CaffGeek/MBACNationals

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Web.Admin/2014/wordpress/wp-includes/nav-menu-template.php

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

/**
 * Create HTML list of nav menu items.
 *
 * @since 3.0.0
 * @uses Walker
 */
class Walker_Nav_Menu extends Walker {
    /**
     * What the class handles.
     *
     * @see Walker::$tree_type
     * @since 3.0.0
     * @var string
     */
    var $tree_type = array( 'post_type', 'taxonomy', 'custom' );

    /**
     * Database fields to use.
     *
     * @see Walker::$db_fields
     * @since 3.0.0
     * @todo Decouple this.
     * @var array
     */
    var $db_fields = array( 'parent' => 'menu_item_parent', 'id' => 'db_id' );

    /**
     * Starts the list before the elements are added.
     *
     * @see Walker::start_lvl()
     *
     * @since 3.0.0
     *
     * @param string $output Passed by reference. Used to append additional content.
     * @param int    $depth  Depth of menu item. Used for padding.
     * @param array  $args   An array of arguments. @see wp_nav_menu()
     */
    function start_lvl( &$output, $depth = 0, $args = array() ) {
        $indent = str_repeat("\t", $depth);
        $output .= "\n$indent<ul class=\"sub-menu\">\n";
    }

    /**
     * Ends the list of after the elements are added.
     *
     * @see Walker::end_lvl()
     *
     * @since 3.0.0
     *
     * @param string $output Passed by reference. Used to append additional content.
     * @param int    $depth  Depth of menu item. Used for padding.
     * @param array  $args   An array of arguments. @see wp_nav_menu()
     */
    function end_lvl( &$output, $depth = 0, $args = array() ) {
        $indent = str_repeat("\t", $depth);
        $output .= "$indent</ul>\n";
    }

    /**
     * Start the element output.
     *
     * @see Walker::start_el()
     *
     * @since 3.0.0
     *
     * @param string $output Passed by reference. Used to append additional content.
     * @param object $item   Menu item data object.
     * @param int    $depth  Depth of menu item. Used for padding.
     * @param array  $args   An array of arguments. @see wp_nav_menu()
     * @param int    $id     Current item ID.
     */
    function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
        $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

        $class_names = '';

        $classes = empty( $item->classes ) ? array() : (array) $item->classes;
        $classes[] = 'menu-item-' . $item->ID;

        /**
         * Filter the CSS class(es) applied to a menu item's <li>.
         *
         * @since 3.0.0
         *
         * @see wp_nav_menu()
         *
         * @param array  $classes The CSS classes that are applied to the menu item's <li>.
         * @param object $item    The current menu item.
         * @param array  $args    An array of wp_nav_menu() arguments.
         */
        $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );
        $class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';

        /**
         * Filter the ID applied to a menu item's <li>.
         *
         * @since 3.0.1
         *
         * @see wp_nav_menu()
         *
         * @param string $menu_id The ID that is applied to the menu item's <li>.
         * @param object $item    The current menu item.
         * @param array  $args    An array of wp_nav_menu() arguments.
         */
        $id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );
        $id = $id ? ' id="' . esc_attr( $id ) . '"' : '';

        $output .= $indent . '<li' . $id . $class_names .'>';

        $atts = array();
        $atts['title']  = ! empty( $item->attr_title ) ? $item->attr_title : '';
        $atts['target'] = ! empty( $item->target )     ? $item->target     : '';
        $atts['rel']    = ! empty( $item->xfn )        ? $item->xfn        : '';
        $atts['href']   = ! empty( $item->url )        ? $item->url        : '';

        /**
         * Filter the HTML attributes applied to a menu item's <a>.
         *
         * @since 3.6.0
         *
         * @see wp_nav_menu()
         *
         * @param array $atts {
         *     The HTML attributes applied to the menu item's <a>, empty strings are ignored.
         *
         *     @type string $title  Title attribute.
         *     @type string $target Target attribute.
         *     @type string $rel    The rel attribute.
         *     @type string $href   The href attribute.
         * }
         * @param object $item The current menu item.
         * @param array  $args An array of wp_nav_menu() arguments.
         */
        $atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args );

        $attributes = '';
        foreach ( $atts as $attr => $value ) {
            if ( ! empty( $value ) ) {
                $value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
                $attributes .= ' ' . $attr . '="' . $value . '"';
            }
        }

