_array($taxonomies) ) {

		$single_taxonomy = true;

		$taxonomies = array($taxonomies);

	}



	foreach ( $taxonomies as $taxonomy ) {

		if ( ! taxonomy_exists($taxonomy) ) {

			$error = & new WP_Error('invalid_taxonomy', __('Invalid Taxonomy'));

			return $error;

		}

	}



	$defaults = array('orderby' => 'name', 'order' => 'ASC',

		'hide_empty' => true, 'exclude' => array(), 'exclude_tree' => array(), 'include' => array(),

		'number' => '', 'fields' => 'all', 'slug' => '', 'parent' => '',

		'hierarchical' => true, 'child_of' => 0, 'get' => '', 'name__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'] );

	if ( !$single_taxonomy || !is_taxonomy_hierarchical($taxonomies[0]) ||

		'' !== $args['parent'] ) {

		$args['child_of'] = 0;

		$args['hierarchical'] = false;

		$args['pad_counts'] = false;

	}



	if ( 'all' == $args['get'] ) {

		$args['child_of'] = 0;

		$args['hide_empty'] = 0;

		$args['hierarchical'] = false;

		$args['pad_counts'] = false;

	}



	$args = apply_filters( 'get_terms_args', $args, $taxonomies );



	extract($args, EXTR_SKIP);



	if ( $child_of ) {

		$hierarchy = _get_term_hierarchy($taxonomies[0]);

		if ( !isset($hierarchy[$child_of]) )

			return $empty_array;

	}



	if ( $parent ) {

		$hierarchy = _get_term_hierarchy($taxonomies[0]);

		if ( !isset($hierarchy[$parent]) )

			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']) : '';

	$key = md5( serialize( compact(array_keys($defaults)) ) . serialize( $taxonomies ) . $filter_key );

	$last_changed = wp_cache_get('last_changed', 'terms');

	if ( !$last_changed ) {

		$last_changed = time();

		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 ) {

		$cache = apply_filters('get_terms', $cache, $taxonomies, $args);

		return $cache;

	}



	$_orderby = strtolower($orderby);

	if ( 'count' == $_orderby )

		$orderby = 'tt.count';

	else if ( 'name' == $_orderby )

		$orderby = 't.name';

	else if ( 'slug' == $_orderby )

		$orderby = 't.slug';

	else if ( 'term_group' == $_orderby )

		$orderby = 't.term_group';

	else if ( 'none' == $_orderby )

		$orderby = '';

	elseif ( empty($_orderby) || 'id' == $_orderby )

		$orderby = 't.term_id';

	else

		$orderby = 't.name';



	$orderby = apply_filters( 'get_terms_orderby', $orderby, $args );



	if ( !empty($orderby) )

		$orderby = "ORDER BY $orderby";

	else

		$order = '';



	$order = strtoupper( $order );

	if ( '' !== $order && !in_array( $order, array( 'ASC', 'DESC' ) ) )

		$order = 'ASC';



	$where = "tt.taxonomy IN ('" . implode("', '", $taxonomies) . "')";

	$inclusions = '';

	if ( !empty($include) ) {

		$exclude = '';

		$exclude_tree = '';

		$interms = wp_parse_id_list($include);

		foreach ( $interms as $interm ) {

			if ( empty($inclusions) )

				$inclusions = ' AND ( t.term_id = ' . intval($interm) . ' ';

			else

				$inclusions .= ' OR t.term_id = ' . intval($interm) . ' ';

		}

	}



	if ( !empty($inclusions) )

		$inclusions .= ')';

	$where .= $inclusions;



	$exclusions = '';

	if ( !empty( $exclude_tree ) ) {

		$excluded_trunks = wp_parse_id_list($exclude_tree);

		foreach ( $excluded_trunks as $extrunk ) {

			$excluded_children = (array) get_terms($taxonomies[0], array('child_of' => intval($extrunk), 'fields' => 'ids', 'hide_empty' => 0));

			$excluded_children[] = $extrunk;

			foreach( $excluded_children as $exterm ) {

				if ( empty($exclusions) )

					$exclusions = ' AND ( t.term_id <> ' . intval($exterm) . ' ';

				else

					$exclusions .= ' AND t.term_id <> ' . intval($exterm) . ' ';

			}

		}

	}



	if ( !empty($exclude) ) {

		$exterms = wp_parse_id_list($exclude);

		foreach ( $exterms as $exterm ) {

			if ( empty($exclusions) )

				$exclusions = ' AND ( t.term_id <> ' . intval($exterm) . ' ';

			else

				$exclusions .= ' AND t.term_id <> ' . intval($exterm) . ' ';

		}

	}



	if ( !empty($exclusions) )

		$exclusions .= ')';

	$exclusions = apply_filters('list_terms_exclusions', $exclusions, $args );

