WP 在菜单中添加属性和 HTML答案

【问题标题】：WP Add Attributes and HTML in MenuWP 在菜单中添加属性和 HTML
【发布时间】：2016-09-02 20:33:03
【问题描述】：

如果我想在菜单中添加一些东西，如果该项目有子项目，我如何在 wp 导航系统中使用 walker，我正在使用以下代码-

<?php
wp_nav_menu(array(
    'menu' => '',
    'container' => 'ul',
    'container_class' => '',
    'container_id' => '',
    'menu_class' => 'nav navbar-nav',
    'menu_id' => 'menu-main-menu',
    'echo' => true,
    'before' => '',
    'after' => '',
    'link_before' => '',
    'link_after' => '',
    'items_wrap' => '<ul id="%1$s" class="%2$s">%3$s</ul>',
    'walker' => '',
    'theme_location' => 'header_menu'
)); ?>

我的结果是这样的

<ul id="menu-main-menu" class="nav navbar-nav">
    <li id="menu-item-16" class="menu-item menu-item-type-custom menu-item-object-custom current-menu-item current_page_item menu-item-home menu-item-has-children dropdown menu-item-16">
        <a href="***">Home</a>
        <ul class="sub-menu">
            <li id="menu-item-18" class="menu-item menu-item-type-post_type menu-item-object-services menu-item-18"><a href="***">Something</a></li>
        </ul>
    </li>
    <li id="menu-item-17" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-17"><a href="***">Sample Page</a></li>
</ul>

但我需要将<ul class="sub-menu"> 替换为<ul role="menu" class=" dropdown-menu">，并将<a href="***">Home</a> 替换为<a href="***" data-toggle="dropdown" class="dropdown-toggle">Home <i class="fa fa-angle-down"></i></a>

【问题讨论】：

标签： php wordpress navigation

【解决方案1】：

您可以通过像这样扩展 walker 来做到这一点：

class custom_sub_walker extends Walker_Nav_Menu {

    public function start_lvl( &$output, $depth = 0, $args = array() ) {
        $indent = str_repeat( "\t", $depth );
        $output .= "\n$indent<ul role=\"menu\" class=\" dropdown-menu\">\n";
    }

    public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
        $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

        $class_names = $value = '';

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

        /*grab the default wp nav classes*/
        $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );

        /*if the current item has children, append the dropdown class*/
        if ( $args->has_children )
            $class_names .= ' dropdown';

        /*if there aren't any class names, don't show class attribute*/
        $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 .'>';

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


        /*if the current menu item has children and it's the parent, set the dropdown attributes*/
        if ( $args->has_children && $depth === 0 ) {
            $atts['href']           = '#';
            $atts['data-toggle']    = 'dropdown';
            $atts['class']          = 'dropdown-toggle';
        } else {
            $atts['href'] = ! empty( $item->url ) ? $item->url : '';
        }

        $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 .'>';

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

    /*  if the current menu item has children and it's the parent item, append the fa-angle-down icon*/
        $item_output .= ( $args->has_children && $depth === 0 ) ? ' <i class="fa fa-angle-down"></i></a>' : '</a>';
        $item_output .= $args->after;

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

    }


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

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

        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 );
    }
}

在你的主题文件夹中使用上面的代码创建一个名为 custom_walker.php 的文件，然后使用 require_once('custom_walker.php'); 将其导入到 functions.php 中，或者将类粘贴到 functions.php 中。

然后调用你的菜单：

<?php
wp_nav_menu( array(
   'menu_class' => 'nav navbar-nav',
   'menu_id' => 'menu-main-menu',
   'theme_location' => 'header_menu'
   'walker' => new custom_sub_walker(),
) );
?>

【讨论】：