WordPress/wp-includes/nav-menu.php

<?php
/**
 * Navigation Menu functions
 *
 * @package WordPress
 * @subpackage Nav_Menus
 * @since 3.0.0
 */

/**
 * Returns a navigation menu object.
 *
 * @since 3.0.0
 *
 * @param string $menu Menu id
 * @return mixed $menu|false Or WP_Error
 */
function wp_get_nav_menu_object( $menu ) {
	if ( ! $menu ) 
		return false;

	$menu_obj = get_term( $menu, 'nav_menu' );

	if ( ! $menu_obj )
		$menu_obj = get_term_by( 'slug', $menu, 'nav_menu' );

	if ( ! $menu_obj )
		$menu_obj = get_term_by( 'name', $menu, 'nav_menu' );

	if ( ! $menu_obj ) {
		$menu_obj = false;
	}

	return $menu_obj;
}

/**
 * Check if navigation menu exists.
 *
 * Returns the menu object, or false if the term doesn't exist.
 *
 * @since 3.0.0
 *
 * @param int|string $menu The menu to check
 * @return bool Whether the menu exists.
 */
function is_nav_menu( $menu ) {
	if ( ! $menu )
		return false;
	
	$menu_obj = wp_get_nav_menu_object( $menu );

	if ( $menu_obj && ! is_wp_error( $menu_obj ) && ! empty( $menu_obj->term_id ) ) 
		return true;
	
	return false;
}

/**
 * Create a Navigation Menu.
 *
 * Optional args:
 * slug - the url friendly version of the nav menu.
 *
 * @since 3.0.0
 *
 * @param string $menu_name Menu Name
 * @param string $args Optional.
 * @return mixed Menu object on sucess|WP_Error on failure
 */
function wp_create_nav_menu( $menu_name, $args = array() ) {
	$menu_exists = get_term_by( 'name', $menu_name, 'nav_menu' );

	if ( $menu_exists )
		return new WP_Error( 'menu_exists', sprintf( __('A menu named <strong>%s</strong> already exists; please try another name.'), esc_html( $menu_exists->name ) ) );

	if ( isset($args['slug']) )
		$slug = $args['slug'];
	else
		$slug = $menu_name;

	$menu = wp_insert_term( $menu_name, 'nav_menu', array('slug' => $slug) );

	if ( is_wp_error($menu) )
		return $menu;

	$result = get_term( $menu['term_id'], 'nav_menu' );

	if ( $result && !is_wp_error($result) ) {
		do_action( 'wp_create_nav_menu', $menu['term_id'] );
		return $result;
	} else {
		return $result;
	}
}

/**
 * Delete a Navigation Menu.
 *
 * @since 3.0.0
 *
 * @param string $menu name|id|slug
 * @return mixed Menu object on sucess|WP_Error on failure
 */
function wp_delete_nav_menu( $menu ) {
	$menu = wp_get_nav_menu_object( $menu );
	if ( ! $menu  )
		return false;

	$menu_objects = get_objects_in_term( $menu->term_id, 'nav_menu' );
	if ( !empty( $menu_objects ) ) {
		foreach ( $menu_objects as $item ) {
			wp_delete_post( $item );
		}
	}

	$result = wp_delete_term( $menu->term_id, 'nav_menu' );

	if ( $result && !is_wp_error($result) ) {
		do_action( 'wp_delete_nav_menu', $menu->term_id );
		return $result;
	} else {
		return $result;
	}
}

/**
 * Save the properties of a menu or create a new menu with those properties.
 *
 * @since 3.0.0
 *
 * @param int $menu_id The ID of the menu
 * @param array $menu_data The array of menu data.
 * @return int The menu's ID.
 */
function wp_update_nav_menu_object( $menu_id = 0, $menu_data = array() ) {
	$menu_id = (int) $menu_id;

	$_menu = wp_get_nav_menu_object( $menu_id );