	$where .= $exclusions;



	if ( !empty($slug) ) {

		$slug = sanitize_title($slug);

		$where .= " AND t.slug = '$slug'";

	}



	if ( !empty($name__like) ) {

		$name__like = like_escape( $name__like );

		$where .= $wpdb->prepare( " AND t.name LIKE %s", $name__like . '%' );

	}



	if ( '' !== $parent ) {

		$parent = (int) $parent;

		$where .= " AND tt.parent = '$parent'";

	}



	if ( $hide_empty && !$hierarchical )

		$where .= ' AND tt.count > 0';



	// don't limit the query results when we have to descend the family tree

	if ( ! empty($number) && ! $hierarchical && empty( $child_of ) && '' === $parent ) {

		if ( $offset )

			$limits = 'LIMIT ' . $offset . ',' . $number;

		else

			$limits = 'LIMIT ' . $number;

	} else {

		$limits = '';

	}



	if ( !empty($search) ) {

		$search = like_escape($search);

		$where .= $wpdb->prepare( " AND (t.name LIKE %s)", '%' . $search . '%');

	}



	$selects = array();

	switch ( $fields ) {

		case 'all':

			$selects = array('t.*', 'tt.*');

			break;

		case 'ids':

		case 'id=>parent':

			$selects = array('t.term_id', 'tt.parent', 'tt.count');

			break;

		case 'names':

			$selects = array('t.term_id', 'tt.parent', 'tt.count', 't.name');

			break;

		case 'count':

			$orderby = '';

			$order = '';

			$selects = array('COUNT(*)');

	}



	$_fields = $fields;



	$fields = implode(', ', apply_filters( 'get_terms_fields', $selects, $args ));



	$join = "INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id";



	$pieces = array( 'fields', 'join', 'where', 'orderby', 'order', 'limits' );

	$clauses = apply_filters( 'terms_clauses', compact( $pieces ), $taxonomies, $args );

	foreach ( $pieces as $piece )

		$$piece = isset( $clauses[ $piece ] ) ? $clauses[ $piece ] : '';



	$query = "SELECT $fields FROM $wpdb->terms AS t $join WHERE $where $orderby $order $limits";



	$fields = $_fields;



	if ( 'count' == $fields ) {

		$term_count = $wpdb->get_var($query);

		return $term_count;

	}



	$terms = $wpdb->get_results($query);

	if ( 'all' == $fields ) {

		update_term_cache($terms);

	}



	if ( empty($terms) ) {

		wp_cache_add( $cache_key, array(), 'terms', 86400 ); // one day

		$terms = apply_filters('get_terms', array(), $taxonomies, $args);

		return $terms;

	}



	if ( $child_of ) {

		$children = _get_term_hierarchy($taxonomies[0]);

		if ( ! empty($children) )

			$terms = & _get_term_children($child_of, $terms, $taxonomies[0]);

	}



	// Update term counts to include children.

	if ( $pad_counts && 'all' == $fields )

		_pad_term_counts($terms, $taxonomies[0]);



	// Make sure we show empty categories that have children.

	if ( $hierarchical && $hide_empty && is_array($terms) ) {

		foreach ( $terms as $k => $term ) {

			if ( ! $term->count ) {

				$children = _get_term_children($term->term_id, $terms, $taxonomies[0]);

				if ( is_array($children) )

					foreach ( $children as $child )

						if ( $child->count )

							continue 2;



				// It really is empty

				unset($terms[$k]);

			}

		}

	}

	reset ( $terms );



	$_terms = array();

	if ( 'id=>parent' == $fields ) {

		while ( $term = array_shift($terms) )

			$_terms[$term->term_id] = $term->parent;

		$terms = $_terms;

	} elseif ( 'ids' == $fields ) {

		while ( $term = array_shift($terms) )

			$_terms[] = $term->term_id;

		$terms = $_terms;

	} elseif ( 'names' == $fields ) {

		while ( $term = array_shift($terms) )

			$_terms[] = $term->name;

		$terms = $_terms;

	}



	if ( 0 < $number && intval(@count($terms)) > $number ) {

		$terms = array_slice($terms, $offset, $number);

	}



	wp_cache_add( $cache_key, $terms, 'terms', 86400 ); // one day



	$terms = apply_filters('get_terms', $terms, $taxonomies, $args);

	return $terms;

}



/**

 * Check if Term exists.

 *

 * Returns the index of a defined term, or 0 (false) if the term doesn't exist.

 *

 * Formerly is_term(), introduced in 2.3.0.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 3.0.0

 *

 * @uses $wpdb

 *

 * @param int|string $term The term to check

 * @param string $taxonomy The taxonomy name to use

 * @param int $parent ID of parent term under which to confine the exists search.