        $item_output = $args->before;
        $item_output .= '<a'. $attributes .'>';
        /** This filter is documented in wp-includes/post-template.php */
        $item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
        $item_output .= '</a>';
        $item_output .= $args->after;

        /**
         * Filter a menu item's starting output.
         *
         * The menu item's starting output only includes $args->before, the opening <a>,
         * the menu item's title, the closing </a>, and $args->after. Currently, there is
         * no filter for modifying the opening and closing <li> for a menu item.
         *
         * @since 3.0.0
         *
         * @see wp_nav_menu()
         *
         * @param string $item_output The menu item's starting HTML output.
         * @param object $item        Menu item data object.
         * @param int    $depth       Depth of menu item. Used for padding.
         * @param array  $args        An array of wp_nav_menu() arguments.
         */
        $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
    }

    /**
     * Ends the element output, if needed.
     *
     * @see Walker::end_el()
     *
     * @since 3.0.0
     *
     * @param string $output Passed by reference. Used to append additional content.
     * @param object $item   Page data object. Not used.
     * @param int    $depth  Depth of page. Not Used.
     * @param array  $args   An array of arguments. @see wp_nav_menu()
     */
    function end_el( &$output, $item, $depth = 0, $args = array() ) {
        $output .= "</li>\n";
    }

} // Walker_Nav_Menu

/**
 * Displays a navigation menu.
 *
 * @since 3.0.0
 *
 * @param array $args {
 *     Optional. Array of nav menu arguments.
 *
 *     @type string        $menu            Desired menu. Accepts (matching in order) id, slug, name. Default empty.
 *     @type string        $menu_class      CSS class to use for the ul element which forms the menu. Default 'menu'.
 *     @type string        $menu_id         The ID that is applied to the ul element which forms the menu.
 *                                          Default is the menu slug, incremented.
 *     @type string        $container       Whether to wrap the ul, and what to wrap it with. Default 'div'.
 *     @type string        $container_class Class that is applied to the container. Default 'menu-{menu slug}-container'.
 *     @type string        $container_id    The ID that is applied to the container. Default empty.
 *     @type callback|bool $fallback_cb     If the menu doesn't exists, a callback function will fire.
 *                                          Default is 'wp_page_menu'. Set to false for no fallback.
 *     @type string        $before          Text before the link text. Default empty.
 *     @type string        $after           Text after the link text. Default empty.
 *     @type string        $link_before     Text before the link. Default empty.
 *     @type string        $link_after      Text after the link. Default empty.
 *     @type bool          $echo            Whether to echo the menu or return it. Default true.
 *     @type int           $depth           How many levels of the hierarchy are to be included. 0 means all. Default 0.
 *     @type string        $walker          Allows a custom walker class to be specified. Default empty.
 *     @type string        $theme_location  Theme location to be used. Must be registered with register_nav_menu()
 *                                          in order to be selectable by the user.
 *     @type string        $items_wrap      How the list items should be wrapped. Default is a ul with an id and class.
 *                                          Uses printf() format with numbered placeholders.
 * }
 * @return mixed Menu output if $echo is false, false if there are no items or no menu was found.
 */
function wp_nav_menu( $args = array() ) {
    static $menu_id_slugs = array();

    $defaults = array( 'menu' => '', 'container' => 'div', 'container_class' => '', 'container_id' => '', 'menu_class' => 'menu', 'menu_id' => '',
    'echo' => true, 'fallback_cb' => 'wp_page_menu', 'before' => '', 'after' => '', 'link_before' => '', 'link_after' => '', 'items_wrap' => '<ul id="%1$s" class="%2$s">%3$s</ul>',
    'depth' => 0, 'walker' => '', 'theme_location' => '' );

    $args = wp_parse_args( $args, $defaults );
    /**
     * Filter the arguments used to display a navigation menu.
     *
     * @since 3.0.0
     *
     * @see wp_nav_menu()
     *
     * @param array $args Array of wp_nav_menu() arguments.
     */
    $args = apply_filters( 'wp_nav_menu_args', $args );
    $args = (object) $args;