	// menu doesn't already exist
	if ( ! $_menu || is_wp_error( $_menu ) ) {
		$_menu = wp_create_nav_menu( $menu_data['menu-name'] );
	}

	if ( $_menu && isset( $_menu->term_id ) && ! is_wp_error( $_menu ) ) {
		$args = array( 
			'description' => ( isset( $menu_data['description'] ) ? $menu_data['description'] : '' ), 
			'name' => ( isset( $menu_data['menu-name'] ) ? $menu_data['menu-name'] : '' ), 
			'parent' => ( isset( $menu_data['parent'] ) ? (int) $menu_data['parent'] : 0 ), 
			'slug' => null, 
		);
	
		$menu_id = (int) $_menu->term_id;

		$update_response = wp_update_term( $menu_id, 'nav_menu', $args );

		if ( ! is_wp_error( $update_response ) ) {
			return $menu_id;
		}
	} else {
		return 0;
	}
}

/**
 * Save the properties of a menu item or create a new one.
 *
 * @since 3.0.0
 *
 * @param int $menu_id The ID of the menu. Required.
 * @param int $menu_item_db_id The ID of the menu item. If "0", creates a new menu item.
 * @param array $menu_item_data The menu item's data.
 * @return int The menu item's database ID or WP_Error object on failure.
 */
function wp_update_nav_menu_item( $menu_id = 0, $menu_item_db_id = 0, $menu_item_data = array() ) {

	$menu_id = (int) $menu_id;
	$menu_item_db_id = (int) $menu_item_db_id;

	$menu = wp_get_nav_menu_object( $menu_id );

	if ( ! $menu || is_wp_error( $menu ) ) {
		return $menu;
	}

	$menu_items = (array) wp_get_nav_menu_items( $menu_id );

	$count = count( $menu_items );

	$defaults = array(
		'menu-item-db-id' => $menu_item_db_id,
		'menu-item-object-id' => 0,
		'menu-item-object' => '',
		'menu-item-parent-id' => 0,
		'menu-item-position' => 0,
		'menu-item-type' => 'custom',
		'menu-item-append' => 'custom',
		'menu-item-title' => '',
		'menu-item-url' => '',
		'menu-item-description' => '',
		'menu-item-attr-title' => '',
		'menu-item-target' => '',
		'menu-item-classes' => '',
		'menu-item-xfn' => '',
	);

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

	if ( 0 == (int) $args['menu-item-position'] ) {
		$last_item = array_pop( $menu_items );
		if ( $last_item && isset( $last_item->ID ) ) {
			$last_data = get_post( $last_item->ID );
			if ( ! is_wp_error( $last_data ) && isset( $last_data->menu_order ) ) {
				$args['menu-item-position'] = 1 + (int) $last_data->menu_order;
			}

		} else {
			$args['menu-item-position'] = $count;
		}
	}
	
	// Populate the menu item object
	$post = array(
		'menu_order' => $args['menu-item-position'],
		'ping_status' => 0,
		'post_content' => $args['menu-item-description'],
		'post_excerpt' => $args['menu-item-attr-title'],
		'post_parent' => $args['menu-item-parent-id'], 
		'post_status' => 'publish', 
		'post_title' => $args['menu-item-title'], 
		'post_type' => 'nav_menu_item', 
		'tax_input' => array( 'nav_menu' => $menu->name ),
	);

	// New menu item
	if ( 0 == $menu_item_db_id ) {
		$menu_item_db_id = wp_insert_post( $post );

	// Update existing menu item
	} else {
		$post['ID'] = $menu_item_db_id;
		wp_update_post( $post );
	}

	if ( 'custom' == $args['menu-item-type'] ) {
		$args['menu-item-object-id'] = $menu_item_db_id;
		$args['menu-item-object'] = 'custom';
	}

	if ( $menu_item_db_id && ! is_wp_error( $menu_item_db_id ) ) {

		$menu_item_db_id = (int) $menu_item_db_id;

		update_post_meta( $menu_item_db_id, '_menu_item_type', sanitize_key($args['menu-item-type']) );
		update_post_meta( $menu_item_db_id, '_menu_item_object_id', (int) $args['menu-item-object-id'] );
		update_post_meta( $menu_item_db_id, '_menu_item_object', sanitize_key($args['menu-item-object']) );
		update_post_meta( $menu_item_db_id, '_menu_item_target', sanitize_key($args['menu-item-target']) );
		// @todo handle sanitizing multiple classes separated by whitespace.
		update_post_meta( $menu_item_db_id, '_menu_item_classes', sanitize_html_class($args['menu-item-classes']) );
		update_post_meta( $menu_item_db_id, '_menu_item_xfn', sanitize_html_class($args['menu-item-xfn']) );

		// @todo: only save custom link urls.
		update_post_meta( $menu_item_db_id, '_menu_item_url', esc_url_raw($args['menu-item-url']) );

		do_action('wp_update_nav_menu_item', $menu_id, $menu_item_db_id, $args );
	}

	return $menu_item_db_id;
}

/**
 * Returns all navigation menu objects.
 *
 * @since 3.0.0
 *
 * @return array menu objects
 */
function wp_get_nav_menus() {
	return get_terms( 'nav_menu', array( 'hide_empty' => false, 'orderby' => 'id' ) );
}


/**
 * Sort menu items by the desired key.
 *
 * @since 3.0.0
 * @access private
 *
 * @param object $a The first object to compare
 * @param object $b The second object to compare
 * @return int -1, 0, or 1 if $a is considered to be respectively less than, equal to, or greater than $b.
 */
function _sort_nav_menu_items($a, $b) {
	global $_menu_item_sort_prop;

	if ( empty( $_menu_item_sort_prop ) ) {
		return 0;
	}

	if ( isset( $a->$_menu_item_sort_prop ) && isset( $b->$_menu_item_sort_prop ) ) {
		$_a = (int) $a->$_menu_item_sort_prop;
		$_b = (int) $b->$_menu_item_sort_prop;

		if ( $a->$_menu_item_sort_prop == $b->$_menu_item_sort_prop ) {
			return 0;	
		} elseif ( 
			( $_a == $a->$_menu_item_sort_prop ) && 
			( $_b == $b->$_menu_item_sort_prop ) 
		) {
			return $_a < $_b ? -1 : 1;
		} else {
			return strcmp( $a->$_menu_item_sort_prop, $b->$_menu_item_sort_prop );
		}
	} else {
		return 0;
	}
}

/**
 * Returns all menu items of a navigation menu.
 *
 * @since 3.0.0
 *
 * @param string $menu menu name, id, or slug
 * @param string $args
 * @return mixed $items array of menu items, else false.
 */
function wp_get_nav_menu_items( $menu, $args = array() ) {
	$menu = wp_get_nav_menu_object( $menu );

	if ( ! $menu )
		return false;
	
	$items = get_objects_in_term( $menu->term_id, 'nav_menu' );

	if ( ! empty( $items ) ) {
		$defaults = array( 'order' => 'ASC', 'orderby' => 'menu_order', 'post_type' => 'nav_menu_item', 'post_status' => 'publish', 'output' => ARRAY_A, 'output_key' => 'menu_order' );
		$args = wp_parse_args( $args, $defaults );
		if ( count( $items ) > 1 )
			$args['include'] = implode( ',', $items );
		else
			$args['include'] = $items[0];

		$items = get_posts( $args );

		if ( ARRAY_A == $args['output'] ) {
			$GLOBALS['_menu_item_sort_prop'] = $args['output_key'];
			usort($items, '_sort_nav_menu_items');
			$i = 1;
			foreach( $items as $k => $item ) {
				$items[$k]->$args['output_key'] = $i++;
			}
		}
	}
	return $items;
}