 * @return mixed Get the term id or Term Object, if exists.

 */

function term_exists($term, $taxonomy = '', $parent = 0) {

	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( stripslashes( $term ) );



	if ( '' === $slug = sanitize_title($term) )

		return 0;



	$where = 't.slug = %s';

	$else_where = 't.name = %s';

	$where_fields = array($slug);

	$else_where_fields = array($term);

	if ( !empty($taxonomy) ) {

		$parent = (int) $parent;

		if ( $parent > 0 ) {

			$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", $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", $else_where_fields), ARRAY_A);

	}



	if ( $result = $wpdb->get_var( $wpdb->prepare("SELECT term_id FROM $wpdb->terms as t WHERE $where", $where_fields) ) )

		return $result;



	return $wpdb->get_var( $wpdb->prepare("SELECT term_id FROM $wpdb->terms as t WHERE $else_where", $else_where_fields) );

}



/**

 * Sanitize Term all fields.

 *

 * Relys 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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses sanitize_term_field Used to sanitize all fields in a term

 *

 * @param array|object $term The term to check

 * @param string $taxonomy The taxonomy name to use

 * @param string $context Default is 'display'.

 * @return array|object Term with all fields sanitized

 */

function sanitize_term($term, $taxonomy, $context = 'display') {



	if ( 'raw' == $context )

		return $term;



	$fields = array('term_id', 'name', 'description', 'slug', 'count', 'parent', 'term_group');



	$do_object = false;

	if ( is_object($term) )

		$do_object = true;



	$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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses $wpdb

 *

 * @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 Either edit, db, display, attribute, or js.

 * @return mixed sanitized field

 */

function sanitize_term_field($field, $value, $term_id, $taxonomy, $context) {

	if ( 'parent' == $field  || 'term_id' == $field || 'count' == $field || 'term_group' == $field ) {

		$value = (int) $value;

		if ( $value < 0 )

			$value = 0;

	}



	if ( 'raw' == $context )

		return $value;



	if ( 'edit' == $context ) {

		$value = apply_filters("edit_term_{$field}", $value, $term_id, $taxonomy);

		$value = apply_filters("edit_{$taxonomy}_{$field}", $value, $term_id);

		if ( 'description' == $field )

			$value = esc_html($value); // textarea_escaped

		else

			$value = esc_attr($value);

	} else if ( 'db' == $context ) {

		$value = apply_filters("pre_term_{$field}", $value, $taxonomy);

		$value = apply_filters("pre_{$taxonomy}_{$field}", $value);

		// Back compat filters

		if ( 'slug' == $field )

			$value = apply_filters('pre_category_nicename', $value);



	} else if ( 'rss' == $context ) {

		$value = apply_filters("term_{$field}_rss", $value, $taxonomy);

		$value = apply_filters("{$taxonomy}_{$field}_rss", $value);

	} else {

		// Use display filters by default.

		$value = apply_filters("term_{$field}", $value, $term_id, $taxonomy, $context);

		$value = apply_filters("{$taxonomy}_{$field}", $value, $term_id, $context);

	}



	if ( 'attribute' == $context )

		$value = esc_attr($value);

	else if ( '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).

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses get_terms()

 * @uses wp_parse_args() Turns strings into arrays and merges defaults into an array.

 *

 * @param string $taxonomy Taxonomy name

 * @param array|string $args Overwrite defaults. See get_terms()

 * @return int How many terms are in $taxonomy

 */

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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 * @uses $wpdb

 *

 * @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 ) {

	global $wpdb;



	$object_id = (int) $object_id;



	if ( !is_array($taxonomies) )

		$taxonomies = array($taxonomies);



	foreach ( (array) $taxonomies as $taxonomy ) {

		$tt_ids = wp_get_object_terms($object_id, $taxonomy, array('fields' => 'tt_ids'));

		$in_tt_ids = "'" . implode("', '", $tt_ids) . "'";

		do_action( 'delete_term_relationships', $object_id, $tt_ids );

		$wpdb->query( $wpdb->prepare("DELETE FROM $wpdb->term_relationships WHERE object_id = %d AND term_taxonomy_id IN ($in_tt_ids)", $object_id) );

		do_action( 'deleted_term_relationships', $object_id, $tt_ids );

		wp_update_term_count($tt_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

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses $wpdb

 * @uses do_action() Calls both 'delete_term' and 'delete_$taxonomy' action

 *	hooks, passing term object, term id. 'delete_term' gets an additional

 *	parameter with the $taxonomy parameter.

