* Creates the initial taxonomies.

 *

 * This function fires twice: in wp-settings.php before plugins are loaded (for

 * backwards compatibility reasons), and again on the 'init' action. We must avoid

 * registering rewrite rules before the 'init' action.

	global $wp_rewrite;

	if ( ! did_action( 'init' ) ) {

		$rewrite = array( 'category' => false, 'post_tag' => false, 'post_format' => false );

	} else {

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

		$rewrite = array(

			'category' => array(

				'hierarchical' => true,

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

				'with_front' => ! get_option('category_base') || $wp_rewrite->using_index_permalinks(),

				'ep_mask' => EP_CATEGORIES,

			),

			'post_tag' => array(

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

				'with_front' => ! get_option('tag_base') || $wp_rewrite->using_index_permalinks(),

				'ep_mask' => EP_TAGS,

			),

			'post_format' => $post_format_base ? array( 'slug' => $post_format_base ) : false,

		);

	}

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

		'hierarchical' => true,

		'query_var' => 'category_name',

		'rewrite' => $rewrite['category'],

		'public' => true,

		'show_ui' => true,

		'_builtin' => true,

	) );

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

	 	'hierarchical' => false,

		'query_var' => 'tag',

		'rewrite' => $rewrite['post_tag'],

		'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,

	) );

	register_taxonomy( 'post_format', 'post', array(

		'public' => true,

		'hierarchical' => false,

		'labels' => array(

			'name' => _x( 'Format', 'post format' ),

			'singular_name' => _x( 'Format', 'post format' ),

		),

		'query_var' => true,

		'rewrite' => $rewrite['post_format'],

		'show_ui' => false,

		'_builtin' => true,

		'show_in_nav_menus' => current_theme_supports( 'post-formats' ),

	) );

 * 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);

}

/**

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

function get_object_taxonomies($object, $output = 'names') {

	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;

		}

 * @uses taxonomy_exists() Checks whether taxonomy exists

	if ( ! taxonomy_exists( $taxonomy ) )

 * Formerly is_taxonomy(), introduced in 2.3.0.

 *

 * @since 3.0.0

 * @return bool Whether the taxonomy exists.

function taxonomy_exists( $taxonomy ) {

	return isset( $wp_taxonomies[$taxonomy] );

 * @uses taxonomy_exists() Checks whether taxonomy exists

	if ( ! taxonomy_exists($taxonomy) )

 * Nothing is returned, so expect error maybe or use taxonomy_exists() to check

 * 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

 * update_count_callback - works much like a hook, in that it will be called when the count is updated.

 * 	Defaults to _update_post_term_count() for taxonomies attached to post types, which then confirms

 * 	that the objects are published before counting them.

 * 	Defaults to _update_generic_term_count() for taxonomies attached to other object types, such as links.

 * public - If the taxonomy should be publicly 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 defaults 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.

 *

	global $wp_taxonomies, $wp;

	if ( ! is_array($wp_taxonomies) )

	$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,

					);

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

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

			'slug' => sanitize_title_with_dashes($taxonomy),

			'with_front' => true,

			'hierarchical' => false,

			'ep_mask' => EP_NONE,

		));

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

			$tag = '(.+?)';

		else

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

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

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

	if ( 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'] );

	$args['object_type'] =  array_unique( (array)$object_type );

	$args['labels'] = get_taxonomy_labels( (object) $args );

	$args['label'] = $args['labels']->name;

	// register callback handling for metabox

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

	do_action( 'registered_taxonomy', $taxonomy, $object_type, $args );

}

/**

 * Builds an object with all taxonomy labels out of a taxonomy object

 *

 * Accepted keys of the label array in the taxonomy object:

 * - name - general name for the taxonomy, usually plural. The same as and overridden by $tax->label. Default is Tags/Categories

 * - singular_name - name for one object of this taxonomy. Default is Tag/Category

 * - search_items - Default is Search Tags/Search Categories

 * - popular_items - This string isn't used on hierarchical taxonomies. Default is Popular Tags

 * - all_items - Default is All Tags/All Categories

 * - parent_item - This string isn't used on non-hierarchical taxonomies. In hierarchical ones the default is Parent Category

 * - parent_item_colon - The same as <code>parent_item</code>, but with colon <code>:</code> in the end

 * - edit_item - Default is Edit Tag/Edit Category

 * - view_item - Default is View Tag/View Category

 * - update_item - Default is Update Tag/Update Category

 * - add_new_item - Default is Add New Tag/Add New Category

 * - new_item_name - Default is New Tag Name/New Category Name

 * - separate_items_with_commas - This string isn't used on hierarchical taxonomies. Default is "Separate tags with commas", used in the meta box.

 * - add_or_remove_items - This string isn't used on hierarchical taxonomies. Default is "Add or remove tags", used in the meta box when JavaScript is disabled.

 * - choose_from_most_used - This string isn't used on hierarchical taxonomies. Default is "Choose from the most used tags", used in the meta box.

 *

 * 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( 'Tags', 'taxonomy general name' ), _x( 'Categories', 'taxonomy general name' ) ),

		'singular_name' => array( _x( 'Tag', 'taxonomy singular name' ), _x( 'Category', 'taxonomy singular name' ) ),

		'search_items' => array( __( 'Search Tags' ), __( 'Search Categories' ) ),

		'popular_items' => array( __( 'Popular Tags' ), null ),

		'all_items' => array( __( 'All Tags' ), __( 'All Categories' ) ),

		'parent_item' => array( null, __( 'Parent Category' ) ),

		'parent_item_colon' => array( null, __( 'Parent Category:' ) ),

		'edit_item' => array( __( 'Edit Tag' ), __( 'Edit Category' ) ),

		'view_item' => array( __( 'View Tag' ), __( 'View Category' ) ),

		'update_item' => array( __( 'Update Tag' ), __( 'Update Category' ) ),

		'add_new_item' => array( __( 'Add New Tag' ), __( 'Add New Category' ) ),

		'new_item_name' => array( __( 'New Tag Name' ), __( 'New Category Name' ) ),

		'separate_items_with_commas' => array( __( 'Separate tags with commas' ), null ),

		'add_or_remove_items' => array( __( 'Add or remove tags' ), null ),

		'choose_from_most_used' => array( __( 'Choose from the most used tags' ), null ),

	);

	$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 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;

 * @param int|array $term_ids Term id or array of term ids of terms that will be used

function get_objects_in_term( $term_ids, $taxonomies, $args = array() ) {

	if ( ! is_array( $term_ids ) )

		$term_ids = array( $term_ids );

	if ( ! is_array( $taxonomies ) )

		$taxonomies = array( $taxonomies );

		if ( ! taxonomy_exists( $taxonomy ) )