    /**
     * Filter whether to short-circuit the wp_nav_menu() output.
     *
     * Returning a non-null value to the filter will short-circuit
     * wp_nav_menu(), echoing that value if $args->echo is true,
     * returning that value otherwise.
     *
     * @since 3.9.0
     *
     * @see wp_nav_menu()
     *
     * @param string|null $output Nav menu output to short-circuit with. Default null.
     * @param object      $args   An object containing wp_nav_menu() arguments.
     */
    $nav_menu = apply_filters( 'pre_wp_nav_menu', null, $args );

    if ( null !== $nav_menu ) {
        if ( $args->echo ) {
            echo $nav_menu;
            return;
        }

        return $nav_menu;
    }

    // Get the nav menu based on the requested menu
    $menu = wp_get_nav_menu_object( $args->menu );

    // Get the nav menu based on the theme_location
    if ( ! $menu && $args->theme_location && ( $locations = get_nav_menu_locations() ) && isset( $locations[ $args->theme_location ] ) )
        $menu = wp_get_nav_menu_object( $locations[ $args->theme_location ] );

    // get the first menu that has items if we still can't find a menu
    if ( ! $menu && !$args->theme_location ) {
        $menus = wp_get_nav_menus();
        foreach ( $menus as $menu_maybe ) {
            if ( $menu_items = wp_get_nav_menu_items( $menu_maybe->term_id, array( 'update_post_term_cache' => false ) ) ) {
                $menu = $menu_maybe;
                break;
            }
        }
    }

    // If the menu exists, get its items.
    if ( $menu && ! is_wp_error($menu) && !isset($menu_items) )
        $menu_items = wp_get_nav_menu_items( $menu->term_id, array( 'update_post_term_cache' => false ) );

    /*
     * If no menu was found:
     *  - Fall back (if one was specified), or bail.
     *
     * If no menu items were found:
     *  - Fall back, but only if no theme location was specified.
     *  - Otherwise, bail.
     */
    if ( ( !$menu || is_wp_error($menu) || ( isset($menu_items) && empty($menu_items) && !$args->theme_location ) )
        && $args->fallback_cb && is_callable( $args->fallback_cb ) )
            return call_user_func( $args->fallback_cb, (array) $args );

    if ( ! $menu || is_wp_error( $menu ) )
        return false;

    $nav_menu = $items = '';

    $show_container = false;
    if ( $args->container ) {
        /**
         * Filter the list of HTML tags that are valid for use as menu containers.
         *
         * @since 3.0.0
         *
         * @param array $tags The acceptable HTML tags for use as menu containers.
         *                    Default is array containing 'div' and 'nav'.
         */
        $allowed_tags = apply_filters( 'wp_nav_menu_container_allowedtags', array( 'div', 'nav' ) );
        if ( in_array( $args->container, $allowed_tags ) ) {
            $show_container = true;
            $class = $args->container_class ? ' class="' . esc_attr( $args->container_class ) . '"' : ' class="menu-'. $menu->slug .'-container"';
            $id = $args->container_id ? ' id="' . esc_attr( $args->container_id ) . '"' : '';
            $nav_menu .= '<'. $args->container . $id . $class . '>';
        }
    }

    // Set up the $menu_item variables
    _wp_menu_item_classes_by_context( $menu_items );

    $sorted_menu_items = $menu_items_with_children = array();
    foreach ( (array) $menu_items as $menu_item ) {
        $sorted_menu_items[ $menu_item->menu_order ] = $menu_item;
        if ( $menu_item->menu_item_parent )
            $menu_items_with_children[ $menu_item->menu_item_parent ] = true;
    }

    // Add the menu-item-has-children class where applicable
    if ( $menu_items_with_children ) {
        foreach ( $sorted_menu_items as &$menu_item ) {
            if ( isset( $menu_items_with_children[ $menu_item->ID ] ) )
                $menu_item->classes[] = 'menu-item-has-children';
        }
    }

    unset( $menu_items, $menu_item );

    /**
     * Filter the sorted list of menu item objects before generating the menu's HTML.
     *
     * @since 3.1.0
     *
     * @param array $sorted_menu_items The menu items, sorted by each menu item's menu order.
     */
    $sorted_menu_items = apply_filters( 'wp_nav_menu_objects', $sorted_menu_items, $args );

    $items .= walk_nav_menu_tree( $sorted_menu_items, $args->depth, $args );
    unset($sorted_menu_items);

