我正在尝试为页面和帖子在wp\\u nav\\u菜单中添加一个类来锚定children元素的链接。是否有办法修改导航菜单漫游器并执行此操作？

基本上，我的定制助行器如下所示：

class Main_Nav extends Walker_Nav_Menu {
        function start_lvl(&$output, $depth) {
            $indent = str_repeat("\\t", $depth);
            $output .= "\\n$indent<ul class=\\"dropdown-menu\\">\\n";
        }
        function start_el(&$output, $item, $depth, $args) {

            if( $depth == 0) {
                    $output .= "<li class=\'menu\'>";
            }               
            if( $depth == 1) {
                    $output .= "<li>";
            }
            $attributes  = \'\';
            ! empty( $item->attr_title ) and $attributes .= \' title="\' . esc_attr( $item->attr_title ) .\'"\';
            ! empty( $item->target )and $attributes .= \' target="\' . esc_attr( $item->target ) .\'"\';
            ! empty( $item->xfn )and $attributes .= \' rel="\' . esc_attr( $item->xfn ) .\'"\';
            ! empty( $item->url )and $attributes .= \' href="\' . esc_attr( $item->url ) .\'"\';

            $title = apply_filters( \'the_title\', $item->title, $item->ID );

            if (/* THE MENU ELEMENT HAS CHILDREN */) {
                    $item_output = 
                    "<a $attributes class=\'menu\'>"
                    . $title
                    . \'</a> \';
            }

            else {
                    $item_output = 
                    "<a $attributes>"
                    . $title
                    . \'</a> \';
            }

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

    }

}

正如你所见，我不知道什么是合适的条件/* THE ELEMENT HAS CHILDREN */.

非常感谢。

UPDATE

多亏了泰米尔语，我将代码更新如下：

class Main_Nav extends Walker_Nav_Menu {
        function start_lvl(&$output, $depth) {
            $indent = str_repeat("\\t", $depth);
            $output .= "\\n$indent<ul class=\\"dropdown-menu\\">\\n";
        }
        function start_el(&$output, $item, $depth, $args) {

            if( $depth == 0) {
                    $output .= "<li class=\'menu\'>";
            }               
            if( $depth == 1) {
                    $output .= "<li>";
            }
            $attributes  = \'\';
            ! empty( $item->attr_title ) and $attributes .= \' title="\' . esc_attr( $item->attr_title ) .\'"\';
            ! empty( $item->target )and $attributes .= \' target="\' . esc_attr( $item->target ) .\'"\';
            ! empty( $item->xfn )and $attributes .= \' rel="\' . esc_attr( $item->xfn ) .\'"\';
            ! empty( $item->url )and $attributes .= \' href="\' . esc_attr( $item->url ) .\'"\';

            $title = apply_filters( \'the_title\', $item->title, $item->ID );

            global $wpdb;
            $query = $wpdb->prepare("SELECT COUNT(*) FROM $wpdb->posts WHERE post_status =\'publish\' AND post_type=\'nav_menu_item\' AND post_parent=%d", $item->ID);
            $child_count = $wpdb->get_var($query);

            if($child_count > 0) { /* THE MENU ELEMENT HAS CHILDREN */
                 $item_output = 
                    "<a $attributes class=\'menu\'>"
                    . $title
                    . \'</a> \';
            } else {
                    $item_output = 
                    "<a $attributes>"
                    . $title
                    . \'</a> \';
            }

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

    }

}

但运气不好：(

class Main_Nav extends Walker_Nav_Menu {
  /**
   * @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 int $current_page Menu item ID.
   * @param object $args
   */
  function start_el(&$output, $item, $depth, $args) {
    global $wp_query;
    $indent = ( $depth ) ? str_repeat( "\\t", $depth ) : \'\';

    $class_names = $value = \'\';

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

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

    $id = apply_filters( \'nav_menu_item_id\', \'menu-item-\'. $item->ID, $item, $args );
    $id = strlen( $id ) ? \' id="\' . esc_attr( $id ) . \'"\' : \'\';

    $output .= $indent . \'<li\' . $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        ) .\'"\' : \'\';

    // Check our custom has_children property.
    if ( $args->has_children ) {
      $attributes .= \' class="menu parent"\';
    }

    $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 display_element( $element, &$children_elements, $max_depth, $depth=0, $args, &$output ) {
    $id_field = $this->db_fields[\'id\'];
    if ( is_object( $args[0] ) ) {
      $args[0]->has_children = ! empty( $children_elements[$element->$id_field] );
    }
    return parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
  }

}

/**
* Custom Nav Classes
* https://v123.tw
*/
add_filter(\'nav_menu_css_class\' , \'v123_nav_class\' , 10 , 2 );
function v123_nav_class ($classes, $item) {
    if (in_array(\'menu-item-has-children\', $classes) ){
        $classes[] = \'other-wordpress-classes\';
    }
    return $classes;
}

global $wpdb;
$query = $wpdb->prepare("SELECT COUNT(*) FROM $wpdb->posts WHERE post_status =\'publish\' AND post_type=\'nav_menu_item\' AND post_parent=%d", $item->ID);
$child_count = $wpdb->get_var($query);
if($child_count > 0) { /* THE MENU ELEMENT HAS CHILDREN */
   .....
} else {
   .....
}