/**
 * Decorates a menu item object with the shared navigation menu item properties.
 *
 * Properties:
 * - db_id: 		The DB ID of the this item as a nav_menu_item object, if it exists (0 if it doesn't exist).
 * - object_id:		The DB ID of the original object this menu item represents, e.g. ID for posts and term_id for categories.
 * - type:		The family of objects originally represented, such as "post_type" or "taxonomy."
 * - object:		The type of object originally represented, such as "category," "post", or "attachment."
 * - append:		The singular label used to describe this type of menu item.
 * - parent:		The DB ID of the original object's parent object, if any (0 otherwise).
 * - url:		The URL to which this menu item points.
 * - title:		The title of this menu item.
 * - target: 		The target attribute of the link element for this menu item.
 * - attr_title:	The title attribute of the link element for this menu item.	 
 * - classes:		The class attribute value for the link element of this menu item.
 * - xfn:		The XFN relationship expressed in the link of this menu item.
 * - description:	The description of this menu item.
 *
 * @since 3.0.0
 *
 * @param object $menu_item The menu item to modify.
 * @return object $menu_item The menu item with standard menu item properties.
 */
function wp_setup_nav_menu_item( $menu_item ) {
	if ( isset( $menu_item->post_type ) ) {
		if ( 'nav_menu_item' == $menu_item->post_type ) {
			$menu_item->db_id = (int) $menu_item->ID;
			$menu_item->object_id = get_post_meta( $menu_item->ID, '_menu_item_object_id', true );
			$menu_item->object = get_post_meta( $menu_item->ID, '_menu_item_object', true );
			$menu_item->type = get_post_meta( $menu_item->ID, '_menu_item_type', true );
			
			if ( 'post_type' == $menu_item->type ) {
				$object = get_post_type_object( $menu_item->object );
				$menu_item->append = $object->singular_label;
				$menu_item->url = get_permalink( $menu_item->object_id );

			} elseif ( 'taxonomy' == $menu_item->type ) {
				$object = get_taxonomy( $menu_item->object );
				$menu_item->append = $object->singular_label;
				$menu_item->url = get_term_link( (int) $menu_item->object_id, $menu_item->object );

			} else {
				$menu_item->append = __('Custom');
				$menu_item->url = get_post_meta( $menu_item->ID, '_menu_item_url', true );
			}
			
			$menu_item->title = $menu_item->post_title;
			$menu_item->target = get_post_meta( $menu_item->ID, '_menu_item_target', true );

			$menu_item->attr_title = strip_tags( $menu_item->post_excerpt );
			$menu_item->description = strip_tags( $menu_item->post_content );

			$menu_item->classes = get_post_meta( $menu_item->ID, '_menu_item_classes', true );
			$menu_item->xfn = get_post_meta( $menu_item->ID, '_menu_item_xfn', true );
		} else {
			$menu_item->db_id = 0;
			$menu_item->object_id = (int) $menu_item->ID;
			$menu_item->type = 'post_type';

			$object = get_post_type_object( $menu_item->post_type );
			$menu_item->object = $object->name;
			$menu_item->append = strtolower( $object->singular_label );

			$menu_item->title = $menu_item->post_title;
			$menu_item->url = get_permalink( $menu_item->ID );
			$menu_item->target = '';

			$menu_item->attr_title = strip_tags( $menu_item->post_excerpt );
			$menu_item->description = strip_tags( $menu_item->post_content );
			$menu_item->classes = '';
			$menu_item->xfn = '';
		}
	} elseif ( isset( $menu_item->taxonomy ) ) {
		$menu_item->ID = $menu_item->term_id;
		$menu_item->db_id = 0;
		$menu_item->object_id = (int) $menu_item->term_id;
		$menu_item->post_parent = (int) $menu_item->parent;
		$menu_item->type = 'taxonomy';

		$object = get_taxonomy( $menu_item->taxonomy );
		$menu_item->object = $object->name;
		$menu_item->append = strtolower( $object->singular_label );

		$menu_item->title = $menu_item->name;
		$menu_item->url = get_term_link( $menu_item, $menu_item->taxonomy );
		$menu_item->target = '';
		$menu_item->attr_title = '';
		$menu_item->description = strip_tags( get_term_field( 'description', $menu_item->term_id, $menu_item->taxonomy ) );
		$menu_item->classes = '';
		$menu_item->xfn = '';

	}

	return apply_filters( 'wp_setup_nav_menu_item', $menu_item );
}
?>