    // Attributes
    if ( ! empty( $args->menu_id ) ) {
        $wrap_id = $args->menu_id;
    } else {
        $wrap_id = 'menu-' . $menu->slug;
        while ( in_array( $wrap_id, $menu_id_slugs ) ) {
            if ( preg_match( '#-(\d+)$#', $wrap_id, $matches ) )
                $wrap_id = preg_replace('#-(\d+)$#', '-' . ++$matches[1], $wrap_id );
            else
                $wrap_id = $wrap_id . '-1';
        }
    }
    $menu_id_slugs[] = $wrap_id;

    $wrap_class = $args->menu_class ? $args->menu_class : '';

    /**
     * Filter the HTML list content for navigation menus.
     *
     * @since 3.0.0
     *
     * @see wp_nav_menu()
     *
     * @param string $items The HTML list content for the menu items.
     * @param array  $args  Array of wp_nav_menu() arguments.
     */
    $items = apply_filters( 'wp_nav_menu_items', $items, $args );
    /**
     * Filter the HTML list content for a specific navigation menu.
     *
     * @since 3.0.0
     *
     * @see wp_nav_menu()
     *
     * @param string $items The HTML list content for the menu items.
     * @param array  $args  Array of wp_nav_menu() arguments.
     */
    $items = apply_filters( "wp_nav_menu_{$menu->slug}_items", $items, $args );

    // Don't print any markup if there are no items at this point.
    if ( empty( $items ) )
        return false;

    $nav_menu .= sprintf( $args->items_wrap, esc_attr( $wrap_id ), esc_attr( $wrap_class ), $items );
    unset( $items );

    if ( $show_container )
        $nav_menu .= '</' . $args->container . '>';

    /**
     * Filter the HTML content for navigation menus.
     *
     * @since 3.0.0
     *
     * @see wp_nav_menu()
     *
     * @param string $nav_menu The HTML content for the navigation menu.
     * @param array  $args     Array of wp_nav_menu() arguments.
     */
    $nav_menu = apply_filters( 'wp_nav_menu', $nav_menu, $args );

    if ( $args->echo )
        echo $nav_menu;
    else
        return $nav_menu;
}

/**
 * Add the class property classes for the current context, if applicable.
 *
 * @access private
 * @since 3.0.0
 *
 * @param array $menu_items The current menu item objects to which to add the class property information.
 */
function _wp_menu_item_classes_by_context( &$menu_items ) {
    global $wp_query, $wp_rewrite;

    $queried_object = $wp_query->get_queried_object();
    $queried_object_id = (int) $wp_query->queried_object_id;

    $active_object = '';
    $active_ancestor_item_ids = array();
    $active_parent_item_ids = array();
    $active_parent_object_ids = array();
    $possible_taxonomy_ancestors = array();
    $possible_object_parents = array();
    $home_page_id = (int) get_option( 'page_for_posts' );

    if ( $wp_query->is_singular && ! empty( $queried_object->post_type ) && ! is_post_type_hierarchical( $queried_object->post_type ) ) {
        foreach ( (array) get_object_taxonomies( $queried_object->post_type ) as $taxonomy ) {
            if ( is_taxonomy_hierarchical( $taxonomy ) ) {
                $term_hierarchy = _get_term_hierarchy( $taxonomy );
                $terms = wp_get_object_terms( $queried_object_id, $taxonomy, array( 'fields' => 'ids' ) );
                if ( is_array( $terms ) ) {
                    $possible_object_parents = array_merge( $possible_object_parents, $terms );
                    $term_to_ancestor = array();
                    foreach ( (array) $term_hierarchy as $anc => $descs ) {
                        foreach ( (array) $descs as $desc )
                            $term_to_ancestor[ $desc ] = $anc;
                    }

                    foreach ( $terms as $desc ) {
                        do {
                            $possible_taxonomy_ancestors[ $taxonomy ][] = $desc;
                            if ( isset( $term_to_ancestor[ $desc ] ) ) {
                                $_desc = $term_to_ancestor[ $desc ];
                                unset( $term_to_ancestor[ $desc ] );
                                $desc = $_desc;
                            } else {
                                $desc = 0;
                            }
                        } while ( ! empty( $desc ) );
                    }
                }
            }
        }
    } elseif ( ! empty( $queried_object->taxonomy ) && is_taxonomy_hierarchical( $queried_object->taxonomy ) ) {
        $term_hierarchy = _get_term_hierarchy( $queried_object->taxonomy );
        $term_to_ancestor = array();
        foreach ( (array) $term_hierarchy as $anc => $descs ) {
            foreach ( (array) $descs as $desc )
                $term_to_ancestor[ $desc ] = $anc;
        }
        $desc = $queried_object->term_id;
        do {
            $possible_taxonomy_ancestors[ $queried_object->taxonomy ][] = $desc;
            if ( isset( $term_to_ancestor[ $desc ] ) ) {
                $_desc = $term_to_ancestor[ $desc ];
                unset( $term_to_ancestor[ $desc ] );
                $desc = $_desc;
            } else {
                $desc = 0;
            }
        } while ( ! empty( $desc ) );
    }