 *

 * @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|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);

	extract($args, EXTR_SKIP);



	if ( isset( $default ) ) {

		$default = (int) $default;

		if ( ! term_exists($default, $taxonomy) )

			unset($default);

	}



	// 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_tt_ids = $wpdb->get_col( "SELECT `term_taxonomy_id` FROM $wpdb->term_taxonomy WHERE `parent` = " . (int)$term_obj->term_id );

		do_action( 'edit_term_taxonomies', $edit_tt_ids );

		$wpdb->update( $wpdb->term_taxonomy, compact( 'parent' ), array( 'parent' => $term_obj->term_id) + compact( 'taxonomy' ) );

		do_action( 'edited_term_taxonomies', $edit_tt_ids );

	}



	$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 );



	do_action( 'delete_term_taxonomy', $tt_id );

	$wpdb->query( $wpdb->prepare( "DELETE FROM $wpdb->term_taxonomy WHERE term_taxonomy_id = %d", $tt_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->query( $wpdb->prepare( "DELETE FROM $wpdb->terms WHERE term_id = %d", $term) );



	clean_term_cache($term, $taxonomy);



	do_action('delete_term', $term, $tt_id, $taxonomy);

	do_action("delete_$taxonomy", $term, $tt_id);



	return true;

}



/**

 * Deletes one existing category.

 *

 * @since 2.0.0

 * @uses wp_delete_term()

 *

 * @param int $cat_ID

 * @return mixed Returns true if completes delete action; false if term doesnt 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.

 *

 * The following information has to do the $args parameter and for what can be

 * contained in the string or array of that parameter, if it exists.

 *

 * The first argument is called, 'orderby' and has the default value of 'name'.

 * The other value that is supported is 'count'.

 *

 * The second argument is called, 'order' and has the default value of 'ASC'.

 * The only other value that will be acceptable is 'DESC'.

 *

 * The final argument supported is called, 'fields' and has the default value of

 * 'all'. There are multiple other options that can be used instead. Supported

 * values are as follows: 'all', 'ids', 'names', and finally

 * 'all_with_object_id'.

 *

 * The fields argument also decides what will be returned. If 'all' or

 * 'all_with_object_id' is choosen or the default kept intact, then all matching

 * terms objects will be returned. If either 'ids' or 'names' is used, then an

 * array of all matching term ids or term names will be returned respectively.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 * @uses $wpdb

 *

 * @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 Change what is returned

 * @return array|WP_Error The requested term data or empty array if no terms found. WP_Error if $taxonomy does not exist.

 */

function wp_get_object_terms($object_ids, $taxonomies, $args = array()) {

	global $wpdb;



	if ( !is_array($taxonomies) )

		$taxonomies = array($taxonomies);



	foreach ( (array) $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');

	$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);

	}



	extract($args, EXTR_SKIP);



	if ( 'count' == $orderby )

		$orderby = 'tt.count';

	else if ( 'name' == $orderby )

		$orderby = 't.name';

	else if ( 'slug' == $orderby )

		$orderby = 't.slug';

	else if ( 'term_group' == $orderby )

		$orderby = 't.term_group';

	else if ( 'term_order' == $orderby )

		$orderby = 'tr.term_order';

	else if ( '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";



	$taxonomies = "'" . implode("', '", $taxonomies) . "'";

	$object_ids = implode(', ', $object_ids);



	$select_this = '';

	if ( 'all' == $fields )

		$select_this = 't.*, tt.*';

	else if ( 'ids' == $fields )

		$select_this = 't.term_id';

	else if ( 'names' == $fields )

		$select_this = 't.name';

	else if ( 'all_with_object_id' == $fields )

		$select_this = 't.*, tt.*, tr.object_id';



	$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 $wpdb->term_relationships AS tr ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy IN ($taxonomies) AND tr.object_id IN ($object_ids) $orderby $order";



	if ( 'all' == $fields || 'all_with_object_id' == $fields ) {

		$terms = array_merge($terms, $wpdb->get_results($query));

		update_term_cache($terms);

	} else if ( 'ids' == $fields || 'names' == $fields ) {

		$terms = array_merge($terms, $wpdb->get_col($query));

	} else if ( '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");

	}



	if ( ! $terms )

		$terms = array();



	return apply_filters('wp_get_object_terms', $terms, $object_ids, $taxonomies, $args);

}



/**

 * Adds a new term to the database. Optionally marks it as an alias of an existing term.

 *

 * Error handling is assigned for the nonexistance of the $taxonomy and $term

 * parameters before inserting. If both the term id and taxonomy exist

 * previously, then an array will be returned that contains the term id and the

 * contents of what is returned. The keys of the array are 'term_id' and

 * 'term_taxonomy_id' containing numeric values.

 *

 * It is assumed that the term does not yet exist or the above will apply. The

 * term will be first added to the term table and then related to the taxonomy

 * if everything is well. If everything is correct, then several actions will be

 * run prior to a filter and then several actions will be run after the filter

 * is run.

 *

 * The arguments decide how the term is handled based on the $args parameter.

