Showing the current page’s parent’s sub-menu items from a custom nav menu in WordPress

링크: http://wordpress.stackexchange.com/questions/32274/display-only-page-specific-sub-menu-items-using-custom-walker

functions.php 파일에 다음 코드 추가

class Custom_Walker_Nav_Sub_Menu extends Walker_Nav_Menu {

var $found_parents = array();

function start_el(&$output, $item, $depth, $args) {

global $wp_query;

//this only works for second level sub navigations
$parent_item_id = 0;

$indent = ( $depth ) ? str_repeat( "t", $depth ) : '';

$class_names = $value = '';

$classes = empty( $item->classes ) ? array() : (array) $item->classes;

$class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item ) );
$class_names = ' class="' . esc_attr( $class_names ) . '"';

if ( ($item->menu_item_parent==0) && (strpos($class_names, 'current-menu-parent')) ) {

$output.= '

<li>';

}

// Checks if the current element is in the current selection

if (strpos($class_names, 'current-menu-item')

|| strpos($class_names, 'current-menu-parent')

|| strpos($class_names, 'current-menu-ancestor')

|| (is_array($this->found_parents) && in_array( $item->menu_item_parent, $this->found_parents )) ) {

// Keep track of all selected parents
$this->found_parents[] = $item->ID;

//check if the item_parent matches the current item_parent
if($item->menu_item_parent!=$parent_item_id){

$output .= $indent . '<li id="menu-item-'. $item->ID . '"' . $value . $class_names .'>';

$attributes = ! empty( $item->attr_title ) ? ' title="' . esc_attr( $item->attr_title ) .'"' : '';
$attributes .= ! empty( $item->target ) ? ' target="' . esc_attr( $item->target ) .'"' : '';

$attributes .= ! empty( $item->xfn ) ? ' rel="' . esc_attr( $item->xfn ) .'"' : '';

$attributes .= ! empty( $item->url ) ? ' href="' . esc_attr( $item->url ) .'"' : '';

$item_output = $args->before;
$item_output .= '<a'. $attributes .'>';

$item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;

$item_output .= '</a>';

$item_output .= $args->after;

$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
}

}

}

function end_el(&$output, $item, $depth) {
// Closes only the opened li

if ( is_array($this->found_parents) && in_array( $item->ID, $this->found_parents ) ) {

$output .= "</li>n";

}

}

function end_lvl(&$output, $depth) {
$indent = str_repeat("t", $depth);

// If the sub-menu is empty, strip the opening tag, else closes it

if (substr($output, -22)=="<ul class="sub-menu">n") {

$output = substr($output, 0, strlen($output)-23);

} else {

$output .= "$indent</ul>n";

}

}

}

sidebar.php 에 다음 코드 추가

$menu_args = array(
'walker' => new Custom_Walker_Nav_Sub_Menu(),

'container' => '',

'menu_class' => 'sister-pages',

s);

wp_nav_menu($menu_args);

How-to get a menu label via $post-> or $page->ID

(현재 페이지 1depth 메뉴의 label 추출)

링크:  http://stackoverflow.com/questions/22806170/how-to-get-a-menu-label-via-post-or-page-id

functions.php에 다음 코드 추가

function get_menu_label_by_post_id($post_id, $menu) {

$menu_title = '';
$nav = wp_get_nav_menu_items($menu);

foreach ( $nav as $item ) {

if ( $post_id == $item->object_id ) {
$menu_title = $item->post_title;

break;

}

}

return ($menu_title !== '') ? $menu_title : get_the_title($post_id);

}

sidebar.php에 다음 코드 추가

echo get_menu_label_by_post_id($post->ID, 'gnb');