WordPress使用wp_nav_menu函数生成需要的class结构

*自定义二级菜单导航开始*/

class wp_bootstrap_navwalker extends Walker_Nav_Menu {public function start_lvl( &$output, $depth = 0, $args = array() ) {

$indent = str_repeat( "\t", $depth );

$output .= $indent.'<ul class="dropdown-menu">';//00001-下拉UL样式

}

public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {

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

//判断标题文字是不是指定文字，然后显示样式

if ( strcasecmp( $item->attr_title, 'divider' ) == 0 && $depth === 1 ) {

$output .= $indent . '<li role="presentation" class="divider">';

} else if ( strcasecmp( $item->title, 'divider') == 0 && $depth === 1 ) {

$output .= $indent . '<li role="presentation" class="divider">';

} else if ( strcasecmp( $item->attr_title, 'dropdown-header') == 0 && $depth === 1 ) {

$output .= $indent . '<li role="presentation" class="dropdown-header">' . esc_attr( $item->title );

} else if ( strcasecmp($item->attr_title, 'disabled' ) == 0 ) {

$output .= $indent . '<li role="presentation" class="disabled"><a href="#">' . esc_attr( $item->title ) . '</a>';

//判断结束

} else {

$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 ) );

if ( $args->has_children )

$class_names .= ' dropdown nav1';//00002-有下拉菜单的父LI的样式

if ( !$args->has_children && $depth === 0 )

$class_names .= ' nav1';//00003-没有下拉菜单的父LI的样式

if ( in_array( 'current-menu-item', $classes ) )

$class_names .= ' active';//00004-当前样式

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

$id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );//00005-菜单所有li的添加ID

$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 item has_children add atts to a.

if ( $args->has_children && $depth === 0 ) {

$atts['href'] = $item->url;

$atts['data-toggle'] = 'dropdown';

$atts['class'] = 'alink';//00006-有下拉的第一个父A的CLASS

$atts['aria-haspopup'] = 'true';//控制父A链接是否可点击

} 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;

if ( $args->has_children && 0 === $depth )

$item_output .= '<a data-toggle="dropdown"'. $attributes .'>';//00007-有下拉的第一个父A里面加内容

elseif ( ! empty( $item->attr_title ) )

$item_output .= '<a'. $attributes .'><span class="glyphicon ' . esc_attr( $item->attr_title ) . '"></span>&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 && 0 === $depth ) ? ' <span class="caret"></span></a>' : '</a>';////00008-有下拉的第一个父A后面加span，也可以加到外面

$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'];

// 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 );

}

}

<?php

wp_nav_menu( array(

'theme_location' => 'topmenu',

'depth' => 2,

'container' => false,

'menu_class' => 'nav navbar-nav navlist',

'menu_id' => 'topmeau',

'fallback_cb' => 'wp_page_menu',

//添加或更改walker参数

'walker' => new wp_bootstrap_navwalker())

);

?>