Question

我已通过Codex和其他示例检查了如何实现wp_nav_menu功能。我几乎完成了我想要的工作，但我遇到了几个问题：

如何为包含子菜单的列表项添加下拉类？
如何在子菜单名后添加班级<b class="caret"></b>？

以下是我想要转换为我的主菜单的HTML代码：

<nav id="master-nav">
                <ul>
                    <li class="active"><a href="index.html">Home</a></li>
                    <li class="dropdown"><a href="#">Features<b class="caret"></b></a>
                        <ul>
                            <li><a href="sections.html">Sections</a></li>
                            <li><a href="typography.html">Typography</a></li>
                            <li><a href="extras.html">Pricing Columns</a></li>
                        </ul>
                    </li>
                    <li><a href="blog.html">Blog</a></li>
                    <li><a href="portfolio.html">Portfolio</a></li>
                    <li><a href="contact.html">Contact</a></li>
                </ul>
            </nav>

这是用于获取输出的函数：

if( has_nav_menu( 'primary' ) ) {
wp_nav_menu( array( 'theme_location' => 'primary', 'container' => 'nav', 'container_id' => 'master-nav') );
}

如何解决上述问题？

Answer 1

您需要创建自己的自定义助行器：

/**
* Class Name: wp_bootstrap_navwalker
 * GitHub URI: https://github.com/twittem/wp-bootstrap-navwalker
 * Description: A custom WordPress nav walker class to implement the Twitter Bootstrap 2.3.2 navigation style in a custom theme using the WordPress built in menu manager.
 * Version: 1.4.3
 * Author: Edward McIntyre - @twittem
 * License: GPL-2.0+
 * License URI: http://www.gnu.org/licenses/gpl-2.0.txt
 */

class wp_bootstrap_navwalker extends Walker_Nav_Menu {

/**
 * @see Walker::start_lvl()
 * @since 3.0.0
 *
 * @param string $output Passed by reference. Used to append additional content.
 * @param int $depth Depth of page. Used for padding.
 */
function start_lvl( &$output, $depth ) {
    $indent = str_repeat( "\t", $depth );
    $output    .= "\n$indent<ul class=\"dropdown-menu\">\n";        
}

/**
 * @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 = 0, $args = array(), $id = 0 ) {
    global $wp_query;
    $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

    /**
     * Dividers & Headers
     * ==================
     * Determine whether the item is a Divider, Header, or regular menu item.
     * To prevent errors we use the strcasecmp() function to so a comparison
     * that is not case sensitive. The strcasecmp() function returns a 0 if 
     * the strings are equal.
     */
    if (strcasecmp($item->title, 'divider') == 0) {
        // Item is a Divider
        $output .= $indent . '<li class="divider">';
    } else if (strcasecmp($item->title, 'divider-vertical') == 0) {
        // Item is a Vertical Divider
        $output .= $indent . '<li class="divider-vertical">';
    } else if (strcasecmp($item->title, 'nav-header') == 0) {
        // Item is a Header
        $output .= $indent . '<li class="nav-header">' . esc_attr( $item->attr_title );
    } else {

        $class_names = $value = '';
        $classes = empty( $item->classes ) ? array() : (array) $item->classes;
        $classes[] = ($item->current) ? 'active' : '';
        $classes[] = 'menu-item-' . $item->ID;
        $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );

        if ($args->has_children && $depth > 0) {
            $class_names .= ' dropdown-submenu';
        } else if($args->has_children && $depth === 0) {
            $class_names .= ' dropdown';
        }

        $class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';

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

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

        $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        ) .'"' : '';
        $attributes .= ($args->has_children)        ? ' data-toggle="dropdown" data-target="'.esc_attr( $item->url).'" class="dropdown-toggle"' : '';

        $item_output = $args->before;

        /**
         * Glyphicons
         * ===========
         * Since the the menu item is NOT a Divider or Header we check the see
         * if there is a value in the attr_title property. If the attr_title
         * property is NOT null we apply it as the class name for the glyphicon.
         */
        if(! empty( $item->attr_title )){
            $item_output .= '<a'. $attributes .'><i class="' . esc_attr( $item->attr_title ) . '"></i>&nbsp;';
        } else {
            $item_output .= '<a'. $attributes .'>';
        }

        $item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
        $item_output .= ($args->has_children && $depth == 0) ? ' <span class="caret"></span></a>' : '</a>';
        $item_output .= $args->after;

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

/**
 * Traverse elements to create list from elements.
 *
 * Display one element if the element doesn't have any children otherwise,
 * display the element and its children. Will only traverse up to the max
 * depth and no ignore elements under that depth. 
 *
 * This method shouldn't be called directly, use the walk() method instead.
 *
 * @see Walker::start_el()
 * @since 2.5.0
 *
 * @param object $element Data object
 * @param array $children_elements List of elements to continue traversing.
 * @param int $max_depth Max depth to traverse.
 * @param int $depth Depth of current element.
 * @param array $args
 * @param string $output Passed by reference. Used to append additional content.
 * @return null Null on failure with no changes to parameters.
 */

function display_element( $element, &$children_elements, $max_depth, $depth, $args, &$output ) {
    if ( !$element ) {
        return;
    }

    $id_field = $this->db_fields['id'];

    //display this element
    if ( is_object( $args[0] ) ) {
       $args[0]->has_children = ! empty( $children_elements[$element->$id_field] );
    }

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

然后在你的主题中你会做这样的事情。

$args = array(
    'theme_location' => 'secondary_navigation',
    'container'      => false,
    'menu_id'    => '',
    'menu_class'=> 'nav navbar-nav',
    'walker' => new wp_bootstrap_navwalker()
);

当然，这是bootstrap walker的一个例子。

将类添加到wp_nav_menu函数（深度2）

1 个答案: