<?php

/**

 * Taxonomy API

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

 */

//

// Taxonomy Registration

//

/**

 * Creates the initial taxonomies.

 *

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

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

 * registering rewrite rules before the 'init' action.

 */

function create_initial_taxonomies() {

	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' ),

	) );

}

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.

 * 	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.

 *

 * 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 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.

 *

 * @package WordPress

 * @subpackage Taxonomy

 * @since 2.3.0

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

 * @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;

	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;

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

	}

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

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

			'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['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');

	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;

}

//

// 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