    $possible_object_parents = array_filter( $possible_object_parents );

    $front_page_url = home_url();

    foreach ( (array) $menu_items as $key => $menu_item ) {

        $menu_items[$key]->current = false;

        $classes = (array) $menu_item->classes;
        $classes[] = 'menu-item';
        $classes[] = 'menu-item-type-' . $menu_item->type;
        $classes[] = 'menu-item-object-' . $menu_item->object;

        // if the menu item corresponds to a taxonomy term for the currently-queried non-hierarchical post object
        if ( $wp_query->is_singular && 'taxonomy' == $menu_item->type && in_array( $menu_item->object_id, $possible_object_parents ) ) {
            $active_parent_object_ids[] = (int) $menu_item->object_id;
            $active_parent_item_ids[] = (int) $menu_item->db_id;
            $active_object = $queried_object->post_type;

        // if the menu item corresponds to the currently-queried post or taxonomy object
        } elseif (
            $menu_item->object_id == $queried_object_id &&
            (
                ( ! empty( $home_page_id ) && 'post_type' == $menu_item->type && $wp_query->is_home && $home_page_id == $menu_item->object_id ) ||
                ( 'post_type' == $menu_item->type && $wp_query->is_singular ) ||
                ( 'taxonomy' == $menu_item->type && ( $wp_query->is_category || $wp_query->is_tag || $wp_query->is_tax ) && $queried_object->taxonomy == $menu_item->object )
            )
        ) {
            $classes[] = 'current-menu-item';
            $menu_items[$key]->current = true;
            $_anc_id = (int) $menu_item->db_id;

            while(
                ( $_anc_id = get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) ) &&
                ! in_array( $_anc_id, $active_ancestor_item_ids )
            ) {
                $active_ancestor_item_ids[] = $_anc_id;
            }

            if ( 'post_type' == $menu_item->type && 'page' == $menu_item->object ) {
                // Back compat classes for pages to match wp_page_menu()
                $classes[] = 'page_item';
                $classes[] = 'page-item-' . $menu_item->object_id;
                $classes[] = 'current_page_item';
            }
            $active_parent_item_ids[] = (int) $menu_item->menu_item_parent;
            $active_parent_object_ids[] = (int) $menu_item->post_parent;
            $active_object = $menu_item->object;

        // if the menu item corresponds to the currently-requested URL
        } elseif ( 'custom' == $menu_item->object ) {
            $_root_relative_current = untrailingslashit( $_SERVER['REQUEST_URI'] );
            $current_url = set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_root_relative_current );
            $raw_item_url = strpos( $menu_item->url, '#' ) ? substr( $menu_item->url, 0, strpos( $menu_item->url, '#' ) ) : $menu_item->url;
            $item_url = untrailingslashit( $raw_item_url );
            $_indexless_current = untrailingslashit( preg_replace( '/' . preg_quote( $wp_rewrite->index, '/' ) . '$/', '', $current_url ) );

            if ( $raw_item_url && in_array( $item_url, array( $current_url, $_indexless_current, $_root_relative_current ) ) ) {
                $classes[] = 'current-menu-item';
                $menu_items[$key]->current = true;
                $_anc_id = (int) $menu_item->db_id;

                while(
                    ( $_anc_id = get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) ) &&
                    ! in_array( $_anc_id, $active_ancestor_item_ids )
                ) {
                    $active_ancestor_item_ids[] = $_anc_id;
                }

                if ( in_array( home_url(), array( untrailingslashit( $current_url ), untrailingslashit( $_indexless_current ) ) ) ) {
                    // Back compat for home link to match wp_page_menu()
                    $classes[] = 'current_page_item';
                }
                $active_parent_item_ids[] = (int) $menu_item->menu_item_parent;
                $active_parent_object_ids[] = (int) $menu_item->post_parent;
                $active_object = $menu_item->object;