 * The following is a list of the available overrides and the defaults.

 *

 * 'alias_of'. There is no default, but if added, expected is the slug that the

 * term will be an alias of. Expected to be a string.

 *

 * 'description'. There is no default. If exists, will be added to the database

 * along with the term. Expected to be a string.

 *

 * 'parent'. Expected to be numeric and default is 0 (zero). Will assign value

 * of 'parent' to the term.

 *

 * 'slug'. Expected to be a string. There is no default.

 *

 * If 'slug' argument exists then the slug will be checked to see if it is not

 * a valid term. If that check succeeds (it is not a valid term), then it is

 * added and the term id is given. If it fails, then a check is made to whether

 * the taxonomy is hierarchical and the parent argument is not empty. If the

 * second check succeeds, the term will be inserted and the term id will be

 * given.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 * @uses $wpdb

 *

 * @uses apply_filters() Calls 'pre_insert_term' hook with term and taxonomy as parameters.

 * @uses do_action() Calls 'create_term' hook with the term id and taxonomy id as parameters.

 * @uses do_action() Calls 'create_$taxonomy' hook with term id and taxonomy id as parameters.

 * @uses apply_filters() Calls 'term_id_filter' hook with term id and taxonomy id as parameters.

 * @uses do_action() Calls 'created_term' hook with the term id and taxonomy id as parameters.

 * @uses do_action() Calls 'created_$taxonomy' hook with term id and taxonomy id as parameters.

 *

 * @param string $term The term to add or update.

 * @param string $taxonomy The taxonomy to which to add the term

 * @param array|string $args Change the values of the inserted term

 * @return array|WP_Error The Term ID and Term Taxonomy ID

 */

function wp_insert_term( $term, $taxonomy, $args = array() ) {

	global $wpdb;



	if ( ! taxonomy_exists($taxonomy) )

		return new WP_Error('invalid_taxonomy', __('Invalid taxonomy'));



	$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);

	$args['name'] = $term;

	$args['taxonomy'] = $taxonomy;

	$args = sanitize_term($args, $taxonomy, 'db');

	extract($args, EXTR_SKIP);



	// expected_slashed ($name)

	$name = stripslashes($name);

	$description = stripslashes($description);



	if ( empty($slug) )

		$slug = sanitize_title($name);



	$term_group = 0;

	if ( $alias_of ) {

		$alias = $wpdb->get_row( $wpdb->prepare( "SELECT term_id, term_group FROM $wpdb->terms WHERE slug = %s", $alias_of) );

		if ( $alias->term_group ) {

			// The alias we want is already in a group, so let's use that one.

			$term_group = $alias->term_group;

		} else {

			// The alias isn't in a group, so let's create a new one and firstly add the alias term to it.

			$term_group = $wpdb->get_var("SELECT MAX(term_group) FROM $wpdb->terms") + 1;

			do_action( 'edit_terms', $alias->term_id );

			$wpdb->update($wpdb->terms, compact('term_group'), array('term_id' => $alias->term_id) );

			do_action( 'edited_terms', $alias->term_id );

		}

	}



	if ( $term_id = term_exists($slug) ) {

		$existing_term = $wpdb->get_row( $wpdb->prepare( "SELECT name FROM $wpdb->terms WHERE term_id = %d", $term_id), ARRAY_A );

		// We've got an existing term in the same taxonomy, which matches the name of the new term:

		if ( is_taxonomy_hierarchical($taxonomy) && $existing_term['name'] == $name && $exists = term_exists( (int) $term_id, $taxonomy ) ) {

			// Hierarchical, and it matches an existing term, Do not allow same "name" in the same level.

			$siblings = get_terms($taxonomy, array('fields' => 'names', 'get' => 'all', 'parent' => (int)$parent) );

			if ( in_array($name, $siblings) ) {

				return new WP_Error('term_exists', __('A term with the name provided already exists with this parent.'), $exists['term_id']);

			} else {

				$slug = wp_unique_term_slug($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;

			}

		} elseif ( $existing_term['name'] != $name ) {

			// We've got an existing term, with a different name, Create the new term.

			$slug = wp_unique_term_slug($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;

		} elseif ( $exists = term_exists( (int) $term_id, $taxonomy ) )  {

			// Same name, same slug.

			return new WP_Error('term_exists', __('A term with the name provided already exists.'), $exists['term_id']);

		}

	} else {

		// This term does not exist at all in the database, Create it.

		$slug = wp_unique_term_slug($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);

		do_action( 'edit_terms', $term_id );

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

		do_action( 'edited_terms', $term_id );

	}



	$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;



	do_action("create_term", $term_id, $tt_id, $taxonomy);

	do_action("create_$taxonomy", $term_id, $tt_id);



	$term_id = apply_filters('term_id_filter', $term_id, $tt_id);



	clean_term_cache($term_id, $taxonomy);



	do_action("created_term", $term_id, $tt_id, $taxonomy);

	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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 * @uses $wpdb

 *

 * @param int $object_id The object to relate to.

