Wordpress Walker_Nav_菜单根据页面id在菜单中选择子元素

我在工作中度过了一段艰难的时光。我想有一个助行器，它可以放置具有特定id的元素的子元素，但我不确定从何处开始

我做了一些研究，但找不到任何基于页面ID的内容。有没有人有任何链接或参考资料来说明如何使其工作

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感谢您提供的信息

已解决

我看起来完全错了，我试图比较帖子ID而不是菜单ID

这是我的完整步行器，修改版的

如果不传递菜单项ID，它将求助于“当前帖子”树

<?php

/* Walker Class for selecting only current nav children.
 * Modified version of Stephen Harris class that adds in support for selecting based on menu_item_id
 *
 * @param int $menu_item_id ID of the menu item you want to select off of (optional)
 *
 * @author Jake Chamberlain
 * @link http://jchamb.com
 * @author Stephen Harris
 * @link http://wp.tutsplus.com/tutorials/creative-coding/understanding-the-walker-class/
 */


class Selective_Walker extends Walker_Nav_Menu
{
    var $menu_item;

    function __construct($menu_item_id = false) {

        $this->menu_item = $menu_item_id;
    }


    // Don't start the top level
    function start_lvl(&$output, $depth=0, $args=array()) {
        if( 0 == $depth )
            return;
        parent::start_lvl($output, $depth,$args);
    }

    // Don't end the top level
    function end_lvl(&$output, $depth=0, $args=array()) {
        if( 0 == $depth )
            return;
        parent::end_lvl($output, $depth,$args);
    }

    // Don't print top-level elements
    function start_el(&$output, $item, $depth=0, $args=array()) {
        if( 0 == $depth && !$this->menu_item )
            return;
        parent::start_el($output, $item, $depth, $args);
    }

    function end_el(&$output, $item, $depth=0, $args=array()) {
       if( 0 == $depth && !$this->menu_item )
          return;
        parent::end_el($output, $item, $depth, $args);
    }

    // Only follow down one branch
    function display_element( $element, &$children_elements, $max_depth, $depth=0, $args, &$output ) {

         // Check if element as a 'current element' class
         $current_element_markers = array( 'current-menu-item', 'current-menu-parent', 'current-menu-ancestor' );
         $current_class = array_intersect( $current_element_markers, $element->classes );

         if( !$this->menu_item)
         {                      
            // If element has a 'current' class, it is an ancestor of the current element
            $ancestor_of_current = !empty($current_class);       

            // If this is a top-level link and not the current, or ancestor of the current menu item - stop here.
            if ( 0 == $depth && !$ancestor_of_current)
                return;

            parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
         }
         else
         {       
            if ( $this->menu_item != $element->menu_item_parent )
                return;

             parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
         }
    }
}

---

已解决

我看起来完全错了，我试图比较帖子ID而不是菜单ID

这是我的完整步行器，修改版的

如果不传递菜单项ID，它将求助于“当前帖子”树

<?php

/* Walker Class for selecting only current nav children.
 * Modified version of Stephen Harris class that adds in support for selecting based on menu_item_id
 *
 * @param int $menu_item_id ID of the menu item you want to select off of (optional)
 *
 * @author Jake Chamberlain
 * @link http://jchamb.com
 * @author Stephen Harris
 * @link http://wp.tutsplus.com/tutorials/creative-coding/understanding-the-walker-class/
 */


class Selective_Walker extends Walker_Nav_Menu
{
    var $menu_item;

    function __construct($menu_item_id = false) {

        $this->menu_item = $menu_item_id;
    }


    // Don't start the top level
    function start_lvl(&$output, $depth=0, $args=array()) {
        if( 0 == $depth )
            return;
        parent::start_lvl($output, $depth,$args);
    }

    // Don't end the top level
    function end_lvl(&$output, $depth=0, $args=array()) {
        if( 0 == $depth )
            return;
        parent::end_lvl($output, $depth,$args);
    }

    // Don't print top-level elements
    function start_el(&$output, $item, $depth=0, $args=array()) {
        if( 0 == $depth && !$this->menu_item )
            return;
        parent::start_el($output, $item, $depth, $args);
    }

    function end_el(&$output, $item, $depth=0, $args=array()) {
       if( 0 == $depth && !$this->menu_item )
          return;
        parent::end_el($output, $item, $depth, $args);
    }

    // Only follow down one branch
    function display_element( $element, &$children_elements, $max_depth, $depth=0, $args, &$output ) {

         // Check if element as a 'current element' class
         $current_element_markers = array( 'current-menu-item', 'current-menu-parent', 'current-menu-ancestor' );
         $current_class = array_intersect( $current_element_markers, $element->classes );

         if( !$this->menu_item)
         {                      
            // If element has a 'current' class, it is an ancestor of the current element
            $ancestor_of_current = !empty($current_class);       

            // If this is a top-level link and not the current, or ancestor of the current menu item - stop here.
            if ( 0 == $depth && !$ancestor_of_current)
                return;

            parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
         }
         else
         {       
            if ( $this->menu_item != $element->menu_item_parent )
                return;

             parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
         }
    }
}

你是摇滚明星！！感谢您发布您的解决方案！真棒@Jake Chamberlain，正是我想要的！你是个摇滚明星！！感谢您发布您的解决方案！真棒@Jake Chamberlain，正是我想要的！