            // give front page item current-menu-item class when extra query arguments involved
            } elseif ( $item_url == $front_page_url && is_front_page() ) {
                $classes[] = 'current-menu-item';
            }

            if ( untrailingslashit($item_url) == home_url() )
                $classes[] = 'menu-item-home';
        }

        // back-compat with wp_page_menu: add "current_page_parent" to static home page link for any non-page query
        if ( ! empty( $home_page_id ) && 'post_type' == $menu_item->type && empty( $wp_query->is_page ) && $home_page_id == $menu_item->object_id )
            $classes[] = 'current_page_parent';

        $menu_items[$key]->classes = array_unique( $classes );
    }
    $active_ancestor_item_ids = array_filter( array_unique( $active_ancestor_item_ids ) );
    $active_parent_item_ids = array_filter( array_unique( $active_parent_item_ids ) );
    $active_parent_object_ids = array_filter( array_unique( $active_parent_object_ids ) );

    // set parent's class
    foreach ( (array) $menu_items as $key => $parent_item ) {
        $classes = (array) $parent_item->classes;
        $menu_items[$key]->current_item_ancestor = false;
        $menu_items[$key]->current_item_parent = false;

        if (
            isset( $parent_item->type ) &&
            (
                // ancestral post object
                (
                    'post_type' == $parent_item->type &&
                    ! empty( $queried_object->post_type ) &&
                    is_post_type_hierarchical( $queried_object->post_type ) &&
                    in_array( $parent_item->object_id, $queried_object->ancestors ) &&
                    $parent_item->object != $queried_object->ID
                ) ||

                // ancestral term
                (
                    'taxonomy' == $parent_item->type &&
                    isset( $possible_taxonomy_ancestors[ $parent_item->object ] ) &&
                    in_array( $parent_item->object_id, $possible_taxonomy_ancestors[ $parent_item->object ] ) &&
                    (
                        ! isset( $queried_object->term_id ) ||
                        $parent_item->object_id != $queried_object->term_id
                    )
                )
            )
        ) {
            $classes[] = empty( $queried_object->taxonomy ) ? 'current-' . $queried_object->post_type . '-ancestor' : 'current-' . $queried_object->taxonomy . '-ancestor';
        }

        if ( in_array(  intval( $parent_item->db_id ), $active_ancestor_item_ids ) ) {
            $classes[] = 'current-menu-ancestor';
            $menu_items[$key]->current_item_ancestor = true;
        }
        if ( in_array( $parent_item->db_id, $active_parent_item_ids ) ) {
            $classes[] = 'current-menu-parent';
            $menu_items[$key]->current_item_parent = true;
        }
        if ( in_array( $parent_item->object_id, $active_parent_object_ids ) )
            $classes[] = 'current-' . $active_object . '-parent';

        if ( 'post_type' == $parent_item->type && 'page' == $parent_item->object ) {
            // Back compat classes for pages to match wp_page_menu()
            if ( in_array('current-menu-parent', $classes) )
                $classes[] = 'current_page_parent';
            if ( in_array('current-menu-ancestor', $classes) )
                $classes[] = 'current_page_ancestor';
        }

        $menu_items[$key]->classes = array_unique( $classes );
    }
}

/**
 * Retrieve the HTML list content for nav menu items.
 *
 * @uses Walker_Nav_Menu to create HTML list content.
 * @since 3.0.0
 * @see Walker::walk() for parameters and return description.
 */
function walk_nav_menu_tree( $items, $depth, $r ) {
    $walker = ( empty($r->walker) ) ? new Walker_Nav_Menu : $r->walker;
    $args = array( $items, $depth, $r );

    return call_user_func_array( array($walker, 'walk'), $args );
}

/**
 * Prevents a menu item ID from being used more than once.
 *
 * @since 3.0.1
 * @access private
 */
function _nav_menu_item_id_use_once( $id, $item ) {
    static $_used_ids = array();
    if ( in_array( $item->ID, $_used_ids ) )
        return '';
    $_used_ids[] = $item->ID;
    return $id;
}
add_filter( 'nav_menu_item_id', '_nav_menu_item_id_use_once', 10, 2 );