 * @param array|int|string $terms The slug or id of the term, will replace all existing

 * related terms in this taxonomy.

 * @param array|string $taxonomy The context in which to relate the term to the object.

 * @param bool $append If false will delete difference of terms.

 * @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();



	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;

		do_action( 'add_term_relationship', $object_id, $tt_id );

		$wpdb->insert( $wpdb->term_relationships, array( 'object_id' => $object_id, 'term_taxonomy_id' => $tt_id ) );

		do_action( 'added_term_relationship', $object_id, $tt_id );

	}



	wp_update_term_count($tt_ids, $taxonomy);



	if ( ! $append ) {

		$delete_terms = array_diff($old_tt_ids, $tt_ids);

		if ( $delete_terms ) {

			$in_delete_terms = "'" . implode("', '", $delete_terms) . "'";

			do_action( 'delete_term_relationships', $object_id, $delete_terms );

			$wpdb->query( $wpdb->prepare("DELETE FROM $wpdb->term_relationships WHERE object_id = %d AND term_taxonomy_id IN ($in_delete_terms)", $object_id) );

			do_action( 'deleted_term_relationships', $object_id, $delete_terms );

			wp_update_term_count($delete_terms, $taxonomy);

		}

	}



	$t = get_taxonomy($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 )

			$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)");

	}



	do_action('set_object_terms', $object_id, $terms, $tt_ids, $taxonomy, $append, $old_tt_ids);

	return $tt_ids;

}



/**

 * 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 truely unique.

 *

 * The only purpose for $term is for appending a parent, if one exists.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 * @uses $wpdb

 *

 * @param string $slug The string that will be tried for a unique slug

 * @param object $term The term object that the $slug will belong too

 * @return string Will return a true unique slug.

 */

function wp_unique_term_slug($slug, $term) {

	global $wpdb;



	if ( ! term_exists( $slug ) )

		return $slug;



	// If the taxonomy supports hierarchy and the term has a parent, make the slug unique

	// by incorporating parent slugs.

	if ( 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;

			$slug .= '-' . $parent_term->slug;

			if ( ! term_exists( $slug ) )

				return $slug;



			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.

	if ( !empty($args['term_id']) )

		$query = $wpdb->prepare( "SELECT slug FROM $wpdb->terms WHERE slug = %s AND term_id != %d", $slug, $args['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;

	}



	return $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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses $wpdb

 * @uses do_action() Will call both 'edit_term' and 'edit_$taxonomy' twice.

 * @uses apply_filters() Will call the 'term_id_filter' filter and pass the term

 *	id and taxonomy id.

 *

 * @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 Overwrite term field values

 * @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;



	// Escape data pulled from DB.

	$term = add_magic_quotes($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');

	extract($args, EXTR_SKIP);



	// expected_slashed ($name)

	$name = stripslashes($name);

	$description = stripslashes($description);



	if ( '' == trim($name) )

		return new WP_Error('empty_term_name', __('A name is required for this term'));



	$empty_slug = false;

	if ( empty($slug) ) {

		$empty_slug = true;

		$slug = sanitize_title($name);

	}



	if ( $alias_of ) {

		$alias = $wpdb->get_row( $wpdb->prepare( "SELECT term_id, term_group FROM $wpdb->terms WHERE slug = %s", $alias_of) );

		if ( $alias->term_group ) {

			// The alias we want is already in a group, so let's use that one.

			$term_group = $alias->term_group;

		} else {

			// The alias isn't in a group, so let's create a new one and firstly add the alias term to it.

			$term_group = $wpdb->get_var("SELECT MAX(term_group) FROM $wpdb->terms") + 1;

			do_action( 'edit_terms', $alias->term_id );

			$wpdb->update( $wpdb->terms, compact('term_group'), array( 'term_id' => $alias->term_id ) );

			do_action( 'edited_terms', $alias->term_id );

		}

	}



	// Check $parent to see if it will cause a hierarchy loop

	$parent = apply_filters( 'wp_update_term_parent', $parent, $term_id, $taxonomy, compact( array_keys( $args ) ), $args );



	// Check for duplicate slug

	$id = $wpdb->get_var( $wpdb->prepare( "SELECT term_id FROM $wpdb->terms WHERE slug = %s", $slug ) );

	if ( $id && ($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));

	}

	do_action( 'edit_terms', $term_id );

	$wpdb->update($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' ) );

	}

	do_action( 'edited_terms', $term_id );



	$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) );

	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 ) );

	do_action( 'edited_term_taxonomy', $tt_id, $taxonomy );



	do_action("edit_term", $term_id, $tt_id, $taxonomy);

	do_action("edit_$taxonomy", $term_id, $tt_id);



	$term_id = apply_filters('term_id_filter', $term_id, $tt_id);



	clean_term_cache($term_id, $taxonomy);



	do_action("edited_term", $term_id, $tt_id, $taxonomy);

	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

 *

 * @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 applyed, 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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 * @uses $wpdb

 *

 * @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 bool Always true when complete.

 */

function wp_update_term_count_now( $terms, $taxonomy ) {

	global $wpdb;



	$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 {

		// Default count updater

		foreach ( (array) $terms as $term) {

			$count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM $wpdb->term_relationships WHERE term_taxonomy_id = %d", $term) );

			do_action( 'edit_term_taxonomy', $term, $taxonomy );

			$wpdb->update( $wpdb->term_taxonomy, compact( 'count' ), array( 'term_taxonomy_id' => $term ) );

			do_action( 'edited_term_taxonomy', $term, $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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @see get_object_taxonomies() for more on $object_type

 * @uses do_action() Will call action hook named, 'clean_object_term_cache' after completion.

 *	Passes, function params in same order.

 *

 * @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);



	foreach ( $object_ids as $id )

		foreach ( get_object_taxonomies($object_type) as $taxonomy )

			wp_cache_delete($id, "{$taxonomy}_relationships");



	do_action('clean_object_term_cache', $object_ids, $object_type);

}





/**

 * Will remove all of the term ids from the cache.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 * @uses $wpdb

 *

 * @param int|array $ids Single or list of Term IDs

 * @param string $taxonomy Can be empty and will assume tt_ids, else will use for context.

 * @param bool $clean_taxonomy Whether to clean taxonomy wide caches (true), or just individual term object caches (false). Default is true.

 */

function clean_term_cache($ids, $taxonomy = '', $clean_taxonomy = true) {

	global $wpdb;

	static $cleaned = array();



	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 ( isset($cleaned[$taxonomy]) )

			continue;

		$cleaned[$taxonomy] = true;



		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);

		}



		do_action('clean_term_cache', $ids, $taxonomy);

	}



	wp_cache_set('last_changed', time(), 'terms');

}





/**

 * Retrieves the taxonomy relationship to the term object id.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @uses wp_cache_get() Retrieves taxonomy relationship from cache

 *

 * @param int|array $id Term object ID

 * @param string $taxonomy Taxonomy Name

 * @return bool|array 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) {

	$cache = wp_cache_get($id, "{$taxonomy}_relationships");

	return $cache;

}





/**

 * Updates the cache for Term ID(s).

 *

 * Will only update the cache for terms not already cached.

 *

 * The $object_ids expects that the ids be separated by commas, if it is a

 * string.

 *

 * It should be noted that update_object_term_cache() is very time extensive. It

 * is advised that the function is not called very often or at least not for a

 * lot of terms that exist in a lot of taxonomies. The amount of time increases

 * for each term and it also increases for each taxonomy the term belongs to.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 * @uses wp_get_object_terms() Used to get terms from the database to update

 *

 * @param string|array $object_ids Single or list of term object ID(s)

 * @param array|string $object_type The taxonomy object type

 * @return null|bool Null value is given with empty $object_ids. False if

 */

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->term_id] = $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_set($id, $terms, "{$taxonomy}_relationships");

		}

	}

}





/**

 * Updates Terms to Taxonomy in cache.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 *

 * @param array $terms List of Term objects to change

 * @param string $taxonomy Optional. Update Term to this taxonomy in cache

 */

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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @access private

 * @since 2.3.0

 *

 * @uses update_option() Stores all of the children in "$taxonomy_children"

 *	 option. That is the name of the taxonomy, immediately followed by '_children'.

 *

 * @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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @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.

 * @return array The subset of $terms that are descendants of $term_id.

 */

function &_get_term_children($term_id, $terms, $taxonomy) {

	$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;



	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;

		}



		if ( $term->term_id == $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;



			if ( $children = _get_term_children($term->term_id, $terms, $taxonomy) )

				$term_list = array_merge($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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @access private

 * @since 2.3.0

 * @uses $wpdb

 *

 * @param array $terms List of Term IDs

 * @param string $taxonomy Term Context

 * @return null Will break from function if conditions are not met.

 */

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();



	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;

		while ( $parent = $terms_by_id[$child]->parent ) {

			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;

		}

	}



	// 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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @access private

 * @since 2.3.0

 * @uses $wpdb

 *

 * @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;



	$object_types = is_array($taxonomy->object_type) ? $taxonomy->object_type : array($taxonomy->object_type);

	$object_types = esc_sql($object_types);



	foreach ( (array) $terms as $term ) {

		$count = $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 ) );

		do_action( 'edit_term_taxonomy', $term, $taxonomy );

		$wpdb->update( $wpdb->term_taxonomy, compact( 'count' ), array( 'term_taxonomy_id' => $term ) );

		do_action( 'edited_term_taxonomy', $term, $taxonomy );

	}

}





/**

 * Generates a permalink for a taxonomy term archive.

 *

 * @since 2.5.0

 *

 * @uses apply_filters() Calls 'term_link' with term link and term object, and taxonomy parameters.

 * @uses apply_filters() For the post_tag Taxonomy, Calls 'tag_link' with tag link and tag ID as parameters.

 * @uses apply_filters() For the category Taxonomy, Calls 'category_link' filter on category link and category ID.

 *

 * @param object|int|string $term

 * @param string $taxonomy (optional if $term is object)

 * @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);

			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 )

		$termlink = apply_filters( 'tag_link', $termlink, $term->term_id );

	elseif ( 'category' == $taxonomy )

		$termlink = apply_filters( 'category_link', $termlink, $term->term_id );



	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.

 *

 * The available defaults are:

 * 'post' : default is 0. The post ID to get taxonomies of.

 * 'before' : default is empty string. Display before taxonomies list.

 * 'sep' : default is empty string. Separate every taxonomy with value in this.

 * 'after' : default is empty string. Display this after the taxonomies list.

 * 'template' : The template to use for displaying the taxonomy terms.

 *

 * @since 2.5.0

 * @uses get_the_taxonomies()

 *

 * @param array $args Override the defaults.

 */

function the_taxonomies($args = array()) {

	$defaults = array(

		'post' => 0,

		'before' => '',

		'sep' => ' ',

		'after' => '',

		'template' => '%s: %l.'

	);



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

	extract( $r, EXTR_SKIP );



	echo $before . join($sep, get_the_taxonomies($post, $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 $post Optional. Post ID or will use Global Post ID (in loop).

 * @param array $args Override the defaults.

 * @return array

 */

function get_the_taxonomies($post = 0, $args = array() ) {

	if ( is_int($post) )

		$post =& get_post($post);

	elseif ( !is_object($post) )

		$post =& $GLOBALS['post'];



	$args = wp_parse_args( $args, array(

		'template' => '%s: %l.',

	) );

	extract( $args, EXTR_SKIP );



	$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'] = $template;



		$terms = get_object_term_cache($post->ID, $taxonomy);

		if ( empty($terms) )

			$terms = wp_get_object_terms($post->ID, $taxonomy, $t['args']);



		$links = array();



		foreach ( $terms as $term )

			$links[] = "<a href='" . esc_attr( get_term_link($term) ) . "'>$term->name</a>";



		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

 * @uses get_object_taxonomies()

 *

 * @param int $post Optional. Post ID

 * @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

 * @uses get_object_term_cache()

 * @uses wp_get_object_terms()

 *

 * @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

 * @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 ( empty( $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 ( $ints && in_array( $object_term->term_id, $ints ) ) return true; // If int, check against term_id

		if ( $strs ) {

			if ( in_array( $object_term->term_id, $strs ) ) 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

 * @uses get_object_taxonomies()

 *

 * @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;



	if ( in_array($taxonomy, $taxonomies) )

		return true;



	return false;

}



/**

 * Get an array of ancestor IDs for a given object.

 *

 * @param int $object_id The ID of the object

 * @param string $object_type The type of object for which we'll be retrieving ancestors.

 * @return array of ancestors from lowest to highest in the hierarchy.

 */

function get_ancestors($object_id = 0, $object_type = '') {

	$object_id = (int) $object_id;



	$ancestors = array();



	if ( empty( $object_id ) ) {

		return apply_filters('get_ancestors', $ancestors, $object_id, $object_type);

	}



	if ( is_taxonomy_hierarchical( $object_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 ( null !== get_post_type_object( $object_type ) ) {

		$object = get_post($object_id);

		if ( ! is_wp_error( $object ) && isset( $object->ancestors ) && is_array( $object->ancestors ) )

			$ancestors = $object->ancestors;

		else {

			while ( ! is_wp_error($object) && ! empty( $object->post_parent ) && ! in_array( $object->post_parent, $ancestors ) ) {

				$ancestors[] = (int) $object->post_parent;

				$object = get_post($object->post_parent);

			}

		}

	}



	return apply_filters('get_ancestors', $ancestors, $object_id, $object_type);

}



/**

 * Returns the term's parent's term_ID

 *

 * @since 3.1.0

 *

 * @param int $term_id

 * @param string $taxonomy

 *

 * @return int|bool 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 wp_update_term_parent filter.

 *

 * @since 3.1.0

 * @uses wp_find_hierarchy_loop()

 *

 * @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;

}